Current Search: Reinhart, Debra (x)
View All Items
Pages
- Title
- Treatment of Leachate Organic Matter through Sunlight Driven Processes.
- Creator
-
Lozinski, Duncan, Reinhart, Debra, Lee, Woo Hyoung, Bolyard, Stephanie, University of Central Florida
- Abstract / Description
-
The ability to manage leachate during post-closure care (PCC) of a landfill may be increasingly difficult as leachate organic matter (LOM) becomes recalcitrant when a landfill ages, requiring advanced and costly treatment technologies. This research investigated the ability to treat LOM through sunlight driven processes, with a focus on photolysis, to provide insight to landfill owners and operators on the potential of wetlands treatment as a means for reducing long-term risks and costs...
Show moreThe ability to manage leachate during post-closure care (PCC) of a landfill may be increasingly difficult as leachate organic matter (LOM) becomes recalcitrant when a landfill ages, requiring advanced and costly treatment technologies. This research investigated the ability to treat LOM through sunlight driven processes, with a focus on photolysis, to provide insight to landfill owners and operators on the potential of wetlands treatment as a means for reducing long-term risks and costs associated with leachate treatment during PCC. The study was completed in eight batch tests, where leachate was exposed to natural sunlight in central Florida for a period of 90 days. It was hypothesized that through photolytic reactions, in particular photolysis, high molecular weight recalcitrant LOM would be degraded to labile, low molecular weight material. To identify the treatment mechanisms, transformation processes were measured using ultraviolet-visible (UV-Vis) spectroscopy, fluorescence excitation-emission matrix spectroscopy (EEMs), size-exclusion chromatography (SEC), and chemical oxygen demand (COD) from the beginning to the end of the test period. Additionally, the ability for nitrogen species to become bioavailable when exposed to sunlight was evaluated for two of the leachate samples using solid-phase extraction (SPE) to fractionate recalcitrant dissolved organic nitrogen (rDON) and bioavailable dissolved organic nitrogen (bDON). Results suggest that treatment of LOM through sunlight driven processes is possible. Treatment is dependent upon the dilution of leachate and characteristics of the LOM. Dilution must be high enough to allow sunlight to penetrate the depth of the liquid. UV-Vis, EEMs, and SEC show that high molecular weight recalcitrant material is undergoing transformation into lower molecular weight material as a result of photolytic and likely biological reactions promoted by sunlight. The ability for nitrogen to become bioavailable when exposed to sunlight was shown to be dependent upon nitrogen concentrations in the sample.
Show less - Date Issued
- 2018
- Identifier
- CFE0007044, ucf:51987
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007044
- Title
- Environmental Study of Solid Waste Collection.
- Creator
-
Maimoun, Mousa, Reinhart, Debra, Mccauley Bush, Pamela, Cooper, Charles, University of Central Florida
- Abstract / Description
-
The growing municipal solid waste generation rates have necessitated more efficient, optimized waste collection facilities. The majority of the US collection fleet is composed of diesel-fueled vehicles which contribute significant atmospheric emissions including greenhouse gases. In order to reduce emissions to the atmosphere, more collection agencies are investigating alternative fuel technologies such as natural gas, biofuels (bio-gas and bio-diesel), and hybrid electric technology. This...
Show moreThe growing municipal solid waste generation rates have necessitated more efficient, optimized waste collection facilities. The majority of the US collection fleet is composed of diesel-fueled vehicles which contribute significant atmospheric emissions including greenhouse gases. In order to reduce emissions to the atmosphere, more collection agencies are investigating alternative fuel technologies such as natural gas, biofuels (bio-gas and bio-diesel), and hybrid electric technology. This research is an in-depth environmental analysis of potential alternative fuel technologies for waste collection vehicles.This study will evaluate the use of alternative fuels by waste collection vehicles. Life-cycle emissions, cost, fuel and energy consumption were evaluated for a wide range of fossil and bio-fuel technologies. Moreover, the energy consumption and the tail-pipe emissions of diesel-fueled waste collection vehicles were estimated using MOVES 2010a software. Emission factors were calculated for a typical waste collection driving cycle as well as constant speed. Finally, the selection of fuel type by the waste collection industry requires consideration of environmental, security, financial, operational, and safety issues. In this study, a qualitative comparison between alternative fuels was performed; a multifactorial assessment of these factors was conducted taking into account the opinion of the waste collection industry of the importance of each factor.Liquid-petroleum fuels have higher life-cycle emissions compared to natural gas; however landfill natural gas has the lowest life-cycle emissions compared to all other fuel categories. Compressed natural gas waste collection vehicles have the lowest fuel cost per collection vehicle mile travel compared to other fuel categories. Moreover, the actual driving cycle of waste collection vehicles consists of repetitive stops and starts during waste collection; this generates more emissions than constant speed driving. Finally, the multifactorial assessment indicates that natural gas and landfill gas have better environmental, economical, and energy security performance than current liquid-petroleum fuels.
Show less - Date Issued
- 2011
- Identifier
- CFE0004133, ucf:49115
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004133
- Title
- Fate of Coated Zinc Oxide in Municipal Solid Waste Landfills.
