Characterization of microbial trophic structures of two anaerobic bioreactors processing sulfate-rich waste streams

A multi-compartment anaerobic bioreactor, designated the anaerobic migrating blanket reactor (AMBR), did not perform well in terms of chemical oxygen demand (COD) removal after an increase in sulfate load, compared to a conventional upflow anaerobic sludge blanket (UASB) reactor. The trophic structures of the bioreactors were characterized by analyzing the electron flows, formation and consumption of fermentation intermediates and terminal product (methane and hydrogen sulfide) formation. Critical performance parameters were linked to operational perturbations such as increase in sulfate load and changes in flow reversal schemes in the AMBR. Both of these manipulations affected the microbial communities, which were monitored by terminal restriction fragment length polymorphism (T-RFLP) analysis targeting the bacterial and archaeal domains. The less stable AMBR did not produce granular biomass, and in response to increased sulfate concentrations, experienced a reversal in the distribution of hydrogenotrophic methanogens that correlated with a shift in electron flow from butyrate to propionate. As this shift occurred, bacterial populations such as butyrate-producing clostridia, became predominant, thus leading to reactor imbalance. The stable UASB reactor developed and retained granules and maintained a relatively stable archaeal community. Sulfate perturbation led to the selection of a novel bacterial group (Thermotogaceae), which was most likely well adapted to the increasingly sulfidogenic conditions in the bioreactor.     

UASB/SBR工艺处理燃料乙醇生产废水工程设计

对燃料乙醇生产废水进行了分质处理,对高浓度废水采用UASB/SBR工艺处理,对于低浓度废水则在其水质满足设计值时,经格栅处理后直接进入预曝池进行好氧处理即可,当其水质高于设计值时则经格栅处理后与高浓度废水一并处理.运行结果表明,在实际进水浓度高于设计值的情况下,出水水质达到了<污水综合排放标准>(GB 8978-1996)的一级标准,表明工艺设计合理,处理效果良好.     

UASB处理高盐制药废水的试验研究

利用3 L的UASB反应器在中温条件下处理高盐有机废水。当进水的COD浓度为2 000~5 000 mg/L,容积负荷为2~5 kg COD/(m3.d)时,逐步提高NaCl浓度。当Cl-浓度从1 000 mg/L增加到5 000 mg/L时,COD去除率从大于90%降到85%左右,但稳定在83%以上。这证明厌氧微生物在Cl-浓度5 000 mg/L时,通过适当驯化,仍能稳定地在高去除率下运行,为高盐工业废水的厌氧处理技术提供了设计依据。     

UASB/接触氧化膜生物反应器在木薯淀粉废水处理中的应用

针对广西木薯淀粉废水因浓度高,酸度大,温度低,季节性明显而处理困难的实际情况,根据连续多月监测水质状况,选择厌氧反应器（UASB）-接触氧化膜生物反应器组合工艺进行处理。该工艺建成后经过4个月的运行表明,实际运行效果良好,系统耐负荷能力极强,解决了企业的环保后顾之忧。本文介绍了该淀粉废水处理系统的组成、重要构筑物及其设计参数等情况,总结了运行效果和工艺特点。     

水解酸化-UASB-低压射流曝气工艺处理废纸制浆造纸废水

采用水解酸化-UASB-低压射流曝气工艺处理废纸制浆废水,对整个工艺及调试运行过程进行详细介绍并对遇到的问题进行分析。实际运行结果表明,该工艺设计合理,运行稳定可靠,总排放口出水COD≤90mg·L-1、SS≤50mg·L-1、BOD5≤20mg·L-1,出水水质可达到《造纸工业水污染排放标准》(GB3544-2008)的要求。     

改进型上流式反应器及其三相分离器的模糊优化设计

本文在 R R VAN DER MEER等人提出的上流式反应器废水厌氧处理的数学描述基础上,建立了一种改进结构的UASB反应器有机质转化率及工艺操作条件与反应器结构尺寸之间的稳态关系,根据反应器结构模糊优化模型求解。在此基础上对其三相分离器进行优化设计,取得了较好的效果。应用该模型可以求出反应器及三相分离器的最佳结构尺寸及有关的工艺操作条件,从而为厌氧反应器及三相分离器的优化设计提供一套完整、有效的方法,同时为过程的运行提供一定的依据。     

UASB/生物接触氧化工艺处理豆制品废水

介绍了＂王致和＂北京延庆生产基地生产废水的水质特点、处理工艺及技术参数.常温下采用UASB反应器/生物接触氧化工艺处理豆制品废水的运行情况表明,该工艺处理效果稳定可靠,产生的沼气和分离的盐可回收利用,获得了较好的经济效益和环境效益.     

UASB/曝气觉淀、IC反应器处理高浓度硫盐有机废水

在赤霉素生产过程中产生的高浓度硫酸盐有机废水,处理难度较大.采用UASB/曝气沉淀/IC反应器工艺处理该废水,UASB中的硫酸盐还原菌将硫酸根还原为硫化物,曝气池中的脱硫杆菌则将硫化物氧化为单质硫,并在沉淀池中去除,IC反应器去除COD.系统稳定运行后,对硫酸盐的去除率>90%,对COD的去除率>80%.     

应用多种CDM方法学分析高浓度有机废水处理项目

按照联合国EB通过的清洁发展机制(CDM)方法学的规定,减排量≤6×104tCO2e/a的CDM项目可采用小型项目方法学.介绍了小型CDM项目方法学AMS.Ⅲ.H(第八版)、AMS.Ⅲ.I(第六版)以及AMS.Ⅰ.C(第十二版)的适用条件,其中任何一种单一方法学均无法完全适用于以UASB 接触氧化法工艺替代原厌氧稳定塘处理工艺、以收集的沼气替代锅炉燃煤的高浓度有机废水处理项目.为此,同时采用以上3种方法学对某项目进行分析,从而解决了方法学适用条件与实际情况有出入的问题,为国内此类项目申请CDM项目提供了一个范例.     

Anaerobic sewage treatment in a one-stage UASB reactor and a combined UASB-Digester system

The treatment of sewage at 15 degrees C was investigated in a one-stage upflow anaerobic sludge blanket (UASB) reactor and a UASB-Digester system. The latter consists of a UASB reactor complemented with a digester for mutual sewage treatment and sludge stabilisation. The UASB reactor was operated at a hydraulic retention time of 6h and a controlled temperature of 15 degrees C, the average sewage temperature during wintertime of some Middle East countries. The digester was operated at 35 degrees C. The UASB-Digester system provided significantly (significance level 5%) higher COD removal efficiencies than the one-stage UASB reactor. The achieved removal efficiencies in the UASB-Digester system and the one-stage UASB reactor for total, suspended, colloidal and dissolved COD were 66%, 87%, 44% and 30%, and 44%, 73%, 3% and 5% for both systems, respectively. The stability values of the wasted sludge from the one-stage UASB reactor and the UASB-Digester system were, respectively, 0.47 and 0.36g CH(4)-COD/g COD. Therefore, the anaerobic sewage treatment at low temperature in a UASB-Digester system is promising.