Sustainable management of scenic and recreational forest based on the integration of forest landscape beauty and recreational functions is the foundation of forest tourism. Adhering to the principles of structural opt...Sustainable management of scenic and recreational forest based on the integration of forest landscape beauty and recreational functions is the foundation of forest tourism. Adhering to the principles of structural optimization, healthy and vital, beautiful landscape, sound function, and comprehensive benefi t, the hotspot and core task in the current construction of scenic and recreational forest is to conserve, transform and improve forest landscape. The ThousandIsland Lake National Forest Park is endowed with peculiar island scenery, it is necessary to construct a stable threedimensional comprehensive protection system covering "mountain, land and lake", enhance the ecological environment conservation of the lake as well as the lakefront wetland, promote the ecological restoration and coloring construction of forest, protect integrality and diversity of the biosystem, and construct ecological urban-rural system using regional scenic spot concept, so as to build the lake into a model of the sustainable operation of scenic and recreational forest.展开更多
This paper is manily to treat the change regularity of the contens,distributions, enrich coefficients and correlative coefficients of some trace and constant elements in the sediments of Late Quaternary rock core from...This paper is manily to treat the change regularity of the contens,distributions, enrich coefficients and correlative coefficients of some trace and constant elements in the sediments of Late Quaternary rock core from Yanwo Lake in the Great Wall Station area, King George Island and to discuss the sedimentary sources in Yanwo Lake and the periodical changes of Late Quaternary climate and the environment in the area. It is concluded that the elastic sedimentary rocks, including volcanic sedimentary rocks, around Yanwo Lake are the major sources of Yanwo Lake sedimentsi the mantle material is also one of its sources and what is more, the continent-sourced materials are transported by the Antarctic glacier.展开更多
The study was conducted on the islands of Lake Ziway, south-central Ethiopia. The aim of the study was to investigate the socio-economic factors affecting the vegetation resources and the indigenous resource managemen...The study was conducted on the islands of Lake Ziway, south-central Ethiopia. The aim of the study was to investigate the socio-economic factors affecting the vegetation resources and the indigenous resource management systems and practices on the islands. Data were collected by field observations, interviews and group discussion. The island communities were engaged in diverse economic activities. The fishing industry was the main pillar of the economy as most of the income (75.7%) was derived from this sector. The existence of diverse economic activities had relieved the pressure on the vegetation resources. The natural vegetation was the major source of fuelwood, construction material, farm implements, edible fruits, medicines, fodder and bee forage. The islanders have maintained the soil and vegetation resources for centuries through their environmental friendly resource management systems and practices. At present, however, the vegetation resources are dwindling due to free livestock grazing, farmland expansion, soil erosion and tree cutting for various purposes, all of which are driven by human population growth. Since the islanders have high respect and trust for the church, integrating environment and development issues with this institution would be more effective. The prevailing natural and anthropogenic factors affecting the vegetation resources on the islands necessitate effective conservation and management interventions.展开更多
As one of the basic theories of biodiversity conservation,island biogeography has been widely accepted in the past decades.Originally,island biogeography was put forward and applied in oceanic environments.But later o...As one of the basic theories of biodiversity conservation,island biogeography has been widely accepted in the past decades.Originally,island biogeography was put forward and applied in oceanic environments.But later on,it was found out that the application was not only limited to oceanic islands,but also in terrestrial environments with relatively isolated conditions.In terms of biodiversity level,island biogeography generally focuses on a small scale,such as species diversity and genetic diversity.The studies of biodiversity on a large-scale based on island biogeography,such as ecosystem and landscape scales,were seldomly conducted.Taking Poyang Lake,the largest fresh water lake in China as case study area,30 grasslands were randomly selected to study whether island biogeography can be applied to grasslands at a landscape level from three island attributes(area,distance and shape),and the most important ecological variable(flooding)in Poyang Lake.The results showed that in general,grasslands have the property of an island,and follow the basic principle of island biogeography.We found the area and flooding duration were the two most important determinants of landscape diversity.There was a significant positive correlation between the grassland area and the landscape diversity,which could be well expressed by logarithmic function model(R2=0.73).There was a