Fuzzy classification combined with spatial prediction was used to assess the state of soil pollution in the peri-urban Beijing area. Total concentrations of As, Cr, Cd, Hg, and Pb were determined in 220 topsoil sample...Fuzzy classification combined with spatial prediction was used to assess the state of soil pollution in the peri-urban Beijing area. Total concentrations of As, Cr, Cd, Hg, and Pb were determined in 220 topsoil samples (0-20 cm) collected using a grid design in a study area of 2600 km2. Heavy metal concentrations were grouped into three classes according to the optimum number of classes and fuzziness exponent using the fuzzy c-mean (FCM) algorithm. Membership values were interpolated using ordinary kriging. The polluted soils of the study area induced by the measured heavy metals were concentrated in the northwest corner and eastern part, especially the southeastern part close to the urban zone, whereas the soils free of pollution were mainly distributed in the southwestern part. The soils with potential risk of heavy metal pollution were located in isolated spots mainly in the northern part and southeastern corner of the study region. The FCM algorithm combined with geostatistical techniques, as compared to conventional single geostatistical kriging methods, could produce a prediction with a quantitative uncertainty evaluation and higher reliability. Successful prediction of soil pollution achieved with FCM algorithm in this study indicated that fuzzy set theory had great potential for use in other areas of soil science.展开更多
[Objectives]To study the characteristics of soil heavy metal contents in facility agriculture of Guangxi and analyze its risks.[Methods]The heavy metal content of 30 surface soil samples taken from facility agricultur...[Objectives]To study the characteristics of soil heavy metal contents in facility agriculture of Guangxi and analyze its risks.[Methods]The heavy metal content of 30 surface soil samples taken from facility agriculture in Guangxi was analyzed.The status of soil heavy metal pollution in facility agriculture of Guangxi was evaluated by the single factor index method,geo-accumulation index method and Hakanson potential ecological risk index method with reference to the soil background value in Guangxi.[Results]Compared with the soil background value in Guangxi,the over-limit rates of heavy metals cadmium,lead,arsenic,chromium,mercury,copper and zinc in soil samples were 56.67%,56.67%,16.67%,30.00%,50.00%,60.00%and 80.00%,respectively.Compared with the screening values of the Soil Environmental Quality-Risk Control Standard for Soil Contamination of Agricultural Land(for trial implementation)(GB15618-2018),the overlimit rates of the heavy metals cadmium,arsenic,copper and zinc in the surface soil of agricultural facilities in Guangxi were 56.67%,10.00%,16.67%and 23.33%,respectively.Except for the average content of soil cadmium exceeding the screening value,the evaluation content of the other six soil heavy metals did not exceed the screening value.According to the evaluation results of the single factor pollution index method,the surface soil arsenic and chromium of the agricultural facilities in Guangxi belonged to the clean level,lead,mercury,and copper belonged to mild pollution,and cadmium and zinc belonged to moderate pollution.According to the evaluation results of the geo-accumulation index,the lead,arsenic,chromium and mercury in the surface soil of the agricultural facilities in Guangxi belonged to the pollution-free level,while the cadmium,copper and zinc belonged to the mild-moderate pollution.According to the evaluation results of the potential ecological risk index method,the potential ecological risks of the heavy metals of lead,arsenic,chromium,copper and zinc in the soil of agricultural facilities in Guangxi belonged to low potential ecological risk level,and the potential ecological risks of cadmium and mercury belonged to moderate risk level.The potential ecological risk index(RI)of the seven heavy metals in the soil was 132.46,which belonged to moderate potential ecological risk.The largest contribution of soil heavy metals to the potential ecological risk index was cadmium and mercury.[Conclusions]Taking the soil of facility agriculture in Guangxi as the object,this paper studied the characteristics of heavy metal content in facility agricultural soil and its risk assessment,in order to provide a scientific basis for facility soil heavy metal risk prevention and control and provide safe technology for facility agriculture.展开更多
