The goal of this project was to design, build, and test a pilot-scale floating modular treatment system for total phosphorus （TP） removal from nutrient-impaired lakes in central Florida, USA. The treatment sys-tem c...The goal of this project was to design, build, and test a pilot-scale floating modular treatment system for total phosphorus （TP） removal from nutrient-impaired lakes in central Florida, USA. The treatment sys-tem consisted of biological and physical-chemical treatment modules. First, investigations of prospective biological and physical-chemical treatment processes in mesocosms and in bench-scale experiments were conducted. Thirteen different mesocosms were constructed with a variety of substrates and combi-nations of macrophytes and tested for TP and orthophosphate （PO4-^3） removal efficiencies and potential areal removal rates. Bench-scale jar tests and column tests of seven types of absorptive media in addition to three commercial resins were conducted in order to test absorptive capacity. Once isolated process testing was complete, a floating island treatment system （FITS） was designed and deployed for eight months in a lake in central Florida. Phosphorus removal efficiencies of the mesocosm systems averaged about 40%-50%, providing an average uptake of 5.0 g.m ^2.a ^1 across all mesocosms. The best-performing mesocosms were a submerged aquatic vegetation （SAV） mesocosm and an algae scrubber （AGS）, which removed 20 and 50 mg.m ^2.d ^1, respectively, for an average removal of 5.5 and 12.0 g.m ^2.a ^1 for the SAV and AGS systems, Of the absorptive media, the best performance was alum residual （AR）, which reduced PO4-^3 concentrations by about 75% after 5 min of contact time. Of the commercial resins tested, the PhosX resin was superior to the others, removing about 40% of phosphorus after 30 rain and 60% after 60min. Under baseline operation conditions during deployment, the FITS exhibited mean PO4-^3 removal efficiencies of 53%; using the 50th and 90th percentile of PO4-^3 removal during deployment, and the footprint of the FITS system, yielded efficiencies for the combined FITS system of 56% and 86%, respectively, and areal phosphorus removal rates between 8.9 and 16.5 g.m ^2.a ^1展开更多
Lakes have different social, economical, and ecological values at different periods of societal development, which make them vulnerable to change. One of the ongoing discussions in urban lake governance in India is th...Lakes have different social, economical, and ecological values at different periods of societal development, which make them vulnerable to change. One of the ongoing discussions in urban lake governance in India is the revitalization of the urban lakes. The core challenge documented in the governance of urban lakes is to address and find balance in the changing and competing value systems. Effectively addressing the change （or priority） in the values linked to the governance systems is a major step toward sustainability of the urban lakes. There is still limited understanding of how the values of urban lakes are progressively linked to the social, ecological and economic values of the urban developments. The paper looks at the interactions and outcomes of the spatial and temporal dynamics of the urban lakes systems especially the values that sustain the institutional and ecological memory. The focus is on the role of values in urban lake governance. The multitier framework for analyzing social-ecological systems CSES） which is in developmental phase at Elinor Ostrom＇s Workshop is used as the guiding framework to build understanding of the urban lake governance in Ahmedabad, India and at the same time contribute to the development of the SES framework.展开更多
Trophic status of some freshwater lakes all over the world, including Russia, Byelorussia, Japan, Sweden and China, has been assessed. The research submitted is based on the approach developed by OECD （Organization E...Trophic status of some freshwater lakes all over the world, including Russia, Byelorussia, Japan, Sweden and China, has been assessed. The research submitted is based on the approach developed by OECD （Organization Economic Cooperation and Development）. Annual total phosphorus averages formed a classification system. A probability assumption for each water body to reach some given trophic status was taken into account. Probability distribution curves for the average lake phosphorus have been analytically approximated.展开更多
基金the Lake Jesup Total Phosphorus Removal Treatment Technologies Floating Island Pilot Project (25104) of St. Johns River Water Management District Palatka+1 种基金 FL USA
文摘The goal of this project was to design, build, and test a pilot-scale floating modular treatment system for total phosphorus （TP） removal from nutrient-impaired lakes in central Florida, USA. The treatment sys-tem consisted of biological and physical-chemical treatment modules. First, investigations of prospective biological and physical-chemical treatment processes in mesocosms and in bench-scale experiments were conducted. Thirteen different mesocosms were constructed with a variety of substrates and combi-nations of macrophytes and tested for TP and orthophosphate （PO4-^3） removal efficiencies and potential areal removal rates. Bench-scale jar tests and column tests of seven types of absorptive media in addition to three commercial resins were conducted in order to test absorptive capacity. Once isolated process testing was complete, a floating island treatment system （FITS） was designed and deployed for eight months in a lake in central Florida. Phosphorus removal efficiencies of the mesocosm systems averaged about 40%-50%, providing an average uptake of 5.0 g.m ^2.a ^1 across all mesocosms. The best-performing mesocosms were a submerged aquatic vegetation （SAV） mesocosm and an algae scrubber （AGS）, which removed 20 and 50 mg.m ^2.d ^1, respectively, for an average removal of 5.5 and 12.0 g.m ^2.a ^1 for the SAV and AGS systems, Of the absorptive media, the best performance was alum residual （AR）, which reduced PO4-^3 concentrations by about 75% after 5 min of contact time. Of the commercial resins tested, the PhosX resin was superior to the others, removing about 40% of phosphorus after 30 rain and 60% after 60min. Under baseline operation conditions during deployment, the FITS exhibited mean PO4-^3 removal efficiencies of 53%; using the 50th and 90th percentile of PO4-^3 removal during deployment, and the footprint of the FITS system, yielded efficiencies for the combined FITS system of 56% and 86%, respectively, and areal phosphorus removal rates between 8.9 and 16.5 g.m ^2.a ^1
文摘Lakes have different social, economical, and ecological values at different periods of societal development, which make them vulnerable to change. One of the ongoing discussions in urban lake governance in India is the revitalization of the urban lakes. The core challenge documented in the governance of urban lakes is to address and find balance in the changing and competing value systems. Effectively addressing the change （or priority） in the values linked to the governance systems is a major step toward sustainability of the urban lakes. There is still limited understanding of how the values of urban lakes are progressively linked to the social, ecological and economic values of the urban developments. The paper looks at the interactions and outcomes of the spatial and temporal dynamics of the urban lakes systems especially the values that sustain the institutional and ecological memory. The focus is on the role of values in urban lake governance. The multitier framework for analyzing social-ecological systems CSES） which is in developmental phase at Elinor Ostrom＇s Workshop is used as the guiding framework to build understanding of the urban lake governance in Ahmedabad, India and at the same time contribute to the development of the SES framework.
文摘Trophic status of some freshwater lakes all over the world, including Russia, Byelorussia, Japan, Sweden and China, has been assessed. The research submitted is based on the approach developed by OECD （Organization Economic Cooperation and Development）. Annual total phosphorus averages formed a classification system. A probability assumption for each water body to reach some given trophic status was taken into account. Probability distribution curves for the average lake phosphorus have been analytically approximated.
