Anaerobic digestion of tannery soak liquor with an aerobic post-treatment

The leather industry occupies a place of prominence in the Indian economy due to its massive potential for employment, growth and exports. The potential environmental impact of tanning is significant. This study focuses on tannery soak liquor, generated by the soaking of hides and skins, which is characterised by high organic load and high salinity. For these reasons, the soak liquor should be segregated and pre-treated separately before being mixed with the composite wastewater, made of all other streams mixed together. The anaerobic digestion of tannery soak liquor was studied using a UASB. COD removal reached 78% at an OLR of 0.5 kg COD m(-3) d(-1), a HRT of 5 days and a TDS concentration of 71 gl(-1). The combination of the UASB with an aerobic post-treatment enhanced the performance of the overall wastewater treatment process and the COD removal efficiency of the combined anaerobic/aerobic treatment system reached 96%. However, for effective operation, the system had to be operated at very low OLRs, which affects the economic viability of such a process.     

Hazards of Industrial Anaerobic Digester Effluent Discharges to Sewer

With the increase in use of anaerobic digesters in industry, there is concern that the direct discharge of effluents (from such plants) to sewer could cause explosive conditions because of increased methane production. The study explored this issue by undertaking laboratory analyses of methane-production rates of sewage and anaerobic digester effluents. A particular sewer was studied and basic calculations were undertaken to try and establish the risk of methane build-up to dangerous levels.     

白龙港污水处理厂污泥厌氧消化系统的设计和调试

白龙港污泥处理工程主要处理白龙港污水处理厂200×104 m3/d污水处理产生的污泥,采用浓缩、中温厌氧消化、污泥脱水和部分脱水污泥干化处理工艺,消化产生的沼气用于加热消化池污泥,多余的沼气作为能源干化脱水污泥。干化处理后冷凝水的余热回收辅助用于污泥消化系统供热。介绍了污泥厌氧消化系统的设计参数、工艺特点及调试情况,可供设计人员参考。     

我国城市污水厂污泥厌氧消化系统的运行现状

对我国400余座城市污水厂污泥处理工艺的调查表明,目前采用污泥厌氧消化工艺的仅46家,主要采用浓缩／中温厌氧／脱水工艺,采用一级厌氧消化和二级厌氧消化的厂家数量接近,其中仅25家的污泥消化系统正在运行,沼气产量约为14×10^4m^3／d,另有6家在调试。污泥厌氧消化工艺在实际应用中仍存在着较多亟待解决的问题,沼气产率低和利用率不高大大削弱了该工艺的优势。     

臭氧氧化/厌氧消化工艺处理CEPT污泥的研究

上海市白龙港污水处理厂采用化学一级强化处理工艺（CEPT），污泥产量大且稳定性差，直接脱水填埋很难满足有关环保要求，因此对其进行稳定化和减量化研究是污泥处理、处置工作的重中之重。为此，开展了臭氧氧化／厌氧消化工艺处理该类污泥的中试研究。结果表明，当臭氧投量为0．08kg／kgDS、臭氧氧化污泥量占进泥量的比例为67％、污泥投配率为5％时，臭氧氧化对厌氧消化的促进作用比较明显，对有机物的降解率较单纯厌氧消化的高约6．3％，产气量增加了近20．1％。此外，投加臭氧还能改善污泥的脱水性能，并减少了脱水时助凝剂的投量。     

传统厌氧消化工艺处理餐饮垃圾的试验研究

对餐饮垃圾进行预处理后，采用传统厌氧消化工艺对其进行处理，考察了对COD、鸭的去除效果和产气中的甲烷含量，分析了容积负荷对反应器厌氧消化性能的影响，确定了较佳的控制参数。结果表明，在反应器温度为（35±1）℃、HRT〉20d、容积负荷〈4．0gCOD／（L·d）的条件下，该工艺对COD的去除率〉80％，对鸭的去除率〉77％；产气中的甲烷含量〉58％。采用该工艺处理餐饮有机垃圾宜采用间歇搅拌，碱度可大于5000mg／L以确保体系的pH值缓冲能力；应控制VFA〈500mg／L，pH值在7．0～7，2。     

