Using the sediment monitoring data of five sections of the Xiling Channel inland waterway of the Pearl River Delta,and using Nemerow composite index,the coefficient of variation,and the index of geoaccumulation( Igeo)...Using the sediment monitoring data of five sections of the Xiling Channel inland waterway of the Pearl River Delta,and using Nemerow composite index,the coefficient of variation,and the index of geoaccumulation( Igeo) and the potential ecological risk index,this paper analyzed and assessed the heavy metal pollution of sediments. The results indicate that Cr reached mild pollution;Cu had a large degree of variation,and the changes of Cr and Zn were significant with fluctuation;the enrichment of heavy metals decreased as follows: Cd > Cu > Cr > Zn> Pb > Ni > Hg > As;Cd had the highest degree of enrichment and belonged to moderate pollution;the ecological hazard of heavy metals was Cd > Hg > Cu > Pb > As > Cr > Ni > Zn,and Cd had the highest ecological hazard and was the main controlling factor of potential ecological risk. In conclusion,the sediments in Xiling Channel inland waterway were polluted by heavy metals to some extent,and cadmium was the main pollutant and had the largest potential ecological risk.展开更多
Due to significant differences in biotic and abiotic properties of soils compared to those of sediments,the predicted underlying microbe-mediated mechanisms of soil carbon emissions in response to warming may not be a...Due to significant differences in biotic and abiotic properties of soils compared to those of sediments,the predicted underlying microbe-mediated mechanisms of soil carbon emissions in response to warming may not be applicable for estimating similar emissions from inlandwater sediments.We addressed this issue by incubating different types of sediments,(including lake,small river,and pond sediments)collected from 36 sites across the Yangtze River basin,under short-term experimentalwarming to explore the effects of climatewarming on sediment carbon emission and the underlying microbe-mediated mechanisms.Our results indicated that under climate warming Cc emissions were affected more than CH_(4) emissions,and that pond sediments may yield a greater relative contribution of CO_(2) to total carbon emissions than lake and river sediments.Warming-induced CO_(2) and CH_(4) increases involve different microbe-mediated mechanisms;Warming-induced sediment CO_(2) emissions were predicted to be directly positively driven by microbial community network modularity,which was significantly negatively affected by the quality and quantity of organic carbon and warming-induced variations in dissolved oxygen,Conversely,warminginduced sediment CH_(4) emissionswere predicted to be directly positively driven bymicrobial community network complexity,which was significantly negatively affected by warminginduced variations in pH.Our findings suggest that biotic and abiotic drivers for sediment CO_(2) and CH_(4) emissions in response to climate warming should be considered separately when predicting sediment organic carbon decomposition dynamics resulting from climate change.展开更多
基金Supported by Science and Technology Planning Project of Zhaoqing City "Research and Development of Key Technologies for Efficient Deep Treatment and Reuse of Decentralized Wastewater in Zhaoqing City"(2018N001)Characteristic Innovation Project of Guangdong Provincial Department of Education(Natural Science)"Research and Development of Key Technologies for Efficient Wastewater Treatment and In-situ Sludge Reduction Based on Bioenhancement and Process Control"(2018KTSCX251)
文摘Using the sediment monitoring data of five sections of the Xiling Channel inland waterway of the Pearl River Delta,and using Nemerow composite index,the coefficient of variation,and the index of geoaccumulation( Igeo) and the potential ecological risk index,this paper analyzed and assessed the heavy metal pollution of sediments. The results indicate that Cr reached mild pollution;Cu had a large degree of variation,and the changes of Cr and Zn were significant with fluctuation;the enrichment of heavy metals decreased as follows: Cd > Cu > Cr > Zn> Pb > Ni > Hg > As;Cd had the highest degree of enrichment and belonged to moderate pollution;the ecological hazard of heavy metals was Cd > Hg > Cu > Pb > As > Cr > Ni > Zn,and Cd had the highest ecological hazard and was the main controlling factor of potential ecological risk. In conclusion,the sediments in Xiling Channel inland waterway were polluted by heavy metals to some extent,and cadmium was the main pollutant and had the largest potential ecological risk.
基金This work was supported by the Major Science and Technology Program for Water Pollution Control and Treatment of China(No.2017ZX07206)the National Natural Science Foundation of China(No.41977322)the National Natural Science Foundation of China(No.41907335).
文摘Due to significant differences in biotic and abiotic properties of soils compared to those of sediments,the predicted underlying microbe-mediated mechanisms of soil carbon emissions in response to warming may not be applicable for estimating similar emissions from inlandwater sediments.We addressed this issue by incubating different types of sediments,(including lake,small river,and pond sediments)collected from 36 sites across the Yangtze River basin,under short-term experimentalwarming to explore the effects of climatewarming on sediment carbon emission and the underlying microbe-mediated mechanisms.Our results indicated that under climate warming Cc emissions were affected more than CH_(4) emissions,and that pond sediments may yield a greater relative contribution of CO_(2) to total carbon emissions than lake and river sediments.Warming-induced CO_(2) and CH_(4) increases involve different microbe-mediated mechanisms;Warming-induced sediment CO_(2) emissions were predicted to be directly positively driven by microbial community network modularity,which was significantly negatively affected by the quality and quantity of organic carbon and warming-induced variations in dissolved oxygen,Conversely,warminginduced sediment CH_(4) emissionswere predicted to be directly positively driven bymicrobial community network complexity,which was significantly negatively affected by warminginduced variations in pH.Our findings suggest that biotic and abiotic drivers for sediment CO_(2) and CH_(4) emissions in response to climate warming should be considered separately when predicting sediment organic carbon decomposition dynamics resulting from climate change.