- Creator
-
Bolyard, Stephanie, Reinhart, Debra, Santra, Swadeshmukul, Randall, Andrew, University of Central Florida
- Abstract / Description
-
Given the increase in nanomaterial (NM) use in consumer products and the large fraction of waste placed in landfills worldwide, the probability of these products reaching municipal solid waste (MSW) landfills at the end of their useful life is high. Since nanotechnology use is still in its early stages, there are currently no regulations pertaining to the disposal of NMs and their fate in MSW landfills is still unknown. Understanding the fate of NMs in MSW landfills is vital to ensure the...
Show moreGiven the increase in nanomaterial (NM) use in consumer products and the large fraction of waste placed in landfills worldwide, the probability of these products reaching municipal solid waste (MSW) landfills at the end of their useful life is high. Since nanotechnology use is still in its early stages, there are currently no regulations pertaining to the disposal of NMs and their fate in MSW landfills is still unknown. Understanding the fate of NMs in MSW landfills is vital to ensure the proper handling of these novel materials from cradle to grave; such research will provide information on how these NMs can be safely introduced into the environment. This research seeks to understand the fate of NMs within waste environments by examining the interactions between NMs and landfill leachate components. The primary focus of this thesis is the effect of Zinc Oxide (ZnO) on biological landfill processes, solids aggregation, and chemical speciation of Zn in landfill leachate following the addition of crystalline, nano-sized ZnO coated with triethoxycaprylylsilane. This research (1) observed the effects of coated ZnO on five-day biochemical oxygen demand (BOD5) and biochemical methane potential (BMP), (2) examined effects of solids aggregation on the fate of ZnO, (3) quantified the concentration of Zinc (Zn) by size fractions, and (4) modeled the chemical speciation of Zn in landfill leachate using Visual MINTEQ.No change in dissolved Zn was observed after coated ZnO was exposed to (")middle-aged(") leachate. Upon exposure to (")mature(") leachate there was an increase in dissolved Zn assumed to be a result of the dissociation of ZnO. Solids data supported the aggregation of particles in both middle aged and mature leachate. There was an increase in the Zn concentration in leachate fractions greater than 1500 nm presumably due to the dispersion of normally insoluble ZnO nanoparticles (NPs) following the interaction with humic acids (HA). ZnO did not inhibit anaerobic or aerobic processes in either middle aged or mature leachate, presumably due to the relatively low concentration of dissolved ionic Zn. Despite the observation of increased dissociation upon exposure to mature leachate, the presence of dissolved organic matter (DOM) may have hindered the ability for dissolved ionic Zn to become bioavailable. Fractionation, BOD5 and BMP tests, and chemical speciation modeling provided insight on the mobility of ZnO in landfills and the absence of inhibitory effects on landfill processes. Aggregation of ZnO NPs may prevent movement through traditional containment systems (i.e. geomembrane liners) due to the increased particle size. However, the increased dispersion suggests that ZnO NPs will be transported out of the landfill in the leachate, however biological treatment of leachate should be unaffected by the presence of ZnO. The bioavailability of Zn was not substantially affected by the presence of ZnO due to affinity of dissolved Zn for DOM. However, due to the heterogeneity of landfill leachate and the utilization of different NM coatings, it is challenging to predict the overall mobility of other NMs in a landfill.
Show less - Date Issued
- 2012
- Identifier
- CFE0004264, ucf:49509
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004264
- Title
- Water and energy costs of landfilled food waste.
- Creator
-
Sarker, Tonmoy, Kibler, Kelly, Reinhart, Debra, Tatari, Omer, University of Central Florida
- Abstract / Description
-
Energy and water are consumed or contaminated during both the production and disposal of wasted food. To date, evaluations of water and energy resources associated with food waste have considered only resources used in food production. To allow for the full characterization of food waste within a Food Energy Water (FEW) nexus framework, this study addresses a fundamental knowledge gap related to the energy and water impacts of food waste after disposal. Fluxes of water and energy related to...
Show moreEnergy and water are consumed or contaminated during both the production and disposal of wasted food. To date, evaluations of water and energy resources associated with food waste have considered only resources used in food production. To allow for the full characterization of food waste within a Food Energy Water (FEW) nexus framework, this study addresses a fundamental knowledge gap related to the energy and water impacts of food waste after disposal. Fluxes of water and energy related to disposal of wasted food in landfills within the state of Florida were characterized. It is estimated that each metric ton (Mg) of landfilled food waste produces 18.1 kWh of energy, while the energy needed for collection, leachate transport, and treatment totals 126.5 kWh/Mg. These values equate to a net energy cost of 108.4 kWh/Mg, which is 110 Million kWh annually in Florida. It was observed that the water footprint of landfilled food waste is related to the assimilation of contaminated effluent and ranges from 2.5 to 58.5 m3 per metric ton of landfilled food waste, depending on the constituent of interest. Up to 58 Million m3 of water may be required annually to assimilate contamination related to landfilled food waste in Florida. We assessed the sensitivity of 14 variables used to estimate energy and water impacts and found that impacts are sensitive to the proportion of landfills collecting and utilizing landfill gas, concentration of constituents in leachate, and volume of effluent. Future research should be focused to improving the characterization of these influential parameters, and to similar FEW analysis of other food waste management technologies, such as composting or anaerobic digestion. Better understanding of water and energy impacts of food waste could inform societal decision making regarding investment in FEW-efficient waste management technologies.
