Pollution assessment and source analysis of rural water environment in North China
In recent years,polices had been issued by Chinese government requiring the improvement of rural living environment and the construction of beautiful rural areas.However,little research on rural water environment was conducted,which hindered the development of rural environmental governance.In this paper,rural river channels and ponds in a town in North China were selected to assess rural water environmental pollution and its ecological risks,and to trace their pollution sources.The results showed that one of 57 survey sites was evaluated as black and odorous water.DO,TS and NH4-N for other survey sites were 2～3 mg·L-1,25～35 cm,and 8～15 mg·L-1,which were close to the standard limits for black odorous water.Only 9％of survey sites meet the surface water Class V standard(18 monitoring indicators).pH,CODMn,CODCr,BOD,NH4-N,TP,TN and fecal coliform bacteria were indicators that exceeded the standard.TP standard index was in moderate level and TN standard index was in severe level.There was varying degrees of heavy metal enrichment in the sediment,with the average concentrations of eight heavy metals such as copper,zinc,mercury,cadmium,chromium,lead,arsenic,and nickel being 0.45～2.73 times of the background values of Tianjin soil.The average soil accumulation index of mercury was 0.64,indicating mild pollution,while the other seven heavy metals were in a clean state.The potential ecological risk index of mercury was about 110,indicating a high ecological hazard.The ecological risk index of the other seven heavy metals was less than 80,indicating a slight ecological hazard.Based on Pearson correlation,principal component analysis,and PMF analysis,the main sources of heavy metal pollution in the study area were transportation sources and atmospheric sedimentation,followed by industrial sources and finally agricultural sources.Overall,the water quality in the study area was poor,and there was a slight enrichment of heavy metals in the sediment,with mercury being the main contributing element to the ecological risk of the sediment.To improve the quality of rural water environment,it was necessary to strengthen the control and governance of agricultural and rural non-point source pollution.
国家科技期刊平台
NSTL
万方数据
