The estuary wetland is the last barrier for inland pollutants flowing into the sea. The possibility to use the natural wetland, mainly reed marsh and Suaeda heteroptera community as land treatment system to polluted ...The estuary wetland is the last barrier for inland pollutants flowing into the sea. The possibility to use the natural wetland, mainly reed marsh and Suaeda heteroptera community as land treatment system to polluted river water was studied. Experimental results indicated that the reed march has a high retention rate to pollutants like COD, N, P and oil. The canal system has high a purification rate to these elements as well. There is also a big potential to use the Suaeda community as a treatment system to exchange water from prawn and crab breeding ponds along the coast. As the pollution problem of coastal seawater has become more and more serious in Eastern China, and Liaohe is among the most seriously polluted 7 rivers in China, this study will greatly contribute to the strategy makers to take suitable reactions.展开更多
The water purification function of natural wetland systems is widely recognized,but rarely studied or scientifically evaluated.Extensive studies have been carried out by various international wetland research communit...The water purification function of natural wetland systems is widely recognized,but rarely studied or scientifically evaluated.Extensive studies have been carried out by various international wetland research communities to quantify the water quality improvement ability of the natural wetlands,in order to maintain such ability and wetland ecological health.This study aims to evaluate the purification function of Zhalong Wetland in China for removing total nitrogen(TN) and phosphorus(TP),based on ex-situ experiments and the development of a combined water quantity-quality model.Experiments and model predictions were carried out with different input TP and TN concentrations.Statistical analyses demonstrated that the relative errors between model simulations and experimental observations for TN and TP were 8.6% and 12.4%,respectively.With water retention time being maintained at 90 d,the removal rate of these pollutants could not reach the required Grade V standards,if the inflow TN concentration was over 42 mg L-1,or the input TP concentration was over 14 mg L-1.The simulation results also demonstrated that,even with Grade V quality standard compliance,when the water inflow from surrounding industries and agriculture lands into Zhalong Wetland reaches 0.3×10 8 m 3 a-1,the maximum TN and TP loads that the reserve can cope with are 1.26×10 3 t a-1 and 0.42×10 3 t a-1,respectively.Overall,this study has produced a significant amount of information that can be used for the protection of water quality and ecological health of Zhalong Wetland.展开更多
Filtration efficiency of Ni(II) from aqueous solution using pristine and modified MWCNTs filters was investigated as a function of Ni(II) ion concentration, p H, and filter mass. MWCNTs were synthesized by CVD method ...Filtration efficiency of Ni(II) from aqueous solution using pristine and modified MWCNTs filters was investigated as a function of Ni(II) ion concentration, p H, and filter mass. MWCNTs were synthesized by CVD method and modified using two complementary treatments, purification(using a mixture of hydrochloric acid and hydrogen peroxide) and functionalization(using nitric acid). The effect and mechanism of each treatment on the structural integrity of pristine MWCNTs has been studied. Morphology of the pristine and modified filters was investigated by Raman Spectrometry(RS), Scanning Electron Microscopy(SEM), Energy Dispersive X-ray Spectroscopy(EDS),Fourier Transform Infrared(FTIR) spectrometry and Thermogravimetric analysis. It was found from Raman spectra that the ratio of the intensity of D-band to that of G-band decreased by purification process, and increased by functionalization process. The adsorption mechanism of Ni(II) onto the surface functional groups of modified MWCNTs was confirmed by FTIR spectrum. The filtration results showed that the removal efficiency of Ni(II) is strongly dependent on pH and could reach 85% at pH = 8. Also, modified MWCNT filters can be reused through many cycles of regeneration with high performance. Functionalized MWCNTs filters may be a promising adsorbent candidate for heavy metal removal from wastewater.展开更多
文摘The estuary wetland is the last barrier for inland pollutants flowing into the sea. The possibility to use the natural wetland, mainly reed marsh and Suaeda heteroptera community as land treatment system to polluted river water was studied. Experimental results indicated that the reed march has a high retention rate to pollutants like COD, N, P and oil. The canal system has high a purification rate to these elements as well. There is also a big potential to use the Suaeda community as a treatment system to exchange water from prawn and crab breeding ponds along the coast. As the pollution problem of coastal seawater has become more and more serious in Eastern China, and Liaohe is among the most seriously polluted 7 rivers in China, this study will greatly contribute to the strategy makers to take suitable reactions.
基金supported by the Knowledge Innovation Programs of Chinese Academy of Sciences (Grant No. KZCX2-YW-Q06-2)the National Basic Research Program of China ("973" Program) (Grant No.2010CB428404)
文摘The water purification function of natural wetland systems is widely recognized,but rarely studied or scientifically evaluated.Extensive studies have been carried out by various international wetland research communities to quantify the water quality improvement ability of the natural wetlands,in order to maintain such ability and wetland ecological health.This study aims to evaluate the purification function of Zhalong Wetland in China for removing total nitrogen(TN) and phosphorus(TP),based on ex-situ experiments and the development of a combined water quantity-quality model.Experiments and model predictions were carried out with different input TP and TN concentrations.Statistical analyses demonstrated that the relative errors between model simulations and experimental observations for TN and TP were 8.6% and 12.4%,respectively.With water retention time being maintained at 90 d,the removal rate of these pollutants could not reach the required Grade V standards,if the inflow TN concentration was over 42 mg L-1,or the input TP concentration was over 14 mg L-1.The simulation results also demonstrated that,even with Grade V quality standard compliance,when the water inflow from surrounding industries and agriculture lands into Zhalong Wetland reaches 0.3×10 8 m 3 a-1,the maximum TN and TP loads that the reserve can cope with are 1.26×10 3 t a-1 and 0.42×10 3 t a-1,respectively.Overall,this study has produced a significant amount of information that can be used for the protection of water quality and ecological health of Zhalong Wetland.
基金Supported by the Program of MSU Development and Russian Foundation for Basic Research(RFBR)(No.14-02-01230a and No.14-02-31147 mol_a)
文摘Filtration efficiency of Ni(II) from aqueous solution using pristine and modified MWCNTs filters was investigated as a function of Ni(II) ion concentration, p H, and filter mass. MWCNTs were synthesized by CVD method and modified using two complementary treatments, purification(using a mixture of hydrochloric acid and hydrogen peroxide) and functionalization(using nitric acid). The effect and mechanism of each treatment on the structural integrity of pristine MWCNTs has been studied. Morphology of the pristine and modified filters was investigated by Raman Spectrometry(RS), Scanning Electron Microscopy(SEM), Energy Dispersive X-ray Spectroscopy(EDS),Fourier Transform Infrared(FTIR) spectrometry and Thermogravimetric analysis. It was found from Raman spectra that the ratio of the intensity of D-band to that of G-band decreased by purification process, and increased by functionalization process. The adsorption mechanism of Ni(II) onto the surface functional groups of modified MWCNTs was confirmed by FTIR spectrum. The filtration results showed that the removal efficiency of Ni(II) is strongly dependent on pH and could reach 85% at pH = 8. Also, modified MWCNT filters can be reused through many cycles of regeneration with high performance. Functionalized MWCNTs filters may be a promising adsorbent candidate for heavy metal removal from wastewater.
