厌氧降解两种苯二甲酸酯的试验研究

以邻苯二甲酸二[2-乙基己]酯(DEHP)和邻苯二甲酸二丁酯(DBP)为研究对象,以废水污泥和填埋场沥出液为接种物,在严格厌氧环境下,进行了苯二甲酸酯生物降解的研究试验。结果表明,DBP有较好的可降解性,去除率大于95％;而DEHP在填埋场沥出液培养样中去除率小于30％;但当接种物为消化污泥时,DEHP的去除率为89．7％。产甲烷的微生物群在邻苯二甲酸二酯的降解过程中起着非常重要的作用。     

连续流新型厌氧反应器处理固体有机废物研究

采用自行设计的连续流厌氧消化反应器,接种瘤胃微生物后,对纤维素进行连续降解,固体有机物质负荷可以达到14g/L·d。在此符合范围内,反应器内pH值、挥发酸产量及产气量都很稳定,不会对反应产生抑制作用。     

Microbial Potential for the Anaerobic Transformation of Simple Homocyclic and Heterocyclic Compounds in Sediments of the Tsengwen River

The ability of microbial populations to mediate the anaerobic transformation of four aromatic compounds (aniline, benzoic acid, pyridine, and quinoline) in sediments of the Tsengwen River was examined. Along the river, from a freshwater (0.0° salinity) to an oceanic (37.0° salinity) environment, five sampling stations were chosen to collect the sediment. Sediment slurries were incubated in an anaerobic mineral salts medium that was amended with multiple electron acceptors, including manganese (IV) and ferric (III) oxides, and the concentrations of the aromatic substrates were followed over a 3- to 4-month period. Most sediment samples showed a complete loss of benzoic acid and quinoline (0.12–0.21 mM) within approximately three months. Pyridine was transformed after a lag period of 53 days in the sediment slurries from the freshwater environment which had been amended with both metal oxide (either Fe (OH)₃ or MnO₂) and inhibitor (either BESA or molybdate). Pyridine was not transformed in other sediment slurries. No significant metabolism of aniline was apparent in any of the sediments.     

Roles of acid-producing bacteria in anaerobic digestion of waste activated sludge

Three acid-producing strains, AFB-1, AFB-2 and AFB-3, were isolated during this study, and their roles in anaerobic digestion of waste activated sludge (WAS) were evaluated. Data of 16S rRNA method showed that AFB-1 and AFB-2 were Bacillus coagulans, and AFB-3 was Escherichia coli. The removal in terms of volatile solids (VS) and total chemical oxygen demand (TCOD) was maximized at 42.7% and 44.7% by inoculating Bacillus coagulans AFB-1. Besides, the optimal inoculum concentration of Bacillus coagulans AFB-1 was 30% (v/v). Solubilization degree experiments indicated that solubilization ratios (SR) of WAS reached 20.8%±2.2%, 17.7%±1.48%, and 11.1%±1.53%. Volatile fatty acids (VFAs) concentrations and compositions were also explored with a gas chromatograph. The results showed that VFAs improved by 98.5%, 53.0% and 11.6% than those of the control, respectively. Biochemical methane potential (BMP) experiments revealed that biogas production increased by 90.7% and 75.3% when inoculating with Bacillus coagulans AFB-1 and AFB-2. These results confirmed that the isolated acid-producing bacteria, especially Bacillus coagulans, was a good candidate for anaerobic digestion of WAS.

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城市污泥两相厌氧消化沼气产量的技术分析

城市污水处理厂所产生的污泥,数量巨大,成分复杂。如何经济、有效地加以利用已成为目前环境工程中深为关注的课题之一。文章探讨了污泥资源化工作中厌氧消化工艺的温度、时间、污泥成分的最佳工艺备件和沼气产生量,以实现污泥工业化利用。     

国外生活垃圾厌氧发酵技术的工程应用

厌氧发酵技术能较好地实现城市生活垃圾的资源化、无害化和减量化,是目前垃圾处理技术一个新的重要发展方向,而国内尚无运行的厌氧发酵处理厂。针对国外厌氧发酵技术的应用情况和发展趋势,侧重于从工程应用方面总结已建厌氧发酵处理厂的发酵技术,为我国厌氧发酵处理厂的建设和运行提供一定的技术支持。     

ABR反应器处理高浓度头孢抗生素废水实验研究

抗生素类制药废水的有机污染物浓度高,可生化性差,微生物不易降解,处理难度很大。采用动态试验对厌氧折流板反应器（ABR）处理某头孢类制药厂废水进行了研究。结果表明,当进水CODCr负荷控制在2．67—3．0kg／（m^3·d）,温度控制在35．4-0．5℃时,ABR对该废水CODCr的去除率可达在50％,且其可生化性得到了有效的提高,促进了废水进一步后续生化处理的运行稳定性。     

