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Title: Using Fluorescence to Characterize Four Day Simulated Distribution System Trihalomethane Content in Florida Groundwaters.
Creator: Ousley, Jonathan, Duranceau, Steven, Lee, Woo Hyoung, Sadmani, A H M Anwar, University of Central Florida
Abstract / Description: The United States Environmental Protection Agency (USEPA) regulates public water systems and has established limits for certain disinfection by products (DBPs) that have been linked to health effects, such as bladder cancer. The regulation of DBPs, specifically total trihalomethanes (TTHMs) and haloacetic acids (HAAs), have encouraged water treatment professionals to assess the type and amount of organic precursors in their supplies. Three of the more common water quality parameters that are...
Show moreThe United States Environmental Protection Agency (USEPA) regulates public water systems and has established limits for certain disinfection by products (DBPs) that have been linked to health effects, such as bladder cancer. The regulation of DBPs, specifically total trihalomethanes (TTHMs) and haloacetic acids (HAAs), have encouraged water treatment professionals to assess the type and amount of organic precursors in their supplies. Three of the more common water quality parameters that are monitored as DBP surrogates include dissolved organic carbon (DOC), ultraviolet absorbance (UV254), and specific ultraviolet absorbance (SUVA). Although DOC, UV254, and SUVA have been effectively correlated to DBP formation, efforts to correlate fluorescence excitation emission matrices (FEEM) to DBP formation remains limited within the drinking water community. In this research, a fluorescence regional integration (FRI) approach was used to compare FEEM with DOC, UV254, and SUVA as an alternative surrogate for characterizing TTHMs for groundwater sources located in south central Florida. To quantitatively evaluate FEEM, DOC, UV254, and SUVA as TTHM precursor surrogate parameters, a statistical correlation analysis was employed. Thirteen groundwater samples were collected from various Central Florida groundwater wells in Lake County, Polk County, and Palm Beach County, and analyzed for FEEM, DOC, UV254, and SUVA prior to determining the four-day TTHM concentration using a simulated distribution system dosing procedure. The FRI method was then used to quantify FEEM by dividing the three-dimensional matrix into five distinct regions, each representing a unique organic constituent. The volume under each region was determined and used for the correlation analysis.It was determined that a combinations of regions III and V of the FEEM possessed a strong linear correlation to four day TTHM content (R2 = 0.95) as compared to DOC (R2 = 0.906), UV254 (R2= 0.84), SUVA (R2 = 0.640), and the individual regions of the FEEM. However, DOC showed the strongest correlation when a second order polynomial regression was used (R2 = 0.937). Results for the individual regions of the FEEM revealed four day simulated TTHM correlation coefficients of 0.25, 0.62, 0.86, 0.74, and 0.88 for regions I through V respectively. These values indicated that a combination of regions III and V, which represent the fulvic and humic-like organic fractions detected by FEEM respectively, was the most accurate four day simulated TTHM precursor surrogate parameter based on the groundwater supplies tested. These results reveal that although DOC is still one of the strongest surrogate parameters to TTHM formation, fluorescence has also shown to also be a potentially strong surrogate for groundwaters. The implications of these results signify that fluorescence monitoring could be a viable method of measuring organic content in groundwaters once the technology further develops.
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Date Issued: 2016
Identifier: CFE0006839, ucf:51782
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006839

Title: Control of Metal-Release and Tuberculation in a Silica-Laden Groundwater Distribution System on the Volcanic Island of Lana'i.
Creator: Myers, Samantha, Duranceau, Steven, Sadmani, A H M Anwar, Lee, Woo Hyoung, University of Central Florida
Abstract / Description: A corrosion control study for two distinct water distribution systems (WDS) has been completed for the Pulama Lana'i Water Company (Pulama). This project evaluated the use of chemical inhibitors to control corrosion and tuberculation within the Manele Bay WDS and the Lana'i City WDS. Pulama provides water to a population of 3,100 residents and is considering incorporating alternative water supplies in the future. Hence, knowing baseline corrosion rates within the WDS was desired.Several...
Show moreA corrosion control study for two distinct water distribution systems (WDS) has been completed for the Pulama Lana'i Water Company (Pulama). This project evaluated the use of chemical inhibitors to control corrosion and tuberculation within the Manele Bay WDS and the Lana'i City WDS. Pulama provides water to a population of 3,100 residents and is considering incorporating alternative water supplies in the future. Hence, knowing baseline corrosion rates within the WDS was desired.Several groundwater wells feed each of the WDS's; however, water quality between wells varies. Well water supplied to the WDS's is generally of high quality, therefore, the historical treatment method has been limited to disinfection prior to distribution. The distribution system consists of several materials of construction, which includes galvanized iron. Valves and pipes within the WDS were experiencing visible corrosion and tuberculation believed to be responsible for variable pressure drop throughout portions of the system.In this work, two corrosion racks, each consisting of two parallel loops, were designed, constructed, and installed at each site. One loop was maintained as a control while the other loop was used for testing alternative corrosion inhibitors. The racks utilized metal sample coupons and linear polarization resistance probes to provide data on corrosion rates of selected metals of interest.Results indicated that the water in Manele Bay experienced no noticeable change between the test loop and control loop when a corrosion inhibitor was added. A first experiment found the corrosion rates reached baseline steady(-)state at 4,000 operational hours. A second experiment found that the corrosion rates reached baseline steady(-)state at 2,200 operational hours. During these two experiments, the addition of a phosphate or silica(-)based inhibitor neither reduced nor increased the corrosion rates of mild steel, lead, and copper.Results from Lana'i City indicated that inhibitors offered little to no positive effect between the control condition and the test condition. During the first experiment, baseline corrosion was reached after 2,400 hours. The addition of a phosphate inhibitor did not reduce nor increase the corrosion rates of mild steel and lead. However, the corrosion rate of copper increased to 1.0mpy from 0.22mpy. The corrosion rate remained elevated after inhibitor feed was terminated. The second experiment reached baseline corrosion rates at 1,400 operational hours. The use of silica inhibitor neither reduced nor increased the corrosion rate of mil steel, lead, and copper.Since corrosion inhibitors were found to be ineffective, a valve exercise and replacement program for Pulama's assets was recommended. This program included: (1) developing a detailed asset inventory, (2) implementing operation and maintenance tasks, (3) forming a valve replacement plan, and (4) establishing long range financial planning. An opinion of probable replacement cost for 200 new valves was conceptually estimated to approximate 3.3 million dollars expended over a 20 year time frame.
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Date Issued: 2016
Identifier: CFE0006152, ucf:51152
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006152

Title: Biological Nutrient Removal (BNR) Process Optimization and Recovery of Embedded Energy Using Biodiesel By-product.
Creator: Salamah, Sultan, Randall, Andrew, Duranceau, Steven, Chopra, Manoj, University of Central Florida
Abstract / Description: Enhanced biological phosphorus removal (EBPR) as well as biological nitrogen removal require a carbon source to be carried out. Volatile fatty acid (VFAs) (mainly acetic and propionic acids) are the major driving force for EBPR. Many domestic wastewaters have an insufficient amount of VFAs. However, carbon sources such as acetic and propionic acids can be produced using primary solids fermentation process. Due to the cost of VFA production, an external carbon source can be added to the...
Show moreEnhanced biological phosphorus removal (EBPR) as well as biological nitrogen removal require a carbon source to be carried out. Volatile fatty acid (VFAs) (mainly acetic and propionic acids) are the major driving force for EBPR. Many domestic wastewaters have an insufficient amount of VFAs. However, carbon sources such as acetic and propionic acids can be produced using primary solids fermentation process. Due to the cost of VFA production, an external carbon source can be added to the biological nutrient removal (BNR) system that can be fermented to provide the desired VFAs. Glycerol (biodiesel by-product) offers a solution to reduce carbon addition cost if can be fermented to acetic and propionic acid or can be used directly as an external carbon substrate for EBPR and denitrification. Using glycerol in wastewater treatment can also offset the biodiesel plant disposal cost and reduce the BNR chemical cost. The main objective of this study was to optimize the prefermentation process and optimize the BNR system using glycerol as an external carbon source. In this work, Optimization of the prefermentation process using glycerol, mixing, and hydrogen gas addition was evaluated. EBPR performance within an A2O-BNR system was evaluated using either a direct glycerol method to the anaerobic zone or by co-fermentation with primary solids. Also, optimization of the nitrogen removal (specifically denitrification) efficiency of a 5-stage BardenphoTM BNR system using either a direct glycerol method to the second anoxic zone or by co-fermentation with primary solids was evaluated. It was found in this study that glycerol was an efficient external carbon substrate for EBPR as well as biological nitrogen removal. The prefermentation experiment showed that glycerol co-fermentation with primary solids produced significantly higher (p(<)0.05) VFAs than primary solids fermentation alone, even more than the possible value from the added glycerol (427 mg-COD/L). The increased VFAs imply that the glycerol addition stimulated additional fermentation of primary solids. Lowering the prefermenter mixing energy (50 to 7 rpm) resulted in a significant increase in VFAs production (80%). Also, purging the headspace of the prefermenter with hydrogen gas did not lead to more VFAs, but significantly (p(<)0.05) increased the propionic acid to acetic acid ratio by 41%. In the A2O-BNR pilot plant experiment, it was found that glycerol is a suitable renewable external substrate to drive enhanced EBPR as well as denitrification. The results from both locations of glycerol addition (direct vs. fermented) were beneficial to the BNR system. Both systems had similar effluent quality and achieved total nitrogen (TN) and total phosphorus (TP) removals up to 86% and 92% respectively. The 5-stage BardenphoTM BNR experiment investigated the location of glycerol addition (direct vs. fermented) on the performance of denitrification in the second anoxic zone and the overall performance. The results from both systems were that glycerol was beneficial to the BNR system and had virtually similar effluent quality. Both systems achieve complete denitrification and excellent removal of TN and TP up to 95% and 89% respectively. Also, the pilot that received fermented glycerol had significantly higher VFAs loading and lower observed yield. The side-stream prefermenter effluent flowing to the second anoxic reactor did not cause high effluent ammonia (NH3) concentration. In summary, the location at which glycerol was added did not affect effluent quality for nitrogen and phosphorus. However, glycerol addition and mixing energy did impact prefermenter performance and effluent quality.
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Date Issued: 2017
Identifier: CFE0006788, ucf:51826
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006788