negative correlation between flooding duration and landscape diversity,which could be described by an inverse model(R2=0.206).The distance to mainland and the shape of grassland were correlated with landscape diversity,but the fitting result of the models was not as good as expected.The possible reason could be that Poyang Lake is a seasonal lake,the water level varies with hydrological conditions,so that the grasslands are not strongly isolated and their shape is not stable enough required by island biogeography.Furthermore,it indicates that besides area,distance and shape attributes,flooding strongly affects the biodiversity of grassland vegetation,and should not be ignored when applying island biogeography theory to Poyang Lake.This study is expected to be a supplement for island biogeography in terrestrial environments,and the results are expected to benefit for the biodiversity conservation in Poyang Lake.展开更多
Lake Vrana on the island of Cres is one of the largest fresh water features on Mediterranean islands. The maximum depth of the lake is 72 m and it stores 220 million m3 of fresh water. The paper provides an overview o...Lake Vrana on the island of Cres is one of the largest fresh water features on Mediterranean islands. The maximum depth of the lake is 72 m and it stores 220 million m3 of fresh water. The paper provides an overview of lake and groundwater temperature measurements to date and recent activities within the EU project "CC-WaterS (Climate Change and Impacts on Water Supply)". Groundwater temperatures in the lake surrounding are almost constant throughout the year, in the range from 14.6 ℃ to 13.1 ℃, while thermodynamic cycle of the lake conforms to the characteristics of a monomictic, medium depth lake in the moderate climate belt. Present and future climate simulations using three limited area models were analyzed (Aladin, Promes and RegCM3), they pointed out further air temperature increase in range of 0.27 ℃/10 yrs to 0.32 ℃/10 yrs. The significant changes of precipitation rates were not indicated. Considering increasing water consumption from the lake, already asserted negative trends, indicated climate changes and possible effects on the lake recharge, it is necessary to establish continual monitoring of parameters that describe lake system behaviour and periodically analyze lake conditions, especially with respect to the extraction for the public water supply.展开更多
Volcanic lakes in the Kuril-Kamchatka region are difficult to access,and for this reason,they remain poorly studied,with only scattered and brief data available.The authors have conducted a study of 10 lake basins usi...Volcanic lakes in the Kuril-Kamchatka region are difficult to access,and for this reason,they remain poorly studied,with only scattered and brief data available.The authors have conducted a study of 10 lake basins using modern digital echolocation survey techniques and have also compiled and summarized published data for 15 lakes in the region,calculating their main morphometric characteristics.It has been established that many caldera lake basins are modified by young explosive funnels,extrusive or effusive domes,and exhibit traces of hydrothermal activity.While lakes of the same genetic type in the Kuril-Kamchatka region are similar in depth and depression forms,the group of caldera lakes shows less homogeneity across all morphometric indicators.It was found that the absolute heights of the reservoirs on Kamchatka Peninsula are generally greater than those on the Kuril Islands,as is often the case with the size of their basins.The volcanic lakes under study can rapidly change their volume and shape under the influence of endogenous processes.For the first time for this region,on the base of repeated observations,underwater extrusive dome rate growth and the approximate rates of 2 lake level changes were calculated.Repeated observations of lakes in the Ksudach calderas(Kamchatka)and on Simushir Island indicate approximate rates of level changes:a decrease ranging within 0.5-0.6 m per year(over a 27-year observation interval)and an increase reaching up to 0.26 m per year(over a 48-year interval).The growth rate of the underwater extrusive dome in Lake Shtyubel has averaged 1-1.6 m per year over the past 25 years.This analysis has facilitated the first generalization regarding the morphology and developmental features of crater and caldera lakes in the Kuril-Kamchatka region of Russia,representing an important step in their study.The results obtained will provide a solid foundation for subsequent research in this region and may be of interest to researchers studying other volcanic lakes.展开更多
Background: The guild concept is useful for understanding the community structure in a land-bridge island system,but most fragmentation studies have focused only on the importance of island area and isolation, other i...Background: The guild concept is useful for understanding the community structure in a land-bridge island system,but most fragmentation studies have focused only on the importance of island area and isolation, other island attributes such as perimeter-area ratio(PAR) were overlooked or understudied.Methods: We have adopted a guild approach to investigate the impacts of island attributes on bird guild richness on a set of 41 recently isolated land-bridge islands in the Thousand Island Lake(TIL), China.Results: We found insectivores had the largest number of species(34 species), fol owed by understory foraging guilds(28 species), omnivores(27 species) and canopy guilds(25 species). Furthermore, our data showed that migrants and residents responded equal y to island area, insectivores and understory guilds were sensitive to island area but omnivores and canopy guilds were not very sensitive. Most guild richness was determined by island area, except for omnivores and canopy guilds.Conclusions: Although PAR or habitat diversity found to be important for bird species richness, our results highlight the importance of island area in maintaining bird diversity in fragmented island systems.展开更多
