Content Distribution And Change Characteristics Study Of Pb, Cu And Zn In Farmland Of Shenyang Suburb

Suburban farmland soil had a great effect on its agricultural production and development as well as citizens’ survival and health. Suburban farmland soil of Shenyang is the research object in this study, with the heavy metal Pb, Cu and Zn of the total amount distribution and spatial-temporal variation characteristics as the research content, and compared with the results of the analysis of soil survey in 2006, calculate the rate of heavy metal accumulation in study area, at the same time for different sources of heavy metal pollution near the cultivated land were analyzed.The main research conclusions are as follows:(1)The pH in soil is between 5.21～8.89 in Shenyang suburb farmland, the mean value is 6.84. The frequency distribution of soil pH is expressed as skewed normal distribution. Soil pH is neutral in Shenbei new district and Tiexi district, relatively lower-value in Dongling district, Yuhong district and Hunnan new district soil.Time variation law of soil pH presents a downward trend overall.(2) The average content of Pb is 102.66 mg·kg-1, is 4.63 times of Shenyang soil background values.More than 94.12% of sampling points are above the background value, in accordance with the administrative division and the results as follows:Yuhong district> Shenbei new district> Hunnan new district> Dongling district> Tiexi district. High levels total amount of heavy metal Pb in soil vertical distribution characteristics have gathered phenomenon more obvious in 0 to 10 cm, and lower content in 10 to 20 cm; Near the area of Pb pollution sources are cumulative effects, governance and improvement of pollution regional present the characteristics of no accumulation and negative cumulative.In general, the average accumulation rate of Pb is 0.27 mg·(kg·a)-1, its content presents the trend of a slight increase.(3) The average content of Cu is 59.79 mg·kg-1,2.43 times that of soil background values in shenyang, all soil samples were more than soil background values; In accordance with the administrative divisions, and the results as follows:Tiexi district> Dongling district> Shenbei new district> Hunnan new district> Yuhong district. High levels total amount of Cu in soil vertical distribution characteristics have gathered phenomenon more obvious in 0 to 10 cm, and lower content in 10 to 20 cm; Cu pollution area are positive and no accumulation characteristics, the regional of governance and improvement is negative cumulative effect, and its proportion is small.Heavy metals Cu accumulation rate to an average of 0.09 mg·(kg·a)-1, its content change is not obvious.(4) The average contents of Zn is 106.79mg·kg-1,1.78 times of soil background values in shenyang, all sampling points are more than soil background values in shenyang; in accordance with the administrative division sorting, and the result is:Shenbei new district> Tiexi district> Yuhong district> Dongling district> Hunnan district; High levels total amount of Zn in soil vertical distribution characteristics have gathered phenomenon more obvious in 0 to 10 cm, and lower content in 10 to 20 cm; Zn is mainly positive cumulative, the proportion is small in no accumulation and negative cumulative effect area;An average cumulative rate is 0.38 mg·(kg·a)-1, its content presents the trend of a slight increase.(5) This article will shenyang suburb farmland soil heavy metal elements Pb and Zn pollution sources are divided into road impact, sewage irrigation, enterprise production, iron and steel smelting, mining area land reclamation, etc., divide the sources of pollution of heavy metal elements Cu for livestock and poultry manure and chemical fertilizers, vegetable greenhouses, sewage irrigation and enterprise pollution, etc.(6) It should be improved by adjusting the industrial structure, technical equipment and promote clean production and control of heavy metal pollution emissions, and study the phytoremediation of the cultivated land pollution measures suitable for shenyang suburbs;At the same time, establish and implement the prevention and control of heavy metal pollution of the relevant laws and regulations and standards, improve the existing monitoring system, the forecast of heavy metal pollution mechanism and evaluation system, to ensure that the area of food supply and production and safety of agricultural products and establish the system of public participation in prevention and control of soil heavy metal pollution.