Title: Evaluation of The Biodegradability and Toxicity of PCA and mPCA.
Creator: Rueda, Juan, Randall, Andrew, Duranceau, Steven, Yestrebsky, Cherie, University of Central Florida
Abstract / Description: The main types of hypergolic propellants used at Kennedy Space Center (KSC) are hydrazine (HZ) and monomethylhydrazine (MMH). HZ and MMH are classified as hazardous materials and they are also known to be potentially carcinogenic to humans; therefore, handling these substances and their waste is strictly regulated. The wastes streams from HZ and MMH have been estimated to be the main hazardous wastes streams at KSC. Currently at KSC these wastes are first neutralized using citric acid and...
Show moreThe main types of hypergolic propellants used at Kennedy Space Center (KSC) are hydrazine (HZ) and monomethylhydrazine (MMH). HZ and MMH are classified as hazardous materials and they are also known to be potentially carcinogenic to humans; therefore, handling these substances and their waste is strictly regulated. The wastes streams from HZ and MMH have been estimated to be the main hazardous wastes streams at KSC. Currently at KSC these wastes are first neutralized using citric acid and then they are transported on public roads for incineration as hazardous materials. A new method using alpha ketoglutaric acid (AKGA) was proposed to treat HZ and MMH wastes. From the reaction of AKGA with HZ and MMH two stable products are formed, 1,4,5,6-tetrahydro-6-oxo-3-pyridazinecarboxylic acid (PCA) and l-methyl-1,4,5,6-tetrahydro-6-oxo-3-pyridazinecarboxylic acid (mPCA), respectively.The cost of purchasing AKGA is greater than the cost of purchasing citric acid; thus, AKGA can only become a cost effective alternative for the treatment of HZ and MMH wastes if the products of the reactions (PCA and mPCA) can be safely disposed of into the sewage system without affecting the treatment efficiency and effluent quality of the wastewater treatment plant (WWTP). In this research mPCA and PCA were analyzed for acute toxicity using fish and crustaceans as well as their effect on the wastewater treatment efficiency and viability using AS microbes, and their biodegradability by AS organisms. Acute toxicity on fish and crustaceans was investigated according to the methods for acute toxicity by USEPA (USEPA Method EPA-821-R-02-012) using Ceriodaphnia dubia (96 hours) and Pimephales promelas (96 hours) as the test organisms. The effect of mPCA and PCA in the treatment efficiency and viability were estimated from respiration inhibition tests (USEPA Method OCSPP 850.3300) and heterotrophic plate counts (HPCs). Lastly, the biodegradability of mPCA and PCA was assessed using the Closed Bottle Test (USEPA Method OPPTS 835.3110). For mPCA, the 96 hours LC50 for C. dubia was estimated at 0.77 (&)#177; 0.06 g/L (with a 95% confidence level) and the NOEC was estimated at 0.5 g/L. For P. promelas, the LC50 was above 1.5 g/L but it was noticed that mPCA had an effect on their behavior. Abnormal behavior observed included loss of equilibrium and curved spine. The NOEC on the fish was estimated at 0.75 g/L. PCA did not exhibit a significant mortality on fish or crustaceans. The LC50 of PCA in P. promelas and C. dubia was (>) 1.5 g/L and the NOEC was 1.5 g/L for both organisms. An Inhibitory effect on the heterotrophic respiration of activated sludge organisms was not observed after exposing them for 180-min to PCA and mPCA at concentrations of up to 1.5 g/L compared to the blank controls. Overall the impact of PCA and mPCA on total respiration rates was small, and only observed at 1,500 mg/L if at all. The difference was apparently caused by inhibition of nitrification rather than heterotrophic inhibition. However due to the variability observed in the measurements of the replicates, it is not possible to firmly conclude that PCA or mPCA at 1,500 mg/L was inhibitory to nitrification.Based on the results from the HPCs, mPCA and PCA did not affect the viability of heterotrophic organisms at 750 mg/L. In the BOD-like closed bottle test using a diluted activated sludge mixed liquor sample, the AS microorganisms were capable of biodegrading up to 67% of a 2 mg/L concentration of PCA (with respect to its theoretical oxygen demand, or ThOD) in 28 days. No biodegradation was observed in the samples containing 2 and 5 mg/L of mPCA after 28 days of incubation using a diluted activated sludge mixed liquor sample as inoculum.The results of this study show that mPCA is more toxic than PCA to Ceriodaphnia dubia and Pimephales promelas. However neither mPCA nor PCA had an effect on the heterotrophic respiration of an AS mixed liquor sample at 1.5 g/L and there was probably no significant inhibition of the nitrification respiration. Samples of PCA and mPCA at 2 and 5 mg/L could not be completely degraded (with respect to their total theoretical oxygen demand) by dilute AS biomass during a 28 day incubation period. mPCA did not show significant degradation in the two different biodegradation tests performed.
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Date Issued: 2013
Identifier: CFE0004744, ucf:49779
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004744

Title: A Comparison of Aluminum and Iron-based Coagulants for Treatment of Surface Water in Sarasota County, Florida.
Creator: Yonge, David, Duranceau, Steven, Randall, Andrew, Cooper, Charles, University of Central Florida
Abstract / Description: In this research, five different coagulants were evaluated to determine their effectiveness at removing turbidity, color and dissolved organic carbon (DOC) from a surface water in Sarasota County, Florida. Bench-scale jar tests that simulated conventional coagulation, flocculation, and sedimentation processes were used. Iron-based coagulants (ferric chloride and ferric sulfate) and aluminum-based coagulants (aluminum sulfate, polyaluminum chloride (PACl) and aluminum chlorohydrate (ACH)) were...
Show moreIn this research, five different coagulants were evaluated to determine their effectiveness at removing turbidity, color and dissolved organic carbon (DOC) from a surface water in Sarasota County, Florida. Bench-scale jar tests that simulated conventional coagulation, flocculation, and sedimentation processes were used. Iron-based coagulants (ferric chloride and ferric sulfate) and aluminum-based coagulants (aluminum sulfate, polyaluminum chloride (PACl) and aluminum chlorohydrate (ACH)) were used to treat a highly organic surface water supply (DOC ranging between 10 and 30 mg/L), known as the Cow Pen Slough, located within central Sarasota County, Florida. Isopleths depicting DOC and color removal efficiencies as a function of both pH and coagulant dose were developed and evaluated. Ferric chloride and ACH were observed to obtain the highest DOC (85% and 70%, respectively) and color (98% and 97%, respectively) removals at the lowest dose concentrations (120 mg/L and 100 mg/L, respectively). Ferric sulfate was effective at DOC removal but required a higher concentration of coagulant and was the least effective coagulant at removing color. The traditional iron-based coagulants and alum had low turbidity removals and they were often observed to add turbidity to the water. PACl and ACH had similar percent removals for color and turbidity achieving consistent percent removals of 95% and 45%, respectively, but PACl was less effective than ACH at removing organics. Sludge settling curves, dose-sludge production ratios, and settling velocities were determined at optimum DOC removal conditions for each coagulant. Ferric chloride was found to have the highest sludge settling rate but also produced the largest sludge quantities. Total trihalomethane formation potential (THMFP) was measured for the water treated with ferric chloride and ACH. As with DOC removal, ferric chloride yielded a higher percent reduction with respect to THMFP.
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Date Issued: 2012
Identifier: CFE0004621, ucf:49936
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004621

