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Title: Assessment of a Surface Water Supply for Source and Treated Distribution System Quality.
Creator: Rodriguez, Angela, Duranceau, Steven, Lee, Woo Hyoung, Sadmani, A H M Anwar, University of Central Florida
Abstract / Description: This study focused on providing a source to tap assessment of surface water systems with respect to (i) the use of alternative biomonitoring tools, (ii) disinfection byproduct (DBP) formation and control, and (iii) corrosion control. In the first study component, two water systems were microbiologically evaluated using adenosine triphosphate (ATP) bioluminescence technology. It was determined that microbial ATP was useful as a surrogate for biomonitoring within a surface water system when...
Show moreThis study focused on providing a source to tap assessment of surface water systems with respect to (i) the use of alternative biomonitoring tools, (ii) disinfection byproduct (DBP) formation and control, and (iii) corrosion control. In the first study component, two water systems were microbiologically evaluated using adenosine triphosphate (ATP) bioluminescence technology. It was determined that microbial ATP was useful as a surrogate for biomonitoring within a surface water system when paired with traditional methods. Although microbial activity differed between distribution systems that used either chloramine or chlorine disinfectant, in both cases flowrate and season affected microbial ATP values. In the second study component, total trihalomethanes (TTHM) and haloacetic acids (HAA5) DBP formation and disinfectant stability was investigated using a novel DBP control process. The method relied on a combination of sulfate, ultraviolet light irradiation, pH, and aeration unit operations. Results indicate respective decreases in 7-day TTHM and HAA5 formation potentials of 36% - 57% and 20% - 47% for the surface waters investigated. In the third component of this work, a corrosion study assessed the effect of disinfectant chemical transitions on the corrosion rates of common distribution system metals. When a chlorine based disinfection system transitioned between chlorine and chloramine, mild steel corrosion increased by 0.45 mils per year (mpy) under chloramine and returned to baseline corrosion rates under chlorine. However, when a chloramine based disinfection system transitioned between chloramine and chlorine, mild steel corrosion increased in tandem with total chlorine levels. Unlike the chlorine system, the mild steel corrosion rates did not return to baseline under chloramine after exposure to 5 mg/L of total chlorine. Surface water systems should consider the use of ATP as a surrogate for biomonitoring, consider the novel treatment process for DBP formation control, and consider corrosion control in disinfectant decision-making activities.
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Date Issued: 2019
Identifier: CFE0007901, ucf:52751
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007901

Title: Harmful Algal Bloom Mitigation using Recycle Concrete Aggregate coated with Fixed-Quat.
Creator: Ezeodurukwe, Ikenna, Lee, Woo Hyoung, Randall, Andrew, Sadmani, A H M Anwar, University of Central Florida
Abstract / Description: Human activities generate surplus nutrients which may lead to algal bloom events in water resources along with serious ecological problems and thus substantial economic losses. Particularly, harmful algal blooms (HABs) represent toxic cyanobacterial blooms which produce cyanotoxins. The primary concerns of HABs are the exposures to a wide variety of cyanotoxins via ingestion of contaminated drinking water, inhalation during recreational activities, and consumption of contaminated fish and...
Show moreHuman activities generate surplus nutrients which may lead to algal bloom events in water resources along with serious ecological problems and thus substantial economic losses. Particularly, harmful algal blooms (HABs) represent toxic cyanobacterial blooms which produce cyanotoxins. The primary concerns of HABs are the exposures to a wide variety of cyanotoxins via ingestion of contaminated drinking water, inhalation during recreational activities, and consumption of contaminated fish and shellfish. However, conventional physical and chemical methods are not always possible to efficiently handle these HABs events. It is urgent to develop viable and rapid solutions to control HABs in field and mitigate the effects of HABs in fresh water, particularly in those that serve as sources of drinking water supply.(&)nbsp;Quaternary ammonium compounds (Quats) represent a wide range of cationic compounds with different formulation that constitutes products for agriculture, domestic and medical and industry. As organic antimicrobial compounds, Quats can be used as alternatives to existing chemical-based technique for HABs control due to its less toxicity and its affinity to variety of surface. In this study, recycled concrete aggregate (RCA) from a regional construction and demolition (C(&)D) waste recycling facility was used as a sustainable and environmentally friendly substrate and coated with a composite of silica-quaternary ammonium compounds (Fixed-Quat).(&)nbsp;Then, the algistatic capabilities of imparting antimicrobial properties of Quats to the RCA surface, which involve the covalent attachment of the biocides to the surfaces (sol-gel technique), were evaluated with HABs-causing algal species, Microcystis aeruginosa. Chlorophyll-a was measured to determine the efficiency of HABs mitigation using Fixed-Quat coated RCA in terms of photosynthetic inactivation of the selected algae. OD660 and pH were measured as key parameters to monitor algal cell growth and cement hydration. Notably, a 61% reduction of chlorophyll-a within 6 hours and complete removal of chlorophyll-a within 8 hours were achieved, indicating that Fixed-Quat coated RCA would be efficient in growth inhibition of Microcystis aeruginosa. Overall, with an appropriate design for field application and further evaluations like lifetime of Quat coating and potential recovery of treated algae, the Fixed-Quat antimicrobial coated RCA would be a promising and sustainable(&)nbsp;alternative to conventional HABs mitigation methods in various aquatic systems.
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Date Issued: 2018
Identifier: CFE0007400, ucf:52066
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007400

