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Evaluation of persulfate for the treatment of manufactured gas plant residualsMcIsaac, Angela January 2013 (has links)
The presence of coal tars in the subsurface associated with former manufactured gas plants (MGPs) offers a remediation challenge due to their complex chemical composition, dissolution behaviour and recalcitrant characteristics. A former MGP site in Clearwater Beach, Florida was characterized and bench-scale analyses were conducted to assess the potential for in situ chemical oxidation (ISCO) using persulfate to treat MGP residuals.
Completion of a conceptual site model identified a homogeneous, silty sand aquifer, with an average hydraulic conductivity of approximately 2.3x10-3 cm/s and a groundwater flow rate of 2 cm/day in the direction of S20°E. Six source zones, three near the water table and three in the deep aquifer were estimated to have a total volume of 108 m3. A multi-level well transect was installed to monitor concentrations of dissolved compounds and to estimate mass discharge downgradient of the source zones over time. On average, the morphology of the aqueous concentrations remained consistent with time. A total mass discharge across the transect of 94 mg/day was estimated for site-specific compounds.
Bench-scale tests were conducted on aquifer sediments and groundwater samples. The aquifer was determined to have a low buffering capacity, low chemical oxygen demand, and low natural oxidant interaction (NOI) with persulfate. Aqueous batch experiments identified the potential for iron (II) activated persulfate to reduce concentrations of BTEX and PAHs below method detection limits (MDLs). Unactivated persulfate was able to reduce BTEX concentrations to below MDLs after 14 days; however, the concentration of PAH compounds remained above MDLs after 14 days. Higher iron doses within the system were shown to be more effective in reducing BTEX and PAH compounds.
Column experiments designed to mimic site conditions were used to evaluate the feasibility of persulfate treatment on impacted sediments from the Clearwater site. Two sets of column experiments were conducted: one using unactivated persulfate followed by alkaline activated persulfate; and one using iron (II) activated persulfate. On average, unactivated persulfate was able to reduce BTEX and PAH aqueous effluent concentrations by > 75% and 40%, respectively, after a total dose of 60 g/g soil. Two additional doses of alkaline activated persulfate (total persulfate dose of ~80g/g soil) in these columns were able to further reduce effluent BTEX and PAH concentrations by > 90% and > 75%, respectively. Iron (II) activated persulfate reduced effluent BTEX concentrations by > 70% and PAHs by > 65% after a total dose of 35 g/g soil. Average reductions in mass for BTEX and PAH compounds were approximately of 48% and 26% respectively in the iron (II) activated persulfate columns, and 24% and 10%, respectively in the alkaline activated persulfate columns.
The potential for the ability to use in situ chemical oxidation using persulfate for the remediation of MGP residuals in the subsurface is evaluated using field measurements and bench-scale experimentation. The reductions observed in aqueous phase compounds in MGP groundwater as observed in the laboratory indicate the potential for reductions in groundwater concentrations at this and other contaminated former MGP sites. However, column experiments, indicating the inability for activated persulfate to reduce all identified compounds in the MGP NAPL suggest source treatment with activated persulfate would not reduce concentrations to below Florida Department of Environmental Protection natural attenuation concentrations.
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Evaluation of persulfate for the treatment of manufactured gas plant residualsMcIsaac, Angela January 2013 (has links)
The presence of coal tars in the subsurface associated with former manufactured gas plants (MGPs) offers a remediation challenge due to their complex chemical composition, dissolution behaviour and recalcitrant characteristics. A former MGP site in Clearwater Beach, Florida was characterized and bench-scale analyses were conducted to assess the potential for in situ chemical oxidation (ISCO) using persulfate to treat MGP residuals.
Completion of a conceptual site model identified a homogeneous, silty sand aquifer, with an average hydraulic conductivity of approximately 2.3x10-3 cm/s and a groundwater flow rate of 2 cm/day in the direction of S20°E. Six source zones, three near the water table and three in the deep aquifer were estimated to have a total volume of 108 m3. A multi-level well transect was installed to monitor concentrations of dissolved compounds and to estimate mass discharge downgradient of the source zones over time. On average, the morphology of the aqueous concentrations remained consistent with time. A total mass discharge across the transect of 94 mg/day was estimated for site-specific compounds.