Marine aquaculture regulates dissimilatory nitrate reduction processes in a typical semi-enclosed bay of southeastern China

Marine aquaculture in semi-enclosed bays can significantly influence nutrient cycling in coastal ecosystems. However, the impact of marine aquaculture on the dynamics of dissimilatory nitrate reduction processes (DNRPs) and the fate of reactive nitrogen remain poorly understood. In this study, the rates of DNRPs and the abundances of related functional genes were investigated in aquaculture and non-aquaculture areas. The results showed that marine aquaculture significantly increased the denitrification (DNF) and dissimilatory nitrate reduction to ammonium (DNRA) rates and decreased the rate of anaerobic ammonium oxidation (ANA), as compared with non-aquaculture sites. DNF was the dominant pathway contributing to the total nitrate reduction, and its contribution to the total nitrate reduction significantly increased from 66.72% at non-aquaculture sites to 78.50% at aquaculture sites. Marine aquaculture can significantly affect the physicochemical characteristics of sediment and the abundances of related functional genes, leading to variations in the nitrate reduction rates. Although nitrate removal rates increased in the marine aquaculture area, ammonification rates and the nitrogen retention index in the aquaculture areas were 2.19 and 1.24 times, respectively, higher than those at non-aquaculture sites. Net reactive nitrogen retention exceeded nitrogen removal in the aquaculture area, and the retained reactive nitrogen could diffuse with the tidal current to the entire bay, thereby aggravating N pollution in the entire study area. These results show that marine aquaculture is the dominant source of nitrogen pollution in semi-enclosed bays. This study can provide insights into nitrogen pollution control in semi-enclosed bays with well-developed marine aquaculture.     

Enhanced nitrogen removal upon the addition of volatile fatty acids from activated sludge by combining calcium peroxide and low-thermal pretreatments

This study investigated a combined low-thermal and CaO₂ pretreatment to enhance the volatile fatty acid (VFA) production from waste activated sludge (WAS). The fermentative product was added to a sequencing batch reactor (SBR) as an external carbon source to enhance nitrogen removal. The results showed that the combined pretreatment improved WAS solubilization, releasing more biodegradable substrates, such as proteins and polysaccharides, from TB-EPS to LB-EPS and S-EPS. The maximum VFA production of 3529 ± 188 mg COD/L was obtained in the combined pretreatment (0.2 g CaO₂/g VS + 70 °C for 60 min), which was 2.1 and 1.4-fold of that obtained from the sole low-thermal pretreatment and the control test, respectively. Consequently, when the fermentative liquid was added as an external denitrification carbon source, the effluent total nitrogen decreased to Class A of the discharge standard for pollutants in rural wastewater treatment plants in most areas of China.     

Acid Orange 7 degradation using methane as the sole carbon source and electron donor

• AO7 degradation was coupled with anaerobic methane oxidation. • Higher concentration of AO7 inhibited the degradation. • The maximum removal rate of AO7 reached 280 mg/(L·d) in HfMBR. • ANME-2d dominated the microbial community in both batch reactor and HfMBR. • ANME-2d alone or synergistic with the partner bacteria played a significant role. Azo dyes are widely applied in the textile industry but are not entirely consumed during the dyeing process and can thus be discharged to the environment in wastewater. However, azo dyes can be degraded using various electron donors, and in this paper, Acid Orange 7 (AO7) degradation performance is investigated using methane (CH₄) as the sole electron donor. Methane has multiple sources and is readily available and inexpensive. Experiments using ¹³C-labeled isotopes showed that AO7 degradation was coupled with anaerobic oxidation of methane (AOM) and, subsequently, affected by the initial concentrations of AO7. Higher concentrations of AO7 could inhibit the activity of microorganisms, which was confirmed by the long-term performance of AO7 degradation, with maximum removal rates of 8.94 mg/(L·d) in a batch reactor and 280 mg/(L·d) in a hollow fiber membrane bioreactor (HfMBR). High-throughput sequencing using 16S rRNA genes showed that Candidatus Methanoperedens, affiliated to ANME-2d, dominated the microbial community in the batch reactor and HfMBR. Additionally, the relative abundance of Proteobacteria bacteria (Phenylobacterium, Pseudomonas, and Geothermobacter) improved after AO7 degradation. This outcome suggested that ANME-2d alone, or acting synergistically with partner bacteria, played a key role in the process of AO7 degradation coupled with AOM.