Title: Evaluating the Integration of Chlorine Dioxide into a Coagulation, Sedimentation, and Filtration Process Treating Surface Water.
Creator: Coleman, Martin, Duranceau, Steven, Lee, Woo Hyoung, Sadmani, A H M Anwar, University of Central Florida
Abstract / Description: Methods of optimizing the coagulation, flocculation, sedimentation, and filtration (CSF) process at a conventional surface water treatment plant (WTP) were conducted to investigate opportunities for the reduction of disinfection by-product (DBP) precursor material. The research had two primary components: (1) optimize coagulant dosage and associated operating pH and (2) investigate pretreatment oxidation with chlorine dioxide (ClO2) and potassium permanganate (KMnO4). To accomplish the first...
Show moreMethods of optimizing the coagulation, flocculation, sedimentation, and filtration (CSF) process at a conventional surface water treatment plant (WTP) were conducted to investigate opportunities for the reduction of disinfection by-product (DBP) precursor material. The research had two primary components: (1) optimize coagulant dosage and associated operating pH and (2) investigate pretreatment oxidation with chlorine dioxide (ClO2) and potassium permanganate (KMnO4). To accomplish the first component, jar tests were conducted at various pH and aluminum sulfate (alum) dosages to model current and potential treatment conditions during the CSF process at a WTP. Isopleths were developed to examine the removal efficiencies of turbidity and natural organic matter (NOM). NOM is a DBP precursor material and was represented by non-purgeable dissolved organic carbon (DOC) throughout the research. Isopleths indicated that at pH 6.2 and a corresponding alum dosage of 20 mg/L (control condition), turbidity and DOC were reduced by 90 and 35 percent, respectively. However, at pH 5.5 and 30 mg/L alum dosage, turbidity removal decreased to 80 percent whereas, DOC removal improved to 50 percent. Jar testing was conducted to evaluate differences in the use of KMnO4 and ClO2 as a pretreatment chemical to observe the reduction of DBP precursor material (i.e., NOM), dissolved iron, and dissolved manganese. Addition of ClO2 was able to reduce total trihalomethanes and haloacetic acid formation potentials (168-hours) up to 40 percent and 15 percent, respectively, and was dependent on chlorine dioxide generation method, dosage, and raw water characteristics. Chlorine dioxide also was shown to remove iron and manganese at levels greater than 99 percent.
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Date Issued: 2018
Identifier: CFE0007396, ucf:52078
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007396

Title: Reducing Sulfuric Acid Pretreatment in a Nanofiltration Process Treating Surficial Groundwater.
Creator: Higgins, Carlyn, Duranceau, Steven, Lee, Woo Hyoung, Sadmani, A H M Anwar, University of Central Florida
Abstract / Description: Nanofiltration (NF) is a pressure driven membrane process employed in drinking water treatment that requires pretreatment for reliable operation. The objective of this research was to determine if NF membranes can proficiently operate with a decreased or eliminated dose of sulfuric acid pretreatment. When used as pretreatment, sulfuric acid prevents calcium carbonate scaling on NF membranes, yet is costly, hazardous, and imparts high sulfate concentrations to NF feed and concentrate streams....
Show moreNanofiltration (NF) is a pressure driven membrane process employed in drinking water treatment that requires pretreatment for reliable operation. The objective of this research was to determine if NF membranes can proficiently operate with a decreased or eliminated dose of sulfuric acid pretreatment. When used as pretreatment, sulfuric acid prevents calcium carbonate scaling on NF membranes, yet is costly, hazardous, and imparts high sulfate concentrations to NF feed and concentrate streams. To conduct this research, a 0.324 million gallon per day (MGD) NF pilot plant was operated for 3,855 run-hours at a flux rate of 15 gallons per square foot-day. The NF pilot unit's process performance, productivity, and water quality were monitored while the sulfuric acid dose was gradually decreased, controlled by monitoring pH that ranged from pH 6.5 (80 mg/L sulfuric acid dose) to pH 7.0 (no sulfuric acid dose). NF pilot productivity, as measured by specific flux, was found to decline when sulfuric acid was eliminated by 2.33 percent, 9.61 percent, and 4.08 percent in the first stage, second stage, and total pilot system, respectively, with no distinguishable increase in pressure drop. Noticeable water quality trends include approximately 75 percent sulfate decrease in feed and concentrate streams, and 20 percent increase of calcium hardness and alkalinity in the permeate stream. After piloting, superimposed elemental imaging analysis revealed that the second stage, tail-end membrane surface was fouled with iron disulfide, calcium carbonate, clay, and natural organic matter. However, flux recovered to normal operating conditions after a membrane cleaning was performed. Results of the pilot study indicated that sulfuric acid could be eliminated from the full-scale NF pretreatment process; however, membrane cleaning frequencies could increase. If applied to the full-scale NF process, elimination of sulfuric acid pretreatment would reduce annual chemical costs by over $70,000.
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Date Issued: 2017
Identifier: CFE0007287, ucf:52148
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007287