城市污水处理厂剩余污泥厌氧消化试验研究

以北京市某污水处理厂的剩余污泥为研究对象，对该污泥的理论产气量进行了估算，考察了投加接种污泥和未投加接种污泥条件下污泥厌氧消化的产气情况，并分析了污泥消化前、后的泥质特点。结果表明：与未接种条件相比，污泥厌氧消化前采用投加接种污泥的方式可大大促进消化反应的进行，加快污泥的产气速率，使厌氧消化周期缩短近1／4，但对污泥的总产气量影响较小；在厌氧消化正常运行条件下，污泥产气量达到总产气量的90％时所需反应时间约为16d，可将其作为污泥厌氧消化工艺较为理想的消化周期；剩余污泥的消化性能差、产气率低、试验产气量占理论产气量的比例〈50％，在工程上单独的剩余污泥不宜采用厌氧消化工艺处理。     

Enhancement of Anaerobic Digestion Using Duckweed (Lemna minor) Enriched with Iron

ABSTRACT This paper describes the enhancement of biogas production in laboratory-scale anaerobic digesters (with batch and semi-continuous operation) using iron-enriched duckweed as a supplement to the digestion of feedstock. The relationship between the level of enhancement achieved and the retention period of the digesters was also investigated. The trials demonstrated that, in batch digesters, iron-enriched duckweed significantly improved the rate of microbial succession. Batch digesters receiving no duckweed took 40 days to reach peak methane production compared to 15 days when duckweed was added. In the semi-continuous digesters, an increase in gas production of about 44% was observed.     

自热式高温好氧消化技术用于污泥处理

系统介绍了自热式高温好氧消化(ATAD)的原理及特点，并详细介绍了ATAD在国外(特别是欧洲和北美)的应用现状及在我国的应用前景。自热式高温好氧消化技术具有反应速度快、停留时间短、病原菌灭活效果好等优点，特别适合于小规模污水处理厂污泥的处理，在我国还没有应用实例。     

中温两相厌氧消化工艺处理混合污泥的效能

采用中温(35℃)两相厌氧消化工艺处理初沉污泥与剩余污泥的混合样(1∶1),以实现污泥的稳定化。结果表明,在水力停留时间约为10 d、有机负荷为2.75 kgVS/(m3.d)时,对TCOD的去除率可达46%,对VS的去除率为41%;产甲烷相反应器的最大比产甲烷活性为0.19LCH4/(gVS.d),并保持相对稳定;两相反应器内污泥的比脱氢酶活性都出现了增长,并维持在25~32μgINTF/(mgVS.h)之间;经消化后污泥的沉降性和脱水性变差。     

Modelling of two-stage anaerobic digestion using the IWA Anaerobic Digestion Model No. 1 (ADM1)

The aim of the study presented was to implement a process model to simulate the dynamic behaviour of a pilot-scale process for anaerobic two-stage digestion of sewage sludge. The model implemented was initiated to support experimental investigations of the anaerobic two-stage digestion process. The model concept implemented in the simulation software package MATLAB/Simulink is a derivative of the IWA Anaerobic Digestion Model No.1 (ADM1) that has been developed by the IWA task group for mathematical modelling of anaerobic processes. In the present study the original model concept has been adapted and applied to replicate a two-stage digestion process. Testing procedures, including balance checks and 'benchmarking' tests were carried out to verify the accuracy of the implementation. These combined measures ensured a faultless model implementation without numerical inconsistencies. Parameters for both, the thermophilic and the mesophilic process stage, have been estimated successfully using data from lab-scale experiments described in literature. Due to the high number of parameters in the structured model, it was necessary to develop a customised procedure that limited the range of parameters to be estimated. The accuracy of the optimised parameter sets has been assessed against experimental data from pilot-scale experiments. Under these conditions, the model predicted reasonably well the dynamic behaviour of a two-stage digestion process in pilot scale.     

