Yangsong Du, Xufeng Guo, Yaer Lou, Weiping Zhou, Shuqing Sha
China University of Geosciences, Beijing 100083, P. R. China

 

 

Pollution of heavy metals in the mining districts

in Tongling region, Anhui Province and its control

 

 

Abstract

 

 

 In many Chinese mining districts and industrial cities, especially mining towns, soil pollution of heavy metals has reached a serious level.  This study focuses on two representative areas, the Shizishan (Lion Hill) and Jiaochong copper mines in Tongling region, Anhui Province.  Following the sampling, chemical analyses, and data processing procedures of the National Environmental Protection Bureau of China, samples of soil and fluvial sediments were collected along former flow channels of wastewater flows in the two mining districts.

 

 Chemical analysis of heavy metal elements was realised. The result indicates that the polluting-grade heavy metals include Cu, Zn, Ph, Hg, and As.  In the soil samples, copper is in adsorbing phase in clay minerals and organics, and lead exists as inorganic sediments or in adsorbing phase.  Since mercury and arsenic are volatile in soil, they have low content levels. In the fluvial sediment samples, copper exists in adsorbing phase, mercury in a commingle form between inorganic and organic phases, and arsenic in As³⁺ phase or adsorbing phase. 

 

 Based on analyzing heavy metal elements in the sediments, the pollution level of heavy metals in the two mining districts was assessed using the Hankanson potential ecologic damage index.  The results suggest that the Shizishan mining district has received a high level of ecologic damage due to a serious level of mercury and copper pollutions. The Jiaochong mining district has a relatively low level of pollution and relatively light ecologic damage. In addition, the level of heavy metal pollution in the soil samples was evaluated using the Nemerow comprehensive index method.  The results indicate that the pollution of Cu, Pb, and Zn is quite serious and reaches to the high pollution level in Shizishan district, and the moderate level in Jiaochong district. This study also assessed the damage of the heavy metal pollution, and provided feasible mitigation measures. 

 

 The authors suggest to remediate the soil by the plant-restoration method, which has received much attention in China and abroad.  Especially with respect to the most serious copper pollution in the Tongling region, densely planted Elasholtzia splendens should be effective in mitigating the pollution problem.