Based on the theory of complex adaptive system(CAS),the optimal allocation model of water resources in sewage irrigation areas was established,which provided new ideas and application value for the rational utilizatio...Based on the theory of complex adaptive system(CAS),the optimal allocation model of water resources in sewage irrigation areas was established,which provided new ideas and application value for the rational utilization of agricultural production and waste water resources.The results demonstrated that the difference of crop energy capture mainly depended on the development stage.Waste water with a certain concentration was able to promote crop growth,while excessive concentration inhibited crop growth.The correlation between water absorption rate and leaf area index was close(R=0.9498,p<0.01).The amount of bad seeds increased at a speed of 34.7·d^-1,when system irrigated randomly in the seedling stage,while it tended to remain stable at a speed of 0.3·d^-1 after plants entering the mature stage which impacted the total yields of crops.展开更多
This research aims to investigate the pollution characteristic of PAHs in Xiaodian sewage irrigation area. The result shows that the concentrations ofPAHs range from 47.94 to 46432.85ng/g while that of the total compo...This research aims to investigate the pollution characteristic of PAHs in Xiaodian sewage irrigation area. The result shows that the concentrations ofPAHs range from 47.94 to 46432.85ng/g while that of the total components of the 16 kinds of PAHs are 5969.81ng/g. PAHs with for rings and more than 4 rings are the main and important pollutants in topsoils of Xiaodian District. The main input of PAHs is combustion source, and the main pollution source in this area is fired coal. The topsoils in Xiaodian District are polluted by human activity in varying degrees. 23 of all 31 topsoil samples have been heavily polluted, especially those located nearby developed industrial townships and irrigation channels.展开更多
Heavy metal contamination in soils has been of wide concern in China in the last several decades. The heavy metal contamination was caused by sewage irrigation, mining and inappropriate utilization of various agrochem...Heavy metal contamination in soils has been of wide concern in China in the last several decades. The heavy metal contamination was caused by sewage irrigation, mining and inappropriate utilization of various agrochemicals and pesticides and so on. The Shenyang Zhangshi irrigation area （SZIA） in China is a representative area of heavy metal contamination of soils resulting from sewage irrigation for about 30 years duration. This study investigated the spatial distribution and temporal variation of soil cadmium contamination in the SZIA. The soil samples were collected from the SZIA in 1990 and 2004; Cd of soils was analyzed and then the spatial distribution and temporal variation of Cd in soils was modelled using kriging methods. The kriging map showed that long-term sewage irrigation had caused serious Cd contamination in topsoil and subsoil. In 2004, the Cd mean concentrations were 1.698 and 0.741 mg/kg, and the maxima 10.150 and 7.567 mg/kg in topsoils （0-20 cm） and subsoils （20-40 cm） respectively. These values are markedly more than the Cd levels in the second grade soil standard in China. In 1990, the Cd means were 1.023 and 0.331 mg/kg, and the maxima 9.400 and 3.156 mg/kg, in topsoils and subsoils respectively. The soil area in 1990 with Cd more than 1.5 mg/kg was 2701 and 206.4 hnl2 in topsoils and subsoils respectively; and in 2004, it was 7592 and 1583 hm^2, respectively. Compared with that in 1990, the mean and maximum concentration of Cd, as well as the soil area with Cd more than 1.5 mg/kg had all increased in 2004, both in topsoils and subsoils.展开更多
The aim of the present work is to investigate the distribution of arsenic（As） in sewage ir-rigation area,to deduce the migration and transformation mechanism of As in soil and groundwater,and to infer the source of ...The aim of the present work is to investigate the distribution of arsenic（As） in sewage ir-rigation area,to deduce the migration and transformation mechanism of As in soil and groundwater,and to infer the source of As in soil and groundwater.This study is carried out in a sewage irrigation area of the Pearl River Delta,China.Surface water samples,soil samples,and groundwater samples from sewage irrigation area were analyzed for As and other elements.As contents in water samples were analyzed by hydride generation-atomic fluorescence spectroscopy,and As fractionation in soil samples was extracted using a seven-step sequential extraction method according to a seven fraction scheme：water soluble,ion exchangeable,bound to carbonate,weakly bound to organic matter,associ-ated with oxides of iron（Fe） and manganese（Mn）,strongly bound to organic matter,and the residual fraction.Waste water has content of As up to 16.8 μg/L in the study area.Soil has enriched As due to the irrigation of soil with waste water,and the total content of As in soil is about 0.7 times higher than the background value.Sequential extraction method reveals that the mean content of residual fraction in soil is more than 70%,releasable fraction（weakly organic fraction,Fe-Mn oxide fraction,and car-bonate fraction） is about 20%-30%,whereas strongly organic and mobile fractions（water soluble and ion exchangeable） are within 0.2%.In the soil profile,the contents of water soluble,ion exchangeable,and carbonate fraction decrease with the depth,whereas the contents of other fractions are irregular with the depth.Using correlation analysis,it is concluded that water soluble fraction is easy to change into ion exchangeable and carbonate fraction,ion exchangeable fraction is easy to change into carbon-ate and Fe-Mn oxide fraction,and carbonate fraction is easy to change into weakly organic and Fe-Mn oxide fraction in the soil of study area.Organic matter and（hydr）oxides of Fe and aluminium（Al） in soil play an important role in controlling the distribution and mobility of As in soil.As concentrations in groundwater range from 2.8 to 21.0 μg/L,and it is inferred that As from waste water and the release of high As sediment（soil and aquifer medium） are the main sources for high As groundwater in study area.Using cluster analysis,it is concluded that reducing ground-water with slightly alkaline is beneficial to en-richment of As in groundwater,and hydroxides of Fe,Mn,and Al also play a key role for the en-richment of As in groundwater of the study area.展开更多
基金Supported by the Science and Technology Research Project of the Ministry of Education(14YJCZH017)the Major State Basic Research Development Program of China(973 Program)(2017YFC0404503)+1 种基金Key Cultivation Project of Lingnan Normal University in 2019(LZ1903)Lingnan Normal University Special Talent Program(ZL2007)
文摘Based on the theory of complex adaptive system(CAS),the optimal allocation model of water resources in sewage irrigation areas was established,which provided new ideas and application value for the rational utilization of agricultural production and waste water resources.The results demonstrated that the difference of crop energy capture mainly depended on the development stage.Waste water with a certain concentration was able to promote crop growth,while excessive concentration inhibited crop growth.The correlation between water absorption rate and leaf area index was close(R=0.9498,p<0.01).The amount of bad seeds increased at a speed of 34.7·d^-1,when system irrigated randomly in the seedling stage,while it tended to remain stable at a speed of 0.3·d^-1 after plants entering the mature stage which impacted the total yields of crops.