Anaerobic treatment of wastewater with high organic content using a stirred tank reactor coupled with a membrane filtration unit

Using a cross-flow membrane bioreactor, high anaerobic conversion rates of three different types of wastewater with varying organic content were achieved. Loading rates obtained were as follows: 20 g CODL(-1) x d(-1) for artificial wastewater, approximately 8 g CODL(-1) x d(-1) from vegetable processing industry (sauerkraut brine) and 6-8 g CODL(-1) x d(-1) for wastewater from an animal slaughterhouse. At stable conditions, COD-removal rates in all three wastewaters were higher than 90%. Methane yields from the treatment of artificial wastewater, sauerkraut brine, and animal slaughterhouse wastewater were in the range of 0.17-0.30, 0.20-0.34, and 0.12-0.32 L(n) x g(-1) COD(-1) fed, respectively. The complete retention of biomass and suspended solids is a unique feature of this treatment process, which combines a high loading capacity and at the same time, high COD removal rates even for complex wastewater containing high concentrations of particulate matter.     

Waste Stabilization Ponds in Europe

The European countries where sewage treatment in waste stabilization ponds is largely developed and commonly used are West Germany (more than 2000 operational systems) and France (about 2500 plants). Portugal has over 50 systems at present and will have about 100 by the year 1993. Spain has more than 10 operational plants and in Denmark there are 50 ponds for tertiary treatment. A survey on the present practice in the countries where the process is largely applied, including size of plants, type of ponds, type of influent and design criteria, is presented. It is found that waste stabilization ponds are particularly appropriate for full treatment of effluents from small communities (less than 5000 population equivalent) and for tertiary treatment following conventional larger plants.     

浅析制药企业工业废水处理

探讨制药企业的工业废水处理工艺，以资借鉴。     

卧式干法厌氧消化技术在秸秆发酵中的应用

厌氧发酵技术是秸秆类农业废弃物极好的资源化处置方式,为了避免大量的沼液产生,干式厌氧发酵越来越受到重视.本文介绍了BRV卧式干法厌氧消化技术,该技术从欧洲林德公司引进,属于卧式平推流干法反应器.结合国外干法和湿法的应用情况,分析了BRV干法厌氧技术特点及处理秸秆的适用性,可实现规模化,全自动控制、连续化生产,特别适合工厂化集中处理秸秆等农业废弃物,具有广阔的应用前景。     

Performance and kinetic evaluation of the anaerobic digestion of two-phase olive mill effluents in reactors with suspended and immobilized biomass

A lab-scale study was conducted on the mesophilic anaerobic digestion of two-phase olive mill effluents constituted by the mixture of the wash waters derived from the initial cleansing of the olives and those obtained in the washing and purification of virgin olive oil. The digestion was conducted in two continuously stirred tank reactors, one with biomass immobilized on Bentonite (reactor B) and other with suspended biomass used as control (reactor C). The reactors B and C operated satisfactorily between hydraulic retention times of 25.0 and 4.0 days and 25.0 and 5.0 days, respectively. Total chemical oxygen demand (TCOD) efficiencies in the ranges of 88.8-72.1% and 87.9-71.2% were achieved in the reactors with immobilized and suspended biomass, respectively, at organic loading rates of between 0.86 and 5.38 g TCOD/ld and 0.86-4.30 g TCOD/ld, respectively. On comparing both reactors for the same OLRs applied, it was observed that the reactor with support was always more efficient and stable showing higher TCOD, SCOD removal efficiencies and lower VFA/alkalinity ratio values than those found in the control reactor. A mass (TCOD) balance around the reactors allowed the methane yield coefficient, Y(G/S), to be obtained, which gave values of 0.31 and 0.30l CH(4)/g TCOD(removed) for reactors B and C, respectively. The cell maintenance coefficients,k(m), obtained by means of this balance were found to be 0.0024 and 0.0036 g TCOD(removed)/g VSSd, respectively. The volumetric methane production rates correlated with the biodegradable TCOD concentration through an equation of the Michaelis-Menten type for the two reactors studied. This proposed model predicted the behavior of the reactors very accurately showing deviations lower than 10% between the experimental and theoretical values of methane production rates.     