Title: Disinfection By-Product Reduction Study of a Small Central Florida Public Water System.
Creator: Staubus, Paul, Duranceau, Steven, Sadmani, A H M Anwar, Randall, Andrew, University of Central Florida
Abstract / Description: The disinfection of water for potabilization has proven to be one of the most significant public achievements of the 20th century. Although chemical disinfectants are successfully utilized to inactivate acute pathogenic organisms, they may react with natural organic matter (NOM) to produce potentially-harmful disinfection by-products (DBPs). As a result, the United States Environmental Protection Agency regulates DBPs such as total trihalomethanes (TTHMs) and haloacetic acids (HAAs). The...
Show moreThe disinfection of water for potabilization has proven to be one of the most significant public achievements of the 20th century. Although chemical disinfectants are successfully utilized to inactivate acute pathogenic organisms, they may react with natural organic matter (NOM) to produce potentially-harmful disinfection by-products (DBPs). As a result, the United States Environmental Protection Agency regulates DBPs such as total trihalomethanes (TTHMs) and haloacetic acids (HAAs). The research herein is focused on the formation, removal, and control of TTHMs and HAAs in a small public water system (PWS) in Polk County, Florida (County). Pilot-scale tests were implemented to determine the efficacy of stripping TTHMs using single-pass spray and recirculating tray aeration systems, both operating at flows of 3 gallons per minute. In the spray aerator evaluation, an average TTHM reduction of 29.5% was recorded. With tray aeration, a 46.7% reduction of TTHMs was observed after a single pass through the assembly. The benefits of additional recirculation appeared to decrease significantly after four passes, at a TTHM removal of 85.5%. A raw water blending effort was conducted to model bypass around granular activated carbon (GAC) adsorption vessels. The results demonstrated the feasibility of a 50% blend in full-scale treatment operations. With this blend, chlorine residuals and HAA concentrations were able to be controlled throughout 48 hours of incubation at 30(&)deg;C. From the data collected, a water quality plan was developed for the County's Waverly PWS. The plan to control the formation of DBPs integrated a recirculating tray aeration process for TTHM stripping complemented with GAC adsorption process for removing DBP precursors.The estimated conceptual operating cost was approximated at $24,000 annually. This cost considered carbon replacement as well as the recirculation pump operation. If the recommended 50% GAC bypass is applied, the conceptual operating cost reduces to approximately $15,250 annually.
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Date Issued: 2018
Identifier: CFE0007249, ucf:52175
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007249

Title: Assessing the Impact of Radionuclides Released into the Floridan Aquifer by a Massive Sinkhole on Local Municipal Water Supplies.
Creator: Arenas Daza, Maria, Duranceau, Steven, Sadmani, A H M Anwar, Wang, Dingbao, University of Central Florida
Abstract / Description: In late August 2016, a sinkhole spanning 45 feet (13.7 meters) in diameter opened at a phosphate fertilizer facility (Mosaic Company) near Mulberry, Florida, leaking an estimated 215 million gallons (813,000 cubic meters) of radionuclide-contaminated water 300 feet into the Floridan aquifer. An investigation to determine possible impacts to the environment and local community drinking water supplies was implemented that focused on two 1.5 million gallon per day (MGD) Tampa Bay Water (TBW)...
Show moreIn late August 2016, a sinkhole spanning 45 feet (13.7 meters) in diameter opened at a phosphate fertilizer facility (Mosaic Company) near Mulberry, Florida, leaking an estimated 215 million gallons (813,000 cubic meters) of radionuclide-contaminated water 300 feet into the Floridan aquifer. An investigation to determine possible impacts to the environment and local community drinking water supplies was implemented that focused on two 1.5 million gallon per day (MGD) Tampa Bay Water (TBW) production wells and two Polk County Utilities (PCU) water treatment facilities. Water samples collected between June 2017 and January 2018 at the TBW and PCU sites were found to contain radionuclides below regulated levels. To evaluate the effectiveness of membrane treatment should the TBW and PCU drinking water wells be affected by the spill in the future, bench-scale, flat-sheet reverse osmosis (RO) and nanofiltration (NF) membrane process testing was performed using TBW and PCU wellfield sample aliquots. NF and RO were shown to be capable of removing at minimum of 86 and 92 percent, respectively, of the barium content that had been spiked into groundwater testing aliquots. Based on testing results, a conceptual opinion of probable capital cost for a membrane process ranged from $1.7 and $3.5 million for a 0.25 MGD and 2.0 MGD design capacity, respectively. Process operation and maintenance costs ranged between $0.99/Kgal and $0.26/Kgal for a 0.25 MGD and 2.0 MGD design capacity, respectively. The amortized total cost based on a 20-year period and 8 percent interest rate ranged between $1.88/Kgal for a 0.25 MGD and $0.49/Kgal for a 2.0 MGD design capacity plant. An estimate of unavailable water value due to a long-term well shut-down was approximated as $0.64/Kgal.
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Date Issued: 2018
Identifier: CFE0006970, ucf:52911
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006970

