Bulking in aerobic biological systems treating dairy processing wastewaters

The aerobic biological treatment of dairy processing wastewaters is associated with poor sludge settling bulking, and this has been largely linked to the high soluble organic component in these wastewaters, and high chemical oxygen demand COD: NP ratios. Strategies to minimize sludge bulking in activated sludge systems or sequencing batch reactors have been identified and include the operation of these systems under extended aeration conditions, and the incorporation of an anaerobic or anoxic zone to facilitate the degradation of the readily metabolized lactose in the wastewater. Filamentous bacteria linked with sludge bulking in the industry have been associated with various operating conditions.     

邻苯二酚对厌氧微生物的毒性作用

用厌氧颗粒污泥处理含不同浓度的邻苯二酚的废水,以甲烷气体的产气速率来衡量厌氧颗粒污泥中产甲烷菌的活性,研究了它们对厌氧污泥的毒性。研究结果可为制革废水的厌氧处理提供依据。     

Microbial analyses by fluorescence in situ hybridization of well-settled granular sludge in brewery wastewater treatment plants

The characteristics of granular sludge from full-scale upflow anaerobic sludge blanket reactors used for the treatment of brewery wastewater were investigated. Fluorescence in situ hybridization (FISH) analyses of settled granules from a reactor that had been treating brewery wastewater stably at COD removal rates of over 90% for more than 6 months showed that a methanogen of the genus Methanosaeta was predominant near the granule surface and that Bacteria were not abundant. The center of the granules was composed of dead or resting cells, or both, which were used as a support for active archaeal and bacterial cells near the surface. Periodic analysis of granules from full-scale plants showed that granules containing methanogens deep within them tended to float. Granules with a Bacteria layer on the surface also tended to float. On the basis of these findings, well-settled granules are considered to have methanogens that develop near the granule surface so that the gases generated during methane fermentation are readily released.     

Anaerobic fluidized bed membrane bioreactor for wastewater treatment

Anaerobic membrane bioreactors have potential for energy-efficient treatment of domestic and other wastewaters, membrane fouling being a major hurdle to application. It was found that fouling can be controlled if membranes are placed directly in contact with the granular activated carbon (GAC) in an anaerobic fluidized bed bioreactor (AFMBR) used here for post-treatment of effluent from another anaerobic reactor treating dilute wastewater. A 120-d continuous-feed evaluation was conducted using this two-stage anaerobic treatment system operated at 35 °C and fed a synthetic wastewater with chemical oxygen demand (COD) averaging 513 mg/L. The first-stage was a similar fluidized-bed bioreactor without membranes (AFBR), operated at 2.0-2.8 h hydraulic retention time (HRT), and was followed by the above AFMBR, operating at 2.2 h HRT. Successful membrane cleaning was practiced twice. After the second cleaning and membrane flux set at 10 L/m(2)/h, transmembrane pressure increased linearly from 0.075 to only 0.1 bar during the final 40 d of operation. COD removals were 88% and 87% in the respective reactors and 99% overall, with permeate COD of 7 ± 4 mg/L. Total energy required for fluidization for both reactors combined was 0.058 kWh/m(3), which could be satisfied by using only 30% of the gaseous methane energy produced. That of the AFMBR alone was 0.028 kWh/m(3), which is significantly less than reported for other submerged membrane bioreactors with gas sparging for fouling control.     

氯化钠和铬鞣剂对厌氧微生物毒性的研究

用甲烷气体的产气速率来衡量厌氧颗粒污泥的产甲烷活性 ,以厌氧颗粒污泥处理含不同浓度氯化钠和铬鞣剂的废水 ,研究氯化钠和铬鞣剂对厌氧颗粒污泥的毒性。研究结果可为制革废水的厌氧处理提供参考依据。     

厌氧颗粒污泥中毒的判断及处理方法

介绍了利用厌氧法处理制浆废水过程中,厌氧颗粒污泥中毒的初步判断及厌氧颗粒污泥恢复活性的处理方法。     

Recent development of anaerobic digestion processes for energy recovery from wastes

Anaerobic digestion leads to the overall gasification of organic wastewaters and wastes, and produces methane and carbon dioxide; this gasification contributes to reducing organic matter and recovering energy from organic carbons. Here, we propose three new processes and demonstrate the effectiveness of each process. By using complete anaerobic organic matter removal process (CARP), in which diluted wastewaters such as sewage and effluent from a methane fermentation digester were treated under anaerobic condition for post-treatment, the chemical oxygen demand (COD) in wastewater was decreased to less than 20 ppm. The dry ammonia-methane two-stage fermentation process (Am-Met process) is useful for the anaerobic treatment of nitrogen-rich wastes such as waste excess sludge, cow feces, chicken feces, and food waste without the dilution of the ammonia produced by water or carbon-rich wastes. The hydrogen-methane two-stage fermentation (Hy-Met process), in which the hydrogen produced in the first stage is used for a fuel cell system to generate electricity and the methane produced in the second stage is used to generate heat energy to heat the two reactors and satisfy heat requirements, is useful for the treatment of sugar-rich wastewaters, bread wastes, and biodiesel wastewaters.     