Heavy metal (loid)(HM) accumulation in the soil and the HM spatiotemporal distribution have important implication for soil pollution prevention and remediation. The present study investigated the concentrations and sp...Heavy metal (loid)(HM) accumulation in the soil and the HM spatiotemporal distribution have important implication for soil pollution prevention and remediation. The present study investigated the concentrations and spatiotemporal distributions of lead (Pb), mercury (Hg), cadmium (Cd), chromium (Cr) and arsenic (As) in the topsoil of a coal chemical plant in Ningxia Aulonomous region (Ningxia), China. Topsoil samples (/?= 153) were obtained using the checkerboard method, and the HM concentrations were determined. The soil residual rates of the five HMs were measured with leaching experinients and were applied in a soil environmental capacity model to predict the quarHitiHive variation of the HM concentrations. The predicted results were employed to estimate the HM spatiotemporal distribution within 2() years with the Kriging technique. The number of sampling sites, where all five HM concentratio ns exceed their corresponding background values in Ningxia, would be increased from 0 to 90% within 1() years of the plant operation. In addition, Pb and Cd were distributed along the traffic routes. Mercury and As were distributed near fuel gas emission vents. Chromium was mainly accumulated in slag dumps. The study may provide the theoretical and practical foun d at ion for future HM pollution control in coal chemical plants.展开更多
This paper deals with the soil-environmental standard. According to the current situation of researching on the soil-environmental quality guideline at home and abroad, and on the basis of the foundations and principl...This paper deals with the soil-environmental standard. According to the current situation of researching on the soil-environmental quality guideline at home and abroad, and on the basis of the foundations and principles of enacting the soil-environmental standard, the soil environment quality guideline values of Hg, Cd, Pb and As were suggested.展开更多
Regional guidelines for soil heavy metals,in conjunction with specific crops,are proposed to better assess soil environmental quality.In this study,large amounts of soils with different levels of Pb/Cd/As pollution we...Regional guidelines for soil heavy metals,in conjunction with specific crops,are proposed to better assess soil environmental quality.In this study,large amounts of soils with different levels of Pb/Cd/As pollution were collected in Guangdong Province,China,to carry out a pot experiment,which was closer to the actual situation and properties of the heavy metal contaminated soils.Taking the widely planted vegetable pakchoi as the research object,we analyzed the correlations between the Pb/Cd/As concentrations in pakchoi and the total or available soil Pb/Cd/As concentrations and established their optimal regression equations.And then,the total and available soil Pb/Cd/As thresholds for pakchoi were calculated according to the allowable Pb/Cd/As limits in pakchoi and were compared with the current soil assessment standards.Furthermore,a lot of paired vegetable-soil samples in field were collected and their pollution situations were assessed by both the current limit thresholds and the calculated thresholds.Obviously,it was more consistent to assess the Cd and As pollution situation of the vegetable and soil samples with the calculated soil thresholds than the current soil assessment thresholds.It further proved that it was necessary to explore the soil heavy metal thresholds for safety of vegetable in specific regions,which would be more scientific and practical to guide safety production of local agricultural products and effective utilization of soil resources.展开更多
The present investigation deals with the assessment of pollution status along the wetland of Thane Creek, which has been subjected to a lot of pollution from the Asia’s biggest Thane—Belapur Industrial Complex locat...The present investigation deals with the assessment of pollution status along the wetland of Thane Creek, which has been subjected to a lot of pollution from the Asia’s biggest Thane—Belapur Industrial Complex located at the south of Mumbai harbor along the west coast of India. This paper advocates habitat conservation and ecological studies with special reference to the physico-chemical characteristics and heavy metal pollution in the soil along the creek area. In the present investigation, the pH, electrical conductivity, bulk density, alkalinity and chlorinity values recorded were observed to be high during dry seasons and low during rainy season. The soil samples were also analyzed for their heavy metal contents like nickel, zinc, cadmium, copper, iron, arsenic and mercury. It was observed that, the concentration of these heavy metals increases gradually in dry seasons, followed by sharp decrease during rainy season. These heavy metals have a marked effect on the aquatic flora and fauna which through bio magnification enter the food chain and ultimately affect the human beings as well. The present experimental data on heavy metal pollution in soil samples collected along Kalwa bridge of Thane Creek points out to the need of regular monitoring of water resources and further improvement in the industrial waste water treatment methods. If the present conditions continue for a long period, the creek may soon become ecologically inactive.展开更多
基金Project supported by the National Natural Science Foundation of China (Nos. 40571065 and 40235054)the National Key Basic Research Support Foundation of China (No. G1999045707).