Title: Mathematical Modeling of Carbon Removal in the A-Stage Activated Sludge System.
Creator: Nogaj, Thomas, Randall, Andrew, Duranceau, Steven, Chopra, Manoj, Jimenez, Jose, University of Central Florida
Abstract / Description: This research developed a dynamic activated sludge model (ASM) to better describe the overall removal of organic substrate, quantified as chemical oxygen demand (COD), from A-stage high rate activated sludge (HRAS) systems. This dynamic computer model is based on a modified ASM1 (Henze et al., 2000) model. It was determined early in the project that influent soluble COD, which is normally represented by a single state variable in ASM1, had to be subdivided into two state variables (SBs and...
Show moreThis research developed a dynamic activated sludge model (ASM) to better describe the overall removal of organic substrate, quantified as chemical oxygen demand (COD), from A-stage high rate activated sludge (HRAS) systems. This dynamic computer model is based on a modified ASM1 (Henze et al., 2000) model. It was determined early in the project that influent soluble COD, which is normally represented by a single state variable in ASM1, had to be subdivided into two state variables (SBs and SBf, or slow and fast fractions) to simulate the performance of A-stage systems. Also, the addition of state variables differentiating colloidal COD from suspended COD was necessary due to short hydraulic residence times in A-stage systems which do not allow for complete enmeshment and bioflocculation of these particles as occurs in conventional activated sludge systems (which have longer solid retention times and hydraulic retention times). It was necessary to add several processes (both stoichiometry and kinetic equations) to the original ASM1 model including heterotrophic growth on both soluble substrate fractions and bioflocculation of colloidal solids. How to properly quantify heterotrophic growth on SBs and SBf resulted in two separate approaches with respect to process kinetic equations. In one approach the SBf was metabolized preferentially over SBs which was only utilized when SBf was not available. This is referred to as the Diauxic Model. In the other approach SBf and SBs were metabolized simultaneously, and this is referred to as the Dual Substrate Model. The Dual Substrate Model calibrated slightly better than the Diauxic Model for one of the two available pilot studies data sets (the other set was used for model verification). The Dual Substrate A-stage model was used to describe the effects of varying specific operating parameters including solids retention time (SRT), dissolved oxygen (DO), influent COD and temperature on the effluent COD:N ratio. The effluent COD:N ratio target was based on its suitability for a downstream nitrite shunt (i.e. nitritation/denitritation) process. In the downstream process the goal is to eliminate nitrite oxidizing bacteria (NOB) from the reactor while selecting for ammonia oxidizing bacteria (AOB). The results showed that a low SRT ((<)0.25 d) can produce high effluent substrates (SB and CB), and elevated COD:N ratios consistent with NOB out-selection downstream, the HRAS model was able to predict the measured higher fraction of CB in the A-stage effluent at lower SRTs and DO concentrations, and to achieve the benefits of operating an A-stage process, while maintaining an effluent COD:N ratio suitable for a downstream nitritation/denitritation process, an A-stage SRT in the range of 0.1 to 0.25 d should be maintained.This research also included an analysis of A-stage pilot data using stoichiometry to determine the bio-products formed from soluble substrate removed in an A-stage reactor. The results were used to further refine the process components and stoichiometric parameters to be used in the A-stage dynamic computer model, which includes process mechanisms for flocculation and enmeshment of particulate and colloidal substrate, hydrolysis, production of extracellular polymeric substances (EPS) and storage of soluble biodegradable substrate. Analysis of pilot data and simulations with the dynamic computer model implied (indirectly) that storage products were probably significant in A-stage COD removal.
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Date Issued: 2015
Identifier: CFE0005677, ucf:50161
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005677

Title: Dishwashing Water Recycling System and Related Water Quality Standards for Military Use.
Creator: Church, Jared, Lee, Woo Hyoung, Randall, Andrew, Duranceau, Steven, University of Central Florida
Abstract / Description: As the demand for reliable and safe water supplies increases, both water quality and available quantity are being challenged by population growth and climate change. Greywater reuse is becoming a common practice worldwide; however, in remote locations of limited water supply, such as those encountered in military installations, it is desirable to expand its classification to include dishwashing water to maximize the conservation of fresh water. Given that no standards for dishwashing...
Show moreAs the demand for reliable and safe water supplies increases, both water quality and available quantity are being challenged by population growth and climate change. Greywater reuse is becoming a common practice worldwide; however, in remote locations of limited water supply, such as those encountered in military installations, it is desirable to expand its classification to include dishwashing water to maximize the conservation of fresh water. Given that no standards for dishwashing greywater reuse by the military are currently available, the current study determined a specific set of water quality standards for dishwater recycling systems for U.S military field operations. A tentative water reuse standard for dishwashing water was developed based on federal and state regulations and guidelines for non-potable water, and the developed standard was cross-evaluated by monitoring water quality data from a full-scale dishwashing water recycling system using an innovative electrocoagulation and ultrafiltration process. A quantitative microbial risk assessment (QMRA) was also performed based on exposure scenarios derived from literature data. As a result, a specific set of dishwashing water reuse standards for field analysis (simple, but accurate) was finalized as follows: turbidity ((<)1 NTU), E. coli ((<)50 cfu mL-1), and pH (6(-)9). UV254 was recommended as a surrogate for organic contaminants (e.g., BOD5), but requires further calibration steps for validation. The developed specific water standard is the first for dishwashing water reuse and will be expected to ensure that water quality is safe for field operations, but not so stringent that design complexity, cost, and operational and maintenance requirements will not be feasible for field use. In addition the parameters can be monitored using simple equipment in a field setting with only modest training requirements and real-time or rapid sample turn-around. This standard may prove useful in future development of civilian guidelines.
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Date Issued: 2015
Identifier: CFE0005773, ucf:50061
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005773

