Mercury speciation transformation in sewage of the sewage treatment process

Abstract

Abstract In order to reveal the occurrence characteristics and speciation transformation of mercury in the sewage treatment plant, the sewage of each process unit in Mai dao sewage treatment plant was taken as the research object, the total mercury (THg), particulate mercury (PHg) and dissolved mercury (DHg) in the samples was determined for 7 consecutive days. The results showed that the THg in influent water was 474.6±148.4ng/L, and had a large daily variance, and that in effluent was 27.8±8.2 ng/L. THg in wastewater was closely related to the degree of organic pollution. PHg accounted for a larger proportion in raw sewage (PHg/THg was 73.5%), and the proportion of DHg increased after treatment. The total removal efficiency of THg was 94.1%, and PHg contributed a lot. The removal of mercury mainly occurred in the secondary biological treatment process.