文摘Fuzzy classification combined with spatial prediction was used to assess the state of soil pollution in the peri-urban Beijing area. Total concentrations of As, Cr, Cd, Hg, and Pb were determined in 220 topsoil samples (0-20 cm) collected using a grid design in a study area of 2600 km2. Heavy metal concentrations were grouped into three classes according to the optimum number of classes and fuzziness exponent using the fuzzy c-mean (FCM) algorithm. Membership values were interpolated using ordinary kriging. The polluted soils of the study area induced by the measured heavy metals were concentrated in the northwest corner and eastern part, especially the southeastern part close to the urban zone, whereas the soils free of pollution were mainly distributed in the southwestern part. The soils with potential risk of heavy metal pollution were located in isolated spots mainly in the northern part and southeastern corner of the study region. The FCM algorithm combined with geostatistical techniques, as compared to conventional single geostatistical kriging methods, could produce a prediction with a quantitative uncertainty evaluation and higher reliability. Successful prediction of soil pollution achieved with FCM algorithm in this study indicated that fuzzy set theory had great potential for use in other areas of soil science.
基金Supported by Key Research and Development Program of Guangxi(Gui Ke AB18221096)Fund of Guangxi Academy of Agricultural Sciences(2019ZX121Gui Nong Ke 2020ZX03)
文摘[Objectives]To study the characteristics of soil heavy metal contents in facility agriculture of Guangxi and analyze its risks.[Methods]The heavy metal content of 30 surface soil samples taken from facility agriculture in Guangxi was analyzed.The status of soil heavy metal pollution in facility agriculture of Guangxi was evaluated by the single factor index method,geo-accumulation index method and Hakanson potential ecological risk index method with reference to the soil background value in Guangxi.[Results]Compared with the soil background value in Guangxi,the over-limit rates of heavy metals cadmium,lead,arsenic,chromium,mercury,copper and zinc in soil samples were 56.67%,56.67%,16.67%,30.00%,50.00%,60.00%and 80.00%,respectively.Compared with the screening values of the Soil Environmental Quality-Risk Control Standard for Soil Contamination of Agricultural Land(for trial implementation)(GB15618-2018),the overlimit rates of the heavy metals cadmium,arsenic,copper and zinc in the surface soil of agricultural facilities in Guangxi were 56.67%,10.00%,16.67%and 23.33%,respectively.Except for the average content of soil cadmium exceeding the screening value,the evaluation content of the other six soil heavy metals did not exceed the screening value.According to the evaluation results of the single factor pollution index method,the surface soil arsenic and chromium of the agricultural facilities in Guangxi belonged to the clean level,lead,mercury,and copper belonged to mild pollution,and cadmium and zinc belonged to moderate pollution.According to the evaluation results of the geo-accumulation index,the lead,arsenic,chromium and mercury in the surface soil of the agricultural facilities in Guangxi belonged to the pollution-free level,while the cadmium,copper and zinc belonged to the mild-moderate pollution.According to the evaluation results of the potential ecological risk index method,the potential ecological risks of the heavy metals of lead,arsenic,chromium,copper and zinc in the soil of agricultural facilities in Guangxi belonged to low potential ecological risk level,and the potential ecological risks of cadmium and mercury belonged to moderate risk level.The potential ecological risk index(RI)of the seven heavy metals in the soil was 132.46,which belonged to moderate potential ecological risk.The largest contribution of soil heavy metals to the potential ecological risk index was cadmium and mercury.[Conclusions]Taking the soil of facility agriculture in Guangxi as the object,this paper studied the characteristics of heavy metal content in facility agricultural soil and its risk assessment,in order to provide a scientific basis for facility soil heavy metal risk prevention and control and provide safe technology for facility agriculture.
