Xu Wei-Chao, Meng Xiao-Jun, Yin Li, Zhang Yu-Xiu, Li Hai-Bo, Cao Hong-Bin
School of Chemical and Environmental Engineering, China University of Mining & Technology (Beijing), Beijing 100083, China.
Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
Huan Jing Ke Xue. 2016 Jul 8;37(7):2689-2695. doi: 10.13227/j.hjkx.2016.07.036.
Thiocyanate (SCN) is one of the main sources of COD in coking wastewater, and SCN removal efficiency of the aerobic unit impacts the requirement of discharging standard. Microbial population in the activated sludge plays an important role in SCN removal of coking wastewater treatment. However, the community structure has rarely been reported. Using SCN as the sole carbon and energy source, the removal of 100 mg·L,300 mg·L and 600 mg·L SCN by activated sludge was studied and 454 sequencing technology was applied to investigate the biodiversity of SCN-degrading bacteria. The results showed that 100-600 mg·L SCN could be effectively removed by acclimated activated sludge, the higher SCN concentration, the higher removal efficiency, but the lower bacterial community diversity indices. The bacterial communities in initial and acclimated sludge samples were mainly composed of Proteobacteria, Bacteroidetes, Chlorobi, Planctomycetes, Acidobacteria, Nitrospira, Firmicutes and Unclassified bacteria. Bacteroidetes and Proteobacteria were dominant phyla in the sludge. was responsible for SCN biodegradation in coking wastewater, and its abundance in three sludge samples was 3.07%, 8.63% and 0.27%, respectively. When the concentration of SCN was less than 300 mg·L, was the main degrading bacteria. While at 600 mg·L SCN, low-abundance degrading bacteria might have synergistic degradation effect. These results have important significance for revealing SCN removal mechanism in the coking wastewater treatment.
硫氰酸盐（SCN）是焦化废水中化学需氧量（COD）的主要来源之一，好氧单元对SCN的去除效率影响排放标准的达标要求。活性污泥中的微生物种群在焦化废水处理中SCN的去除过程中起着重要作用。然而，其群落结构鲜有报道。以SCN作为唯一碳源和能源，研究了活性污泥对100 mg·L、300 mg·L和600 mg·L SCN的去除情况，并应用454测序技术研究了SCN降解菌的生物多样性。结果表明，驯化后的活性污泥能够有效去除100 - 600 mg·L的SCN，SCN浓度越高，去除效率越高，但细菌群落多样性指数越低。初始污泥样品和驯化污泥样品中的细菌群落主要由变形菌门、拟杆菌门、绿菌门、浮霉菌门、酸杆菌门、硝化螺旋菌门、厚壁菌门和未分类细菌组成。拟杆菌门和变形菌门是污泥中的优势菌门。 负责焦化废水中SCN的生物降解，其在三个污泥样品中的丰度分别为3.07%、8.63%和0.27%。当SCN浓度小于300 mg·L时， 是主要的降解菌。而在SCN浓度为600 mg·L时，低丰度降解菌可能具有协同降解作用。这些结果对于揭示焦化废水处理中SCN的去除机制具有重要意义。
