Construction wastes were selected as the adsorbents and static and dynamic adsorption batch experiments were carried out to investigate the adsorption of Pb to construction wastes with different particle size gradatio...Construction wastes were selected as the adsorbents and static and dynamic adsorption batch experiments were carried out to investigate the adsorption of Pb to construction wastes with different particle size gradations in the simulated stormwater runoff system.The experimental results show that the pseudo-second-order kinetics model can better characterize the adsorption process of Pb than the pseudo-first-order kinetics model.The adsorption equilibrium data can be well fitted by the Freundlich isotherm model. The construction wastes with different tested size gradations can greatly remove Pb from stormwater runoff and their average removal rate can reach up to 99%.The construction wastes with narrow size distribution can better remove Pb but with worse permeability than those with wide size distribution. The particle size gradation of construction wastes greatly influences the equilibrium time rate and the capacity of Pb adsorption.The equilibrium adsorption rate and capacity are 18.1 μg/min and 5.5 μg/g respectively for the construction wastes with the size of 2.36 to 4.75 mm which are the greatest among the different size gradations.The present study provides a scientific basis for effectively controlling Pb pollution from stormwater runoff and the construction wastes resource utilization.展开更多
利用亚洲季风区帕默尔干旱指数(PDSI)重建格点数据集(Monsoon Asia Drought Atlas,MADA)中长江源及附近地区的5个格点序列,通过PDSI与长江源区径流量的相关分析,发现5个格点的第一主成分(PC1)与长江源区夏季(6-8月)平均径流量的相关性最...利用亚洲季风区帕默尔干旱指数(PDSI)重建格点数据集(Monsoon Asia Drought Atlas,MADA)中长江源及附近地区的5个格点序列,通过PDSI与长江源区径流量的相关分析,发现5个格点的第一主成分(PC1)与长江源区夏季(6-8月)平均径流量的相关性最大(r=0.609,N=50,α<0.001)。由此,重建了1300-2005年长江源区夏季径流量变化,并运用独立验证法对重建结果的可靠性进行了检验,运用小波分析方法对重建径流序列进行周期分析。结果表明:近706 a,长江源区经历了显著的丰水期13个、枯水期15个,其中持续时间最长的丰水期为1513-1573年,持续时间最长的枯水期为1389-1414年;重建序列主要存在2~6、10~13、20~26、30~50、50~70 a的显著周期振荡。重建序列与海表温度的相关性表明,长江源区径流变化可能与厄尔尼诺-南方涛动(ENSO)、大西洋年际振荡(AMO)、北大西洋涛动(NAO)、太平洋年代际振荡(PDO)等有关。展开更多
Stormwater runoff has become an important source of surface water pollution. Bioretention, a low impact development measure in urban stormwater management, has been proven to be effective in the removal of pollutants ...Stormwater runoff has become an important source of surface water pollution. Bioretention, a low impact development measure in urban stormwater management, has been proven to be effective in the removal of pollutants from stormwater runoff, with appropriate bioretention media. In this study, construction wastes were selected as bioretention media to remove heavy metals from stormwater runoff. Static and dynamic adsorption batch experiments were carried out to investigate the adsorption of heavy metals in simulated stormwater runoff system with construction wastes in different particle sizes. The experimental results show that the pseudo-secondorder kinetic model characterizes the adsorption process and the adsorption equilibrium data are well described by Freundlich isotherm model. The construction wastes used can remove heavy metals from stormwater runoff effectively, with their average removal rates all more than 90%. The particle size of construction wastes greatly influences the equilibrium time, rate and adsorption capacity for heavy metals.展开更多
基金The National Natural Science Foundation of China(No.51208022)the National Science and Technology Major Project of China(No.2011ZX07301-004-01)
文摘Construction wastes were selected as the adsorbents and static and dynamic adsorption batch experiments were carried out to investigate the adsorption of Pb to construction wastes with different particle size gradations in the simulated stormwater runoff system.The experimental results show that the pseudo-second-order kinetics model can better characterize the adsorption process of Pb than the pseudo-first-order kinetics model.The adsorption equilibrium data can be well fitted by the Freundlich isotherm model. The construction wastes with different tested size gradations can greatly remove Pb from stormwater runoff and their average removal rate can reach up to 99%.The construction wastes with narrow size distribution can better remove Pb but with worse permeability than those with wide size distribution. The particle size gradation of construction wastes greatly influences the equilibrium time rate and the capacity of Pb adsorption.The equilibrium adsorption rate and capacity are 18.1 μg/min and 5.5 μg/g respectively for the construction wastes with the size of 2.36 to 4.75 mm which are the greatest among the different size gradations.The present study provides a scientific basis for effectively controlling Pb pollution from stormwater runoff and the construction wastes resource utilization.
基金Supported by the National Natural Science Foundation of China(51208022)the National Water Pollution Control and Management Technology Major Project(2011ZX07301-004-01)
文摘Stormwater runoff has become an important source of surface water pollution. Bioretention, a low impact development measure in urban stormwater management, has been proven to be effective in the removal of pollutants from stormwater runoff, with appropriate bioretention media. In this study, construction wastes were selected as bioretention media to remove heavy metals from stormwater runoff. Static and dynamic adsorption batch experiments were carried out to investigate the adsorption of heavy metals in simulated stormwater runoff system with construction wastes in different particle sizes. The experimental results show that the pseudo-secondorder kinetic model characterizes the adsorption process and the adsorption equilibrium data are well described by Freundlich isotherm model. The construction wastes used can remove heavy metals from stormwater runoff effectively, with their average removal rates all more than 90%. The particle size of construction wastes greatly influences the equilibrium time, rate and adsorption capacity for heavy metals.
