Study on Heavy Metal Pollution Characteristics and its Health Risk Assessment from Sludge of Sewage Treatment Plants in Industrial Parks

Abstract Background In order to study the characteristics of heavy metal pollution from sludge in industrial parks and the effective methods of health risk assessment, in this paper, the pollution characteristics of eight heavy metals including Zn, Cu, Pb, Hg, Cr, Ni, As, Cd in sludge of sewage treatment plants in Nanjing MV Industrial Park were comprehensively evaluated and compared by using Nemerow Index Method, Muller Index Method and Matter element extension method. On this basis, the health risk assessment models of non-carcinogenic and carcinogenic heavy metals were constructed, and the health risks caused by four kinds of non-carcinogenic heavy metals Pb, Zn, Cu, Hg and four kinds of carcinogenic heavy metals Cr, As,Cd, Nicontained in sludge were evaluated by using the practical data of Nanjing Industrial Park. Results According to the evaluation results of heavy metal pollution characteristics in sludge of sewage treatment plants in Nanjing MV Industrial Park, the order of different pollution levels under different assessment methods is as follows: the level of the Nemerow Index Method assessment was low, the level of the Muller Index Method assessment was high, and the level of Grey Clustering Method assessment was relatively moderate. In the health risk assessment of heavy metals, the results showed that the order of effects of non-carcinogenic heavy metals on health risk ranged from large to small was: Hg, Cu, Pb, and Zn, and the health risk of non-carcinogenic heavy metal in children was much higher than that in adults. Similarly, the order of effects of carcinogenic heavy metal health risk ranged from large to small was Cd, Cr, Ni and As, and the health risk of carcinogenic heavy metal in children was slightly lower than that in adults. Conclusions It can be seen that there is a certain degree of heavy metal pollution in the sludge of the sewage treatment plant in Nanjing MV Industrial Park, which affects the environmental quality in the park and the health risks of residents. This study verifies the assessment method of the heavy metal pollution characteristics and health risk is effective, and its research results have a guiding role in the management of heavy metal pollution in the sludge of the sewage treatment plant in Nanjing MV Industrial Park. It also has significant theoretical support for the government to formulate the eco-environmental quality standards and related policies of industrial parks.