Pollution and potential ecological risk assessment of heavy metal of the sludge in treatment plants in Beijing

Abstract

In 2016, it had been monitored for one year that the heavy metals of sludge in six treatment plants in Beijing. In this paper, several indexes were applied to assess the heavy metals of sludge in treatment plants, including the single factor index, the Nemerow composite index and the potential ecological risk index. The results showed that the concentration of Zn was the highest among the six heavy metals in the treatment plants. The treatment plants with different water intake, the transnormal items of heavy metals of the sludge in these plants are also different. The comprehensive pollution levels of sludge of five treatment plants are all warning line. The other one is better, its comprehensive pollution level is clean. The comprehensive risk indexes of sludge of five treatment plants are belonging to medium contamination. The other one is worse, belonging to the high ecological risk.