| As a kind of emerging organic contaminants in water environment, pharmaceuticals and personal care products'(PPCPs) environmental and security risks have caused worldwide attention. As a kind of PPCPs, sulfonamide antibiotics has been generally detected in domestic and foreign environment. Because of the imperfection of municipal wastewater collecting system in our country, the outlet sewage directly discharge into the urban river without any treatment. The sewage discharged into the river not only contain conventional pollutants, but also contain a certain concentration of sulfonamide antibiotics, which can cause serious damage to the ecological environment of the receiving water body. This research thus focused on the present situation of sulfonamide antibiotics pollution in our country and considered the need of the project whose name is"Water quality improvement research from Nan hulu brige to Sun cunzha in Daxing, Beijing", and then studied the removal effect of conventional pollutants and sulfathiazole (ST), sulfamethoxazole (SMX), sulfadiazine (SD) in the domestic sewage by the combined process of biological aerated filter (BAF) and subsurface wastewater infiltration system (SWIS) applied to the sewage outlets.The research has studied the removal effeciencies of COD, NH4+-N, TN, TP in domestic sewage by the combined process of BAF and SWIS. When the gas-water radio was 5:1, the backwash period was 7 days and the upflow velocity was 0.6 m/h, the best treatment effeciencies of BAF had been achieved. When the BAF running at the best operating condition, The removal efficiencies of COD, NH4+-N, TN and TP reached to 85.7%,82.6%,23.8%, 53.8%, respectively. The SWIS adopted an intermittent operation to improve total nitrogen and total phosphorus removal. Each cycle of the intermittent operation included a floodingperiod of 12 h and a drying period of 12 h. In the flooding period the system was continuously fed with BAF effluent at a hydraulic loading of 5 cm·h-1. The removal effeciencies of COD, NH4+-N, TN and TP over the operation period were achieved at average rates Of 41.3%, 62.8%,64.3%,67.1%, respectively.The total removal rates of COD, NH4+-N, TN and TP were 91.6%,93.5%,72.8%and 84.8%, respectively.The artical studied the removal effeciencies of sulfonamide antibiotics in the combined progress. The results showed that the removal effeciencies of ST, SMX, SD were 53.01%,63.3%,68.8%, respectively. The removal efficiency of the three kinds of sulfonamide antibiotics were ordered as sulfamethoxazole> sulfadiazine> sulfathiazol.The research of the impacts of ST, SMX, SD on the microbial community structure of the BAF was carried out by using MiSeq sequencing. Indices such as Chaol, Shannon, coverage, and OTU were used to analyze the diversity of the microbial community, and the results showed that the microbial diversity decreased at the beginning of adding sulfonamide antibiotics. As time went by, the microbial diversity had recovered but still below the level before the adding sulfonamide antibiotics.The method of Taxonomy was used to analyze the structure of microbial community. The results indicated that, the adding of three kinds of sulfonamide antibiotics had caused impacts on the phylum, class, genus of microbial community. |
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