The removal of sulfate and metals from mine waters using bacterial sulfate reduction: Pilot plant results

A treatment process that bacterially converts sulfate into elemental sulfur via a hydrogen sulfide intermediate was demonstrated at pilot scale for the treatment of three mine waters that contained metals and sulfate. Ethanol served as the bacterial carbon and energy source. The mine waters were treated at rates that ranged from 50–150 L day⁻¹. Contaminant concentrations up to 13 mg L⁻¹ copper, 0.1 mg L⁻¹ mercury, 0.04 mg L⁻¹ cadmium, 3.5 mg L⁻¹ zinc, 0.68 mg L⁻¹ cobalt, 1.3 mg L⁻¹ nickel, 49 mg L⁻¹ iron, and 63 mg L⁻¹ aluminum were removed to meet water quality effluent limits. Manganese removal was about 80% under normal operating conditions but increased to 96% when the process was optimized for manganese removal. The process was shown to be capable of decreasing sulfate concentrations from 1800 mg L⁻¹ to less than 250 mg L⁻¹, nitrate from 100 mg L⁻¹ to less than 1 mg L⁻¹, arsenic from 8 mg L⁻¹ to less than 0.03 mg L⁻¹, and calcium from 310 mg L⁻¹ to less than 100 mg L⁻¹. Acid mine waters were neutralized using bacterially-generated alkalinity; no external alkalinity source was needed.     

IMBR-A/O工艺对生活污水脱氮除磷的研究

采用自行设计的A/O一体式膜生物反应器对生活污水的脱氮除磷进行了研究.结果表明:硝化菌受pH值影响较大,通过投加小苏打来控制硝化O段pH值为6.5～7.0,使其满足硝化菌生长的范围,此时,NH4 -N的去除率达99%以上,出水浓度基本稳定在0.5mg·L-1以下;由于反硝化A段的DO值较高,使反硝化细菌受到抑制造成了系统出水TN值较高,但也能达到80%以上的去除率;TP的去除是由于取样污泥带出了部分磷以及微生物生长消耗了部分磷.     

膜生物反应器用于微污染地表水处理的中试研究

引言 地表水作为主要的饮用水源水,其日益严重的污染问题给传统的水处理工艺带来巨大挑战.将膜生物反应器(MBR)应用于微污染水处理,进行饮用水制备是解决上述问题的一项新技术[1].向MBR内投加粉末活性炭(PAC)所形成的MBR-PAC组合工艺集物理吸附、生物净化和膜分离于一体,具有良好的污染物去除能力.目前,将MBR作为微污染水处理主体工艺的研究并不多见.香港大学的李晓岩等[2]研究证实MBR组合工艺处理微污染水效果良好.清华大学的莫罹等[3]也进行了类似的研究.但均限于小试试验,并且对相应的膜污染问题关注不多.     

乳酸杆菌半连续式高密度培养的研究

研究了乳酸杆菌的半连续高密度培养,探讨更换新鲜培养基对菌体浓度、解除代谢产物抑制等的影响,结果表明,经3次培养后菌体浓度达到9.3×1012cfu/mL。并对3次培养过程进行动力学分析,设计了培养-分离耦合生物反应器,用于恒浊连续高密度培养。     

Microorganisms in landfill bioreactors for accelerated stabilization of solid wastes

Landfill bioreactors (LBRs) with management of leachate and biogas have presented numerous advantages such as accelerated stabilization of solid wastes, reduced amount of leachate, and in situ leachate treatment. Such advantages have minimized environmental risks, have allowed extension of the useful life of the landfill site, and have fostered cost reduction. LBRs of three types have been developed using both anaerobic and aerobic modes: anaerobic, aerobic, and hybrid. Microorganisms in landfills cause various reactions related with organic fractions and heavy metals. Such functions have been stimulated in LBRs by recirculation of leachate with or without aeration. To date, most studies of microorganisms in LBRs have analyzed bacteria and archaea based on 16S rRNA genes and have analyzed fungi based on 18S rRNA genes from a taxonomical viewpoint. Indicator genes for specific functions in LBRs such as nitrification, denitrification, and methane production have also been monitored. The population dynamics of microorganisms in LBRs have been partially clarified, but the obtained data remain limited because of highly heterogeneous features of solid wastes inside LBRs. Systematic monitoring of microorganisms should be established to improve LBR performance.     

