Bai Yang, Zhang Yaobin, Quan Xie, Chen Shuo
Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China E-mail:
Water Sci Technol. 2016;73(4):827-34. doi: 10.2166/wst.2015.558.
An integrated fixed-film activated sludge (IFAS) process (G1) and an activated sludge anoxic-oxic process (G2) were operated at nitrate liquor recirculation ratio (R) of 100, 200 and 300% to investigate the feasibility of enhancing nitrogen removal efficiency (RTN) and reducing R by improving simultaneous nitrification and denitrification (SND) in the IFAS process. The results showed that the effluent NH4(+)-N and total nitrogen (TN) of G1 at R of 200% were less than 1.5 and 14.5 mg/L, satisfying the Chinese discharge standard (NH4(+)-N < 5 mg/L; TN < 15 mg/L). However, the effluent NH4(+)-N and TN of G2 at R of 300% were higher than 8.5 and 15.3 mg/L. It indicated that better RTN could be achieved at a lower R in the IFAS process. The polymerase chain reaction-denaturing gradient gel electrophoresis results implied that nitrifiers and denitrifiers co-existed in one microbial community, facilitating the occurrence of SND in the aerobic reactor of G1, and the contribution of SND to TN removal efficiency ranged 15-19%, which was the main reason that the RTN was improved in the IFAS process. Therefore, the IFAS process was an effective method for improving RTN and reducing R. In practical application, this advantage of the IFAS process can decrease the electricity consumption for nitrate liquor recirculation flow, thereby saving operational costs.
运行一体式固定膜活性污泥法(IFAS)工艺(G1)和活性污泥缺氧-好氧工艺(G2),硝酸盐回流比(R)分别为100%、200%和300%,以研究通过提高IFAS工艺中的同步硝化反硝化(SND)来提高脱氮效率(RTN)并降低R的可行性。结果表明,R为200%时G1的出水NH₄⁺-N和总氮(TN)分别小于1.5和14.5mg/L,满足中国排放标准(NH₄⁺-N<5mg/L;TN<15mg/L)。然而,R为300%时G2的出水NH₄⁺-N和TN高于8.5和15.3mg/L。这表明在IFAS工艺中较低的R下可实现更好的RTN。聚合酶链反应-变性梯度凝胶电泳结果表明,硝化菌和反硝化菌共存于一个微生物群落中,促进了G1好氧反应器中SND的发生,SND对TN去除效率的贡献范围为15%-19%,这是IFAS工艺中RTN提高的主要原因。因此,IFAS工艺是提高RTN和降低R的有效方法。在实际应用中,IFAS工艺的这一优势可降低硝酸盐回流流量的电力消耗,从而节省运营成本。