Show less - Date Issued
- 2017
- Identifier
- CFE0006654, ucf:51233
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006654
- Title
- Application of Landfill Treatment Approaches for the Stabilization of Municipal Solid Waste.
- Creator
-
Bolyard, Stephanie, Reinhart, Debra, Santra, Swadeshmukul, Randall, Andrew, University of Central Florida
- Abstract / Description
-
This research focused on the fundamental requirements of stabilizing a mature landfill using three treatment approaches as well as the implications of discharging leachate organic matter (LOM) to wastewater treatment plants (WWTPs). Three treatment approaches aimed at removing releasable carbon and nitrogen from mature landfills including flushing with clean water, leachate recirculation with ex-situ chemical oxidation, and leachate recirculation with ex-situ chemical oxidation and in-situ...
Show moreThis research focused on the fundamental requirements of stabilizing a mature landfill using three treatment approaches as well as the implications of discharging leachate organic matter (LOM) to wastewater treatment plants (WWTPs). Three treatment approaches aimed at removing releasable carbon and nitrogen from mature landfills including flushing with clean water, leachate recirculation with ex-situ chemical oxidation, and leachate recirculation with ex-situ chemical oxidation and in-situ aeration were evaluated. After extensive treatment of the waste in the flushing bioreactor (FB) scenarios, the overall biodegradable fraction was reduced relative to mature waste. Leachate quality improved for all FBs but through different mechanisms. Flushing was the most effective approach at removing biodegradable components and improving leachate quality. A mass balance on carbon and nitrogen revealed that a significant fraction still remained in the waste. Solid waste and leachate samples from the anaerobic bioreactors and FBs were characterized using Fourier Transform Infrared (FTIR) to provide a better understanding of changes in waste characteristics when waste transitions from mature to stabilized. Organic functional groups associated with aliphatic methylene were present in leachate and solid waste samples during the early stages of anaerobic degradation and disappeared once these wastes underwent treatment. Once the waste was stabilized, the FTIR spectra of leachate and solid waste were dominated by inorganic functional groups (carboxylic acid/carbonate group, carbonate, quartz, and clay minerals). Leachate is commonly co-treated with domestic wastewater due to the cost and complexity of on-site treatment. The organic constituents in leachate can be problematic for WWTPs as their recalcitrant components pass through conventional treatment processes, impacting effluent quality. Twelve leachates where characterized for total nitrogen (TN) and dissolved organic nitrogen (DON). The average concentration of TN and DON in leachate was 1,160 and 40.7 mg/L, respectively. Leachates were fractionated based on hydrophobic (recalcitrant; rDON) and hydrophilic (bioavailable; bDON) properties. The average concentrations of bDON and rDON were 16.5 and 18.4 mg/L, respectively. Multiple leachate and wastewater co-treatment simulations were carried out to assess the treatment of leachate nitrogen at historic nitrogen removal levels of four WWTPs and the effects on wastewater effluent quality for four WWTPs. The effluent quality exceeded typical TN limits of 3 to 10 mg/L at leachate volumetric contributions of 10%. The maximum calculated pass through concentrations of rDON and DON at 10% volumetric contribution for the twelve leachates was 4.77 and 9.71 mg/L, respectively. The effects of LOM on wastewater effluent quality was further evaluated in the field. Results showed that leachate detection for each field study could be determined using UV254 nm absorbance. DON and dissolved organic carbon (DOC) concentrations increased at significant levels in leachate-impacted wastewater samples. The DON decreased through the treatment train, suggesting that this parameter was effectively removed, while DOC persisted. DOC pass through coincided with an increase in color and UV254 nm absorption. In effluents, the UV254 nm transmittance was just below the minimum 65% disinfection requirement at dilutions greater than 1%. Leachate-impacted wastewater showed a higher concentration of humic-like peaks during fluorescence measurements than wastewater without leachate.
Show less - Date Issued
- 2016
- Identifier
- CFE0006076, ucf:50959
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006076
- Title
- Bioremediation of a Trichloroethene DNAPL Source Zone Utilizing a Partitioning Electron Donor - Field Implementation.
- Creator
-
Bartlett, Joseph, Randall, Andrew, Reinhart, Debra, Wang, Dingbao, Daprato, Rebecca, University of Central Florida
- Abstract / Description
-
Trichloroethene (TCE) is a chlorinated volatile organic compound (CVOC) that can be found in industrial and household products. It is typically used as a solvent or degreaser. TCE can have detrimental health impacts and is known to be carcinogenic to humans. Federal and state regulatory drivers determine the need to assess and remediate soil and groundwater contaminated with CVOCs. There are many different methods for remediation; however, bioremediation has the ability to breakdown TCE all...
