ABR处理低浓度废水的污泥颗粒化研究

通过两个ABR反应器不同启动方式的对比,考察了污泥颗粒化的进程。试验以污水厂的厌氧污泥为对象,以颗粒污泥的粒径、形成特征等作为评价污泥颗粒化的指标,分析了控制进水CODcr浓度和改变水力停留时间两种运行方式对污泥颗粒化的影响。试验结果表明,两种启动运行方式均能够实现污泥的颗粒化,但在颗粒粒径和颗粒化程度上有所区别。培养出的颗粒污泥形状一般为球形或椭球形,直径在1 mm～2 mm。污泥结构紧密,表面较光滑,以丝状产甲烷菌为主。     

Aerobic granulation of pure bacterial strain Bacillus thuringiensis

The objective of this study is to cultivate aerobic granules by pure bacterial strain, Bacillus thuringiensis, in a sequencing batch reactor. Stable granules sized 2.0–2.2 mm were formed in the reactor after a five-week cultivation. These granules exhibited excellent settling attributes, and degraded phenol at rates of 1.49 and 1.19 g phenol/(g VSS?d) at 250 and 1500 mg/L of phenol concentration, respectively. Confocal laser scanning microscopic test results show that Bacillus thuringiensis was distributed over the initial small aggregates, and the outer edge of the granule was away from the core regime in the following stage.     

Alternating nitrogen feeding strategy induced aerobic granulation: Influencing conditions and mechanism

Effective cultivation of stable aerobic granular sludge (AGS) is a crucial step in the successful application of this technology, and the formation of AGS could be facilitated by some environmental stress conditions. Four identical sequencing batch reactors (SBRs) were established to investigate the aerobic granulation process under the same alternating ammonia nitrogen feeding strategy superimposed with different environmental conditions (inorganic carbon source, temperature, N/COD). Although various superimposed conditions induced a significant difference in the size, settling velocity, mechanic strength of AGS, mature aerobic granules could be successfully obtained in all four reactors after 70 days' operation, indicating the alternating ammonia nitrogen feeding strategy was the most critical factor for AGS formation. Based on the results of redundancy analysis, the presence of an inorganic carbon source could facilitate the cultivation of AGS with nitrification function, while the moderate temperature and fluctuant N/COD might benefit the cultivation of more stable AGS. In addition, superimposed stress conditions could result in the difference in the microbial population between four reactors, but the population diversity and abundance of microorganisms were not the determinants of AGS formation. This study provided an effective method for the cultivation of AGS by using alternating ammonia nitrogen feeding strategy.     

大气颗粒物监测分析及今后研究课题

概述了 PM1 0 和 PM2 .5今后的研究方向。目前我国尚未开展 PM2 .5的常规监测 ,PM1 0 的自动监测中尚存在一些技术问题 ,且尚未公布 PM1 0 自动监测的技术性标准 ,为了满足各级环境监测站的工作需求 ,在附录中介绍了国外关于PM1 0 和 PM2 .5的监测仪器和方法标准 ,并介绍了 2 0 0 0年日本颁布的 PM2 .5自动监测技术规定     

利用FISH和DGGE对产甲烷颗粒污泥中微生物种群的研究

利用FISH和DGGE技术对厌氧反应器内处于不同运行阶段的4个产甲烷颗粒污泥进行研究,考察其中真细菌和古细菌的种群结构,并对其中的优势古细菌进行系统发育分析.FISH结果表明,颗粒污泥中真细菌含量明显高于古细菌,真细菌主要分布在颗粒污泥外层,古细菌则主要分布在内层;DGGE结果表明,随着反应器COD负荷的增加以及运行时间的延长,真细菌种群结构相对较稳定,而古细菌种群结构则发生了较明显变化,其中占优势的古细菌种类逐渐减少;将有代表性的7个古细菌条带切胶回收并测序,结果显示,反应器运行后期占优势的菌种主要包括甲烷微粒菌(Methanocorpusculum)、甲烷杆菌(Methanobacterium)和甲烷髦毛菌(Methanosaeta)等.