Several methods for analysis of dissolved total phosphorus in seawater were reviewed. Discussions were focused on UVirradiation and persulphate oxidation methods which are the most popular dissolved organic phosphorus...Several methods for analysis of dissolved total phosphorus in seawater were reviewed. Discussions were focused on UVirradiation and persulphate oxidation methods which are the most popular dissolved organic phosphorus determinationmethods presently. The compounds used for the phosphorus recovery test were categorized into three groups accordingto their chemical structure. It was found that low power UV irradiation can decompose POC or PC bonds efficientlybut may be inefficient for POP bonds. Heating-bath in acid condition is useful for decomposing POP bonds. Usingthe continuous flow analysis system (Auto-analyzer II), UV digestion and heating-bath, series experiments were carriedout based on the above analysis. Eleven model compounds were employed for the phosphorus recovery test and thefactors influencing the decomposition efficiency of dissolved compounds containing phosphorus were clarified. Finally,the optimal design for determination of dissolved total phosphorus in seawater based on the routine continuous flowanalysis system was presented. For the organic mono-phosphate, the recovery is more than 90% and a recovery of33%~51% was obtained for inorganic or organic polyphosphates. Up to now, this is the highest decompositionefficiency for dissolved phosphorus based on the continuous flow analysis system.展开更多
This study investigates phosphorus (P) concentrations and fluxes in tile drains, overland flow, and streamflow at a high temporal resolution during 7 spring storms in anagricultural watershed in Indiana, USA. Research...This study investigates phosphorus (P) concentrations and fluxes in tile drains, overland flow, and streamflow at a high temporal resolution during 7 spring storms in anagricultural watershed in Indiana, USA. Research goals include a better understanding of 1) how bulk precipitation and antecedent moisture conditions affect P concentrations and fluxes at the watershed scale;2) how P concentrations and fluxes measured in tile drains translate to the whole watershed scale;3) whether P losses to the stream are significantly affected by overland flow. Results indicate that bulk precipitation and antecedent moisture conditions are not good predictors of SRP or TP losses (either concentration or flux) to the stream. However, along with previously published storm data in this watershed, results indicate a threshold-based behavior whereby SRP and TP fluxes significantly increase with precipitation when bulk precipitation exceeds 4 cm. Although total SRP and TP fluxes are very much driven by flow, SRP and TP fluxes are somewhat limited by the amount of P available for leaching for most storms. On average, SRP fluxes in tile drains are 13% greater than in the stream, and stream SRP fluxes account for 45% of TP fluxes at the watershed scale. Our results indicate that when P is the primary concern, best management practices aimed at reducing P losses via tile drains are likely to have the most effect on P exports at the watershed scale.展开更多
As the development of city economy,Zhongdong River in Hangzhou was seriously polluted,with the worst water quality.In order to obtain the effect of water diversion and distribution from Qiantang River on the water qua...As the development of city economy,Zhongdong River in Hangzhou was seriously polluted,with the worst water quality.In order to obtain the effect of water diversion and distribution from Qiantang River on the water quality of Zhongdong River,7-year continuous monitoring was conducted,which was at the fixed stations before and after the water diversion and distribution.After the water diversion project,the dissolved oxygen concentration of the river water was one to two times higher than before,and the ammonia nitrogen and total phosphorus decreased by 60%and 65%,respectively.When increased the amount of water diversion,the dissolved oxygen concentration of the river water elevated by 13%,and the ammonia nitrogen,total phosphorus and potassium permanganate index decreased by 8%,3%and 14%,respectively.The reason for the river water pollution was contributed to the combined sewer system and riverway sludge,especially during the rainfall,the dissolved oxygen concentration of Zhongdong River sharply declined by 95%,while the ammonia nitrogen and total phosphorus increased by 90%and 87%,respectively.The research results could provide theoretic basis for sustainable improvement of Zhongdong River water quality and river management department making the related regulations and policies.展开更多
Spatial variations in phytoplankton community within a large mesotrophic reservoir （Miyun reservoir, North China） were investigated in relation to variations in physico-chemical properties, nutrient concentrations, ...Spatial variations in phytoplankton community within a large mesotrophic reservoir （Miyun reservoir, North China） were investigated in relation to variations in physico-chemical properties, nutrient concentrations, temperature and light conditions over a 5 month period in 2009. The dynamics of phytoplankton community was represented by the dominance of cyanobacteria through summer and fall, following with a short term dominance of chlorophyta in late fall, and a relatively high abundance of diatom in October; on the other hand, maximum phytoplankton biomass was recorded in the north shallow region of Miyun reservoir with a higher nutrients level. Particular attention was paid to the impacts of environmental conditions on the growth of two cyanobacteria genera, the toxin-producing Microcystis and the taste ＆ odor-producing Oscillatoria. Microcystis biomass was in general greatly affected by water temperature and mixing depth/local water depth ratio in this reservoir, while the Oscillatoria biomass in the surface and middle layers was greatly affected by total dissolved phosphorus, and that in the bottom layer was related with the Secchi depth/local water depth ratio. Abundant Oscillatoria biomass was observed only in late September when Microcystis biomass decreased and allowed sufficient light go through.展开更多
基金The research was supported by the National Basic Research Program(“973”Program)of China under contract No.2002CB412405the Key Science and Technology Plan of the Ministry of Education of China under contract No.[2000]156-00079the Joint Sino-German Project under contract No.03F0189A.