Title: In-Plant and Distribution System Corrosion Control for Reverse Osmosis, Nanofiltration, and Anion Exchange Process Blends.
Creator: Jeffery, Samantha, Duranceau, Steven, Randall, Andrew, Wang, Dingbao, University of Central Florida
Abstract / Description: The integration of advanced technologies into existing water treatment facilities (WTFs) can improve and enhance water quality; however, these same modifications or improvements may adversely affect finished water provided to the consumer by public water systems (PWSs) that embrace these advanced technologies. Process modification or improvements may unintentionally impact compliance with the provisions of the United States Environmental Protection Agency's (USEPA's) Safe Drinking Water Act ...
Show moreThe integration of advanced technologies into existing water treatment facilities (WTFs) can improve and enhance water quality; however, these same modifications or improvements may adversely affect finished water provided to the consumer by public water systems (PWSs) that embrace these advanced technologies. Process modification or improvements may unintentionally impact compliance with the provisions of the United States Environmental Protection Agency's (USEPA's) Safe Drinking Water Act (SDWA). This is especially true with respect to corrosion control, since minor changes in water quality can affect metal release. Changes in metal release can have a direct impact on a water purveyor's compliance with the SDWA's Lead and Copper Rule (LCR). In 2010, the Town of Jupiter (Town) decommissioned its ageing lime softening (LS) plant and integrated a nanofiltration (NF) plant into their WTF. The removal of the LS process subsequently decreased the pH in the existing reverse osmosis (RO) clearwell, leaving only RO permeate and anion exchange (AX) effluent to blend. The Town believed that the RO-AX blend was corrosive in nature and that blending with NF permeate would alleviate their concern. Consequently, a portion of the NF permeate stream was to be split between the existing RO-AX clearwell and a newly constructed NF primary clearwell. The Town requested that the University of Central Florida (UCF) conduct research evaluating how to mitigate negative impacts that may result from changing water quality, should the Town place its AX into ready-reserve. The research presented in this document was focused on the evaluation of corrosion control alternatives for the Town, and was segmented into two major components: 1.The first component of the research studied internal corrosion within the existing RO clearwell and appurtenances of the Town's WTF, should the Town place the AX process on standby. Research related to WTF in-plant corrosion control focused on blending NF and RO permeate, forming a new intermediate blend, and pH-adjusting the resulting mixture to reduce corrosion in the RO clearwell. 2.The second component was implemented with respect to the Town's potable water distribution system. The distribution system corrosion control research evaluated various phosphate-based corrosion inhibitors to determine their effectiveness in reducing mild steel, lead and copper release in order to maintain the Town's continual compliance with the LCR.The primary objective of the in-plant corrosion control research was to determine the appropriate ratio of RO to NF permeate and the pH necessary to reduce corrosion in the RO clearwell. In this research, the Langelier saturation index (LSI) was the corrosion index used to evaluate the stability of RO:NF blends. Results indicated that a pH-adjusted blend consisting of 70% RO and 30% NF permeate at 8.8-8.9 pH units would produce an LSI of +0.1, theoretically protecting the RO clearwell from corrosion.The primary objective of the distribution system corrosion control component of the research was to identify a corrosion control inhibitor that would further reduce lead and copper metal release observed in the Town's distribution system to below their respective action limits (ALs) as defined in the LCR. Six alternative inhibitors composed of various orthophosphate and polyphosphate (ortho:poly) ratios were evaluated sequentially using a corrosion control test apparatus. The apparatus was designed to house mild steel, lead and copper coupons used for weight loss analysis, as well as mild steel, lead solder and copper electrodes used for linear polarization analysis. One side of the apparatus, referred to as the (")control condition,(") was fed potable water that did not contain the corrosion inhibitor, while the other side of the corrosion apparatus, termed the (")test condition,(") was fed potable water that had been dosed with a corrosion inhibitor. Corrosion rate measurements were taken twice per weekday, and water quality was measured twice per week. Inhibitor evaluations were conducted over a span of 55 to 56 days, varying with each inhibitor. Coupons and electrodes were pre-corroded to simulate existing distribution system conditions. Water flow to the apparatus was controlled with an on/off timer to represent variations in the system and homes. Inhibitor comparisons were made based on their effectiveness at reducing lead and copper release after chemical addition. Based on the results obtained from the assessment of corrosion inhibitors for distribution system corrosion control, it appears that Inhibitors 1 and 3 were more successful in reducing lead corrosion rates, and each of these inhibitors reduced copper corrosion rates. Also, it is recommended that consideration be given to use of a redundant single-loop duplicate test apparatus in lieu of a double rack corrosion control test apparatus in experiments where pre-corrosion phases are implemented. This recommendation is offered because statistically, the control versus test double loop may not provide relevance in data analysis. The use of the Wilcoxon signed ranks test comparing the initial pre-corroding phase to the inhibitor effectiveness phase has proven to be a more useful analytical method for corrosion studies.
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Date Issued: 2013
Identifier: CFE0005008, ucf:50001
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005008

Title: Study of the Formation and Control of Disinfection By-Products Originating from a Surface Water Supply on the Volcanic Island of Guam.
Creator: Laberge, Erica, Duranceau, Steven, Randall, Andrew, Lee, Woo Hyoung, University of Central Florida
Abstract / Description: Three oxidants have been evaluated for use as alternative chemical pretreatments for Fena Lake, a surface water that supplies the U.S. Navy's Public Water System (PWS) on the volcanic island of Guam. The study consisted of two investigative components. The first and primary component included a bench-scale evaluation to study the effects of different pre-oxidant chemicals on the formation of chlorinated disinfection by-products (DBPs). The second and ancillary component included a series of...
Show moreThree oxidants have been evaluated for use as alternative chemical pretreatments for Fena Lake, a surface water that supplies the U.S. Navy's Public Water System (PWS) on the volcanic island of Guam. The study consisted of two investigative components. The first and primary component included a bench-scale evaluation to study the effects of different pre-oxidant chemicals on the formation of chlorinated disinfection by-products (DBPs). The second and ancillary component included a series of water treatment and distribution system management studies that analyzed DBP formation within the treatment plant and water distribution system. The goal of this research was to reduce total trihalomethane (TTHM) and the five haloacetic acid (HAA5) formations in the PWS.In the primary component of the research, raw surface water from Fena Lake was collected by U.S. Navy personnel and shipped to University of Central Florida (UCF) laboratories for experimentation. Bench-scale tests that simulated the coagulation, flocculation, sedimentation and filtration (CSF) that comprises the Navy Water Treatment Plant (NWTP) were used to evaluate the use of two alternative pre-oxidants, potassium permanganate (KMnO4) and chlorine dioxide (ClO2) in lieu of gaseous chlorine (Cl2). The research assessed DBP formation by comparing several pretreatment scenarios, namely: (1) no pretreatment, (2) chlorine pretreatment, and (3) alternative oxidant pretreatment. KMnO4 pretreatment resulted in the lowest percent reduction of TTHMs and HAA5 relative to chlorine pretreatment, at 5.7% and 22.7%, respectively; however, this amount was still a reduction from the results demonstrated for the chlorine pretreatment condition. Without using a pre-oxidant, TTHM and HAA5 formation were reduced by 22.8% and 37.3%, respectively, relative to chlorine pretreatment. Chlorine dioxide demonstrated the greatest TTHM and HAA5 reduction relative to chlorine pretreatment at 34.4% and 53.3%, respectively.The second component of research consisted of a series of studies that evaluated distribution system operations and management alternatives to identify opportunities that could achieve DBP reduction within the PWS. Three concerns that were addressed were the NWTP's compliance with the U.S. Environmental Protection Agency's (USEPA's) Stage 2 Disinfectants/Disinfection By-Products (D/DBP) Rule, variable hydraulic detention times within a small subdivision in the distribution system, and severe weather. It was determined that: (1) A decision based on in-plant studies to cease prechlorination at the NWTP resulted in a decrease in TTHMs and HAA5s throughout the distribution system by 62% and 75%, respectively; (2) A fluoride tracer study led to the discovery of a valved pipeline responsible for elevated DBPs because of excessive water age that when exercised and managed resolved intermittent DBP spikes in the PWS; and (3) when the NWTP's ballasted floc clarifier (BFC) was operated in-series prior to the conventional CSF process during severe weather conditions the TTHM and HAA5 were below 39 ug/L and 29 ug/L, respectively, proving BFC in-series is a practical option for the plant during severe weather.
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Date Issued: 2014
Identifier: CFE0005515, ucf:50299
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005515

Title: Application and Optimization of Membrane Processes Treating Brackish and Surficial Groundwater for Potable Water Production.
Creator: Tharamapalan, Jayapregasham, Duranceau, Steven, Cooper, Charles, Randall, Andrew, Clausen, Christian, University of Central Florida
Abstract / Description: The research presented in this dissertation provides the results of a comprehensive assessment of the water treatment requirements for the City of Sarasota. The City's drinking water supply originates from two sources: (1) brackish groundwater from the Downtown well field, and (2) Floridan surficial groundwater from the City's Verna well field. At the time the study was initiated, the City treated the brackish water supply using a reverse osmosis process that relied on sulfuric acid for pH...
Show moreThe research presented in this dissertation provides the results of a comprehensive assessment of the water treatment requirements for the City of Sarasota. The City's drinking water supply originates from two sources: (1) brackish groundwater from the Downtown well field, and (2) Floridan surficial groundwater from the City's Verna well field. At the time the study was initiated, the City treated the brackish water supply using a reverse osmosis process that relied on sulfuric acid for pH adjustment as a pretreatment method. The Verna supply was aerated at the well field before transfer to the City's water treatment facility, either for softening using an ion exchange process, or for final blending before supply.For the first phase of the study to evaluate whether the City can operate its brackish groundwater RO process without acid pretreatment, a three-step approach was undertaken that involved: (1) pilot testing the plan to reduce the dependence on acid, (2) implementing the plan on the full-scale system with conservative pH increments, and (3) continuous screening for scale formation potential by means of a (")canary(") monitoring device. Implementation of the study was successful and the annual savings in operating expenditure to the City is projected to be about $120,000.From the acid elimination study, using the relationship between electrical conductivity in water and total dissolved solids in water samples tested, a dynamic approach to evaluate the performance of the reverse osmosis plant was developed. This trending approach uses the mass transfer coefficient principles of the Homogeneous Solution Diffusion Model. Empirical models were also developed to predict mass transfer coefficients for solutes in terms of total dissolved solids and sodium. In the second phase of the study, the use of nanofiltration technology to treat aerated Verna well field water was investigated. The goal was to replace the City's existing ion exchange process for the removal of hardness and total dissolved solids. Different pretreatment options were evaluated for the nanofiltration pilot to remove colloidal sulfur formed during pre-aeration of the groundwater. Sandfilters and ultrafiltration technology were evaluated as pretreatment. The sandfilter was inadequate as a pre-screen to the nanofiltration pilot. The ultrafiltration pilot (with and without a sandfilter as a pre-screen) proved to be an adequate pretreatment to remove particulates and colloids, especially the sulfur colloids in the surficial groundwater source. The nanofiltration pilot, was shown to be an efficient softening process for the Verna well field water, but it was impacted by biofoulants like algae. The algae growth was downstream of the ultrafiltration process, and so chlorination was used in the feed stream of the ultrafiltration process with dechlorination in the nanofiltration feed stream using excess bisulfite to achieve stable operations. Non-phosphonate based scale inhibitors were also used to reduce the availability of nutrients for biofilm growth on the nanofiltration membranes.The combined ultrafiltration-nanofiltration option for treatment of the highly fouling Verna water samples is feasible with chlorination (to control biofouling) and subsequent dechlorination. Alternatively, the study has shown that the City can also more economically and more reliably use ultrafiltration technology to filter all water from its Verna well field and use its current ion exchange process for removal of excess hardness in the water that it supplies.
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Date Issued: 2012
Identifier: CFE0004609, ucf:49926
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004609

