Geochemical Features And Sources Identification Of Pb In Paddy Soil And Rice In Zhuzhou Suburbs,Hunan

The pace of modern urbanization is accelerating,and agricultural soils around the city are polluted by heavy metals and cause concern,among which Pb pollution is particularly serious.Pb pollution in the atmosphere easily enters the edible parts of crops,while the solubility of Pb in the soil increases under acidic conditions and is more likely to migrate.Rice is widely cultivated in my country and is the largest food crop,especially in the South,where it has been seriously polluted as the main crop.In order to ensure the safety of agricultural soil quality and the safety of rice,the research on heavy metal pollution of farmland soil around the city has become very important.In this paper,after comprehensive thinking,we selected the paddy soil and rice in the suburbs of Zhuzhou City,Hunan Province for Pb pollution research.From the form of element occurrence,migration and transformation,and isotope characteristics,we carried out geochemistry of soil,rice,water,water sediments and suspended solids.Investigation and analysis to obtain information on heavy metal pollution in the area.Investigate and study the distribution of regional Pb pollution from an overall perspective,conduct Pb pollution evaluation in accordance with current national pollution and food safety standards,and comprehensively analyze the sources of pollution in the study area by analyzing the multi-media Pb pollution situation and spatial analysis.Here are the main results:1?Through the geochemical survey of soil and rice in the agricultural area near Zhuzhou,the distribution of heavy metal elements in the surface soil and rice in the area was found.The Pb content in the soil and rice varied widely.surrounding area.The high value areas of rice Pb are mainly concentrated in the southern area of the study area,there is a big difference between the two.2?The results of element correlation studies show that there is a significant positive correlation between Pb-Cd in paddy soil.There is no definite correlation between rice elements;the correlation between rice and paddy soil elements is not clear.3? The Pb in the deep soil mainly appears in the state of residue and the combination of iron and manganese oxide,and the proportion of active Pb in the surface soil increases significantly.4? Lead pollution risk assessment was conducted on the soil and rice in the study area.The single factor pollution index method was used to evaluate the quality of soil and rice lead pollution,and it was found that the soil lead pollution in the work area was relatively light,and the high content of Pb in crops was mainly related to atmospheric lead pollution.5?The water chemistry survey found that the water quality of the Xiangjiang River flowing into Zhuzhou is good,and the Pb element content is lower than the national surface water environmental quality standards of Class I.However,the Pb element of the water discharged from the sewage canal of the Zhuzhou smelter in the Qingshuitang industrial zone is seriously exceeding the standard,and it is one of the important sources of Pb pollution in the Xiangjiang River.The Pb content in the Hengyang-Zhuzhou sediments in the lower reaches of the Xiangjiang River is low,and the pollution degree is light.6?Based on the analysis of the topography and the Pb content of the Xiangjiang medium,it is believed that the Xiangjiang River is not the source of soil pollution around Zhuzhou.Lead pollution source comes from the northwest direction.It is speculated that it mainly comes from the pollution of Zhuzhou smelter,urban human activities,agriculture,etc.It is a smelter,and the south may be mainly related to human activities.From the Pb isotope tracing results,the pollution may be diverse,in addition to mainly from Zhuzhou smelter and Qunfeng small smelter,there are other sources.