化学
絮凝作用
缺氧水域
胞外聚合物
化学需氧量
磷
腐植酸
核化学
吸附
环境化学
傅里叶变换红外光谱
废水
环境工程
化学工程
有机化学
肥料
吸附
生物膜
生物
细菌
工程类
遗传学
作者
Xiaohui Xu,Lanhe Zhang,Xiangdong Zhang,Xiaohui Guan,Dezhou Wei
标识
DOI:10.1016/j.jes.2021.07.012
摘要
Manganese ion (Mn2+) generated from metallurgical, steel making and chemical industries enters sewage treatment plants and affects the sludge activity and flocculation. The effect of Mn2+ 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 characterized 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 Mn2+, EPS and sludge flocculation. The results showed that low concentration of Mn2+ (<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 Mn2+ increased total EPS, sludge contact angle, Zeta potential and sludge particle size, and thus enhanced sludge flocculation. However, high concentration of Mn2+ (>10 mg/L) hindered microbial flocculation and reduced removal efficiencies of the pollutants. When Mn2+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 Mn2+ 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 Mn2+ resulted in the degradation of humic acids. However, it did not give rise to significant morphology changes of EPS.
科研通智能强力驱动
Strongly Powered by AbleSci AI