The carbon isotopic composition of organic matter (δ^13Corg) was determined in two sediment cores (IIL1 and IIL9) recovered from Inexpressible Island, Ross Sea, Antarctica, and analyzed to identify the sources of...The carbon isotopic composition of organic matter (δ^13Corg) was determined in two sediment cores (IIL1 and IIL9) recovered from Inexpressible Island, Ross Sea, Antarctica, and analyzed to identify the sources of that organic matter. The δ^13Corg values of sediments of IIL9 were found to vary between -14.6‰ and -11.6‰, with a mean of-13.4‰ (n=48). These values were significantly higher than those of IIL1 sediments which varied between -23.2‰ and -20.4‰, with a mean of-21.8%o (n=55). The variation in δ^13Corg values in these two sediment cores indicate different sources of organic matter, The relatively high 6~3Corg values in IIL9 are in accordance with a source from algae, while the low δ^13Corg values in IIL1 evince significant influence from penguin guano with algae as the secondary source. Compared with the reference data from other high-latitude lake sediments and plants, the δ^13Corg values in IIL9 were extremely high, a result likely related to intense competition for CO2 assimilation among algal species during the growing season in this relatively shallow pond. These results indicate that sedimentary δ^13Corg is a reliable proxy for paleo-primary productivity in ponds at Inexpressible Island.展开更多
The sedimentary background and sedimentary environment of the Lower Cretaceous of Lingshan Island,Shandong,remain unclear.There is considerable controversy as to whether the sedimentary environment was marine or conti...The sedimentary background and sedimentary environment of the Lower Cretaceous of Lingshan Island,Shandong,remain unclear.There is considerable controversy as to whether the sedimentary environment was marine or continental.In this study,analyses were conducted with respect to indicators of paleosalinity,the chemical composition of clay,paleobiota,the characteristics of strata exhibiting salinization in eastern China during the Early Cretaceous,and the relationship between paleosalinity and paleoclimate.The results indicate that the sedimentary environment of the Lower Cretaceous Laiyang Group of Lingshan Island was that of a salified lake rather than a marine environment.This study not only provides a reference for determining the sedimentary environment of the Lower Cretaceous Laiyang Group of Lingshan Island but also offers a new perspective for the study of Cretaceous strata with salinization characteristics in eastern China.展开更多
おhe impact of modifications of the surface characteristics on local climate is simulated with a numerical mesoscale model in the Yangtze delta region, east of China. The simulated reference case with the current surf...おhe impact of modifications of the surface characteristics on local climate is simulated with a numerical mesoscale model in the Yangtze delta region, east of China. The simulated reference case with the current surface properties shows that there is urban heat island in Shanghai city which is located in the center of this region. The modifications of surface characteristics due to the urbanization around Shanghai will lead to the change of local air circulation and redistribution of surface temperature. Simulation for this case shows that the urbanization around Shanghai has little effect on Shanghai, but will extend the area of heat island. Another case is assumed that the area of grassland is kept as 50% while the urban areas are extended. Compared with the case of pure urbanization, the maximum reduction of surface air temperature is 2.0oC in the daytime and 2.3oC at night.展开更多
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
基金Sponsored by Key Soft Science Research Program of Hangzhou City(20150834M12)
文摘Sustainable management of scenic and recreational forest based on the integration of forest landscape beauty and recreational functions is the foundation of forest tourism. Adhering to the principles of structural optimization, healthy and vital, beautiful landscape, sound function, and comprehensive benefi t, the hotspot and core task in the current construction of scenic and recreational forest is to conserve, transform and improve forest landscape. The ThousandIsland Lake National Forest Park is endowed with peculiar island scenery, it is necessary to construct a stable threedimensional comprehensive protection system covering "mountain, land and lake", enhance the ecological environment conservation of the lake as well as the lakefront wetland, promote the ecological restoration and coloring construction of forest, protect integrality and diversity of the biosystem, and construct ecological urban-rural system using regional scenic spot concept, so as to build the lake into a model of the sustainable operation of scenic and recreational forest.