Title: Ozone and GAC Treatment of a Central Florida Groundwater for Sulfide and Disinfectant By-Product Control.
Creator: Lamoureux, Tara, Duranceau, Steven, Randall, Andrew, Wang, Dingbao, University of Central Florida
Abstract / Description: This study evaluated the combination of ozone and granular activated carbon (GAC) treatment for the removal of sulfide and disinfection byproduct (DBP) precursors in drinking water at the pilot-scale. The research conducted was performed at the Auxiliary (Aux) and Main Water Treatment Plants (WTPs) in Sanford, Florida. Both WTPs rely upon groundwater sources that contain total sulfide ranging from 0.02 to 2.35 mg/L and total organic carbon (TOC) ranging from 0.61 to 2.20 mg/L. The Aux WTP's...
Show moreThis study evaluated the combination of ozone and granular activated carbon (GAC) treatment for the removal of sulfide and disinfection byproduct (DBP) precursors in drinking water at the pilot-scale. The research conducted was performed at the Auxiliary (Aux) and Main Water Treatment Plants (WTPs) in Sanford, Florida. Both WTPs rely upon groundwater sources that contain total sulfide ranging from 0.02 to 2.35 mg/L and total organic carbon (TOC) ranging from 0.61 to 2.20 mg/L. The Aux WTP's raw water contains, on average, 88% more sulfide and 24% more TOC than the Main WTP. Haloacetic acids (HAA5) and total trihalomethanes (TTHMs) comprise the regulated forms of DBPs. HAA5 are consistently below the maximum contaminant level (MCL) of 60 ?g/L, while TTHM ranges from 70 to 110 ?g/L, at times exceeding the MCL of 80 ?g/L in the distribution system. Ozone alone removed total sulfide and reduced UV-254 by about 60% at the Aux Plant and 35% at the Main Plant. Producing an ozone residual of 0.50 mg/L prevented the formation of bromate while removing approximately 35 to 60% concentration of DBP precursors as measured by UV-254. Operating the GAC unit at an empty bed contact time (EBCT) of 10 minutes for the Aux Plant and 5.5 minutes for the Main Plant resulted in 75% and 53% of UV-254 reduction, respectively. The average 120 hour TTHM formation potential for the Aux and Main Plants were 66 ?g/L and 52 ?g/L, respectively, after treatment by ozone and GAC. GAC exhaustion was deemed to have occurred after seven weeks for the Aux Plant and eleven weeks for the Main Plant. The GAC columns operated in three phases: an adsorption phase, a transitional phase, and a biologically activated carbon (BAC) phase. The GAC adsorption phase was found to produce the lowest TTHMs; however, TTHMs remained less than 80 ?g/L during the BAC stage at each plant. BAC exhaustion did not occur during the course of this study. Ozone-GAC reduced chlorine demand by 73% for the Aux Plant and 10% for the Main Plant.
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Date Issued: 2013
Identifier: CFE0004708, ucf:49824
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004708

Title: Study of the Effect of Surface Morphology on Mass Transfer and Fouling Behavior of Reverse Osmosis and Nanofiltration Membrane Processes.
Creator: Fang, Yuming, Duranceau, Steven, Randall, Andrew, Wang, Dingbao, Yestrebsky, Cherie, University of Central Florida
Abstract / Description: Reverse osmosis (RO) and nanofiltration (NF) membranes are pressure driven, diffusion controlled process. The influence of surface characteristics on membrane process performance is considered significant and is not well understood. Current mass transport models generally assume constant mass transfer coefficients (MTCs) based on a homogeneous surface. This work evaluated mass transfer processes by incorporating surface morphology into a diffusion-based model assuming MTCs are dependent on...
Show moreReverse osmosis (RO) and nanofiltration (NF) membranes are pressure driven, diffusion controlled process. The influence of surface characteristics on membrane process performance is considered significant and is not well understood. Current mass transport models generally assume constant mass transfer coefficients (MTCs) based on a homogeneous surface. This work evaluated mass transfer processes by incorporating surface morphology into a diffusion-based model assuming MTCs are dependent on the thickness variation of the membrane's active layer. To mathematically create such a surface layer, Gaussian random vectors embedded in a software system (MATLAB) were used to generate a three-dimensional ridge and valley active layer morphologies. A (")SMOOTH(") script was incorporated to reduce the influence of outlying data and make the hypothetical surfaces visually comparable to the AFM images. A non-homogeneous solution diffusion model (NHDM) was then developed to account for surface variations in the active layer. Concentration polarization (CP) is also affected by this non-homogeneous surface property; therefore, the NHDM was modified by incorporating the CP factor. In addition, recent studies have shown that the membrane surface morphology influences colloidal fouling behavior of RO and NF membranes. With consideration of the spatial variation of the cake thickness along the membranes, a fouling model was established by assuming cake growth is proportional to the localized permeate flow. Flux decline was assumed to be controlled by the resistance of cake growth and accumulated particle back diffusion at the membrane surface.A series of simulations were performed using operating parameters and water qualities data collected from a full-scale brackish water reverse osmosis membrane water treatment plant. The membrane channel was divided into a thousand uniform slices and the water qualities were determined locally through a finite difference approach. Prediction of the total dissolved solid (TDS) permeate concentration using the model was found to be accurate within 5% to 15% as an average percentage of difference (APD) using the NHDM developed in this research work. A comparison of the NHDM and the modified NHDM for concentration polarization (CP) with the commonly accepted homogeneous solution diffusion model (HSDM) using pilot-scale brackish water RO operating data indicated that the NHDM is more accurate when the solute concentration in the feed stream is low, while the NHDMCP appears to be more predictive of permeate concentration when considering high solute feed concentration. Simulation results indicated that surface morphology affects the water qualities in the permeate stream. Higher salt passage was expected to occur at the valley areas when diffusion mass transfer would be greater than at the peaks where the thin-film membrane is thicker. A rough surface tends to increase the TDS accumulation on the valley areas, causing an enhanced osmotic pressure at the valleys of membrane.To evaluate the impact of surface morphology on RO and NF performance, fouling experiments were conducted using flat-sheet membrane and three different nanoparticles, which included SiO2, TiO2 and CeO2. In this study, the rate and extent of fouling was markedly influenced by membrane surface morphology. The atomic force microscopy (AFM) analysis revealed that the higher fouling rate of RO membranes compared to that of NF membranes is due to the inherent ridge-and-valley morphology of the RO membranes. This unique morphology increases the surface roughness, leading to particle accumulation in the valleys, causing a higher flux decline than in smoother membranes. Extended fouling experiments were conducted using one of the RO membranes to compare the effect of different particles on actual water. It was determined that membrane flux decline was not affected by particle type when the feed water was laboratory grade water. On the other hand, membrane flux decline was affected by particle type when diluted seawater served as the feed water. It was found that CeO2 addition resulted in the least observable flux decline and fouling rate, followed by SiO2 and TiO2. Fouling simulation was conducted by fitting the monitored flux data into a cake growth rate model. The model was discretized by a finite difference method to incorporate the surface thickness variation. The ratio of cake growth term (k_1) and particle back diffusion term (k_2) was compared in between different RO and NF membranes. Results indicate that k_2 was less significant for surfaces that exhibited a higher roughness. It was concluded that the valley areas of thin-film membrane surfaces have the ability to capture particles, limiting particle back diffusion.
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Date Issued: 2013
Identifier: CFE0004837, ucf:49707
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004837