Title: Integrating Spray Aeration and Granular Activated Carbon for Disinfection By-Product Control in a Potable Water System.
Creator: Rodriguez, Angela, Duranceau, Steven, Lee, Woo Hyoung, Sadmani, A H M Anwar, University of Central Florida
Abstract / Description: Public water systems add disinfectants in water treatment to inactivate microbial pathogens. Chlorine, when used as a disinfectant, reacts with natural organic matter in the water to form trihalomethane (THM) and haloacetic acid (HAA5) disinfection by-products (DBPs), which are suspected carcinogens. The Safe Drinking Water Act's Disinfectant and Disinfection By-Product (D/DBP) Rules were promulgated by the U.S. Environmental Protection Agency to regulate the amount of DBPs in water systems....
Show morePublic water systems add disinfectants in water treatment to inactivate microbial pathogens. Chlorine, when used as a disinfectant, reacts with natural organic matter in the water to form trihalomethane (THM) and haloacetic acid (HAA5) disinfection by-products (DBPs), which are suspected carcinogens. The Safe Drinking Water Act's Disinfectant and Disinfection By-Product (D/DBP) Rules were promulgated by the U.S. Environmental Protection Agency to regulate the amount of DBPs in water systems. Regulatory compliance is based on maximum contaminant levels (MCL), measured as a locational running annual average (LRAA), for total THM (TTHM) and HAA5 of 80 (&)#181;g/L and 60 (&)#181;g/L, respectively. Regulated DBPs, if consumed in excess of EPA's MCL standard over many years, may increase chronic health risks. In order to comply with the D/DBP Rules, the County of Maui Department of Water Supply (DWS) adopted two DBP control technologies. A GridBee(&)#174; spray-aeration process was place into DWS's Lower Kula water system's Brooks ground storage tank in February of 2013. In March of 2015 the second DBP control technology, granular activated carbon (GAC), was integrated into DWS's Pi'iholo surface water treatment plant. To investigate the integration effectiveness of GAC and spray-aeration into a water system for DBP control, DBP data was gathered from the system between August of 2011 and August 2016, and analyzed relative to cost and performance.Prior to the spray aeration and GAC integration, it was found that TTHM levels at the LRAA compliance site ranged between 58.5 (&)#181;g/L and 125 (&)#181;g/L (at times exceeding the MCL). Additionally, HAA5 levels at the LRAA compliance site ranged between 21.2 and 52.0 (&)#181;g/L. The concerted efforts of the GAC and GridBee(&)#174; system was found to reduce LRAA TTHM and HAA5 concentrations to 38.5 (&)#181;g/L and 20.5 (&)#181;g/L, respectively, in the Lower Kula system. Hypothesis testing utilizing t-Tests confirmed that TTHMs levels were controlled by the spray aeration system and the GAC was responsible for controlling HAA5 formation. Although TTHM levels were reduced by 58 percent, and HAA5 levels by 48 percent, the estimated cumulative annual operation and maintenance (O(&)M) cost of the two systems was $1,036,000. In light of the cost analysis, total organic carbon (TOC)-based models for predicting LRAA TTHM and HAA5 levels were developed as equation (i) and (ii), respectively:(i) TTHM (&)#181;g/L = (32.5 x (TOC ppm)) + 5.59, (ii) HAA5 (&)#181;g/L = (8.37 x (TOC ppm)) + 12.4.The TTHM model yielded an R2 of 0.93, and the HAA5 model had an R2 of 0.52. F-Tests comparing predicted LRAA TTHM and HAA5 levels to actual LRAA TTHM and HAA5 levels determined no statistically-significant difference. With the knowledge of how the GAC and spray aerator controlled DBPs in the water system, a cost-effective and practical treatment operating parameter was developed. The parameter, Pi'iholo water plant filter effluent TOC content, can serve as an indicator that operators would use to alter DBP treatment process flow set points to achieve cost-effective treatment. Furthermore, the significant annual cost contribution by the GAC, coupled with HAA5 levels below DWS's MCLG, led to the recommendation of variable frequency drive (VFD) pumps for the GAC system. The addition of VFD pumps should reduce the frequency of carbon change outs while preserving adequate HAA5 control in the system.
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Date Issued: 2016
Identifier: CFE0006841, ucf:52881
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006841