文摘This paper is manily to treat the change regularity of the contens,distributions, enrich coefficients and correlative coefficients of some trace and constant elements in the sediments of Late Quaternary rock core from Yanwo Lake in the Great Wall Station area, King George Island and to discuss the sedimentary sources in Yanwo Lake and the periodical changes of Late Quaternary climate and the environment in the area. It is concluded that the elastic sedimentary rocks, including volcanic sedimentary rocks, around Yanwo Lake are the major sources of Yanwo Lake sedimentsi the mantle material is also one of its sources and what is more, the continent-sourced materials are transported by the Antarctic glacier.
文摘The study was conducted on the islands of Lake Ziway, south-central Ethiopia. The aim of the study was to investigate the socio-economic factors affecting the vegetation resources and the indigenous resource management systems and practices on the islands. Data were collected by field observations, interviews and group discussion. The island communities were engaged in diverse economic activities. The fishing industry was the main pillar of the economy as most of the income (75.7%) was derived from this sector. The existence of diverse economic activities had relieved the pressure on the vegetation resources. The natural vegetation was the major source of fuelwood, construction material, farm implements, edible fruits, medicines, fodder and bee forage. The islanders have maintained the soil and vegetation resources for centuries through their environmental friendly resource management systems and practices. At present, however, the vegetation resources are dwindling due to free livestock grazing, farmland expansion, soil erosion and tree cutting for various purposes, all of which are driven by human population growth. Since the islanders have high respect and trust for the church, integrating environment and development issues with this institution would be more effective. The prevailing natural and anthropogenic factors affecting the vegetation resources on the islands necessitate effective conservation and management interventions.
基金supported by the National Natural Science Foundation of China(Nos.41961036,41901130).
文摘As one of the basic theories of biodiversity conservation,island biogeography has been widely accepted in the past decades.Originally,island biogeography was put forward and applied in oceanic environments.But later on,it was found out that the application was not only limited to oceanic islands,but also in terrestrial environments with relatively isolated conditions.In terms of biodiversity level,island biogeography generally focuses on a small scale,such as species diversity and genetic diversity.The studies of biodiversity on a large-scale based on island biogeography,such as ecosystem and landscape scales,were seldomly conducted.Taking Poyang Lake,the largest fresh water lake in China as case study area,30 grasslands were randomly selected to study whether island biogeography can be applied to grasslands at a landscape level from three island attributes(area,distance and shape),and the most important ecological variable(flooding)in Poyang Lake.The results showed that in general,grasslands have the property of an island,and follow the basic principle of island biogeography.We found the area and flooding duration were the two most important determinants of landscape diversity.There was a significant positive correlation between the grassland area and the landscape diversity,which could be well expressed by logarithmic function model(R2=0.73).There was a negative correlation between flooding duration and landscape diversity,which could be described by an inverse model(R2=0.206).The distance to mainland and the shape of grassland were correlated with landscape diversity,but the fitting result of the models was not as good as expected.The possible reason could be that Poyang Lake is a seasonal lake,the water level varies with hydrological conditions,so that the grasslands are not strongly isolated and their shape is not stable enough required by island biogeography.Furthermore,it indicates that besides area,distance and shape attributes,flooding strongly affects the biodiversity of grassland vegetation,and should not be ignored when applying island biogeography theory to Poyang Lake.This study is expected to be a supplement for island biogeography in terrestrial environments,and the results are expected to benefit for the biodiversity conservation in Poyang Lake.