Show moreTrichloroethene (TCE) is a chlorinated volatile organic compound (CVOC) that can be found in industrial and household products. It is typically used as a solvent or degreaser. TCE can have detrimental health impacts and is known to be carcinogenic to humans. Federal and state regulatory drivers determine the need to assess and remediate soil and groundwater contaminated with CVOCs. There are many different methods for remediation; however, bioremediation has the ability to breakdown TCE all the way to harmless gasses (ethene and ethane). Bioremediation requires dechlorinating microbes (indigenous or augmented), electron donor (food source), and an electron acceptor (CVOCs). Electron donors are typically injected into the target area and are distributed naturally throughout the subsurface. A partitioning electron donor (PED) has the ability to partition from the dissolved phase into low permeability zones and/or dense non-aqueous phase liquids (DNAPLs) (i.e. source zones), and then be slowly released and readily metabolized at the DNAPL:water interface. This thesis summarizes the first field scale PED implementation with the main research objective of evaluating whether utilizing a PED for bioremediation of a TCE source zone is achievable. Based on laboratory studies, n-butyl acetate (nBA) was selected as the PED for application in a TCE source area, selected at Cape Canaveral Air Force Station's Launch Complex 34, identified as Hot Spot 1. Hot Spot 1 has a zone of high concentration TCE in a low permeability clay layer at a depth of approximately 40 feet below land surface (ft BLS). Implementation included the recirculation of groundwater above and below the clay layer without PED injection for comparative analysis (baseline flux), then with PED injection in, above, and below the clay layer (system operation phase). The groundwater was recirculated using a solar powered recirculation system, which consisted of a pair of extraction wells in the center of the treatment area, screened above and below the low permeability layer, and a set of five peripheral injection well pairs, similarly screened, used to create an inward hydraulic gradient and promote horizontal flow across the top and base of the clay layer. Groundwater concentrations in the treatment area were monitored using three monitoring well clusters (each with six depth intervals ranging from 23 to 61 ft BLS) and existing monitoring wells in the treatment area. The groundwater recirculation system was operated, without addition of PED, for approximately four weeks to establish the baseline flux condition. PED was then introduced to the subsurface by injecting 34,000 gallons of a solution containing nBA (3,000 mg/L) and conservative tracers (bromide and/or iodide) using direct push technology (DPT) at 20 locations from approximately 23 to 62 ft BLS. Confirmation sampling (DPT groundwater and monitoring well sampling) was conducted to assess the PED distribution after injection activities. The recirculation system remained off after PED injection for approximately four weeks to allow the PED to partition into the DNAPL and to facilitate the acclimation and establishment of biomass within the treatment area. The recirculation system was then restarted and operated for approximately one year. Groundwater sampling was performed regularly to assess mass flux and microbial reductive dechlorination. PED amendment was successfully injected above, in, and below the low permeability layer, as evidenced by positive detections of nBA from soil and groundwater sampling within the treatment area immediately following the injection event. The implementation was also successful in reducing contaminant mass from both soil and groundwater.CVOC mass removed during the baseline flux phase (pre-PED injection; 14 March 2011 to 18 April 2011) was calculated based on groundwater sampling data and totaled 14 pounds (lbs). All of the mass removed during the baseline flux phase was from the high permeability layer, indicating that mass removed was dissolved phase mass above and below the clay layer. Mass removal was likely a result of extraction and dilution from operation of the recirculation system. The mass removal rate during the baseline flux phase was approximately 0.40 pounds per day (lbs/day).CVOC mass removed during the system operation phase (post-PED injection; 9 August 2011 to 11 September 2012) was calculated based on groundwater and soil sampling data and totaled 110 lbs. Of the 110 lbs removed, 78 lbs of CVOC mass was removed from the high permeability layer and 32 lbs was removed from the low permeability layer, indicating that not only dissolved phase mass in the high permeability layer was removed, but source zone material sorbed into the low permeability layer was removed as well. Mass removed from the low permeability layer was likely a result degredation (ie. reductive dechlorination) at and around the DNAPL:water interface. The mass removal rate during the system operation phase was approximately 0.28 lbs/day. The higher rate of removal during the baseline flux phase is likely due to the initial removal of a significant amount of dissolved phase CVOCs and not the mass sorbed into the low permeability layer.In general, TCE and cis-1,2-dichloroethene (cDCE) concentrations decreased during the baseline flux phase with no increase in vinyl chloride (VC) concentration, indicating removal via extraction and dilution and not reductive dechlorination. Following the PED injection, TCE and cDCE concentrations generally decreased with increases observed in VC concentrations, indicative of reductive dechlorination. Ethene concentration was monitored to assess complete dechlorination from TCE to ethene. Average ethene concentration detected in samples collected from treatment zone monitoring wells increased from 52.8 micrograms per liter (?g/L) (pre-injection; April 2011) to 408 ?g/L (September 2012), indicating complete dechlorination of CVOCs was occurring. In addition, dechlorinating microbial biomass increased significantly, as evidenced by increases in average Dhc (dechlorinating microbial culture) and vcrA (specific gene of culture responsible for breaking down VC through to ethene) concentrations detected in samples collected from treatment zone monitoring wells; Dhc increased from 8.5x106 gene copies/L (pre-injection; April 2011) to 5.0x107 gene copies/L (September 