Title: Cost and Environmental Impacts of Leachate Nitrogen/Phosphorus Management Approaches.
Creator: Alanezi, Alaa, Reinhart, Debra, Randall, Andrew, Sadmani, A H M Anwar, University of Central Florida
Abstract / Description: Landfill leachate is a challenging wastewater to discharge into municipal wastewater treatment plants (WWTPs), the most common approach for leachate management, due to the presence of contaminants that may affect the performance of the treatment plant. Treatment, disposal, and transportation of leachate are expensive and therefore a concern. Currently, sidestream treatment is becoming increasingly common in WWTPs prior to returning the liquid to the plant influent. For this research, a new...
Show moreLandfill leachate is a challenging wastewater to discharge into municipal wastewater treatment plants (WWTPs), the most common approach for leachate management, due to the presence of contaminants that may affect the performance of the treatment plant. Treatment, disposal, and transportation of leachate are expensive and therefore a concern. Currently, sidestream treatment is becoming increasingly common in WWTPs prior to returning the liquid to the plant influent. For this research, a new treatment scheme is introduced combining centrate and leachate to reduce contaminants, recover phosphorous and nitrogen through struvite precipitation, and reduce energy requirements through anaerobic ammonium oxidation (Anammox). By combining the two waste streams, the respective limited nutrients (nitrogen in centrate and nitrogen in leachate) can be removed in a low cost chemical treatment resources can be recovered. Carbon contaminants and remaining nutrients can be removed in subsequent innovative biological treatment units. The objective of this thesis is to conduct a cost analysis and environmental assessment of the proposed novel treatment approach and to compare it to more traditional landfill on-site leachate treatment approaches (e.g., membrane bioreactors (MBR) and sequencing batch reactors (SBR)). The study was completed with the use of spreadsheet-based models. Spreadsheets have been developed to evaluate treatment costs (Capital + O(&)M) for both the proposed nutrient recovery/biological and traditional on-site leachate treatments. Transportation costs of leachate to the WWTP have been studied and analyzed by the use of a spreadsheet model as a function of distance. Results suggest that treatment using Struvite (-) Aerobic Granular Sludge (-) Anammox (SGA) was higher in cost compared to traditional approaches. However, positive outcomes from this process include: lower N_2 O emissions, lower power consumption, struvite fertilizer, and overall recovery of nitrogen and phosphorus with the combination of centrate and leachate.
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Date Issued: 2018
Identifier: CFE0007147, ucf:52310
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007147

Title: Comparison of a modified and traditional rapid infiltration basin for treatment and control of nutrients in wastewater effluent.
Creator: Cormier, Jessica, Duranceau, Steven, Wang, Dingbao, Sadmani, A H M Anwar, University of Central Florida
Abstract / Description: Rapid infiltration basins (RIB) have been historically used in Florida for groundwater recharge, effluent disposal, or a combination of both. However, this technique has proven ineffective in providing nitrogen control unless the RIB is modified in some manner. In this study, a traditional RIB was compared to a modified RIB constructed with manufactured biosorption activated media (BAM) to evaluate nitrate removal from reclaimed water. The RIBs are used for reclaimed and excess storm water...
Show moreRapid infiltration basins (RIB) have been historically used in Florida for groundwater recharge, effluent disposal, or a combination of both. However, this technique has proven ineffective in providing nitrogen control unless the RIB is modified in some manner. In this study, a traditional RIB was compared to a modified RIB constructed with manufactured biosorption activated media (BAM) to evaluate nitrate removal from reclaimed water. The RIBs are used for reclaimed and excess storm water disposal. Few, if any, studies have been published where BAM-modified RIBs have been used for this purpose. In this work, a mixture of clay, tire crumb, and sand (CTS) was selected to serve as the BAM material (Bold and Gold(TM) CTS media). Each RIB was constructed with two feet of either sand or BAM, covering more than 43,600 square feet of surface area. The BAM-modified RIB had an initial 90 pounds per cubic-foot in-place density, and the density of the control RIB approximated about 94 pounds per cubic-foot. Over an eight-month period, loadings to the BAM RIB and control RIB approximated 5.4 million gallons (MG) per acre each. Water samples, collected from lysimeters installed below the 2-foot of sand or BAM materials, were gathered monthly during 2017 (except for September and October due to the impacts of hurricane Irma); these samples were analyzed for water quality to determine nitrate removal. Soil moisture and weather data were also collected over the study period. This study demonstrated the nitrate removal effectiveness of a field-scale BAM-modified RIB as compared to a traditional field-scale sand-based RIB. Results suggest that BAM removed 30 percent more nitrates than the Control (78% and 47%, respectively) under the conditions of the study. Furthermore, BAM removed higher percentages of TN (31%) and TP (62%) than the Control (12% and 28%, respectively).
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Date Issued: 2018
Identifier: CFE0007566, ucf:52583
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007566

