水环境中非点源污染的研究

对水环境中非点源污染的来源、特点、危害3方面进行了阐述.分析了非点源污染的研究方法,并回顾了非点源污染数学模型的发展.随着地理信息系统(GlS)、全球定位系统(GPS)和遥感技术(RS)的发展,3S技术已经成为非点源污染研究的重要工具.展望了非点源污染的研究前景.最后依据非点源污染产生的机理,从技术防治和管理防治两方面提出了非点源污染防治的有效措施.     

模糊控制强化生物除磷SBR系统的除磷过程

采用在线ORP和pH仪对两个平行的强化生物除磷(EBPR)SBR反应系统的厌氧放磷、缺氧吸磷和好氧吸磷过程进行监测。针对聚糖菌(GAO)和聚磷菌(PAO)的竞争和影响PAO和反硝化聚磷菌(DPAO)的各种因素,验证了以氧化还原电位(ORP)和pH作为除磷过程模糊控制参数的可行性和有效性。在此基础上,确立了厌氧／好氧(A／O)SBR系统和厌氧／缺氧(A2)SBR系统除磷过程的模糊控制策略。对ORP和pH的在线检测不仅可以模糊控制厌氧放磷、缺氧吸磷和好氧吸磷过程所需时间,节约能源优化处理效果,而且可以指示系统运行效果和功能微生物种群的竞争行为。     

A2N反硝化除磷脱氮系统处理生活污水研究

研究了生活污水COD／TN比值变化对A2N反硝化除磷脱氮新工艺去除氮、磷的影响情况。同时利用间歇试验着重探讨了DNPAOs污泥在不同硝态氮浓度、不同电子受体时的摄磷和放磷状况。A2N连续流工艺长期的运行结果表明：双泥系统的建立(生物膜硝化池独立于除磷污泥)可以降低碳源的好氧消耗,较大程度地减少聚磷菌和反硝化菌之间对碳源的竞争,同时保证了生长速率较小的硝化菌可以在稳定状态中生长,利于增强系统脱氮除磷的稳定性。     

UNITANK系统不同运行方式下污泥膨胀的特点与控制

由于连续进水、连续出水的UNITANK系统在流态上接近完全混合,基质浓度梯度大大降低,这对于控制污泥膨胀是较为不利的。试验表明,UNITANK系统的单级好氧处理系统在较低或较高的有机负荷下易发生污泥膨胀,在中等负荷下若使得进水池溶解氧充足则可控制污泥膨胀的发生;脱氮除磷处理系统由于进行缺氧搅拌的边池可起到缺氧选择器的作用,其不发生污泥膨胀的有机负荷限值范围较单级好氧处理系统大;与SBR系统相比,UNITANK系统控制污泥膨胀的能力相对较弱。     

高亚硝态氮钝化清洗废水的生物处理及过程控制

钝化清洗废水含有高浓度亚硝态氮,采用普通活性污泥难以进行生物处理。采用亚硝态氮废水富集亚硝态氮氧化菌(NOB),以富含NOB污泥的SBR装置处理模拟化学清洗钝化废水,并提出了该处理工艺的过程控制策略。结果表明:该工艺可以在300 min内完全氧化亚硝态氮浓度高达2000 mg·L-1的钝化废水,高浓度亚硝态氮没有对生物降解过程产生明显抑制;反应过程中DO浓度的变化与亚硝态氮氧化过程存在相关性,溶解氧浓度的移动斜率变化(DO-MSC)可作为亚硝态氮氧化过程控制参数;当DO-MSC0.02时,亚硝态氮氧化过程结束,此时可停止曝气。批次试验结果显示在不同曝气量(0.02~0.125 m3·h-1)和不同温度条件(15~30℃)下,DO-MSC指数均可有效指示亚硝态氮氧化终点。     

