In this paper, the bottom of the Dianshan Lake was selected as a test sample. The dynamic release of contaminated sediments into the overlying water column was experimentally investigated in an open water channel unde...In this paper, the bottom of the Dianshan Lake was selected as a test sample. The dynamic release of contaminated sediments into the overlying water column was experimentally investigated in an open water channel under different hydrodynamic conditions. The experimental results indicate that the Total Phosphorus （TP） release process can be divided into three stages： rapid release, slow release and equilibration release. In the initial release stage the measured TP concentration changes along the depth. The TP concentration near the sediment-water interface is higher than that near the water surface, but the TP concentration becomes uniform along the depth after 3 h. The dynamic release of re-suspension sediment pollutants is about 6 times higher than the static release of sediment-water interface. There are three main types of release mechanism： diffusion release, re-suspended pore water mixing release and re-suspended particles desorbing release.展开更多
Abstract： The water quality of Dianshan Lake in Shanghai Municipality, China, is impacted by nutrient losses from agricultural lands around the lake. In this study, nine types of agricultural land use were monitored ...Abstract： The water quality of Dianshan Lake in Shanghai Municipality, China, is impacted by nutrient losses from agricultural lands around the lake. In this study, nine types of agricultural land use were monitored in 2010 and 2011, and a correlation analysis between nutrient losses from agricultural non-point sources （NPS） and nutrient stocks in the lake was conducted over monthly and seasonal time periods. The results indicate that the monthly average concentration of total nitrogen （TN） ranged from 1.41 to 7.34 mg/L in 2010 and from 1.52 to 5.90 mg/L in 2011, while the monthly average concentration of total phosphorous （TP） ranged from 0.11 to 0.26 mg/L in 2010 and from 0.13 to 0.30 mg/L in 2011. The annual loss of TN from agricultural NPS was 195.55 tons in 2010 and 208.40 tons in 2011. The cultivation of water oat made the largest contribution to the loss of TN. The annual loss of TP was 44.58 tons in 2010 and 48.12 tons in 2011, and multi-vegetable cultivation made the largest contribution to the loss of TP. The results of correlation analysis show that the monthly stocks of TN and TP in the lake have a positive correlation with the monthly losses of TN and TP from agricultural NPS. According to the seasonal data, the stocks of TN and TP in the lake both have a much stronger correlation with the losses of TN and TP from agricultural NPS in summer than in other seasons. Agricultural NPS pollution control should be the main focus for the water resource conservation in this area.展开更多
Water pollution has become a serious worldwide problem, especially for lakes with a large stagnant water body. Is it possible to develop high quality water from a heavily polluted river system quickly? This paper intr...Water pollution has become a serious worldwide problem, especially for lakes with a large stagnant water body. Is it possible to develop high quality water from a heavily polluted river system quickly? This paper introduces an innovative technology termed SPP (separation, prevention and protection) for this purpose. Its feasibility is preliminarily examined using Dianshan Lake in Shang- hai as an example. Due to its very high population density and intensive industrial activities, almost all waterways in Shanghai are heavily polluted, including the lake. However, the data analysis shows that clean water always appears after heavy rains, especially in its suburban areas. Once the 1<sup>st</sup> flush water is discharged to downstream, high-quality water can be developed from its Dianshan Lake by using the SPP strategy. The Vollenweider model is used to analyze SPP’s feasibility. The results show that the water quality of the Dianshan Lake can be remediated as a drinking water source within 120 days if the SPP strategy is applied. It is suggested that Jinze reservoir’s water should come from the Dianshan lake, not Taipu River to improve the quality of water supply. It is highly recommended for other cities in the world to consider the SPP technology if needed.展开更多
Nutrient loadings from upstream watersheds can have significant impacts on the water quality of receiving water bodies.Usually,a major river is selected as the target for water quality studies,and the impact of minor ...Nutrient loadings from upstream watersheds can have significant impacts on the water quality of receiving water bodies.Usually,a major river is selected as the target for water quality studies,and the impact of minor rivers tends to be ignored.It is very important to evaluate whether the impact of small rivers on the downstream water quality is negligible.River water sampling and discharge modeling using SWAT were used to analyze the contribution of small rivers to water quality in a receiving lake.From this analysis,it was determined that the inflowing total nitrogen(TN)and total phosphorus(TP)concentrations from all target rivers exceeded the lake water environmental standards set by the Ministry of the Environment.The contribution of suspended sediment(SS)and TN loads from small rivers did not vary markedly compared with their relative discharge contributions to the lake,at approximately 20%.However,the impact on TP loads to the lake from small rivers was 9.1%higher than their relative flow contributions,accounting for 28.2% of the TP loading.Thus,there is a potential to underestimate the impact of ungauged small rivers if only the major river is selected to evaluate the downstream lake water quality.展开更多
基金the National Natural Science Foundation of China (Grant Nos. 10972134, 11032007)the Shanghai Program for Innovative Research Team in Universities
文摘In this paper, the bottom of the Dianshan Lake was selected as a test sample. The dynamic release of contaminated sediments into the overlying water column was experimentally investigated in an open water channel under different hydrodynamic conditions. The experimental results indicate that the Total Phosphorus （TP） release process can be divided into three stages： rapid release, slow release and equilibration release. In the initial release stage the measured TP concentration changes along the depth. The TP concentration near the sediment-water interface is higher than that near the water surface, but the TP concentration becomes uniform along the depth after 3 h. The dynamic release of re-suspension sediment pollutants is about 6 times higher than the static release of sediment-water interface. There are three main types of release mechanism： diffusion release, re-suspended pore water mixing release and re-suspended particles desorbing release.