A comparison of two bench‐scale anaerobic systems used for the treatment of dairy effluents

The objective of this work was to compare two anaerobic reactor configurations, a hybrid upflow anaerobic sludge blanket (UASBh) reactor and an anaerobic sequencing batch reactor with immobilised biomass (ASBBR) treating dairy effluents. The reactors were fed with effluent from the milk pasteurisation process (effluent 1—E1) and later with effluent from the same process combined with the one from the cheese manufacturing (effluent 2—E2). The ASBBR reactor showed average organic matter removal efficiency of 95.2% for E1 and 93.5% for E2, while the hybrid UASB reactor showed removal efficiencies of 90.3% and 80.1% respectively.     

改进型AGSFB处理麦草制浆中段废水

用改进型AGSFB(厌氧颗粒污泥流化床)处理麦草制浆中段废水,在常温(23±3)℃条件下,研究讨论HRT、回流比以及上升流速、容积负荷等因素对中段废水处理的影响。在停留时间为20h、回流比为5:1、上升流速为2.3m·h-1、容积负荷为0.92kgCOD·(m3·d)-1的条件下,CODCr、色度的去除率分别为53%、40%,可以有效地去除麦草浆中段废水的COD和色度。     

制浆造纸废水处理中常见厌氧反应器

介绍并比较了工程中常见的几种厌氧反应器的工艺特点及其参数选择,并指出了实际运行中需要注意的问题。     

新型(IC)厌氧反应器处理酒厂废水的试验研究

采用新型的内循环(IC)厌氧反应器处理酒厂废水,研究了水力条件、进水方式和温度对IC厌氧反应器形成内循环和运行性能以及COD去除率的影响,进而确定IC厌氧反应器最适宜的容积负荷率。研究结果表明:最佳的进水方式是以切线方向从底部进入,这时,在一定的进水速度下,可形成缓慢的上升旋流和保持良好的内循环,从而能达到较好的污泥膨胀率和较高的COD去除率;最佳的水力停留时间为6h;最适宜的进水温度为35℃,这时的污泥膨胀率为68%,COD去除率为80%;IC厌氧反应器最适宜容积负荷率为20kg(/m3.d),此时COD去除率为80%左右。     

乳制品加工废水的深度处理及资源回用研究进展与策略

乳制品加工废水是一种典型的食品工业废水,因其具有排水量大、有机物含量高、水质稳定性差等特点,直接排放极易污染受纳水体。乳制品加工废水的深度处理及资源回用已成为实现该行业可持续发展的关键。本文对近年来乳制品加工废水的处理方法和资源化开发的相关研究进行概括总结,分析了各种方法的优势和工业应用的瓶颈问题,并提出了一种泡沫分离-序列间歇式活性污泥法（sequencing batch reactor,SBR）-膜分离相结合的废水综合处理策略。首先,利用泡沫分离法回收乳制品加工废水中的酪蛋白,泡沫液中的沉淀物质可作为牲畜饲料添加剂,而溶液可用作微生物发酵的培养基来合成清洁燃料或构建微生物燃料电池。随后,运用SBR法降低出水的COD、BOD₅和磷酸盐含量。最后,利用膜分离法脱除废水中的硝酸盐,并将其用于生产生物肥料。该策略的废水深度处理周期较短,浓缩液处理后可实现资源回收,淡化液可作为循环冷却或农田灌溉用水使用。     

Multi-scale individual-based model of microbial and bioconversion dynamics in aerobic granular sludge

Aerobic granular sludge is a novel compact biological wastewater treatment technology for integrated removal of COD (chemical oxygen demand), nitrogen, and phosphate charges. We present here a multiscale model of aerobic granular sludge sequencing batch reactors (GSBR) describing the complex dynamics of populations and nutrient removal. The macro scale describes bulk concentrations and effluent composition in six solutes (oxygen, acetate, ammonium, nitrite, nitrate, and phosphate). A finer scale, the scale of one granule (1.1 mm of diameter), describes the two-dimensional spatial arrangement of four bacterial groups--heterotrophs, ammonium oxidizers, nitrite oxidizers, and phosphate accumulating organisms (PAO)--using individual based modeling (IbM) with species-specific kinetic models. The model for PAO includes three internal storage compounds: polyhydroxyalkanoates (PHA), poly phosphate, and glycogen. Simulations of long-term reactor operation show how the microbial population and activity depends on the operating conditions. Short-term dynamics of solute bulk concentrations are also generated with results comparable to experimental data from lab scale reactors. Our results suggest that N-removal in GSBR occurs mostly via alternating nitrification/denitrification rather than simultaneous nitrification/denitrification, supporting an alternative strategy to improve N-removal in this promising wastewater treatment process.     