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: 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: Long-term Carbon and Copper Impact on Nutrient Removal via Green Sorption Media in Dynamic Linear Ditch Environments.
Creator: Ordonez, Diana, Chang, Ni-bin, Randall, Andrew, Sadmani, A H M Anwar, University of Central Florida
Abstract / Description: Nutrient-laden stormwater runoff causes environmental and ecological impacts on receiving water bodies. Biosorption Activated Media (BAM) composed of the sand, tire crumb, and clay have been implemented in stormwater best management practices due to its ability to efficiently remove nutrients from stormwater runoff, such as in roadside linear ditches, via unique chemophysical and microbiological processes. In this study, a set of fixed-bed columns were set up to simulate some external forces...
Show moreNutrient-laden stormwater runoff causes environmental and ecological impacts on receiving water bodies. Biosorption Activated Media (BAM) composed of the sand, tire crumb, and clay have been implemented in stormwater best management practices due to its ability to efficiently remove nutrients from stormwater runoff, such as in roadside linear ditches, via unique chemophysical and microbiological processes. In this study, a set of fixed-bed columns were set up to simulate some external forces in roadside linear ditches and examine how these external forces affect the performance of BAM. In our experiment, scenario 1 simulates the impact that animals such as tortoises, moles and ants produce conduits on the top layer of BAM. Scenario 2 simulates the presence of animals on BAM, together with external compaction. Finally, scenario 3 simulates external compaction such as traffic compaction alone. Furthermore, two baseline conditions were included to sustain the impact assessment of these three scenarios, respectively. They are the long-term presence of carbon in stormwater as carbon can be transported by stormwater runoff from neighboring crop fields, and the long-term presence of copper ions in stormwater as copper depositions can also be found because of electrical wiring, roofing, stormwater ponds disinfection and automobile brake pads in transportation networks. This systematic assessment encompasses some intertwined field complexity in real world systems driven by different hydraulic conditions, microbial ecology, Dissolved Organic Nitrogen (DON) reshape/removal, and long-term addition of carbon and copper (alone) on the effectiveness of total nitrogen removal. The removal efficiencies are substantially linked to varying microbial processes including mineralization, ammonification, nitrification, denitrification, and even dissimilatory nitrate reduction to ammonium, each of which is controlled by different dominant microbial species. The identification of DON compounds at the molecular level was done via a Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-IR-MS) whereas the quantitation of microbial species was done by using quantitative Polymerase Chain Reaction (qPCR). The results from the interactions between microbial ecology and DON decomposition were compared to the external forces and baseline conditions to obtain a holistic understanding of the removals efficiencies of total nitrogen. With the aid of qPCR and FT-IR-MS, this study concluded that the long-term presence of carbon is beneficial for nutrient removal whereas the long-term copper addition inhibits nutrient removal.
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Date Issued: 2019
Identifier: CFE0007847, ucf:52816
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007847

Title: Adsorption Capacity Assessment of Advance Green Environmental Media to Remove Nutrients from Stormwater-Runoff.
Creator: Elhakiem, Hanan, Chang, Ni-bin, Sadmani, A H M Anwar, Yu, Haofei, University of Central Florida
Abstract / Description: Best Management Practices (BMPs) in stormwater treatment are a suite of treatment alternatives to deal with pollutant removal problems from stormwater runoff. Biosorption-activated media (BAM) are green sorption media consists of recycled materials have shown excellent nutrient removal as an effective BMP by enhancing physicochemical and microbiological processes. In this study, Iron-Filling Green Environmental Media (denoted as IFGEM-3) and Advanced Green Environmental Media 1 and 2 (denoted...
Show moreBest Management Practices (BMPs) in stormwater treatment are a suite of treatment alternatives to deal with pollutant removal problems from stormwater runoff. Biosorption-activated media (BAM) are green sorption media consists of recycled materials have shown excellent nutrient removal as an effective BMP by enhancing physicochemical and microbiological processes. In this study, Iron-Filling Green Environmental Media (denoted as IFGEM-3) and Advanced Green Environmental Media 1 and 2 (denoted as AGEM-1 and AGEM-2) were produced and tested for their adsorption capacities as well as removal and recovery potential for phosphate, nitrate, and ammonia against natural soil (baseline) collected from a stormwater retention basin in Ocala, FL. A set of isotherm and column tests were conducted at room temperature with varying contact times. Two media with the best adsorption performances were further tested to determine their life expectancy. The green sorption media characteristics and adsorption behaviors were further analyzed and realized by using a few existing isotherm models. The collected data on physical properties such as hydraulic conductivity, porosity, surface area, and density help justifying the comparative results. The results showed that AGEM-2 has the highest average nitrate removal efficiency (76.55%) when compared to IFGEM-3 (39.0%) and AGEM-1 (33.67%). Furthermore, IFGEM-3, AGEM-1 and AGEM-2 achieved the highest phosphate removals after only 30 minutes of contact time. It is indicative that IFGEM-3, AGEM-1 and AGEM-2 media all produced ammonia and the rates of production consistently increase as contact time increases. However, AGEM-2 generated an average of 35.22% more ammonia than IFGEM-3 and AGEM-1 suggesting it can be further utilized as a soil amendment. Natural soil showed no nutrient removal, however. The maximum adsorption capacities (qmax) derived by the isothermal test at high influent concentrations of 2mg/L phosphate and 2mg/L nitrate were found to be less than the qmax obtained from the column tests for IFGEM-3 and AGEM-2 with respect to nitrate. IFGEM-3 and AGEM-2 were further tested with respect to nitrate for their maximum adsorption capacities and their life expectancies based on column tests. The results indicated that AGEM-2 has a longer life expectancy and a higher adsorption capacity than IFGEM-3, in terms of nitrate removal, which is consistent with isotherm results. It is recommended that AGEM-2 be selected for nutrient removal in future stormwater treatment based on its better adsorption performance and recovery potential. ?
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Date Issued: 2019
Identifier: CFE0007800, ucf:52332
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007800

