降解苯胺和氯苯胺类污染物好氧污泥颗粒化及微生物种群结构分析

Start-up,formation and microbial community analysis of aerobic granules in SABR for treatment of organic wastewater containing aniline and chloroanilines

摘要:

以序批式气提生物反应器(SABR)为平台,研究了苯胺和氯苯胺类有毒有机废水处理过程好氧污泥颗粒化。结果表明,通过缩短污泥沉降时间、逐步提升目标污染物进水负荷,反应器连续运行3个月,最终在污泥沉降时间5min、COD负荷1.0~3.6kg/(m³.d)、苯胺和氯苯胺负荷1kg/(m³.d)条件下实现污泥颗粒化,COD、苯胺和氯苯胺去除率分别稳定在90%、99.9%以上;获得的成熟好氧颗粒粒径在0.45~2.5mm,SOUR稳定在150mgDO/(gVSS·h)以上,颗粒污泥EPS中PN含量为28.0±1.9mg/gVSS,PN/PS比值为6.5mg/mg,苯胺类比降解速率达0.18g/(g·d);应用PCR-DGGE分子指纹图谱技术分析了稳定运行的颗粒化反应器内好氧污泥微生物种群结构,结果表明好氧颗粒内主要细菌分属β-Proteobacteria、γ-Proteobacteria及Flavobacteria等类群,优势菌为Pseudomonas sp.、Flavobacterium sp.;与已获得的降解氯苯胺好氧颗粒相比,苯胺存在下培养获得的好氧颗粒污泥微生物菌群结构更为丰富。

Abstract:

The granulation of aerobic sludges for high-rate biodegradation of organic wastewater containing aniline and chloroanilines was investigated in a laboratory-scale sequencing airlift bioreactor (SABR). Aerobic granules were observed in 15days after start-up in SABR. After subsequent 83days, SABR was operated sequentially in superficial air velocity of 2.4cm/s, COD loadings of 1.0～3.6kg/(m³·d) and (chloro-)anilines loadings increased stepwise to 1kg/(m³·d), a steady-state performance of aerobic granular SABR was achieved at last, as evidenced by high and stable COD and (chloro-)anilines removal efficiencies of above 90% and 99.9%, respectively. Mature granules with median size of 0.45～2.5mm, minimal settling velocity of 62.1m/h, and SVI of 56mL/g were developed. Aerobic granular sludge displayed noteworthy SOUR, specific (chloro-)anilines degradation rates, PN content and PN/PS ratio in EPS extracts as 154mgDO/(gVSS·h), 0.18g/(gVSS·d), 28.0±1.9mg/gVSS and 6.5mg/mg respectively, indicating that they had high activity and ability to withstand high (chloro-)anilines loadings. Phylogenetic analysis of (chloro-)anilines-degrading aerobic granules indicated that β-、γ-Proteobacteria and Flavobacteria were dominant classes and the predominance bacteria were closely related to Pseudomonas sp. and Flavo-bacterium sp. Compared to chloroanilines-degrading aerobic granules, the population diversity was higher in the aniline and chloroaniline-degrading aerobic granules.