基于高分子载体与活性炭对比处理白酒废水的研究

实验以高分子材料做载体,与多孔颗粒活性炭(GAC)在完全相同的条件下,作厌氧流化床固定化微生物处理白酒废水的对比性研究.6d后加入已经分离出来的高效厌氧微生物,结果表明,新型高分子载体能有效促进厌氧菌固定化,可比GAC缩短反应器启动时间12d左右;且在进水COD值为3957.4mg/L、pH值为7.30、膨胀率为50%、水力停留时间为9h的条件下,COD的云除率为90.5%.     

蔗渣湿法堆垛备料废水的治理研究

现在不少工厂甘蔗渣采用湿法堆垛，但湿法堆垛产生了大量高浓度有机废水，这对备料厂的废水处理增加了不小的难度。本文对甘蔗渣喷淋高浓度有机废水进行了厌氧处理和厌氧—好氧处理的实验研究。结果表明：当废水进水pH在7．5，CODcr及BOD5分别在6500—10000mg/L和4000一6500mg/L时，经过厌氧处理后，coD。和BOD5去除率能达到90％和94％；经过厌氧—好氧处理后，CODcr和BOD5去除率能达到95％以上，都取得了显著的效果。     

啤酒工业废水治理技术研究

结合啤酒企业的实际情况,对啤酒工业废水的治理现状进行探讨,提出一条合理的治理途径,即实行“清浊分流”,对高浓度人机废水进行厌氧（ＵＡＳＢ）＋接触氧化二级生化处理,可实现啤酒废水的达标排放,且费用低,操作管理方便。     

有机负荷对CSTR-UASB两相厌氧系统的影响

采用连续流CSTR-UASB两相厌氧反应装置,CSTR以人工配制的红糖水作为发酵底物,其液相末端产物作为UASB的反应底物,污水处理厂剩余污泥作为反应器的启动污泥,反应器实现稳定运行（CSTR为乙醇型发酵）后,在其它参数不变的情况下,通过改变有机负荷,研究其对CSTR-UASB两相厌氧系统的影响.有机负荷从12 kg/（m^3·d）提升至32 kg/（m^3·d）的过程分为六个阶段,结果表明厌氧活性污泥产氢能力持续升高,在有机负荷为32 kg/（m^3·d）时,最大产氢量为12.8L/d,较初始有机负荷12 kg/（m^3·d）时提高了71.9％;产甲烷量随有机负荷的升高先增大后减小,在有机负荷为24 kg/（m^3·d）时,最大产甲烷量为18.5L/d;当有机负荷提高至28 kg/（m^3·d）时,总COD去除率达最大值72％.因此,CSTR-UASB两相厌氧系统对红糖废水具有较好的降解效果,同时能源回收效率较高.     

新型高效废水厌氧生物处理反应器研究进展

近年来,废水的厌氧生物处理工艺以其独特的技术优势受到人们的广泛关注,并发展了以厌氧膨胀颗粒污泥床、内循环式厌氧反应器、厌氧上流污泥床-过滤器和厌氧序批式间歇反应器等为代表的第三代新型高效厌氧反应器.本文综述了这些厌氧反应器的形成、结构、工作原理以及典型应用,比较了这些系统的运行特点及存在的问题,最后展望了该研究领域的发展及这些系统的应用前景.     

Effect of temperature on the fate of genes encoding tetracycline resistance and the integrase of class 1 integrons within anaerobic and aerobic digesters treating municipal wastewater solids

The objective of this research was to investigate the ability of anaerobic and aerobic digesters to reduce the quantity of antibiotic resistant bacteria in wastewater solids. Lab-scale digesters were operated at different temperatures (22 °C, 37 °C, 46 °C, and 55 °C) under both anaerobic and aerobic conditions and fed wastewater solids collected from a full-scale treatment facility. Quantitative PCR was used to track five genes encoding tetracycline resistance (tet(A), tet(L), tet(O), tet(W), and tet(X)) and the gene encoding the integrase (intI1) of class 1 integrons. Statistically significant reductions in the quantities of these genes occurred in the anaerobic reactors at 37 °C, 46 °C, and 55 °C, with the removal rates and removal efficiencies increasing as a function of temperature. The aerobic digesters, in contrast, were generally incapable of significantly decreasing gene quantities, although these digesters were operated at much shorter mean hydraulic residence times. This research suggests that high temperature anaerobic digestion of wastewater solids would be a suitable technology for eliminating various antibiotic resistance genes, an emerging pollutant of concern.     

An overview of various technologies for the treatment of dairy wastewaters

Dairy industries have shown tremendous growth in size and number in most countries of the world. These industries discharge wastewater which is characterized by high chemical oxygen demand, biological oxygen demand, nutrients, and organic and inorganic contents. Such wastewaters, if discharged without proper treatment, severely pollute receiving water bodies. In this article, the various recent advancements in the treatment of dairy wastewater have been discussed and the areas where further research is needed have been identified.