文摘Several methods for analysis of dissolved total phosphorus in seawater were reviewed. Discussions were focused on UVirradiation and persulphate oxidation methods which are the most popular dissolved organic phosphorus determinationmethods presently. The compounds used for the phosphorus recovery test were categorized into three groups accordingto their chemical structure. It was found that low power UV irradiation can decompose POC or PC bonds efficientlybut may be inefficient for POP bonds. Heating-bath in acid condition is useful for decomposing POP bonds. Usingthe continuous flow analysis system (Auto-analyzer II), UV digestion and heating-bath, series experiments were carriedout based on the above analysis. Eleven model compounds were employed for the phosphorus recovery test and thefactors influencing the decomposition efficiency of dissolved compounds containing phosphorus were clarified. Finally,the optimal design for determination of dissolved total phosphorus in seawater based on the routine continuous flowanalysis system was presented. For the organic mono-phosphate, the recovery is more than 90% and a recovery of33%~51% was obtained for inorganic or organic polyphosphates. Up to now, this is the highest decompositionefficiency for dissolved phosphorus based on the continuous flow analysis system.
文摘This study investigates phosphorus (P) concentrations and fluxes in tile drains, overland flow, and streamflow at a high temporal resolution during 7 spring storms in anagricultural watershed in Indiana, USA. Research goals include a better understanding of 1) how bulk precipitation and antecedent moisture conditions affect P concentrations and fluxes at the watershed scale;2) how P concentrations and fluxes measured in tile drains translate to the whole watershed scale;3) whether P losses to the stream are significantly affected by overland flow. Results indicate that bulk precipitation and antecedent moisture conditions are not good predictors of SRP or TP losses (either concentration or flux) to the stream. However, along with previously published storm data in this watershed, results indicate a threshold-based behavior whereby SRP and TP fluxes significantly increase with precipitation when bulk precipitation exceeds 4 cm. Although total SRP and TP fluxes are very much driven by flow, SRP and TP fluxes are somewhat limited by the amount of P available for leaching for most storms. On average, SRP fluxes in tile drains are 13% greater than in the stream, and stream SRP fluxes account for 45% of TP fluxes at the watershed scale. Our results indicate that when P is the primary concern, best management practices aimed at reducing P losses via tile drains are likely to have the most effect on P exports at the watershed scale.
基金Supported by the National Science Foundation of China(31500394)the Foundation and Frontier Technology Research Program of Henan Province(152300410133)the Backbone Teachers Scheme of Zhongyuan University of Technology(2014 Personnel Department of Zhongyuan University of Technology 35)
文摘As the development of city economy,Zhongdong River in Hangzhou was seriously polluted,with the worst water quality.In order to obtain the effect of water diversion and distribution from Qiantang River on the water quality of Zhongdong River,7-year continuous monitoring was conducted,which was at the fixed stations before and after the water diversion and distribution.After the water diversion project,the dissolved oxygen concentration of the river water was one to two times higher than before,and the ammonia nitrogen and total phosphorus decreased by 60%and 65%,respectively.When increased the amount of water diversion,the dissolved oxygen concentration of the river water elevated by 13%,and the ammonia nitrogen,total phosphorus and potassium permanganate index decreased by 8%,3%and 14%,respectively.The reason for the river water pollution was contributed to the combined sewer system and riverway sludge,especially during the rainfall,the dissolved oxygen concentration of Zhongdong River sharply declined by 95%,while the ammonia nitrogen and total phosphorus increased by 90%and 87%,respectively.The research results could provide theoretic basis for sustainable improvement of Zhongdong River water quality and river management department making the related regulations and policies.
基金supported by the National Natural Science Foundation of China (No. 50938007)
文摘Spatial variations in phytoplankton community within a large mesotrophic reservoir （Miyun reservoir, North China） were investigated in relation to variations in physico-chemical properties, nutrient concentrations, temperature and light conditions over a 5 month period in 2009. The dynamics of phytoplankton community was represented by the dominance of cyanobacteria through summer and fall, following with a short term dominance of chlorophyta in late fall, and a relatively high abundance of diatom in October; on the other hand, maximum phytoplankton biomass was recorded in the north shallow region of Miyun reservoir with a higher nutrients level. Particular attention was paid to the impacts of environmental conditions on the growth of two cyanobacteria genera, the toxin-producing Microcystis and the taste ＆ odor-producing Oscillatoria. Microcystis biomass was in general greatly affected by water temperature and mixing depth/local water depth ratio in this reservoir, while the Oscillatoria biomass in the surface and middle layers was greatly affected by total dissolved phosphorus, and that in the bottom layer was related with the Secchi depth/local water depth ratio. Abundant Oscillatoria biomass was observed only in late September when Microcystis biomass decreased and allowed sufficient light go through.