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

Title: The Effect of Recycled Backwash Water Operations on Fouling in a Coagulation-Ultrafiltration Process and Impact of Preozonation on Membrane Productivity.
Creator: Biscardi, Paul, Duranceau, Steven, Sadmani, A H M Anwar, Lee, Woo Hyoung, Clausen, Christian, University of Central Florida
Abstract / Description: This dissertation consists of research that focused on pretreatment strategies to reduce fouling of ultrafiltration (UF) membranes used for drinking water treatment, and was segmented into four key components. (1) In the first component of the work, the long-term fouling behavior of a polyethersulfone (PES) hollow-fiber UF membrane was studied at the pilot-scale for treatment of surface water over a one-year period. Pilot testing of a coagulation-flocculation-sedimentation (CFS) pretreatment...
Show moreThis dissertation consists of research that focused on pretreatment strategies to reduce fouling of ultrafiltration (UF) membranes used for drinking water treatment, and was segmented into four key components. (1) In the first component of the work, the long-term fouling behavior of a polyethersulfone (PES) hollow-fiber UF membrane was studied at the pilot-scale for treatment of surface water over a one-year period. Pilot testing of a coagulation-flocculation-sedimentation (CFS) pretreatment system revealed that chemically irreversible fouling was poorly correlated with turbidity and total organic carbon. It was also shown that recycled backwash water may have impacted membrane process performance, and that chemically irreversible fouling was responsive to changes in pretreatment configuration. (2) In the second component, pre-oxidation with ozone (preozonation) was then studied as a pretreatment process to reduce natural organic matter (NOM) fouling at the pilot-scale. This work suggested that preozonation reduced long-term chemically irreversible fouling. The chemically reversible fouling index increased by 59%, indicating that preozonation changed the characteristics of the foulants, yielding more effective chemically enhanced backwashes. (3) Bench-scale work that studied changes in NOM characteristics associated with the improved process performance were performed using fluorescent excitation-emission (EEM) spectroscopy and high-performance size-exclusion chromatography (HPSEC). Specifically, ozone was applied prior to a CFS-UF process and compared to a CFS-UF condition without ozone as the control. Although CFS reduced turbidity by 29%, ozone, when integrated with CFS increased turbidity by 58%, impacting downstream UF performance. As expected, ozone, when integrated with CFS and UF reduced filtrate true color by 40%, UV254 absorbance by 11%, and SUVA by 30%, relative to the control, indicating that preozonation changed the characteristics of the dissolved organic carbon present in the source water. (4) Follow-up bench-scale research using fluorescent EEM spectroscopy and HPSEC assessed operational strategies that impacted organic fouling. Specifically, the fate of fluorescing substances during the recycling of membrane backwash water (MBWW) ahead of CFS-UF process was investigated. Bench-scale UF membranes were used to generate MBWW from a CFS-treated surface water containing 21 mg/L dissolved organic carbon (DOC) registering a 0.95 cm-1 UV254 absorbance that had been coagulated with 100 mg/L with polyaluminum chloride. CFS settled water, when processed with UF, produced MBWW containing 9 mg/L DOC registering a 0.25 cm-1 UV254 absorbance. HPSEC with UV254 detection demonstrated an analogous UV254 reduction as measured by detector response. However, fluorescence EEM spectroscopy revealed that protein-like substances, known to be associated with irreversible fouling, had been concentrated in the MBWW. In order to evaluate recycling operations on overall DOC removal in a CFS-UF process, a blend of 30% MBWW with 70% of raw water was treated, resulting in an overall DOC removal of 73%. However, without MBWW recycle, the CFS-UF process removed less of the influent DOC (63%). In summary, this research demonstrated that NOM characteristics within MBWW should be considered when recycling backwash water in PES membrane operations, and that preozonation reduces chemically irreversible fouling when incorporated into a CSF-UF system.
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Date Issued: 2016
Identifier: CFE0006074, ucf:50951
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006074