文摘Lake Vrana on the island of Cres is one of the largest fresh water features on Mediterranean islands. The maximum depth of the lake is 72 m and it stores 220 million m3 of fresh water. The paper provides an overview of lake and groundwater temperature measurements to date and recent activities within the EU project "CC-WaterS (Climate Change and Impacts on Water Supply)". Groundwater temperatures in the lake surrounding are almost constant throughout the year, in the range from 14.6 ℃ to 13.1 ℃, while thermodynamic cycle of the lake conforms to the characteristics of a monomictic, medium depth lake in the moderate climate belt. Present and future climate simulations using three limited area models were analyzed (Aladin, Promes and RegCM3), they pointed out further air temperature increase in range of 0.27 ℃/10 yrs to 0.32 ℃/10 yrs. The significant changes of precipitation rates were not indicated. Considering increasing water consumption from the lake, already asserted negative trends, indicated climate changes and possible effects on the lake recharge, it is necessary to establish continual monitoring of parameters that describe lake system behaviour and periodically analyze lake conditions, especially with respect to the extraction for the public water supply.
基金support of the State Assignments of the Institute of Marine Geology and Geophysics,Far Eastern Branch of the Russian Academy of Sciences and the Institute of Geography of the Russian Academy of Sciences(FMWS-2024-0005).
文摘Volcanic lakes in the Kuril-Kamchatka region are difficult to access,and for this reason,they remain poorly studied,with only scattered and brief data available.The authors have conducted a study of 10 lake basins using modern digital echolocation survey techniques and have also compiled and summarized published data for 15 lakes in the region,calculating their main morphometric characteristics.It has been established that many caldera lake basins are modified by young explosive funnels,extrusive or effusive domes,and exhibit traces of hydrothermal activity.While lakes of the same genetic type in the Kuril-Kamchatka region are similar in depth and depression forms,the group of caldera lakes shows less homogeneity across all morphometric indicators.It was found that the absolute heights of the reservoirs on Kamchatka Peninsula are generally greater than those on the Kuril Islands,as is often the case with the size of their basins.The volcanic lakes under study can rapidly change their volume and shape under the influence of endogenous processes.For the first time for this region,on the base of repeated observations,underwater extrusive dome rate growth and the approximate rates of 2 lake level changes were calculated.Repeated observations of lakes in the Ksudach calderas(Kamchatka)and on Simushir Island indicate approximate rates of level changes:a decrease ranging within 0.5-0.6 m per year(over a 27-year observation interval)and an increase reaching up to 0.26 m per year(over a 48-year interval).The growth rate of the underwater extrusive dome in Lake Shtyubel has averaged 1-1.6 m per year over the past 25 years.This analysis has facilitated the first generalization regarding the morphology and developmental features of crater and caldera lakes in the Kuril-Kamchatka region of Russia,representing an important step in their study.The results obtained will provide a solid foundation for subsequent research in this region and may be of interest to researchers studying other volcanic lakes.
