好氧污泥颗粒化影响因素的分析

结合近年来国内外学者关于好氧污泥颗粒化的研究成果,对影响好氧污泥颗粒化的影响因素进行了较为深入系统的分析,提出了适宜的运行控制条件及所需注意的问题。     

连续曝气SBR快速培养AGS及反应器流态的CFD解析

配制模拟番茄酱废水,在高径比为10的SBR反应器中,考察连续曝气条件下好氧颗粒污泥（AGS）的除污性能和微生物特性的变化。建立流体动力学模型,模拟反应器中气〖CD*2〗液〖CD*2〗污泥三相流的流态,以了解其对污泥颗粒化的影响机理。结果表明：污泥完全颗粒化后,对番茄酱废水中COD、NH3-N和PO3-4-P的去除率分别为94.37%、93.55%和9092%;绿弯菌门(Chloroflexi)、拟杆菌门(Bacteroidetes)和厚壁菌门(Firmicutes)丰度显著提高,假丝酵母菌（Candidatus saccharibacteria）为除磷功能微生物;反应器内的流态结构呈环流和旋涡流,水力剪切力的大小与颗粒粒径呈正相关,颗粒形态与流态分布有关。     

Betaine removal during thermo- and mesophilic aerobic batch biodegradation of beet molasses vinasse: influence of temperature and pH on the progress and efficiency of the process

The key issue in achieving a high extent of biodegradation of beet molasses vinasse is to establish the conditions for the assimilation of betaine, which is the main pollutant in this high-strength industrial effluent. In the present study, aerobic batch biodegradation was conducted over the temperature range of 27-63°C (step 9°C), at a pH of 6.5 and 8.0, using a mixed culture of bacteria of the genus Bacillus. Betaine was assimilated at 27-54°C and the pH of 8.0, as well as at 27-45°C and the pH of 6.5. The processes where betaine was assimilated produced a high BOD(5) removal, which exceeded 99.40% over the temperature range of 27-45°C at the pH of 8.0, as well as at 27°C and the pH of 6.5. Maximal COD removal (88.73%) was attained at 36°C and the pH of 6.5. The results indicate that the process can be applied on an industrial scale as the first step in the treatment of beet molasses vinasse.     

HCR工艺处理富硫酸盐味精废水的试验研究

试验研究结果表明，HCR工艺完全能够适应处理具有浓度CODcr和SO^2-4的味精废水，在进水CODcr的浓度高于10000mg/L,SO^2-4浓度主同于14000mg/L时，其CODcr的去除率在80％以上，说明SO^2-4离子不影响HCR工艺去除有机物的能力，HCR工艺容积负荷和污泥负荷都很高，污泥产生量少，因此其综合成本比一般方法要低，HCR工艺应该是处理味精放心水的最佳推选工艺之一，但是运行过程中，泡沫问题仍然值得注意。     

Individual stages of bacterial dichloromethane degradation mapped by carbon and chlorine stable isotope analysis

The fractionation of carbon and chlorine stable isotopes of dichloromethane(CH_2Cl_2,DCM)upon dechlorination by cells of the aerobic methylotroph Methylobacterium extorquens DM4 and by purified DCM dehalogenases of the glutathione S-transferase family was analyzed.Isotope effects for individual steps of the multi-stage DCM degradation process,including transfer across the cell wall from the aqueous medium to the cell cytoplasm,dehalogenase binding,and catalytic reaction,were considered.The observed carbon and chlorine isotope fractionation accompanying DCM consumption by cell supensions and enzymes was mainly determined by the breaking of C\Cl bonds,and not by inflow of DCM into cells.Chlorine isotope effects of DCM dehalogenation were initially masked in high density cultures,presumably due to inverse isotope effects of non-specific DCM oxidation under conditions of oxygen excess.Glutathione cofactor supply remarkably affected the correlation of variations of DCM carbon and chlorine stable isotopes(Δδ~(13)C/Δδ~(37)Cl),increasing corresponding ratio from 7.2–8.6 to 9.6–10.5 under conditions of glutathione deficiency.This suggests that enzymatic reaction of DCM with glutathione thiolate may involve stepwise breaking and making of bonds with the carbon atom of DCM,unlike the uncatalyzed reaction,which is a one-stage process,as shown by quantum-chemical modeling.     

Organic and nitrogen removal from landfill leachate in aerobic granular sludge sequencing batch reactors

Granule sequencing batch reactors (GSBR) were established for landfill leachate treatment, and the COD removal was analyzed kinetically using a modified model. Results showed that COD removal rate decreased as influent ammonium concentration increasing. Characteristics of nitrogen removal at different influent ammonium levels were also studied. When the ammonium concentration in the landfill leachate was 366 mg L⁻¹, the dominant nitrogen removal process in the GSBR was simultaneous nitrification and denitrification (SND). Under the ammonium concentration of 788 mg L⁻¹, nitrite accumulation occurred and the accumulated nitrite was reduced to nitrogen gas by the shortcut denitrification process. When the influent ammonium increased to a higher level of 1105 mg L⁻¹, accumulation of nitrite and nitrate lasted in the whole cycle, and the removal efficiencies of total nitrogen and ammonium decreased to only 35.0% and 39.3%, respectively. Results also showed that DO was a useful process controlling parameter for the organics and nitrogen removal at low ammonium input.     

陆地石油污染生物降解技术的进展

生物治理石油环境污染具有处理费用低、效果好、无二次污染等优点，近年来得到广泛重视和发展应用，并已在治理土壤、岩石及地下水石油污染等方面取得了较好的效果。在此对就地或集中治理过程的近期发展进行了综述，讨论了强化治理过程的途径与展望以及在我国实验室和现场开发的前景。     

生物转鼓过滤器中一株好氧反硝化菌的分离鉴定与降解特性研究

从稳定运行处理NO废气的生物转鼓过滤器中筛选分离到1株好氧反硝化细菌DN3,发现该菌在好氧条件下能有效去除培养液中的硝酸根,培养28h后的反硝化率大于80%.扫描电镜结果显示,菌株DN3为短杆菌,带有鞭毛,大小为(0.4～0.8)μm ×(2.0～2.5)μm,菌落表面呈现乳白色.通过生理生化特性及16S rRNA基因...     

Use of additive and pretreatment to control odors in municipal kitchen waste during aerobic composting

The effects of adding a bulking agent and chemically pretreating municipal kitchen waste before aerobic composting were studied using a laboratory-scale system. The system used 20-L reactors and each test lasted 28 days. The objective was to decrease NH₃ and H₂S emissions during composting. The bulking agent, dry cornstalks, was mixed with the kitchen waste to give a mixture containing 15% (wet weight) bulking agent. A combined treatment was also conducted, in which kitchen waste mixed with the bulking agent was pretreated with ferric chloride (FeCl₃). Less leachate was produced by the composted kitchen waste mixed with bulking agent than by the kitchen waste alone, when the materials had reached the required maturity. The presence of cornstalks also caused less H₂S to be emitted, but had little impact on the amount of NH₃ emitted. The FeCl₃ was found to act as an effective chemical flocculant, and its presence significantly decreased the amounts of NH₃ and H₂S emitted. Kitchen waste mixed with cornstalks and treated with FeCl₃ emitted 42% less NH₃ and 76% less H₂S during composting than did pure kitchen waste.