Heavy Metals Pollution Assessment And Spatial Variability Analysis In Soil Of Farmland In North Suburb Of Xuzhou

Farmland soil was polluted by various wastes, which was derived from coalmining and derivatives industry companies. Pollutants, which posed serious threats onhuman beings, would be accumulated in crops by biological accumulation andtransferred in human body with food-chain finally. Therefore, farmland soil near thecoal mining area needed to be monitored and analyzed. The research object of thispaper is cultivated farmland in Pangzhuang mine and its surrounding industrial area inthe north of Xuzhou. The paper determinate and evaluate heavy metals(Zn,Pb,Cd,Cr,Cu) pollution in the research area of farmland soil. Sourceapportionment of heavy metals was analyzed based on the investigation of pollutionsources, and characteristics of spatial variability were studied based on thegeo-statistics.We have drawn the conclusions that:(1) The pollution of Zn was the most serious, and the pollution of Cd came thenext. Cu、Cr and Pb were lower than the Soil Environmental Quality Standard II. Znwas increasing with the time during June to September2012,and then reducing withthe two quarters. The reduction quantity reached a maximum during March to June2013. Pb,Cd,Cr and Cu presented fluctuant change with time.(2) The variation extent of pH was very low in research area soil. pH andZn,Pb,Cd,Cr,Cu were uncorrelated. Zn was very significantly positive correlated withCd. Zn and Pb,Cr were uncorrelated. Pb was very significantly positive correlatedwith Cu. There was a lower negative correlation between Pb and Cd,and mediumpositive correlation between Pb and Cr. Cr was very significantly positive correlatedwith Cu. The research area soil was polluted by heavy metals compound pollution. Znand Cd might have similar sources. Pb and Cu,Cr might have similar sources. Themain pollution sources were industrial coal pollution and urban traffic pollution.(3) The influence degree was: Zn＞Cd＞Cu＞Cr＞Pb according to single-factorpollution index in research area soil. The result of Nemoro synthesis index was thatfly-ash stacking and “Times Road” to be the moderate pollution, and the rest of otherpoints was light pollution levels. The result of potential ecological risk index was:Cd＞Cu＞Zn＞Pb＞Cr.(4) The result of Kriging interpolation was that heavy metals were shown in spots.Most of Zn was the north,west and south of the research area, while the east wasless.The content of Zn was the highest at Zhangxiaolou mine especially. Pb was a bit higher in the north and south of the research area, and the distribution of Pb wasfeatured by island. Cd was higher in the northeast, and showed trend of gradualdecrement from north to south. Cr showed trend of gradual decrement from west toeast. Most of Cr was the north,west and south of the research area, and had the samespatial distribution pattern with Zn. Most of Cu was the north,northwest and south ofthe research area, while the east is less.