2012) and vcrA increased from 5.0x103 gene copies/L (April 2011) to 6.8x107 gene copies/L (September 2012).TOC concentration was shown to generally increase following the injection activities, then decrease through the system operation period, indicating the electron donor was successfully injected into the subsurface, and was being utilized by the indigenous dechlorinating microbial population. Remaining TOC at the site was minimal, with an average TOC concentration of 21 mg/L (September 2012) detected in samples collected from treatment zone monitoring wells, decreasing from 250 mg/L (August 2011) just following injection. If reductive dechlorination were to continue to occur, more electron donor would be needed.The reduction of CVOC concentrations at the site are likely due to reductive dechlorination as a result of the PED amendment injection, as evidenced by: (i) the production of daughter products relative to the degradation of TCE; (ii) the production of ethene; (iii) the production of dechlorinating microbial mass; and (iv) the reduction of electron donor.Although effective, nBA was utilized and depleted quicker than an industry electron donor would be expected to last, depleting within 12 months, as opposed to two to three years. Based on this alone, it appears that nBA would not be a good candidate for full scale implementation at this or other sites; however, to provide a true comparative analysis, side-by-side test plots would be recommended at the site, one utilizing nBA and one utilizing a standard substrate. This would ensure both electron donor options are being subjected to the same geophysical and geochemical settings and the same or similar contaminant concentrations.
Show less - Date Issued
- 2016
- Identifier
- CFE0006439, ucf:51457
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006439
- Title
- Life-cycle Greenhouse Gas Emissions and Water Footprint of Residential Waste Collection and Management Systems.
- Creator
-
Maimoun, Mousa, Reinhart, Debra, McCauley, Pamela, Cooper, David, University of Central Florida
- Abstract / Description
-
Three troublesome issues concerning residential curbside collection (RCC) and municipal solid waste (MSW) management systems in the United States motivated this research. First, reliance upon inefficient collection and scheduling procedures negatively affect RCC efficiency, greenhouse gas (GHG) emissions, and cost. Second, the neglected impact of MSW management practices on water resources. Third, the implications of alternative fuels on the environmental and financial performance of waste...
Show moreThree troublesome issues concerning residential curbside collection (RCC) and municipal solid waste (MSW) management systems in the United States motivated this research. First, reliance upon inefficient collection and scheduling procedures negatively affect RCC efficiency, greenhouse gas (GHG) emissions, and cost. Second, the neglected impact of MSW management practices on water resources. Third, the implications of alternative fuels on the environmental and financial performance of waste collection where fuel plays a significant rule. The goal of this study was to select the best RCC program, MSW management practice, and collection fuel. For this study, field data were collected for RCC programs across the State of Florida. The garbage and recyclables generation rates were compared based on garbage collection frequency and use of dual-stream (DS) or single-stream (SS) recyclables collection system. The assessment of the collection programs was evaluated based on GHG emissions, while for the first time, the water footprint (WFP) was calculated for the most commonly used MSW management practices namely landfilling, combustion, and recycling. In comparing alternative collection fuels, two multi-criteria decision analysis (MCDA) tools, TOPSIS and SAW, were used to rank fuel alternatives for the waste collection industry with respect to a multi-level environmental and financial decision matrix. The results showed that SS collection systems exhibited more than a two-fold increase in recyclables generation rates, and a ~2.2-fold greater recycling efficiency compared to DS. The GHG emissions associated with the studied collection programs were estimated to be between 36 and 51 kg CO2eq per metric ton of total household waste (garbage and recyclables), depending on the garbage collection frequency, recyclables collection system (DS or SS) and recyclables compaction. When recyclables offsets were considered, the GHG emissions associated with programs using SS were estimated between -760 and -560, compared to between -270 and -210 kg CO2eq per metric ton of total waste for DS programs. In comparing the WFP of MSW management practices, the results showed that the WFP of waste landfilling can be reduced through implementing bioreactor landfilling. The WFP of electricity generated from waste combustion was less than the electricity from landfill gas. Overall, the WFP of electricity from MSW management practices was drastically less than some renewable energy sources. In comparing the WFP offsets of recyclables, the recycling of renewable commodities, e.g. paper, contributed to the highest WFP offsets compared to other commodities, mainly due to its raw material acquisition high WFPs. This suggests that recycling of renewable goods is the best management practice to reduce the WFP of MSW management. Finally, the MCDA of alternative fuel technologies revealed that diesel is still the best option, followed by hydraulic-hybrid waste collection vehicles (WCVs), then landfill gas (LFG) sourced natural gas, fossil natural gas and biodiesel. The elimination of the fueling station criterion from the financial criteria ranked LFG-sourced natural gas as the best option; suggesting that LFG sourced natural gas is the best alternative to fuel WCV when accessible. In conclusion, field data suggest that RCC system design can significantly impact recyclables generation rate and efficiency, and consequently determine environmental and economic impact of collection systems. The WFP concept was suggested as a method to systematically assess the impact of MSW management practices on water resources. A careful consideration of the WFP of MSW management practices and energy recovered from MSW management facilities is essential for the sustainable appropriation of water resources and development.
