A case study on the occurrence, transport, and fate of mercury species in a sewage treatment plant in Jiaozuo, China

• Published in: Environmental science and pollution research international 2018-08, Vol.25 (22), p.21616-21622
• Main Authors: Liu, Hao, Cui, Ying, Li, Hua, Mao, Yuxiang
• Format: Article
• Language: English
• Subjects: Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; China; Dimethylmercury; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental Monitoring; Environmental science; Mercury; Mercury (metal); Mercury - analysis; Mercury - chemistry; Methylmercury; Methylmercury Compounds - analysis; Municipal wastes; Municipal wastewater; Raw sewage; Research Article; Sewage - analysis; Sewage disposal; Sewage sludge; Sewage treatment; Sewage treatment plants; Waste Water Technology; Wastewater treatment plants; Water Management; Water Pollutants, Chemical - analysis; Water Pollution Control
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-018-2312-8

Occurrence and fate of sewage- and sludge-borne total mercury (THg) and methylmercury (MeHg) have received little attention, although they might be an important component of the global Hg inventory. To address the knowledge gap, sewage and sewage sludge (SS) samples were collected from a secondary municipal sewage treatment plant (MSTP) located in Jiaozuo, China. Total Hg in the raw sewage varied between 95.3 ng/L and 1.2 × 10 3  ng/L, while MeHg occurred in the sewage within ranges of 2.7–21.3 ng/L. On average, 93.4% of THg and 89.1% of MeHg were removed from the raw sewage by the MSTP. Around 80% of net THg input into the MSTP was transported to the SS, while 80% of net MeHg input was decomposed during the treatment processes. Thus, MSTPs would be regarded as an important sink of sewage-borne THg and MeHg. On the other hand, MeHg widely occurred in the SS, with concentrations between 7.2 and 10.2 ng/g, accounting for 0.2% of the corresponding THg contents in the SS. Occurrence of THg and MeHg in the SS indicated that SS would be a significant source of MeHg and THg to the environment.