污泥浓度与曝气强度对MBR运行的综合影响

高污泥浓度可以在减少剩余污泥产量的同时提高系统的容积负荷，但经济曝气强度随污泥浓度的增加呈指数递增，从而使能耗大大增加。为解决这一矛盾，进行了一体式A／O法膜生物反应器处理城市污水的试验，结果表明：过高或过低的污泥浓度和曝气强度都会影响膜生物反应器对COD、NH3-N、TN等污染物的去除效果，并且会加剧膜污染。膜生物反应器存在临界污泥浓度和经济曝气强度，在试验条件下分别为4．73g／L和451L／（m^2·h）。     

The cost of a package plant membrane bioreactor

The capital and operating costs associated with a small package plant MBR for small-scale domestic duty has been appraised based on a medium-strength municipal wastewater. The three main membrane configurations were considered, these being multi-tube, hollow fibre and flat sheet, with the most appropriate plant design chosen for each configuration. The analysis proceeded via a consideration of the estimated amortised capital costs of the plant individual components and their installation, coupled with operating costs based largely on energy demand and residuals management. Energy demand was calculated from aeration and pumping costs, with aeration based on a combination of empirical relationships for membrane aeration and mass balance, and the modified Activated Sludge Model version 2 used for estimating tank size and sludge generation. Results indicate that it is possible to produce a single household MBR at a capital cost similar to the current market cost for package treatment plants. Desludging and maintenance of these plants is similar but power requirements for an MBR are around 4 times that associated with more conventional package plants. Economies of scale exist from 6-20 p.e. plants but above 20 p.e. there is little cost difference per head, due to the design assumptions made. CAPEX and OPEX are to some extent interchangeable; reductions in CAPEX are associated with an increase in OPEX and vice versa. Whilst costs are high, the market for package MBRs is significantly influenced by the recycling potential of the effluent produced.     

给水管壁生物膜附着异养菌与水中悬浮菌活性比较

使用生物膜培养反应器（RAB），在实验室的可控条件下，待挂片上的生物膜达到稳定后进行间歇运行，分别对生物膜中异养菌及水中悬浮菌的活性进行了研究。结果发现，在间歇运行模式下，AOC浓度随着运行时间的延长而不断下降，经过了24h后由最初的64μg／L下降到28μg／L（以乙酸碳计）。水中的悬浮菌和生物膜中异养菌的数量均随着运行时间先增加后下降，但前者波动较大。在前12h，悬浮菌和生物膜上附着细菌的活性都有所增加，之后悬浮菌的活性迅速降低，而生物膜上附着细菌的活性仅有小幅度下降，表明其对环境的适应能力要强于水中的悬浮菌。     

动态膜生物反应器处理公路服务区污水

动态膜生物反应器(DMBR)结合了传统生物处理和膜过滤的优点,能处理高浓度污水。介绍了某公路服务区污水采用动态膜生物反应器处理系统工程的工艺特点、建设情况、技术经济指标及设计经验等。该工程的运行实践表明,动态膜生物反应器适用于公路服务区污水处理。     

新型膜生物反应器的设计及其性能研究

结合无泡曝气原理和气体反冲洗方法,设计了一种新型的一体式膜生物反应器(MBR),并将其与传统MBR进行了对比.结果表明,当处理黄麻生物脱胶废水时,在相同的运行条件下,新型MBR中混合液的DO含量明显高于传统MBR,对COD的去除效果也明显好于传统MBR;另外,与传统MBR相比,新型MBR具有膜过滤压力小、膜污染轻、能耗低等优点.