Show less - Date Issued
- 2015
- Identifier
- CFE0005656, ucf:50174
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005656
- Title
- Beneficial Utilization of Municipal Solid Waste Incineration Ashes as Sustainable Road Construction Materials.
- Creator
-
Tasneem, Kazi, Nam, Boo Hyun, Chopra, Manoj, Reinhart, Debra, Sohn, Yongho, University of Central Florida
- Abstract / Description
-
Incineration of municipal solid waste (MSW) is common for energy recovery, and management of municipal solid waste incineration (MSWI) ashes has received a growing attention around the world. In the U.S., generation of MSW has increased up to 65% since 1980, to the current level of 251 million tons per year with 53.8% landfilled, 34.5% recycled and composted, and 11.7% incinerated with energy recovery. In the process of incineration, MSWI ash is being produced as byproducts; about 80 to 90%...
Show moreIncineration of municipal solid waste (MSW) is common for energy recovery, and management of municipal solid waste incineration (MSWI) ashes has received a growing attention around the world. In the U.S., generation of MSW has increased up to 65% since 1980, to the current level of 251 million tons per year with 53.8% landfilled, 34.5% recycled and composted, and 11.7% incinerated with energy recovery. In the process of incineration, MSWI ash is being produced as byproducts; about 80 to 90% of the MSWI ash is bottom ash (BA) and 10 to 20% is fly ash (FA) by weight. The current practice of the U.S. is to combine both BA and FA to meet the criteria to qualify as non-hazardous, and all combined ashes are disposed in landfills.European countries have utilized MSWI BA as beneficial construction materials by separating it from FA. The FA is mostly limited to landfill disposal as hazardous material due to its high content of toxic elements and salts. BA has been actively recycled in the areas of roadbed, asphalt paving, and concrete products in many of European and Asian countries. In those countries, recycling programs (including required physical properties and environmental criteria) of ash residue management have been developed so as to encourage and enforce the reuse of MSWI ashes instead of landfill disposal. Moreover, many studies have demonstrated the beneficial use of MSWI ashes as engineering materials with minimum environmental impacts.On the other hand, the U.S. has shown a lack of consistent and effective management plans, as well as environmental regulations for the use of MSWI ashes., Due to persistent uncertainty of engineering properties and inconsistency in the Federal and State regulations in the U.S., however, the recycling of the MSWI ashes has been hindered and they are mostly disposed in landfills.In this research work, current management practice, existing regulations, and environmental consequences of MSWI ashes utilization are comprehensively reviewed worldwide and nationwide with an emphasis of the potential area of its utilization in asphalt paving and concrete product. This research also entails a detailed chemical and microstructural characterization of MSWI BA and FA produced from a Refuse Derived Fuel (RDF) facility in Florida so that the MSWI ash is well characterized for its beneficial uses as construction materials.The material characterization includes Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), and X-ray Diffraction (XRD) techniques. In addition, leaching experiments have been conducted to investigate the environmental properties (e.g. leachate concentration) of BA and ash-mixed hot mix asphalt (HMA) and Portland cement concrete (PCC). Leaching results reveals the reduced leaching potential of toxic material from MSWI ashes while incorporated in HMA and PCC. Lastly, a preliminary experimental approach has been devised for the vitrification of FA which is a promising thermal process of transferring material into glassy state with higher physical and chemical integrity to reduce toxicity so that utilization of FA can be possible.
Show less - Date Issued
- 2014
- Identifier
- CFE0005425, ucf:50404
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005425
- Title
- A Systems Approach to Sustainable Energy Portfolio Development.
- Creator
-
Hadian Niasar, Saeed, Reinhart, Debra, Madani Larijani, Kaveh, Wang, Dingbao, Lee, Woo Hyoung, Pazour, Jennifer, University of Central Florida
- Abstract / Description
-
Adequate energy supply has become one of the vital components of human development and economic growth of nations. In fact, major components of the global economy such as transportation services, communications, industrial processes, and construction activities are dependent on adequate energy resources. Even mining and extraction of energy resources, including harnessing the forces of nature to produce energy, are dependent on accessibility of sufficient energy in the appropriate form at the...
