Detoxification Of Groundwater Arsenic By Fermented Pine Bark And Peanut Shells

The water quality indices of total nitrogen and nitrate nitrogen and ammonia nitrogen of in the Qingyuan watershed of upper Hunhe River were monitored in four periods of spring and summer and autumn and winter.The characteristics of nitrogen pollution in the watershed and its relationship with the surrounding land use/cover were analyzed and evaluated.The spatial distribution of landscape source and sink was identified by Location-Weighted Landscape Contrast Index method.The nitrogen Mass Balance Model was used to identify the nitrogen budget and spatial pattern of the watershed.The main conclusions are as follows:(1)the rate of over-standard limit of total nitrogen and ammonia nitrogen in surface water in the study area is higher,up to 90.13% and 42.76% respectively.The total nitrogen and nitrate nitrogen are in the high level,and the ammonia nitrogen is in the medium and low level.The water quality is the best in the wet season and the worst in the dry season.The water quality is in the medium level in the autumn and the snowmelt period.The level of nitrogen pollution gradually increased from the upstream to the downstream,and the spatial variation characteristics of nitrogen correspond to the gradient of human activity intensity.River nitrogen mainly comes from dry land,urban and rural construction land and livestock and poultry breeding areas.The accumulated excreta of cattle and sheep in the unused land needs to be paid more attention during the ice and snow melting period.Water quality management of paddy drainage is too.(2)location-Weighted Landscape Contrast Index of Hunhe River main flow in the study area is at a higher level(LCI > 2),and the LCI values in the southeast and North are at a lower level(LCI < 0).(3)the main input of nitrogen in the study area is chemical fertilizer,the total input is14733 T,and chemical fertilizer,nitrogen deposition and nitrogen mineralization account for 54.92%,19.62% and 25.46% respectively.The main output of nitrogen is ammonia volatilization and plant absorption,which account for 90% of total nitrogen output.Totalnitrogen output is 6593 t.Ammonia volatilization,denitrification and plant absorption account for 50.77%,9.56% and 39.67% respectively.The total nitrogen surplus of the watershed is 8141 t,accounting for about 60% of the nitrogen input.The surplus of nitrogen in spring and summer is higher than that in autumn and winter.The nitrogen surplus in the two sides of Hunhe River in the middle of the watershed and the area with concentrated cultivated land is at a high level.(4)to control the number of fertilization,improve the way of fertilization,manage the scattered sewage discharge in rural residential areas and livestock breeding areas,study the ecological compensation method,plan and practice the best management measures of non-point source pollution(BMP)is an effective way to achieve the management of surface water environmental nitrogen pollution in the water source protection area or similar other areas.