Bench-scale tests were conducted on aquifer sediments and groundwater samples. The aquifer was determined to have a low buffering capacity, low chemical oxygen demand, and low natural oxidant interaction (NOI) with persulfate. Aqueous batch experiments identified the potential for iron (II) activated persulfate to reduce concentrations of BTEX and PAHs below method detection limits (MDLs). Unactivated persulfate was able to reduce BTEX concentrations to below MDLs after 14 days; however, the concentration of PAH compounds remained above MDLs after 14 days. Higher iron doses within the system were shown to be more effective in reducing BTEX and PAH compounds.
Column experiments designed to mimic site conditions were used to evaluate the feasibility of persulfate treatment on impacted sediments from the Clearwater site. Two sets of column experiments were conducted: one using unactivated persulfate followed by alkaline activated persulfate; and one using iron (II) activated persulfate. On average, unactivated persulfate was able to reduce BTEX and PAH aqueous effluent concentrations by > 75% and 40%, respectively, after a total dose of 60 g/g soil. Two additional doses of alkaline activated persulfate (total persulfate dose of ~80g/g soil) in these columns were able to further reduce effluent BTEX and PAH concentrations by > 90% and > 75%, respectively. Iron (II) activated persulfate reduced effluent BTEX concentrations by > 70% and PAHs by > 65% after a total dose of 35 g/g soil. Average reductions in mass for BTEX and PAH compounds were approximately of 48% and 26% respectively in the iron (II) activated persulfate columns, and 24% and 10%, respectively in the alkaline activated persulfate columns.
The potential for the ability to use in situ chemical oxidation using persulfate for the remediation of MGP residuals in the subsurface is evaluated using field measurements and bench-scale experimentation. The reductions observed in aqueous phase compounds in MGP groundwater as observed in the laboratory indicate the potential for reductions in groundwater concentrations at this and other contaminated former MGP sites. However, column experiments, indicating the inability for activated persulfate to reduce all identified compounds in the MGP NAPL suggest source treatment with activated persulfate would not reduce concentrations to below Florida Department of Environmental Protection natural attenuation concentrations.
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Gas flaring, government policies and regulations in Nigeria : 2008, a myth or reality / V.B. AghoginAghogin, Bemigho Victor January 2008 (has links)
The issue of gas flaring and the attendant environmental effects have become a common sight in the Niger Delta. Apart from being a wastage of natural resources, it is a menace to the global existence of man. The incidences of acid rain and the disruption of economic life of the locals, basically farming and fishing, have led to consistent and irresistible agitation by the people of the Niger Delta for an end to gas flaring. The consistent release of harmful gases through gas flaring, with devastating effect on the surrounding environment of the Niger Delta region is discussed in this work.
This dissertation examines why successive governments have not succeeded in their quest for a solution to gas flaring; policies and regulations are not being effectively implemented, and why despite the fact that flaring has been outlawed in Nigeria since 1st January 1984, it is still going on 24 years after. Flaring continues unabated undermining the consequences it has on the people and the effects on climate change.
Interviews and case studies were used to examine the factors responsible for the non implementation of government policies and regulations, and why the consistent extension of flare-out deadline. Countries with outstanding results were examined in order to draw a baseline for the Nigeria situation.
The research revealed that the Nigerian government has not enforced environmental regulations effectively because of its interests in the business of the multinationals. In addition there has been the dependence of environmental monitoring and regulatory agencies on government funding. This has drastically affected the proficiencies of the control and the insignificant penalties imposed on companies that flare gas.
The need for government to play the role of an umpire rather than business partner with the multinationals is therefore of paramount importance. It is also pertinent that the regulatory and monitoring agencies be independent of government's supervision. More stringent measures, (ranging from more cost per a thousand standard cubic feet of gas flared to closure of platform(s) and/or outright withdrawal of license), should also be put in place to serve as deterrent to erring oil companies. / Thesis (M.Ing. (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2009.