Show moreAdequate energy supply has become one of the vital components of human development and economic growth of nations. In fact, major components of the global economy such as transportation services, communications, industrial processes, and construction activities are dependent on adequate energy resources. Even mining and extraction of energy resources, including harnessing the forces of nature to produce energy, are dependent on accessibility of sufficient energy in the appropriate form at the desired location. Therefore, energy resource planning and management to provide appropriate energy in terms of both quantity and quality has become a priority at the global level. The increasing demand for energy due to growing population, higher living standards, and economic development magnifies the importance of reliable energy plans. In addition, the uneven distribution of traditional fossil fuel energy sources on the Earth and the resulting political and economic interactions are other sources of complexity within energy planning. The competition over fossil fuels that exists due to gradual depletion of such sources and the tremendous thirst of current global economic operations for these sources, as well as the sensitivity of fossil fuel supplies and prices to global conditions, all add to the complexity of effective energy planning. In addition to diversification of fossil fuel supply sources as a means of increasing national energy security, many governments are investing in non-fossil fuels, especially renewable energy sources, to combat the risks associated with adequate energy supply. Moreover, increasing the number of energy sources also adds further complication to energy planning. Global warming, resulting from concentration of greenhouse gas emissions in the atmosphere, influences energy infrastructure investments and operations management as a result of international treaty obligations and other regulations requiring that emissions be cut to sustainable levels. Burning fossil fuel, as one of the substantial driving factors of global warming and energy insecurity, is mostly impacted by such policies, pushing forward the implementation of renewable energy polices. Thus, modern energy portfolios comprise a mix of renewable energy sources and fossil fuels, with an increasing share of renewables over time. Many governments have been setting renewable energy targets that mandate increasing energy production from such sources over time. Reliance on renewable energy sources certainly helps with reduction of greenhouse gas emissions while improving national energy security. However, the growing implementation of renewable energy has some limitations. Such energy technologies are not always as cheap as fossil fuel sources, mostly due to immaturity of these energy sources in most locations as well as high prices of the materials and equipment to harness the forces of nature and transform them to usable energy. In addition, despite the fact that renewable energy sources are traditionally considered to be environmentally friendly, compared to fossil fuels, they sometimes require more natural resources such as water and land to operate and produce energy. Hence, the massive production of energy from these sources may lead to water shortage, land use change, increasing food prices, and insecurity of water supplies. In other words, the energy production from renewables might be a solution to reduce greenhouse gas emissions, but it might become a source of other problems such as scarcity of natural resources.The fact that future energy mix will rely more on renewable sources is undeniable, mostly due to depletion of fossil fuel sources over time. However, the aforementioned limitations pose a challenge to general policies that encourage immediate substitution of fossil fuels with renewables to battle climate change. In fact, such limitations should be taken into account in developing reliable energy policies that seek adequate energy supply with minimal secondary effects. Traditional energy policies have been suggesting the expansion of least cost energy options, which were mostly fossil fuels. Such sources used to be considered riskless energy options with low volatility in the absence of competitive energy markets in which various energy technologies are competing over larger market shares. Evolution of renewable energy technologies, however, complicated energy planning due to emerging risks that emanated mostly from high price volatility. Hence, energy planning began to be seen as investment problems in which the costs of energy portfolio were minimized while attempting to manage associated price risks. So, energy policies continued to rely on risky fossil fuel options and small shares of renewables with the primary goal to reduce generation costs. With emerging symptoms of climate change and the resulting consequences, the new policies accounted for the costs of carbon emissions control in addition to other costs. Such policies also encouraged the increased use of renewable energy sources. Emissions control cost is not an appropriate measure of damages because these costs are substantially less than the economic damages resulting from emissions. In addition, the effects of such policies on natural resources such as water and land is not directly taken into account. However, sustainable energy policies should be able to capture such complexities, risks, and tradeoffs within energy planning. Therefore, there is a need for adequate supply of energy while addressing issues such as global warming, energy security, economy, and environmental impacts of energy production processes. The effort in this study is to develop an energy portfolio assessment model to address the aforementioned concerns.This research utilized energy performance data, gathered from extensive review of articles and governmental institution reports. The energy performance values, namely carbon footprint, water footprint, land footprint, and cost of energy production were carefully selected in order to have the same basis for comparison purposes. If needed, adjustment factors were applied. In addition, the Energy Information Administration (EIA) energy projection scenarios were selected as the basis for estimating the share of the energy sources over the years until 2035. Furthermore, the resource availability in different states within the U.S. was obtained from publicly available governmental institutions that provide such statistics. Specifically, the carbon emissions magnitudes (metric tons per capita) for different states were extracted from EIA databases, states' freshwater withdrawals (cubic meters per capita) were found from USGS databases, states' land availability values (square kilometers) were obtained from the U.S. Census Bureau, and economic resource availability (GDP per capita) for different states were acquired from the Bureau of Economic Analysis.In this study, first, the impacts of energy production processes on global freshwater resources are investigated based on different energy projection scenarios. Considering the need for investing on energy sources with minimum environmental impacts while securing maximum efficiency, a systems approach is adopted to quantify the resource use efficiency of energy sources under sustainability indicators. The sensitivity and robustness of the resource use efficiency scores are then investigated versus existing energy performance uncertainties and varying resource availability conditions. The resource use efficiency