Title: THE EFFECTS OF BAM AS AN ADSORPTIVE MEDIA ON PHOSPHORUS REMOVAL IN STORMWATER.
Creator: Salamah, Sultan, Randall, Andrew, Duranceau, Steven, Chopra, Manoj, University of Central Florida
Abstract / Description: To maintain the quality of receiving water bodies, it is desirable to remove total phosphorus (TP) in stormwater runoff. Many media filtration technologies have been developed to achieve TP and soluble reactive phosphorus (SRP) removal. Efficient media adsorption is essential to insure control of stormwater phosphorus inputs to the receiving water body. This project develops and analyzes a functionalized Biosorption Media (BAM) to remove phosphorus species from stormwater runoff. One goal of...
Show moreTo maintain the quality of receiving water bodies, it is desirable to remove total phosphorus (TP) in stormwater runoff. Many media filtration technologies have been developed to achieve TP and soluble reactive phosphorus (SRP) removal. Efficient media adsorption is essential to insure control of stormwater phosphorus inputs to the receiving water body. This project develops and analyzes a functionalized Biosorption Media (BAM) to remove phosphorus species from stormwater runoff. One goal of this project is to find the BAM values for coefficients such as maximum adsorption capacity (QM: 4.35E-05) for the media through SRP isotherm equilibrium experiments using the Langmuir and Freundlich models. In addition, an upflow column experiment was also performed to study BAM nutrient removal from stormwater runoff. Finally, the information from the isotherm and the column experiments are used to estimate the life expectancy or quantity required of the media, and to define the effectiveness of BAM in phosphorus removal. The result of this study shows that BAM is a feasible stormwater treatment that can remove 60% SRP and (>)40% TP at temperature between 21-23 (&)deg;C. The media is adequately modeled by both the Langmuir and the Freundlich models over the concentration range of interest in stormwater.
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Date Issued: 2014
Identifier: CFE0005244, ucf:50589
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005244

Title: Trihalomethane Removal and Re-Formation in Spray Aeration Processes Treating Disinfected Groundwater.
Creator: Smith, Cassandra, Duranceau, Steven, Randall, Andrew, Lee, Woo Hyoung, University of Central Florida
Abstract / Description: Historically, chlorination has been widely utilized as a primary and secondary disinfectant in municipal water supplies. Although chlorine disinfection is effective in inactivating pathogenic microbes, the use of chlorine creates the unintentional formation of regulated chemicals. On January 4, 2006, the United States Environmental Protection Agency (EPA) promulgated the Stage 2 Disinfectants/Disinfection by-product rule (DBPR) that focuses on public health protection by limiting exposure to...
Show moreHistorically, chlorination has been widely utilized as a primary and secondary disinfectant in municipal water supplies. Although chlorine disinfection is effective in inactivating pathogenic microbes, the use of chlorine creates the unintentional formation of regulated chemicals. On January 4, 2006, the United States Environmental Protection Agency (EPA) promulgated the Stage 2 Disinfectants/Disinfection by-product rule (DBPR) that focuses on public health protection by limiting exposure to four trihalomethanes (THM) and five haloacetic acids (HAA5), formed when chlorine is used for microbial pathogen control. This thesis examines post-aeration TTHM formation when employing spray-aeration processes to remove semi-volatile TTHMs from chlorinated potable water supplies.A bench scale air stripping unit was designed, constructed and operated to evaluate spray aeration for the removal of the four regulated trihalomethane (THM) species from potable drinking water including bromodichloromethane, bromoform, dibromochloromethane, chloroform. The study was conducted using finished bulk water samples collected from two different water treatment facilities (WTFs) located in Oviedo and Babson Park, Florida. Both treatment plants treat groundwater; however, Oviedo's Mitchell Hammock WTF (MHWTF) supply wells contain dissolved organic carbon and bromide DBP precursors whereas the Babson Park WTF #2 (BPWTF2) supply well contains dissolved organic carbon DBP precursors but is absent of bromide precursor. Three treatment scenarios were studied to monitor impacts on total trihalomethane (TTHM) removal and post-treatment (post-aeration) TTHM formation potential, including 1) no treatment (non-aerated control samples), 2) spray aeration via specially fabricated GridBee(&)#174; nozzle for laboratory-scale applications, 3) spray aeration via a commercially available manufactured BETE(&)#174; nozzle used for full-scale applications. Select water quality parameters, chlorine residual, and total trihalomethane concentrations were monitored throughout the study. The GridBee(&)#174; spray nozzle resulted in TTHM removals ranging from 45.2 (&)#177; 3.3% for the BPWTF2 samples, and 37.7 (&)#177; 3.1% for the MHWTF samples. The BETE(&)#174; spray nozzle removed 54.7(&)#177;3.9% and 48.1(&)#177;6.6% of total trihalomethanes for the Babson Park and Mitchell Hammock WTF samples, respectively. The lower percent removals at the MHWTF are attributed to the detectable presence of bromide and subsequent formation of hypobromous acid in the samples. Post spray aeration TTHM formation potentials were monitored and it was found that the MHWTF experienced significantly higher formation potentials, once again due to the presence of hypobromous acid which led to increases in overall TTHM formation over time in comparison with the Babson Park WTF #2 TTHM formation samples. In addition, chlorine residuals were maintained post spray aeration treatment, and initial chlorine residual and trihalomethane concentrations did not significantly impact overall spray nozzle performance. Among other findings, it was concluded that spray nozzle aeration is a feasible option for the Babson Park WTF #2 for TTHM compliance. For Oviedo's Mitchell Hammock WTF spray aeration was successful in removing TTHMs, however it was not effective in maintaining DBP rule compliance due to the excessive nature of DBP formation in the water samples. This study was not intended to serve as an assessment of varying nozzle technologies; rather, the focus was on the application of spray aerators for TTHM removal and post-formation in drinking water systems.
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Date Issued: 2015
Identifier: CFE0005715, ucf:50117
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005715

Title: Evaluation of Iron and Manganese Control for a Volcanic Surface Water Supply Treated with Conventional Coagulation, Sedimentation and Filtration Processes.
Creator: Hall, Christine, Duranceau, Steven, Lee, Woo Hyoung, Randall, Andrew, University of Central Florida
Abstract / Description: A research project assessing the effectiveness of potassium permanganate (KMnO4) for the treatment of iron (Fe) and manganese (Mn) has been conducted by the University of Central Florida (UCF) on behalf of the United States Navy with regards to the water supply on the island of Guam, located in the Marianas Islands. The study consisted of three basic investigative components: one that examined the use of potassium permanganate for iron and manganese control for Fena Lake, a second that...
Show moreA research project assessing the effectiveness of potassium permanganate (KMnO4) for the treatment of iron (Fe) and manganese (Mn) has been conducted by the University of Central Florida (UCF) on behalf of the United States Navy with regards to the water supply on the island of Guam, located in the Marianas Islands. The study consisted of three basic investigative components: one that examined the use of potassium permanganate for iron and manganese control for Fena Lake, a second that examined the existing unit operations that comprised the Navy's water treatment plant (NWTP), and a third that examined iron and manganese field sampling analytical procedures.In the first and primary component of the research, surface water from Fena Lake located within the Naval Magazine in proximity of Santa Rita, Guam was collected at several different lake depths and initially analyzed for iron and manganese using inductively coupled plasma. Subsequent aliquots of Fena Lake collected at the various water depths were transferred to jars then dosed with varying amounts of potassium permanganate after which iron and manganese content was determined. The jars were covered to simulate actual lake to plant transfer conditions experienced at the Navy's on-island facilities. A portion of the jars was dosed with potassium permanganate prior to metals analysis in order to allow for comparisons of baseline conditions. To represent conventional treatment processes, the water samples were then coagulated with aluminum sulfate prior to filtration to remove the oxidized manganese and iron formed from the addition of the potassium permanganate. Coagulated aliquots were filtered and collected to evaluate residual dissolved iron and manganese content. Based on the results of the jar tests it was determined that manganese was reduced by 95% or greater and that iron was completely removed to below the analytical detection limit (0.001 mg/L). It was determined that the potassium permanganate dose required for oxidation of iron was 0.94 mg/mg iron and for manganese was 1.92 mg/mg manganese. It was also observed that when the jars containing aliquots that turned brown in color after potassium permanganate dosing meant that iron and manganese were present and were being oxidized; however, water samples that turned pink were found to be over-dosed with potassium permanganate. The pink water is an undesired characteristic and could result in customer complaints when distributed to the system.The second component of research focused on NWTP existing conditions. Water samples were collected after each key unit operation within the NWTP and analyzed for iron and manganese. This was to determine if pre-chlorination at Fena Lake was effective at removing iron and manganese that could be present in the source water. Analysis was conducted where pre-chlorination at Fena Lake was practiced as well as when no pretreatment was practiced prior to the NWTP. It was determined that the iron and manganese were not detected downstream of the coagulation unit operation within the NWTP even when pre-chlorination was not practiced. Consequently pre-chlorination of Fena Lake source water was not required for controlling iron and manganese under the conditions experienced in this study.A third study was also implemented to confirm that 0.1-micron filters are appropriate for use in preparing samples for analytical determination of iron and manganese analysis at various points within the NWTP. The filtration step is important to delineate between dissolved and suspended iron and manganese forms. Standard Methods 3120B recommends the use of 0.45-micron filters, although based on literature it has been shown that oxidized manganese particles may be smaller than a 0.45-micron pore size. Unless a coagulant was used, the oxidized manganese may not be fully removed via the 0.45-micron filter. To verify the effectiveness of using a 0.1-micron filter, a jar test was conducted to compare the use of a 0.1-micron filter, a 0.45-micron filter, and a 0.45-micron filter after the sample has been coagulated. It was found that the use of a 0.1-micron filter was superior to the use of 0.45-micron filters even with coagulant addition when directly comparing between dissolved and suspended iron and manganese forms. It is recommended that 0.1-microns be utilized in lieu of historically recommended 0.45-micron filters for sample preparation procedures.
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Date Issued: 2014
Identifier: CFE0005180, ucf:50655
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005180