污水处理厂污泥消化系统设计及运行

介绍了郑州和天津的2座污水处理厂污泥消化系统(包括设计污泥量及含水率、污泥投配系统、消化池型及参数选择、搅拌系统、沼气系统、热水循环系统)的设计。对其中郑州某污水处理厂的运行情况进行分析,总结其存在的问题及从中应吸取的经验。可供污水处理厂污泥消化系统的设计参考。     

青岛麦岛污水处理厂污泥消化及热电联产运行管理经验

污泥厌氧消化/热电联产是一项重要节能工艺技术,对于提高资源和能源利用效率意义重大。完善的管理是保证污泥消化及热电联产系统稳定高效运行的关键环节。麦岛污水处理厂将Multiflo^?Trio初沉污泥与生物滤池剩余污泥进行混合,形成沼气产率较高的混合污泥,并进行中温厌氧消化,所产沼气进入热电联产系统用于发电及沼气锅炉,回收余热作为污泥消化及厂区采暖热源。10余年来,麦岛污水处理厂的污泥消化及热电联产系统实现了安全、稳定、高效的运行,保证了污泥的资源化、减量化、无害化处理及利用。介绍了青岛麦岛污水处理厂污泥厌氧消化及热电联产的运行情况,探讨如何在污泥消化及热电联产间做好运行管理和调控,使之形成良性循环。     

有机垃圾厌氧消化系统失稳预警指标的研究进展

厌氧消化作为一种符合生态原理的生物处理技术,将环境保护和能源回收有机地结合在一起。它是多种厌氧微生物共同参与、分阶段有序进行的复杂串联代谢过程;其中产甲烷菌对环境最敏感、代谢速率最慢,产甲烷阶段往往是厌氧消化系统的瓶颈;水解酸化与产甲烷两阶段不能较好地匹配,极易受到抑制。现有常规工艺运行监控指标(如pH值、碱度、挥发性脂肪酸浓度、沼气产率以及沼气成分等)对厌氧消化系统运行状况的指示性相对迟缓、滞后,因而厌氧消化稳定性早期警示物的研究受到世界各国的广泛关注。目前厌氧消化系统失稳预警指标主要基于中间代谢产物、关键代谢调控物以及厌氧系统内生物体的变化等三方面的研究,但还没有一种公认的厌氧消化系统失稳预警指标。在系统分析现有厌氧系统失稳预警指标优缺点的基础上,从理论上提出了基于"厌氧生物系统微生物菌落变化、基质代谢途径调控以及中间代谢产物分析"的多方位预警响应指标体系的综合评价方法,并指出表征厌氧消化过程的生物体特性及关键微生物群落变化的指标,应是今后厌氧消化系统失稳预警指标努力的方向。     

外循环厌氧—好氧工艺处理啤酒废水工程设计

在华润雪花啤酒(兴安)有限公司废水处理站改造工程中,采用了外循环(EC)厌氧-好氧工艺,厌氧反应器的外循环和内循环共用一套回流系统,其独特的旋流配水装置、多层三相分离器联用设计,使反应器具有水力上升速度高、配水均匀、污泥浓度大的特点.工程设计规模为 1000 m3/d,经过三个多月的调试运行,出水COD≤80 mg/L、BOD5≤20 mg/L、SS≤70 mg/L,达到<啤酒工业污染物排放标准>(GB 19821-2005).该工艺投资少、占地面积小、高效低耗、剩余污泥量少、运行费用低,具有推广价值.