基金supported by the Project of the Shanghai Science and Technology Committee(Grants No.08DZ1203200 and 08DZ1203205)
文摘Abstract： The water quality of Dianshan Lake in Shanghai Municipality, China, is impacted by nutrient losses from agricultural lands around the lake. In this study, nine types of agricultural land use were monitored in 2010 and 2011, and a correlation analysis between nutrient losses from agricultural non-point sources （NPS） and nutrient stocks in the lake was conducted over monthly and seasonal time periods. The results indicate that the monthly average concentration of total nitrogen （TN） ranged from 1.41 to 7.34 mg/L in 2010 and from 1.52 to 5.90 mg/L in 2011, while the monthly average concentration of total phosphorous （TP） ranged from 0.11 to 0.26 mg/L in 2010 and from 0.13 to 0.30 mg/L in 2011. The annual loss of TN from agricultural NPS was 195.55 tons in 2010 and 208.40 tons in 2011. The cultivation of water oat made the largest contribution to the loss of TN. The annual loss of TP was 44.58 tons in 2010 and 48.12 tons in 2011, and multi-vegetable cultivation made the largest contribution to the loss of TP. The results of correlation analysis show that the monthly stocks of TN and TP in the lake have a positive correlation with the monthly losses of TN and TP from agricultural NPS. According to the seasonal data, the stocks of TN and TP in the lake both have a much stronger correlation with the losses of TN and TP from agricultural NPS in summer than in other seasons. Agricultural NPS pollution control should be the main focus for the water resource conservation in this area.
文摘Water pollution has become a serious worldwide problem, especially for lakes with a large stagnant water body. Is it possible to develop high quality water from a heavily polluted river system quickly? This paper introduces an innovative technology termed SPP (separation, prevention and protection) for this purpose. Its feasibility is preliminarily examined using Dianshan Lake in Shang- hai as an example. Due to its very high population density and intensive industrial activities, almost all waterways in Shanghai are heavily polluted, including the lake. However, the data analysis shows that clean water always appears after heavy rains, especially in its suburban areas. Once the 1<sup>st</sup> flush water is discharged to downstream, high-quality water can be developed from its Dianshan Lake by using the SPP strategy. The Vollenweider model is used to analyze SPP’s feasibility. The results show that the water quality of the Dianshan Lake can be remediated as a drinking water source within 120 days if the SPP strategy is applied. It is suggested that Jinze reservoir’s water should come from the Dianshan lake, not Taipu River to improve the quality of water supply. It is highly recommended for other cities in the world to consider the SPP technology if needed.
基金This study was partially supported by two grants-in-aid for scientific research:KAKENHI:24780234 and 25281054.
文摘Nutrient loadings from upstream watersheds can have significant impacts on the water quality of receiving water bodies.Usually,a major river is selected as the target for water quality studies,and the impact of minor rivers tends to be ignored.It is very important to evaluate whether the impact of small rivers on the downstream water quality is negligible.River water sampling and discharge modeling using SWAT were used to analyze the contribution of small rivers to water quality in a receiving lake.From this analysis,it was determined that the inflowing total nitrogen(TN)and total phosphorus(TP)concentrations from all target rivers exceeded the lake water environmental standards set by the Ministry of the Environment.The contribution of suspended sediment(SS)and TN loads from small rivers did not vary markedly compared with their relative discharge contributions to the lake,at approximately 20%.However,the impact on TP loads to the lake from small rivers was 9.1%higher than their relative flow contributions,accounting for 28.2% of the TP loading.Thus,there is a potential to underestimate the impact of ungauged small rivers if only the major river is selected to evaluate the downstream lake water quality.