Title: Modeling wastewater indicators and effects of contaminant removal strategies on groundwater and spring discharge in a karst aquifer.
Creator: Reed, Erin, Duranceau, Steven, Wang, Dingbao, Sadmani, A H M Anwar, Rowney, Alexander, University of Central Florida
Abstract / Description: This dissertation reports on research related to groundwater and contaminant transport to the Volusia Blue Spring (VBS), an Outstanding Florida Water Body located in Volusia County (Florida). The integration of springshed water quality and contaminant fate and transport (CFT) modeling played key roles in the evaluation of anthropogenic recharge impacts on VBS. To study anthropogenic recharge into the karst limestone aquifer, wastewater effluent, golf course ponds, septic tanks, groundwater...
Show moreThis dissertation reports on research related to groundwater and contaminant transport to the Volusia Blue Spring (VBS), an Outstanding Florida Water Body located in Volusia County (Florida). The integration of springshed water quality and contaminant fate and transport (CFT) modeling played key roles in the evaluation of anthropogenic recharge impacts on VBS. To study anthropogenic recharge into the karst limestone aquifer, wastewater effluent, golf course ponds, septic tanks, groundwater monitoring wells, and VBS discharge were sampled for boron, nitrate-nitrogen, nitrate-oxygen and their isotopes spatially throughout the VBS springshed. Data related to natural water features, rainfall, land use, water use, treated wastewater discharge, and septic tank effluent flows was used as inputs to the three-dimensional CFT model developed from an integration of MODFLOW-2000 and MT3DMS. The model was calibrated and validated from field observed water levels and water quality taken throughout the springshed. The purpose of this model is to understand groundwater and spring water quality throughout the VBS springshed. Water quality and model results indicate that water from the surficial aquifer in surrounding urban areas contributed to the flow and water quality at the spring's boil. Protection scenarios that included wetland treatment systems and the conversion of targeted septic systems to sewer were simulated to estimate future reductions of anthropogenic nutrients transported to the Spring. Of the scenarios evaluated in this study, targeted septic system removal results in the greatest benefit with a 36% nitrate decrease in a forty-year projection of spring discharge water quality. Results from this combined water quality and model development approach is expected to contribute an understanding of anthropogenic impacts from the urbanized developments overlying and surrounding the karst VBS aquifer.
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Date Issued: 2016
Identifier: CFE0006701, ucf:51903
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006701

Title: DEVELOPMENT AND APPLICATION OF MICROELECTRODES TO STUDY IN SITU DISINFECTANT LOSS AND CORROSION ON METAL SURFACE.
Creator: Ma, Xiangmeng, Lee, Woo Hyoung, Duranceau, Steven, Sadmani, A H M Anwar, Chumbimuni Torres, Karin, University of Central Florida
Abstract / Description: The primary objective of this research was to develop, fabricate, evaluate and utilize microelectrodes to metal coupons in artificial water system. In the brass experiment, it presented profiles of direct measurements of free chlorine/monochloramine, oxygen and pH to brass and cement based coupons. In monochloraminated water, brass showed a much faster corrosion process under observation. Profiles showed a less monochloramine consumption with as high as 7% greater oxygen utilization comparing...
Show moreThe primary objective of this research was to develop, fabricate, evaluate and utilize microelectrodes to metal coupons in artificial water system. In the brass experiment, it presented profiles of direct measurements of free chlorine/monochloramine, oxygen and pH to brass and cement based coupons. In monochloraminated water, brass showed a much faster corrosion process under observation. Profiles showed a less monochloramine consumption with as high as 7% greater oxygen utilization comparing to the brass in free chlorine solution, reflecting oxygen could be a major part of the corrosion initiation process. While cement showed less reactive characteristics to disinfectants and oxygen compared to the brass profiles, however, pH showed a significant rise for cement coupon under monochloramine condition. In galvanic experiment, the developed lead micro-ISE (100 (&)#181;m tip diameter) showed excellent performance toward soluble lead (Pb2+) with the sensitivity of 22.2 (&)#177; 0.5 mV decade-1 and limit of detection (LOD) of 1.22(&)#215;10-6 M (0.25 mg L-1). The response time was less than 10 seconds with a working pH range of 2.0 (-) 7.0. Using the lead micro-ISE, lead concentration microprofiles were measured from the bulk to the metal surface over time. Combined with two-dimensional (2D) pH map, this work clearly demonstrated that lead leaching at the metal surface is non-uniform and lower surface pH leads to higher lead leaching from the surface. Once significant pH variation (?pH: 6.0) was developed across brass-lead joint coupon, even a small pH change (?pH: 0.6) within the Pb/Sn alloy resulted in 4 times different surface lead concentrations (42.93 vs. 11.61 mg L-1) and 5 times different fluxes (18.5(&)#215;10-6 vs. 3.5(&)#215;10-6 mg cm-2 s-1). Continuous surface lead leaching monitoring and surface characterization found that free chlorine is the primary contributor to lead leaching.
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Date Issued: 2017
Identifier: CFE0007289, ucf:52165
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007289

Title: Investigating Novel Water Treatment Methods and Monitoring Techniques for Sulfide-Laden Groundwater Supplies.
Creator: Yoakum, Benjamin, Duranceau, Steven, Lee, Woo Hyoung, Sadmani, A H M Anwar, Moore, Sean, University of Central Florida
Abstract / Description: This dissertation reports on research related to novel water treatment and monitoring techniques for sulfide-laden groundwater supplies. The dissertation is divided into several chapters with four core chapters focused on investigations studying a novel water treatment method or monitoring technique. The first investigation assessed the efficacy of multi-pass spray aeration treatment to remove trihalomethanes (THMs) and to reduce the total THM formation potential (TTHMFP) of an aerated water...
Show moreThis dissertation reports on research related to novel water treatment and monitoring techniques for sulfide-laden groundwater supplies. The dissertation is divided into several chapters with four core chapters focused on investigations studying a novel water treatment method or monitoring technique. The first investigation assessed the efficacy of multi-pass spray aeration treatment to remove trihalomethanes (THMs) and to reduce the total THM formation potential (TTHMFP) of an aerated water column post-aeration. A recirculating spray aeration pilot unit was constructed to make this assessment. To assess the effect of multi-pass spray aeration on the TTHMFP, water was recirculated through a fabricated spray nozzle for various lengths of time. Results showed that multi-pass spray aeration can remove chloroform, dichlorobromomethane, dibromochloromethane and bromoform to below detection levels ((<) 0.7 ppb) for the waters investigated. Additionally, spray aeration reduced the TTHMFP of chlorinated water. Results suggest multi-pass spray aeration may be a viable treatment option for some bromide container waters. Results also indicate that multi-pass spray aeration removes bromide from the bulk water in the form of organically bound volatile compounds.The second investigation assessed the efficacy of using pre-existing tray aeration infrastructure to comply with disinfection by-product (DBP) regulations. To assess the efficacy of tray aerators to reduce the concentration TTHMs a pilot tray aerator was constructed. Results showed that after five tray passes (each pass consisting of water being passed over five trays) the concentration of TTHMs was below the detection limit ((<) 0.7 ppb) for the water investigated. To assess the efficacy of tray aeration at full-scale, a water treatment plant and the distribution system it serves were monitored for eight months. Results showed an approximate 40 ppb reduction in the TTHM concentration at two on-site monitoring locations and the one off-site monitoring location (initial concentrations being approximately 54 ppb, 60 ppb and 73 ppb, respectively). Results suggest that the utility managing the full-scale system could comply with DBP regulations by using the pre-existing tray aeration infrastructure to reduce formed THMs on-site where regulated haloacetic acids are not predominant.The third investigation assessed the efficacy of using biological activated carbon (BAC) to remove disinfection by-product precursor matter to comply with DBP regulations. To research this method, a pilot scale BAC filter was operated for three independent test runs. In addition, two full-scale WTPs using BAC were monitored over time. Results showed an approximate 40 percent removal of dissolved organic carbon (DOC) during the three pilot runs and an approximate 55 percent removal of DOC during full-scale monitoring. Results showed that the reduction in DOC reduced the TTHMFP of BAC treated water. Results suggest that BAC treatment could be a viable treatment option to comply with DBP regulations in the sulfide-laden water studied.The fourth investigation assessed the suitability of oxidation reduction potential (ORP) to monitor the effectiveness of an oxidizing media filter used to remove sulfur from a sulfide-laden groundwater. Results showed that ORP was more useful as a measurement technique as compared to free chlorine residual when assessing filter bed health and regeneration effectiveness. It was determined that when the ORP measurement taken from within the oxidative media layer was below 500 mV, the filter bed was not providing treatment, and manganese could be released. Results showed a significant increase in turbidity ((>) 2 NTU) and total manganese ((>) 0.05 mg/L) occurred when the ORP within the filter bed dropped below 400 mV. More frequent cycling of the filters was found to be an effective treatment option to maintain ORP values above an identified 400 mV operational threshold.
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Date Issued: 2017
Identifier: CFE0007141, ucf:52317
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007141

