厌氧E-MBR反应器在焦化废水处理中的微生物特性研究

Study on rapid start-up of anaerobic E-MBR and microbial characteristics and membrane fouling

摘要:

[目的] 将厌氧的膜生物反应器（MBR）与微生物燃料电池（MFC）耦合的厌氧电辅助膜生物反应器（E-MBR）应用于实际工业焦化废水处理。[方法] 通过正交实验优化了反应器进水的培养条件为PO₄^3–14.3 mg/L、Fe²⁺0.2 mg/L、Fe³⁺0.1 mg/L、Co²⁺0.1 mg/L和Mn²⁺0.2 mg/L。在此条件下考察了该反应器对系统中有机污染物的去除效率及厌氧污泥的污泥特性、产电性能、胞外聚合物（EPS）、微生物群落结构及膜污染的影响。[结果] 结果表明，与未优化的培养条件相比，工业焦化废水COD的去除率提高了23%；污泥浓度（MLSS）、比重、沉降速度增加，污泥体积指数（SVI）降低，表明污泥颗粒化及沉降性能提高；污泥中溶解性EPS （SMP）、松散态EPS （LB-EPS）及紧密结合态EPS （TB-EPS）这3种组分中的蛋白质与多糖的比例（P/C）分别降低0.12、0.25和0.16，表明污泥更易于被降解；厌氧污泥的产电性能增强；高通量分子测序结果表明，反应器中污泥的群落结构发生了明显的变化，优势菌群突出；经扫描电镜（SEM）对比结果表明，反应器阴极膜的污染情况也得到了一定的减缓。[结论] 优化进水培养条件可以达到使反应器污水处理效率提高、清理周期缩短和运行更稳定等效果，对于工业废水处理技术的节能环保方面提供一定的理论依据。

关键词:厌氧电辅助膜生物反应器;正交优化实验;污泥特性;导电性能;微生物群落结构;膜污染

Abstract:

[Objective] In this paper, an anaerobic electrical membrane bioreactor (E-MBR) coupled the anaerobic membrane bioreactor (MBR) and microbial fuel cell (MFC) was applied in the industrial coking wastewater treatment. [Methods] The culture conditions including nutrients and metal elements of the influent of the reactor were optimized by orthogonal experiments as 14.3 mg/L PO₄^3–, 0.2 mg/L Fe²⁺, 0.1mg/L Fe³⁺, 0.1mg/L Co²⁺, 0.2 mg/L Mn²⁺. Under this conditions, the removal efficiency of COD, the sludge characteristics, electrical performance, extracellular polymers (EPS), microbial community structure and membrane fouling of anaerobic sludge in the reactor were investigated. [Results] The results showed the removal rate of COD was increased by 23% compared with that without optimization. Meanwhile, sludge concentration (MLSS), specific gravity and the settling speed increased, while the sludge volume index (SVI) decreased, indicating that the enhancement of the anaerobic sludge granulation and settling performance. Each component of the EPS of the sludge such as the ratio of protein to polysaccharide (P/C) soluble microbial products (SMP), loose EPS (LB-EPS) and tightly bound EPS (TB-EPS) decreased by 0.12, 0.25 and 0.16, respectively, which indicated that sludge was more easily degraded. The electrical performance of the anaerobic sludge was enhanced. The results of high-throughput molecular sequencing manifested that the community structure of sludge in the reactor had changed significantly, and the dominant bacteria group was prominent. The results of scanning electron microscopy (SEM) showed that the pollution of the cathode membrane of the reactor was also reduced. [Conclusion] The optimization of influent culture conditions could improve the efficiency of wastewater treatment, shorten the cleaning cycle and make the operation more stable, which provided a theoretical basis for energy saving and environmental protection of industrial wastewater treatment technology.

Key words:anaerobic electrical membrane bioreactor;orthogonal optimization experiment;sludge characteristics;conductivity;microbial community structures;membrane fouling