of the energy sources is then regionalized for different resource limitation conditions in states within the U.S. Finally, a sustainable energy planning framework is developed based on Modern Portfolio Theory (MPT) and Post-Modern Portfolio Theory (PMPT) with consideration of the resource use efficiency measures and associated efficiency risks.In the energy-water nexus investigation, the energy sources are categorized into 10 major groups with distinct water footprint magnitudes and associated uncertainties. The global water footprint of energy production processes are then estimated for different EIA energy mix scenarios over the 2012-2035 period. The outcomes indicate that the water footprint of energy production increases by almost 50% depending on the scenario. In fact, growing energy production is not the only reason for increasing the energy related water footprint. Increasing the share of water intensive energy sources in the future energy mix is another driver of increasing global water footprint of energy in the future. The results of the energies' water footprint analysis demonstrate the need for a policy to reduce the water use of energy generation. Furthermore, the outcomes highlight the importance of considering the secondary impacts of energy production processes besides their carbon footprint and costs. The results also have policy implications for future energy investments in order to increase the water use efficiency of energy sources per unit of energy production, especially those with significant water footprint such as hydropower and biofuels.In the next step, substantial efforts have been dedicated to evaluating the efficiency of different energy sources from resource use perspective. For this purpose, a system of systems approach is adopted to measure the resource use efficiency of energy sources in the presence of trade-offs between independent yet interacting systems (climate, water, land, economy). Hence, a stochastic multi-criteria decision making (MCDM) framework is developed to compute the resource use efficiency scores for four sustainability assessment criteria, namely carbon footprint, water footprint, land footprint, and cost of energy production considering existing performance uncertainties. The energy sources' performances under aforementioned sustainability criteria are represented in ranges due to uncertainties that exist because of technological and regional variations. Such uncertainties are captured by the model based on Monte-Carlo selection of random values and are translated into stochastic resource use efficiency scores. As the notion of optimality is not unique, five MCDM methods are exploited in the model to counterbalance the bias toward definition of optimality. This analysis is performed under (")no resource limitation(") conditions to highlight the quality of different energy sources from a resource use perspective. The resource use efficiency is defined as a dimensionless number in scale of 0-100, with greater numbers representing a higher efficiency. The outcomes of this analysis indicate that despite increasing popularity, not all renewable energy sources are more resource use efficient than non-renewable sources. This is especially true for biofuels and different types of ethanol that demonstrate lower resource use efficiency scores compared to natural gas and nuclear energy. It is found that geothermal energy and biomass energy from miscanthus are the most and least resource use efficient energy alternatives based on the performance data available in the literature. The analysis also shows that none of the energy sources are strictly dominant or strictly dominated by other energy sources. Following the resource use efficiency analysis, sensitivity and robustness analyses are performed to determine the impacts of resource limitations and existing performance uncertainties on resource use efficiency, respectively. Sensitivity analysis indicates that geothermal energy and ethanol from sugarcane have the lowest and highest resource use efficiency sensitivity, respectively. Also, it is found that from a resource use perspective, concentrated solar power (CSP) and hydropower are respectively the most and least robust energy options with respect to the existing performance uncertainties in the literature.In addition to resource use efficiency analysis, sensitivity analysis and robustness analysis, of energy sources, this study also investigates the scheme of the energy production mix within a specific region with certain characteristics, resource limitations, and availabilities. In fact, different energy sources, especially renewables, vary in demand for natural resources (such as water and land), environmental impacts, geographic requirements, and type of infrastructure required for energy production. In fact, the efficiency of energy sources from a resource use perspective is dependent upon regional specifications, so the energy portfolio varies for different regions due to varying resource availability conditions. Hence, the resource use efficiency scores of different energy technologies are calculated based on the aforementioned sustainability criteria and regional resource availability and limitation conditions (emissions, water resources, land, and GDP) within different U.S. states, regardless of the feasibility of energy alternatives in each state. Sustainability measures are given varying weights based on the emissions cap, available economic resources, land, and water resources in each state, upon which the resource use efficiency of energy sources is calculated by utilizing the system of systems framework developed in the previous step. Efficiency scores are graphically illustrated on GIS-based maps for different states and different energy sources. The results indicate that for some states, fossil fuels such as coal and natural gas are as efficient as renewables like wind and solar energy technologies from resource use perspective. In other words, energy sources' resource use efficiency is significantly sensitive to available resources and limitations in a certain location.Moreover, energy portfolio development models have been created in order to determine the share of different energy sources of total energy production, in order to meet energy demand, maintain energy security, and address climate change with the least possible adverse impacts on the environment. In fact, the traditional (")least cost(") energy portfolios are outdated and should be replaced with (")most efficient(") ones that are not only cost-effective, but also environmentally friendly. Hence, the calculated resource use efficiency scores and associated statistical analysis outcomes for a range of renewable and nonrenewable energy sources are fed into a portfolio selection framework to choose the appropriate energy mixes associated with the risk attitudes of decision makers. For this purpose, Modern Portfolio Theory (MPT) and Post-Modern Portfolio Theory (PMPT) are both employed to illustrate how different interpretations of (")risk of return(") yield different energy portfolios. The results indicate that 2012 energy mix and projected world's 2035 energy portfolio are not sustainable in terms of resource use efficiency and could be substituted with more reliable, more effective portfolios that address energy security and global warming with minimal environmental and economic impacts.
Show less - Date Issued
- 2013
- Identifier
- CFE0005001, ucf:50020
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005001