文摘This research aims to investigate the pollution characteristic of PAHs in Xiaodian sewage irrigation area. The result shows that the concentrations ofPAHs range from 47.94 to 46432.85ng/g while that of the total components of the 16 kinds of PAHs are 5969.81ng/g. PAHs with for rings and more than 4 rings are the main and important pollutants in topsoils of Xiaodian District. The main input of PAHs is combustion source, and the main pollution source in this area is fired coal. The topsoils in Xiaodian District are polluted by human activity in varying degrees. 23 of all 31 topsoil samples have been heavily polluted, especially those located nearby developed industrial townships and irrigation channels.
基金The National Natural Science Foundation of China (No. 20477029)the National Basic Research Program (973) of China (No.2004CB418506)the Basic Research Program of Educational Department of Liaoning Government (No. 05L262)
文摘Heavy metal contamination in soils has been of wide concern in China in the last several decades. The heavy metal contamination was caused by sewage irrigation, mining and inappropriate utilization of various agrochemicals and pesticides and so on. The Shenyang Zhangshi irrigation area （SZIA） in China is a representative area of heavy metal contamination of soils resulting from sewage irrigation for about 30 years duration. This study investigated the spatial distribution and temporal variation of soil cadmium contamination in the SZIA. The soil samples were collected from the SZIA in 1990 and 2004; Cd of soils was analyzed and then the spatial distribution and temporal variation of Cd in soils was modelled using kriging methods. The kriging map showed that long-term sewage irrigation had caused serious Cd contamination in topsoil and subsoil. In 2004, the Cd mean concentrations were 1.698 and 0.741 mg/kg, and the maxima 10.150 and 7.567 mg/kg in topsoils （0-20 cm） and subsoils （20-40 cm） respectively. These values are markedly more than the Cd levels in the second grade soil standard in China. In 1990, the Cd means were 1.023 and 0.331 mg/kg, and the maxima 9.400 and 3.156 mg/kg, in topsoils and subsoils respectively. The soil area in 1990 with Cd more than 1.5 mg/kg was 2701 and 206.4 hnl2 in topsoils and subsoils respectively; and in 2004, it was 7592 and 1583 hm^2, respectively. Compared with that in 1990, the mean and maximum concentration of Cd, as well as the soil area with Cd more than 1.5 mg/kg had all increased in 2004, both in topsoils and subsoils.
基金supported by the National Basic Research Program (973) of China (No. 2010CB428804-1)the Basic Scientific Study Fund from the Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sci-ences (Nos. SK200801, SK200911)
文摘The aim of the present work is to investigate the distribution of arsenic（As） in sewage ir-rigation area,to deduce the migration and transformation mechanism of As in soil and groundwater,and to infer the source of As in soil and groundwater.This study is carried out in a sewage irrigation area of the Pearl River Delta,China.Surface water samples,soil samples,and groundwater samples from sewage irrigation area were analyzed for As and other elements.As contents in water samples were analyzed by hydride generation-atomic fluorescence spectroscopy,and As fractionation in soil samples was extracted using a seven-step sequential extraction method according to a seven fraction scheme：water soluble,ion exchangeable,bound to carbonate,weakly bound to organic matter,associ-ated with oxides of iron（Fe） and manganese（Mn）,strongly bound to organic matter,and the residual fraction.Waste water has content of As up to 16.8 μg/L in the study area.Soil has enriched As due to the irrigation of soil with waste water,and the total content of As in soil is about 0.7 times higher than the background value.Sequential extraction method reveals that the mean content of residual fraction in soil is more than 70%,releasable fraction（weakly organic fraction,Fe-Mn oxide fraction,and car-bonate fraction） is about 20%-30%,whereas strongly organic and mobile fractions（water soluble and ion exchangeable） are within 0.2%.In the soil profile,the contents of water soluble,ion exchangeable,and carbonate fraction decrease with the depth,whereas the contents of other fractions are irregular with the depth.Using correlation analysis,it is concluded that water soluble fraction is easy to change into ion exchangeable and carbonate fraction,ion exchangeable fraction is easy to change into carbon-ate and Fe-Mn oxide fraction,and carbonate fraction is easy to change into weakly organic and Fe-Mn oxide fraction in the soil of study area.Organic matter and（hydr）oxides of Fe and aluminium（Al） in soil play an important role in controlling the distribution and mobility of As in soil.As concentrations in groundwater range from 2.8 to 21.0 μg/L,and it is inferred that As from waste water and the release of high As sediment（soil and aquifer medium） are the main sources for high As groundwater in study area.Using cluster analysis,it is concluded that reducing ground-water with slightly alkaline is beneficial to en-richment of As in groundwater,and hydroxides of Fe,Mn,and Al also play a key role for the en-richment of As in groundwater of the study area.