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Gas flaring, government policies and regulations in Nigeria : 2008, a myth or reality / V.B. AghoginAghogin, Bemigho Victor January 2008 (has links)
The issue of gas flaring and the attendant environmental effects have become a common sight in the Niger Delta. Apart from being a wastage of natural resources, it is a menace to the global existence of man. The incidences of acid rain and the disruption of economic life of the locals, basically farming and fishing, have led to consistent and irresistible agitation by the people of the Niger Delta for an end to gas flaring. The consistent release of harmful gases through gas flaring, with devastating effect on the surrounding environment of the Niger Delta region is discussed in this work.
This dissertation examines why successive governments have not succeeded in their quest for a solution to gas flaring; policies and regulations are not being effectively implemented, and why despite the fact that flaring has been outlawed in Nigeria since 1st January 1984, it is still going on 24 years after. Flaring continues unabated undermining the consequences it has on the people and the effects on climate change.
Interviews and case studies were used to examine the factors responsible for the non implementation of government policies and regulations, and why the consistent extension of flare-out deadline. Countries with outstanding results were examined in order to draw a baseline for the Nigeria situation.
The research revealed that the Nigerian government has not enforced environmental regulations effectively because of its interests in the business of the multinationals. In addition there has been the dependence of environmental monitoring and regulatory agencies on government funding. This has drastically affected the proficiencies of the control and the insignificant penalties imposed on companies that flare gas.
The need for government to play the role of an umpire rather than business partner with the multinationals is therefore of paramount importance. It is also pertinent that the regulatory and monitoring agencies be independent of government's supervision. More stringent measures, (ranging from more cost per a thousand standard cubic feet of gas flared to closure of platform(s) and/or outright withdrawal of license), should also be put in place to serve as deterrent to erring oil companies. / Thesis (M.Ing. (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2009.
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House of Waste / House of WasteStrömbäck, Miriam January 2021 (has links)
I Sverige är industrin och samhället i stort sett helt skilda, där det är näst intill omöjligt att närma sig och observera vad som faktiskt sker i våra kraftverk eller återbruk. Placeringen långt ifrån städerna, avsaknaden av design eller koppling till omgivningen, och de stora skyltarna med “inträde förbjuden” förstärker inte bara känslan av alienation - men också tron om att industrin är något smutsigt, som är negativt för miljön och samhället. Estetiken spelar en avgörande roll i att minska den allmänt negativa synen kopplat till industribyggnader samt att integrera dem i våra samhällen. Ett mindre industriellt utseende möjliggör en mer central placering, vilket förbättrar många typer av industriers effektivitet och kapacitet. Genom att skapa en lokal kraftproduktion, använda oss av de lokala resurserna, samt lyfta fram våra industribyggnader som landmärken så som de var i början av 1900-talet kan arkitekturen skapa en ny samhörighet, syfte och stolthet i samhällena. Mitt mål har varit att omdefiniera samspelet mellan avfall, energiproduktion och arkitektur, för att bjuda in samhället att vara en del av vår energiproduktion. Med House of waste har jag undersökt hur en biogasanläggning, som med fördel placeras på landsbygden i närhet till gårdar, inte bara kan inhysa ett socialt program utan vara publik i sin kärna. / The Swedish industry and society are widely separated and it is more or less impossible to approach and observe our industries. The location of the industries far away from our cities, the lack of connection to the surrounding context, and the many signs of “no entry” do not only strengthen the idea of alienation - but also the belief that industry is something dangerous hazardous as well as negative for the environment and our societies. Aesthetics play an important role in reducing the negative associations with industrial buildings as well as integrating them into our communities. A less industrial appearance can make a more central location acceptable, which is beneficial for the efficiency and capacity of most plants. By creating an infrastructure regarding local energy production, using the local resources and giving our industrial buildings aesthetic consideration, the architecture can create a new type of belonging, purpose and pride in our communities. The aim of the project has been to redefine the relationship between waste, energy production and architecture. House of Waste investigates how a biogas plant, not only can house a social program - but be a public building at its core.
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