不同COD浓度下低基质厌氧氨氧化的启动特征

采用厌氧序批式反应器(ASBR)处理NH4+-N和NO2--N浓度分别为(25. 00±0. 40) mg·L~(-1)和(33. 00±0. 60) mg·L~(-1)的模拟废水,在温度为30℃时,投加乙酸钠控制COD浓度分别为5. 00、15. 00、30. 00和50. 00 mg·L~(-1),研究对厌氧氨氧化启动的影响.结果表明:①4种COD浓度下分别经过74、94、106和129 d均能成功启动厌氧氨氧化. COD浓度为15. 00 mg·L~(-1)和30. 00 mg·L~(-1)时,反应器脱氮性能较好,稳定运行后,平均出水NH4+-N浓度分别为1. 98 mg·L~(-1)和1. 89 mg·L~(-1),平均出水NO2--N浓度低于0. 62 mg·L~(-1),平均出水TN浓度分别为2. 37、2. 28 mg·L~(-1);②启动过程中反硝化对脱氮的平均贡献率逐渐降低至4. 78%、9. 59%、10. 21%和36. 50%,厌氧氨氧化对脱氮的平均贡献率逐渐上升至95. 22%、90. 41%、89. 79%和63. 50%;③厌氧氨氧化活性分别在第44、76、86和114 d时超过反硝化活性,最后分别达到0. 700、0. 690、0. 670和0. 510mg·(g·h)~(-1),反硝化活性分别为0. 110、0. 130、0. 240和0. 410 mg·(g·h)~(-1).该研究结果可为厌氧氨氧化技术在实际工程中的应用提供参考.     

污水厂污泥与厨余垃圾厌氧/混合厌氧消化研究进展

本文主要对国内外城市污水厂污泥与厨余垃圾混合厌氧消化的研究进行了综述,介绍了厌氧消化技术在污水厂污泥和厨余垃圾处理处置中的应用,对两种废物单独厌氧消化和混合厌氧消化技术进行了比较,分析了城市污水厂污泥与厨余垃圾混合厌氧消化的可行性以及工艺参数对混合厌氧消化的影响,并对城市污水厂污泥与厨余垃圾的混合厌氧消化技术的研究和应用提出了展望。     

微生物对石油烃类的降解机理

文章分析了生物降解需要的条件、环境因素对石油烃微生物降解的影响,石油烃类的有氧降解机理、有氧降解方式,石油烃类的厌氧降解机理、厌氧降解过程中某些无机含氧化合物作受氢体的递氢过程,石油烃类化合物微生物降解难易程度,提出了以后应进一步重视原油的生物降解应用于我国微生物采油的研究。     

前置回流式反硝化-硝化组合反应器（UBF-BAF）处理高氨氮制药废水

针对常州市某生化制药公司高浓度氨氮制药废水SBR处理工艺,改用前置回流式UBF-BAF组合工艺进行了试验研究.结果表明,在厌氧生物膜的作用下,前置式UBF反应器内不仅依次发生了有机物分解的水解酸化和产甲烷的碳化反应,而且还同步发生了含氮化合物的反硝化和厌氧氨氧化反应,表现出COD、氨氮、亚硝酸盐氮和总氮浓度同步降低.B...     

厌氧颗粒污泥膨胀床（EGSB）反应器处理高硫酸盐有机废水的厌氧生物脱硫试验

采用人工配制的高硫酸盐有机废水模拟青霉素废水,研究其经过EGSB反应器厌氧处理后的出水,在厌氧条件下采用生物法将其转化为单质硫的脱硫工艺.当保持S2-/NO3-在1.7—1.8时,S2-保持高去除率且不会进一步生成硫酸盐.脱硫反应器与EGSB反应器联合运行,处理系统运行参数为：进水COD浓度为6000 mg·L-1,硫...     

天然和水热合成针铁矿对有机物厌氧分解释放CH4的影响

以乙酸钠为碳源,通过序批式实验研究了天然和水热合成针铁矿对铁还原菌-甲烷菌厌氧微生物生化系统中CH4释放量的影响.通过对实验过程中气体组分、溶液中总有机碳(TOC)、总无机碳(TIC)、Fe2+等主要组分的分析测定和固体产物的X-射线衍射(XRD)分析,结合对矿物的比表面(BET)、XRD、X-射线荧光光谱(XRF)分析表征,探讨了针铁矿在铁还原菌存在下对有机物厌氧消化产CH4的影响和作用机制.利用修正Gompertz方程对累计产CH4和CO2量进行拟合.结果表明,与对照实验组相比,添加针铁矿能使CH4累计释放量提前60～78 d达到最大值,并且能有效降低CO2释放量达30%～67%,添加水热合成针铁矿较之天然针铁矿更能促进CH4释放和减少CO2释放;固体产物分析表明添加针铁矿促使菱铁矿形成固定部分CO2.     