文摘Heavy metal (loid)(HM) accumulation in the soil and the HM spatiotemporal distribution have important implication for soil pollution prevention and remediation. The present study investigated the concentrations and spatiotemporal distributions of lead (Pb), mercury (Hg), cadmium (Cd), chromium (Cr) and arsenic (As) in the topsoil of a coal chemical plant in Ningxia Aulonomous region (Ningxia), China. Topsoil samples (/?= 153) were obtained using the checkerboard method, and the HM concentrations were determined. The soil residual rates of the five HMs were measured with leaching experinients and were applied in a soil environmental capacity model to predict the quarHitiHive variation of the HM concentrations. The predicted results were employed to estimate the HM spatiotemporal distribution within 2() years with the Kriging technique. The number of sampling sites, where all five HM concentratio ns exceed their corresponding background values in Ningxia, would be increased from 0 to 90% within 1() years of the plant operation. In addition, Pb and Cd were distributed along the traffic routes. Mercury and As were distributed near fuel gas emission vents. Chromium was mainly accumulated in slag dumps. The study may provide the theoretical and practical foun d at ion for future HM pollution control in coal chemical plants.
文摘This paper deals with the soil-environmental standard. According to the current situation of researching on the soil-environmental quality guideline at home and abroad, and on the basis of the foundations and principles of enacting the soil-environmental standard, the soil environment quality guideline values of Hg, Cd, Pb and As were suggested.
基金supported by the Natural Science Foundation of Guangdong,China (2015A030313571)the Guangdong Provincial Science and Technology Projects,China (2014A020208069 and 2013B020204001)the the Guangdong Provincial Agricultural Standardization Research Project for 2016,China (YCN[2016]310)
文摘Regional guidelines for soil heavy metals,in conjunction with specific crops,are proposed to better assess soil environmental quality.In this study,large amounts of soils with different levels of Pb/Cd/As pollution were collected in Guangdong Province,China,to carry out a pot experiment,which was closer to the actual situation and properties of the heavy metal contaminated soils.Taking the widely planted vegetable pakchoi as the research object,we analyzed the correlations between the Pb/Cd/As concentrations in pakchoi and the total or available soil Pb/Cd/As concentrations and established their optimal regression equations.And then,the total and available soil Pb/Cd/As thresholds for pakchoi were calculated according to the allowable Pb/Cd/As limits in pakchoi and were compared with the current soil assessment standards.Furthermore,a lot of paired vegetable-soil samples in field were collected and their pollution situations were assessed by both the current limit thresholds and the calculated thresholds.Obviously,it was more consistent to assess the Cd and As pollution situation of the vegetable and soil samples with the calculated soil thresholds than the current soil assessment thresholds.It further proved that it was necessary to explore the soil heavy metal thresholds for safety of vegetable in specific regions,which would be more scientific and practical to guide safety production of local agricultural products and effective utilization of soil resources.
文摘The present investigation deals with the assessment of pollution status along the wetland of Thane Creek, which has been subjected to a lot of pollution from the Asia’s biggest Thane—Belapur Industrial Complex located at the south of Mumbai harbor along the west coast of India. This paper advocates habitat conservation and ecological studies with special reference to the physico-chemical characteristics and heavy metal pollution in the soil along the creek area. In the present investigation, the pH, electrical conductivity, bulk density, alkalinity and chlorinity values recorded were observed to be high during dry seasons and low during rainy season. The soil samples were also analyzed for their heavy metal contents like nickel, zinc, cadmium, copper, iron, arsenic and mercury. It was observed that, the concentration of these heavy metals increases gradually in dry seasons, followed by sharp decrease during rainy season. These heavy metals have a marked effect on the aquatic flora and fauna which through bio magnification enter the food chain and ultimately affect the human beings as well. The present experimental data on heavy metal pollution in soil samples collected along Kalwa bridge of Thane Creek points out to the need of regular monitoring of water resources and further improvement in the industrial waste water treatment methods. If the present conditions continue for a long period, the creek may soon become ecologically inactive.