基金supported by the National Natural Science Foundation of China (No. 31170397)the Fundamental Research Funds for the Central Universities
文摘Background: The guild concept is useful for understanding the community structure in a land-bridge island system,but most fragmentation studies have focused only on the importance of island area and isolation, other island attributes such as perimeter-area ratio(PAR) were overlooked or understudied.Methods: We have adopted a guild approach to investigate the impacts of island attributes on bird guild richness on a set of 41 recently isolated land-bridge islands in the Thousand Island Lake(TIL), China.Results: We found insectivores had the largest number of species(34 species), fol owed by understory foraging guilds(28 species), omnivores(27 species) and canopy guilds(25 species). Furthermore, our data showed that migrants and residents responded equal y to island area, insectivores and understory guilds were sensitive to island area but omnivores and canopy guilds were not very sensitive. Most guild richness was determined by island area, except for omnivores and canopy guilds.Conclusions: Although PAR or habitat diversity found to be important for bird species richness, our results highlight the importance of island area in maintaining bird diversity in fragmented island systems.
基金the Chinese Arctic and Antarctic Administration of the State Oceanic Administration for project supportthe United States Antarctic Program (USAP)+2 种基金Antarctic Support Contract and Italian Mario Zucchelli Station for logistical support. R. Murray and A. Mc Kenzie provided valuable assistance in the fieldsupported by the National Natural Science Foundation of China (Grant nos. 41576183 and 41376124)National Science Foundation (Grant no. ANT 0739575)
文摘The carbon isotopic composition of organic matter (δ^13Corg) was determined in two sediment cores (IIL1 and IIL9) recovered from Inexpressible Island, Ross Sea, Antarctica, and analyzed to identify the sources of that organic matter. The δ^13Corg values of sediments of IIL9 were found to vary between -14.6‰ and -11.6‰, with a mean of-13.4‰ (n=48). These values were significantly higher than those of IIL1 sediments which varied between -23.2‰ and -20.4‰, with a mean of-21.8%o (n=55). The variation in δ^13Corg values in these two sediment cores indicate different sources of organic matter, The relatively high 6~3Corg values in IIL9 are in accordance with a source from algae, while the low δ^13Corg values in IIL1 evince significant influence from penguin guano with algae as the secondary source. Compared with the reference data from other high-latitude lake sediments and plants, the δ^13Corg values in IIL9 were extremely high, a result likely related to intense competition for CO2 assimilation among algal species during the growing season in this relatively shallow pond. These results indicate that sedimentary δ^13Corg is a reliable proxy for paleo-primary productivity in ponds at Inexpressible Island.
基金supported by the Fund from the Key Laboratory of Stratigraphy and Palaeontology,Ministry of Natural Resources(Grant No.KLSP 190102)the Graduate Scientific and Technological Innovation Project Financially Supported by Shandong University of Science and Technology(Grant No.SDKDYC 190104)。
文摘The sedimentary background and sedimentary environment of the Lower Cretaceous of Lingshan Island,Shandong,remain unclear.There is considerable controversy as to whether the sedimentary environment was marine or continental.In this study,analyses were conducted with respect to indicators of paleosalinity,the chemical composition of clay,paleobiota,the characteristics of strata exhibiting salinization in eastern China during the Early Cretaceous,and the relationship between paleosalinity and paleoclimate.The results indicate that the sedimentary environment of the Lower Cretaceous Laiyang Group of Lingshan Island was that of a salified lake rather than a marine environment.This study not only provides a reference for determining the sedimentary environment of the Lower Cretaceous Laiyang Group of Lingshan Island but also offers a new perspective for the study of Cretaceous strata with salinization characteristics in eastern China.
文摘おhe impact of modifications of the surface characteristics on local climate is simulated with a numerical mesoscale model in the Yangtze delta region, east of China. The simulated reference case with the current surface properties shows that there is urban heat island in Shanghai city which is located in the center of this region. The modifications of surface characteristics due to the urbanization around Shanghai will lead to the change of local air circulation and redistribution of surface temperature. Simulation for this case shows that the urbanization around Shanghai has little effect on Shanghai, but will extend the area of heat island. Another case is assumed that the area of grassland is kept as 50% while the urban areas are extended. Compared with the case of pure urbanization, the maximum reduction of surface air temperature is 2.0oC in the daytime and 2.3oC at night.
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