玉米秸秆厌氧降解复合菌系的微生物群落结构

以不同来源具有木质纤维素降解能力的环境样品为接种物,以玉米秸秆为唯一碳源,进行了秸秆厌氧降解微生物的驯化培养,构建了8组复合菌系.复合菌系的产气周期为30～50 d,玉米秸秆的总固体(TS)去除率在30%～40%之间.其中6组的甲烷产量(以TS计)为62.1～118.4 mL.g-1,发酵液中挥发性有机酸主要为乙酸、丙酸及丁酸(100～500 mg.L-1),发酵终产物pH为6.5～6.7;而另外2组的甲烷产量较低,在8.5～9.7 mL.g-1之间,但乙酸浓度较高(1 200 mg.L-1左右),发酵终产物pH为5.6～5.9.通过16S rRNA基因克隆文库方法对复合菌系中细菌及古菌的群落结构进行了多样性解析,结果表明细菌主要分为8个不同的类群,其中厚壁菌门(Firmicutes)、拟杆菌门(Bacteroidetes)、互养菌门(Synergistetes)及热袍菌门(Thermotogae)为优势菌群,分别占细菌克隆总数的37.8%、34.3%、11.6%和6.4%;古菌属于甲烷微菌纲(Methanomicrobia)和甲烷杆菌纲(Methanobacteria),分别占古菌克隆总数的61.1%和38.9%.对主要功能菌群在秸秆厌氧降解产甲烷过程中发挥的作用进行了探讨.     

Application of high OLR-fed aerobic granules for the treatment of low-strength wastewater：Performance, granule morphology and microbial community

Aerobic granules, pre-cultivated at the organic loading rate (OLR) of 3.0 kg COD/(m3 ·day), were used to treat low-strength wastewater in two sequencing batch reactors at low OLRs of 1.2 and 0.6 kg COD/(m3 ·day), respectively. Reactor performance, evolution of granule morphology, structure and microbial community at low OLRs under long-term operation (130 days) were investigated. Results showed that low OLRs did not cause significant damage to granule structure as a dominant granule morphology with size over 540 μm was maintained throughout the operation. Aerobic granules at sizes of about 750 μm were finally obtained at the low OLRs. The granule reactors operated at low OLRs demonstrated effective COD and ammonia removals (above 90%), smaller granule sizes and less biomass. The contents of extracellular polymeric substances in the granules were decreased while the ratios of exopolysaccharide/exoprotein were increased (above 1.0). The granules cultivated at the low OLRs showed a smoother surface and more compact structure than the seeded granules. A significant shift in microbial community was observed but the microbial diversity remained relatively stable. Confocal Laser Scanning Microscopy observation showed that the live cells were spread throughout the whole granule, while the dead cells were mainly concentrated in the outer layer of the granule, and the proteins, polysaccharides and lipids were mainly located in the central regime of the granule. In conclusion, granules cultivated at high OLRs show potential for treating low-strength organic wastewater steadily under long-term operation.     

Biomethanation of brewery wastewater using an anaerobic upflow blanket filter

A large flow of effluent is generated from brewery plants and needs treatment before discharging into the environment. A laboratory-scale investigation was conducted to examine the effectiveness of the anaerobic upflow blanket filter (UBF) process for the biomethanation of a brewery effluent. The results show that the process, when operated at ambient temperatures of 20–29°C and influent chemical oxygen demand (COD) of 2440 mg/l, could remove the majority of the organic matter at a low hydraulic retention time. The process produced a potentially usable energy. These results compare favorably with the results obtained from investigations into the biomethanation of brewery effluent using other anaerobic processes.     

Heavy-metal ion complexation by particulate matter in the leachate of solid waste: a multi-method approach

The metal ion binding characteristics of particulate matter obtained from column experiments on the anaerobic digestion of solid waste were studied using a titrimetric approach. The experimental set-up allowed us to study the dynamics of particle bound ligand concentrations during digestion processes typically found in landfills.We developed a continuous titration method by simultaneously using a Cd-sensitive and pH electrode and combining metal and acid/base titrations. This technique allows for a more precise determination of pK_a-log K_M pairs for each ligand than metal titrations alone. The results were compared with titration methods using differential pulse anodic stripping voltammetry (DPASV) and atomic absorption spectroscopy (AAS) with longer equilibration times in order to further characterize ligand properties such as reaction kinetics, the electrochemical lability of the respective complex during DPASV, the distinction between metal adsorption to particulate matter and metal complexation by soluble ligands adhered to particles, reversibility of the binding process by competition studies, and resistance against purging with nitrogen gas.The properties of seven major metal binding ligands were identified and assignments to the most likely functional groups were made. The most important ligand properties are for ligand A: pK_a ≈ 9.2, log K_cd ≈ 7.0 fast reaction kinetics (mercapto groups); ligand B: pK_a = 4.8, log K_Cd ≈ 6.0, slow reaction kinetics (chelates with 3 or 4 carboxylic groups); ligand C: pK_a ≈ 6.0, log K_Cd ≈ 13.0, irreversible metal binding at basic pH-values (uptake inside bacterial cells); ligand D: pK_a = 7.7, log K_Cd = 4.0, runs parallel to N content of particulate matter with digestion time (primary amines neighboring oxo groups); ligand E: pK_a ≈ 12.0, log K_Cd = 9.0, runs parallel to P content of particulate matter (phosphate); ligand F:pK_a > 9.0, log K_{Cdf = pKa + 0.4}, runs parallel to N content of particulate matter (primary amines neighboring SH groups); and ligand G: pK_a ≤ 4.8, log K_Pb ≈ 4.3, strong Pb²⁺ ligand, even at low pH-values.Metal ions were found to be irreversibly bound by ligand C at low heavy-metal concentratins, whereas at higher concentrations the binding is reversible and can be predicted using the mass of the digestion process (methanogenic phase). All other ligands have their concentration maximum in the transition phase between acetogenic and methanogenic phase.