Effect of Mn^(2+)on the phosphorus removal and bioflocculation under anoxic condition  

作　　者：Xiaohui Xu Lanhe Zhang Xiangdong Zhang Xiaohui Guan Dezhou Wei 

机构地区：[1]School of Resources&Civil Engineering,Northeastern University,Shenyang 110819,China [2]School of Chemical Engineering,Northeast Electric Power University,Jilin 132012,China

出　　处：《Journal of Environmental Sciences》2022年第5期37-46,共10页环境科学学报（英文版）

基　　金：This work was supported by the National Natural Science Foundation of China(No.51678119);the Science and Technology Development Program of Jilin Province(No.20180201016SF).

摘　　要：Manganese ion(Mn^(2+))generated from metallurgical,steel making and chemical industries enters sewage treatment plants and affects the sludge activity and flocculation.The effect of Mn^(2+)on the removal of chemical oxygen demand(COD)and total phosphorus(TP)and sludge activity were investigated in anoxic zone of an anaerobic/anoxic/oxic(A2O)process.The compositions and structures of extracellular polymeric substances(EPS)were charac-terized using three-dimensional excitation emission matrix fluorescence spectroscopy(3D-EEM),X-ray photoelectron spectroscopy(XPS)and Fourier transform infrared spectroscopy(FTIR)to reveal the relationship among Mn^(2+),EPS and sludge flocculation.The results showed thatlow concentration of Mn^(2+)(<5 mg/L)improved removal efficiencies of COD and TP and increased the activity of alkaline phosphatase,acid phosphatase and dehydrogenase.Meanwhile,the addition of Mn^(2+)increased total EPS,sludge contact angle,Zeta potential and sludge particle size,and thus enhanced sludge flocculation.However,high concentration of Mn^(2+)(>10 mg/L)hindered microbial flocculation and reduced removal efficiencies of the pollutants.When Mn^(2+)was 5 mg/L,removal efficiencies of COD and TP reached 65%and 90%,respectively.Sludge flocculation was the best and SVI was 70.56 mL//g.The changes of Mn^(2+)concentration caused deviation of groups'compositions in LB-EPS and TB-EPS,where the main components were always protein(PN)and polysaccharide(PS).The addition of Mn^(2+)resulted in the degradation of humic acids.However,it did not give rise to significant morphology changes of EPS.

关 键 词：Mn^(2+) WASTEWATER Anoxic sludge Extracellular polymeric substances (EPS) FLOCCULATION 

分 类 号：X703[环境科学与工程—环境工程]