Title: Anthropogenic Organic Chemical Removal from a Surficial Groundwater and Mass Transfer Modeling in a Nanofiltration Membrane Process.
Creator: Jeffery, Samantha, Duranceau, Steven, Lee, Woo Hyoung, Sadmani, A H M Anwar, Yestrebsky, Cherie, University of Central Florida
Abstract / Description: This dissertation reports on research related to trace organic compounds (TrOCs) in surficial groundwater supplies and their subsequent removal from nanofiltration (NF) membranes. The research was conducted along coastal South Florida in cooperation with the Town of Jupiter Water Utilities, Jupiter, FL (Town). The focus of the research was to determine the extent of reclaimed water impacts on surficial groundwater supplies and subsequent effects on the Town's NF water treatment plant. Routine...
Show moreThis dissertation reports on research related to trace organic compounds (TrOCs) in surficial groundwater supplies and their subsequent removal from nanofiltration (NF) membranes. The research was conducted along coastal South Florida in cooperation with the Town of Jupiter Water Utilities, Jupiter, FL (Town). The focus of the research was to determine the extent of reclaimed water impacts on surficial groundwater supplies and subsequent effects on the Town's NF water treatment plant. Routine monitoring of fourteen TrOCs in reclaimed water and at the water treatment facility revealed varying degrees of TrOC detection in the environment. Certain TrOCs, including caffeine and DEET, were detected in a majority of the water sampling locations evaluated in this work. However, subsequent dilution with highly-treated reverse osmosis (RO) permeate from alternative supplies resulted in TrOCs below detection limits in potable water at the point-of-entry (POE). Pilot testing was employed to determine the extent of TrOC removal by NF. Prior to evaluating TrOC removal, hydraulic transients within the pilot process were first examined to determine the required length of time the pilot needed to reach steady-state. The transient response of a center-port NF membrane process was evaluated using a step-input dose of a sodium chloride solution. The pilot was configured as a two-stage, split-feed, center-exit, 7:2 pressure vessel array process, where the feed water is fed to both ends of six element pressure vessels, and permeate and concentrate streams are collected after only three membrane elements. The transient response was described as a log-logistic system with a maximum delay time of 285 seconds for an 85% water recovery and 267 gallon per minute feed flowrate.Eleven TrOC pilot unit experiments were conducted with feed concentrations ranging from 0.52 to 4,500 ?g/L. TrOC rejection was well-correlated with compound molecular volume and polarizability, with coefficient of determination (R2) values of 0.94. To enhance this correlation, an extensive literature review was conducted and independent literature sources were correlated with rejection. Literature citations reporting the removal effectiveness of an additional sixty-one TrOCs by loose NF membranes (a total of 95 data points) were found to be well-correlated with molecular volume and polarizability, with R2 values of 0.72 and 0.71, respectively.Of the TrOC's detected during this research, the anthropogenic solute caffeine was selected to be modeled using the homogeneous solution diffusion model (HSDM) and the HSDM with film theory (HSDM-FT). Mass transfer coefficients, K_w (water) K_s (caffeine), and k_b (caffeine back-transport) were determined experimentally, and K_s was also determined using the Sherwood correlation method. Findings indicate that caffeine transport through the NF pilot could be explained using experimentally determined K_s values without incorporating film theory, since the HSDM resulted in a better correlation between predicted and actual caffeine permeate concentrations compared to the HSDM-FT and the HSDM using K_s obtained using Sherwood applications. Predicted versus actual caffeine content was linearly compared, revealing R2 values on the order of 0.99, 0.96, and 0.99 for the HSDM without FT, HSDM-FT, and HSDM using a K_s value obtained using the Sherwood correlation method. However, the use of the HSDM-FT and the Sherwood number resulted in the over-prediction of caffeine concentrations in permeate streams by 27 percent and 104 percent, respectively.
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Date Issued: 2016
Identifier: CFE0006331, ucf:51545
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006331

Drinking Water (3)	+ -
nanofiltration (3)	+ -
Corrosion (2)	+ -
Groundwater (2)	+ -
Spray Aeration (2)	+ -

THM (2)	+ -
diffusion (2)	+ -
groundwater (2)	+ -
pilot plant (2)	+ -
reclaimed water (2)	+ -
ATP Bioluminescence (1)	+ -
Algae (1)	+ -
BAM (1)	+ -
Bio-sorption activated media (1)	+ -
Biological Filtration (1)	+ -
Biological Treatment (1)	+ -
Biosorption Activated Media (1)	+ -
Breakthrough curves (1)	+ -
Carbon Impact (1)	+ -
Cations (1)	+ -
Column study (1)	+ -
Copper Impact (1)	+ -
DBP reduction (1)	+ -
Disinfectants (1)	+ -
Disinfection By Product (1)	+ -
Disinfection By-Products (DBPs) (1)	+ -
Disinfection Byproducts Control (1)	+ -
Dissolved Organic Nitrogen (1)	+ -
Distribution System Management (1)	+ -
Distribution System Monitoring (1)	+ -

Sadmani, A H M Anwar (22)	+ -
University of Central Florida (22)	+ -
Duranceau, Steven (18)	+ -
Lee, Woo Hyoung (15)	+ -
Randall, Andrew (4)	+ -

Wang, Dingbao (3)	+ -
Chang, Ni-bin (2)	+ -
Chumbimuni Torres, Karin (2)	+ -
Clausen, Christian (2)	+ -
Rodriguez, Angela (2)	+ -
Alanezi, Alaa (1)	+ -
Arenas Daza, Maria (1)	+ -
Biscardi, Paul (1)	+ -
Coleman, Martin (1)	+ -
Cormier, Jessica (1)	+ -
Elhakiem, Hanan (1)	+ -
Ezeodurukwe, Ikenna (1)	+ -
Higgins, Carlyn (1)	+ -
Jeffery, Samantha (1)	+ -
Ma, Xiangmeng (1)	+ -
Moore, Sean (1)	+ -
Munshi, Faris (1)	+ -
Myers, Samantha (1)	+ -
Ordonez, Diana (1)	+ -
Ousley, Jonathan (1)	+ -
Rawut, Rojina (1)	+ -
Reed, Erin (1)	+ -
Reinhart, Debra (1)	+ -
Rowney, Alexander (1)	+ -
Staubus, Paul (1)	+ -

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