Title: Forward Osmosis for Algae Dewatering and Electrical Field-driven Membrane Fouling Mitigation.
Creator: Munshi, Faris, Lee, Woo Hyoung, Duranceau, Steven, Sadmani, A H M Anwar, Chumbimuni Torres, Karin, University of Central Florida
Abstract / Description: Efficient and low-energy microalgae harvesting is essential for sustainable biofuel production. Forward osmosis (FO) can provide a potential alternative for algae separation with low energy consumption by using osmotic pressure. In this study, an aquaporin-based polyethersulfone (PES) membrane was evaluated for algae dewatering using FO with three different types of draw solutions (DSs: NaCl, KCl and NH4Cl), and under different cross flow velocities (CFVs). 81% of algae dewatering was...
Show moreEfficient and low-energy microalgae harvesting is essential for sustainable biofuel production. Forward osmosis (FO) can provide a potential alternative for algae separation with low energy consumption by using osmotic pressure. In this study, an aquaporin-based polyethersulfone (PES) membrane was evaluated for algae dewatering using FO with three different types of draw solutions (DSs: NaCl, KCl and NH4Cl), and under different cross flow velocities (CFVs). 81% of algae dewatering was achieved with a 29% flux drop. Among three different DSs, although NH4Cl was the best candidate for improved water flux and low reverse salt flux (RSF), it could accelerate cell division, reducing settleability during the FO process. However, RSF originated from NaCl could increase lipid content (~ 49%) in algal biomass probably due to the osmotic imbalance in algal cells. During FO operations, membrane fouling would be an inherent problem against sustainable algae dewatering. In this study, a novel approach was investigated by coupling the FO with an electric field for developing repulsion forces that can prolong the filtration cycle and mitigate foulant attachment. Several electric fields (0.33, 0.13 and 0.03 V mm-1) were applied in continuous and pulsing modes (10sec intervals) to mitigate membrane fouling for effective algae dewatering. The electric field FO configuration used in this study was able to produce 3.8, 2.2 and 2.2 times greater flux at the applied potential of -1.0, -0.4, and -0.1 V, respectively, compared to the control (without an electric field). A high potential of -10 V for 60 sec was applied as an optimal cleaning procedure with a high ability to recover flux (99%). The study also investigated the effect of the electric fields on bulk pH, conductivity, settling velocity, lipid content and microalgal morphology. Overall, this study demonstrates a novel technology for algae dewatering in FO application using the aquaporin-based PES membrane.
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Date Issued: 2019
Identifier: CFE0007507, ucf:52632
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007507

Title: Nanofiltration of Perfluorinated Compounds as a Function of Water Matrix Properties.
Creator: Toure, Hadi, Sadmani, A H M Anwar, Duranceau, Steven, Lee, Woo Hyoung, University of Central Florida
Abstract / Description: Perfluorinated compounds (PFCs) have been manufactured and used in various industries including food packaging, paintings, and coating industries. Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are the most commonly investigated PFCs that have bioaccumulative properties and a strong persistence in environment. Despite the growing interest in using membrane technology to remove PFOA and PFOS from water, little information is available on the impact of natural water...
Show morePerfluorinated compounds (PFCs) have been manufactured and used in various industries including food packaging, paintings, and coating industries. Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are the most commonly investigated PFCs that have bioaccumulative properties and a strong persistence in environment. Despite the growing interest in using membrane technology to remove PFOA and PFOS from water, little information is available on the impact of natural water matrices on the removal of PFOA and PFOS when using nanofiltration (NF). The presence of natural organic matter (NOM) and cations (Ca2+ and Mg2+) in water matrices and their interactions with the PFCs may significantly impact their removal efficiency. The current study compared the rejection of PFOA and PFOS from laboratory-prepared water (deionized water), surface water and groundwater using a commercial NF membrane (NE 70). Three different experiments were conducted for 20 hours using a bench- scale flat sheet unit. Feed and permeate samples were collected and analyzed to determine the PFOA and PFOS concentrations using liquid chromatography-tandem mass spectrometry (LC/MS-MS). The compound rejections varied from 71 to 80 % for PFOA and 42 to 80 % for PFOS. The results showed increased rejection of PFOA/S in the surface water and groundwaters when compared to the laboratory-prepared water. This is likely due to the presence of NOM and cations in the natural water matrices. The permeate flux declined (12.3-56.2 %) as more cations and NOM were present in the feedwater, suggesting that the increased rejection of PFOS in natural waters may be due to membrane pore blockage.
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Date Issued: 2018
Identifier: CFE0007589, ucf:52539
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007589

Corrosion (4)	+ -
Drinking Water (4)	+ -
groundwater (4)	+ -
nanofiltration (4)	+ -
Nanofiltration (3)	+ -

THM (3)	+ -
chlorine dioxide (3)	+ -
drinking water (3)	+ -
membranes (3)	+ -
oxidation (3)	+ -
potassium permanganate (3)	+ -
ultrafiltration (3)	+ -
BAM (2)	+ -
CEB (2)	+ -
Coagulation (2)	+ -
Corrosion Inhibitor (2)	+ -
Disinfection by-products (2)	+ -
Groundwater (2)	+ -
HAA (2)	+ -
PCA (2)	+ -
PCB (2)	+ -
Reverse Osmosis (2)	+ -
Spray Aeration (2)	+ -
Ultrafiltration (2)	+ -
biological nutrient removal (2)	+ -
conventional treatment (2)	+ -
corrosion control (2)	+ -
corrosion inhibitor (2)	+ -
diffusion (2)	+ -
disinfection by products (2)	+ -

ETD Collection (48)	+ -
Honors Collection (2)	+ -

University of Central Florida (50)	+ -
Duranceau, Steven (49)	+ -
Lee, Woo Hyoung (20)	+ -
Randall, Andrew (20)	+ -
Sadmani, A H M Anwar (18)	+ -

Yestrebsky, Cherie (8)	+ -
Clausen, Christian (7)	+ -
Wang, Dingbao (7)	+ -
Chopra, Manoj (3)	+ -
Cooper, Charles (3)	+ -
Rodriguez, Angela (3)	+ -
Boyd, Christopher (2)	+ -
Campiglia, Andres (2)	+ -
Chow, Louis (2)	+ -
Chumbimuni Torres, Karin (2)	+ -
Church, Jared (2)	+ -
Das, Tuhin (2)	+ -
Frazer, Andrew (2)	+ -
Jeffery, Samantha (2)	+ -
Jimenez, Jose (2)	+ -
Mansy, Hansen (2)	+ -
Salamah, Sultan (2)	+ -
Yonge, David (2)	+ -
Zhang, Husen (2)	+ -
Abdelhady, Ramy (1)	+ -
Abdelkareem, Mohamed (1)	+ -
Arenas Daza, Maria (1)	+ -
Biscardi, Paul (1)	+ -
Borgon, Robert (1)	+ -
Coleman, Martin (1)	+ -

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