title: Determination of phosphite in a full-scale municipal wastewater treatment plant.
abstract: Phosphite (HPO3(2-), +3), a reduced P species in the P biogeochemical cycle, was monitored in a full-scale municipal wastewater treatment plant (MWTP) that uses an anaerobic/anoxic/aerobic-membrane bioreactor (A(2)/O-MBR) technology for treating mixed wastewater (56% industrial wastewater and 44% domestic wastewater) from June 2013 to May 2014. Wastewater samples were collected from influent after having gone through the fine grille, anaerobic tank, anoxic tank, and aerobics tank, respectively. The final stage yielded effluent. Results confirmed the presence of phosphite in the MWTP ranging from 4.62 ± 1.00 μg P L(-1) to 34.30 ± 3.49 μg P L(-1) in influent and from 1.15 ± 0.5 μg P L(-1) to 4.42 ± 0.9 μg P L(-1) in effluent. Phosphite accounted for approximately 0.15% to 2.27% of total soluble phosphorus (TSP). During the A(2)/O-MBR process, the average removal of phosphite was 82.41 ± 7.45%. The anaerobic biological treatment removed the most phosphite from wastewater in this study. Spatially, phosphite concentrations decreased gradually as the wastewater treatment process progressed. Seasonally, the phosphite concentrations in spring and winter were higher than those in summer and autumn. The phosphite concentration in effluent was of the same order of magnitude as that in nearby natural water, which suggested MWTP effluent may be an important phosphite contributor to the natural water.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University 210023, Jiangsu, P. R. China. jjgeng@nju.edu.cn.
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Yu
authors.forename: Jinju
authors.initials: J
authors.lastname: Geng
authors.forename: Hongqiang
authors.initials: H
authors.lastname: Ren
authors.forename: Han
authors.initials: H
authors.lastname: Chao
authors.forename: Huimin
authors.initials: H
authors.lastname: Qiu
mesh_terms: D004784:Environmental Monitoring; D017905:Phosphites / Q000032:analysis*; D014865:Waste Disposal, Fluid; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D017905:Phosphites; D062065:Wastewater; D014874:Water Pollutants, Chemical