SBR法处理垃圾渗滤液的反硝化过程中NO~-_2积累的研究

The nitrite accumulation in the denitrification process is investigated with sequencing batch reactor (SBR) treating pre-treated landfill leachate in anoxic/anaerobic up-flow anaerobic sludge bed (UASB). Nitrite accumulates obviously at different initial nitrate concentrations (64.9,54.8,49.3 and 29.5 mg•L－1) and low temperatures, and the two break points on the oxidation-reduction potential (ORP) profile indicate the completion of nitrate and nitrite reduction. Usually, the nitrate reduction rate is used as the sole parameter to characterize the denitrification rate, and nitrite is not even measured. For accuracy, the total oxidized nitrogen (nitrate + nitrite) is used as a measure, though details characterizing the process may be overlooked. Additionally, batch tests are conducted to investigate the effects of C/N ratios and types of carbon sources on the nitrite accumulation during the denitrification. It is observed that carbon source is sufficient for the reduction of nitrate to nitrite, but for further reduction of nitrite to nitrogen gas, is deficient when C/N is below the theoretical critical level of 3.75 based on the stoichiometry of denitrification. Five carbon sources used in this work, except for glucose, may cause the nitrite accumulation. From experimental results and cited literature, it is concluded that Alcaligene species may be contained in the SBR activated-sludge system.     

高氨氮垃圾渗滤液SBR法短程深度生物脱氮

以实际垃圾填埋场渗滤液为研究对象,应用SBR系统对该类废水短程生物脱氮的可行性进行研究,重点考察了短程生物脱氮实现、稳定及系统的脱氮性能.结果表明,经过95天的运行,SBR系统成功实现并维持了稳定短程生物脱氮,平均亚硝积累率在92.5%以上.获得了稳定的脱氮性能,NH4+-N,TN平均去除率分别在97.2%和91.7%以上.DO、ORP和pH曲线的特征点能够准确判断硝化和反硝化终点,可作为SBR处理垃圾渗滤液短程生物脱氮过程的控制参数.相对于氨氧化菌,亚硝酸盐氧化菌对FA、FNA更敏感,因此两者协同作用抑制亚硝酸盐氧化菌活性,再辅以过程控制,能够准确判断硝化终点,实现NOB从系统硝化菌群中逐渐被淘洗,AOB成为优势菌种的目标,这是系统长期维持稳定短程生物脱氮的决定因素,FISH检测结果证明了这一点.     

Denitrification and Dephosphatation by Anaerobic/Anoxic Sequencing Batch Reactor

Removal of denitrifying phosphorus was verified in a laboratory anaerobic/anoxic sequencing batch reactor (A/A SBR). The results obtained demonstrated that the anaerobic/anoxic strategy can enrich the growth of denitrifying phosphorus removing bacteria (DPB) and take up phosphate under anoxic condition by using nitrate as the electron acceptor. The phosphorus removal efficiency was higher than 90% and the effluent phosphate concentration was lower than lmg·L-1 after the A/A SBR was operated in a steady-state. When the chemical oxygen demand(COD) of influent was lower than 180mg·L-1, the more COD in the influent was, the higher efficiency of phosphorus removal could be attained under anoxic condition. However, simultaneous presence of carbon and nitrate would be detrimental to denitrifying phosphorus removal. Result of influence of sludge retention time (SRT) on denitrifying phosphorus removal suggested that the decrease of SRT caused a washout of DPB and consequently the enhanced biological phosphorus     

污泥固体停留时间对实时控制生物脱氮SBR中亚硝酸盐积累的影响

In this study,four sequencing batch reactors(SBR),with the sludge retention time(SRT)of 5,10,20 and 40 d,were used to treat domestic wastewater,and the effect of SRT on nitrite accumulation in the biological nitrogen removal SBR was investigated.The real-time control strategy based on online parameters,such as pH,dissolved oxygen(DO)and oxidation reduction potential(ORP),was used to regulate the nitrite accumulation in SBR. The model-based simulation and experimental results showed that with the increase of SRT,longer time was needed to achieve high level of nitritation.In addition,the nitrite accumulation rate(NAR)was higher when the SRT was relatively shorter during a 112-day operation.When the SRT was 5 d,the system was unstable with the mixed liquor suspended solids(MLSS)decreased day after day.When the SRT was 40 d,the nitrification process was significantly inhibited.SRT of 10 to 20 d was more suitable in this study.The real-time control strategy combined with SRT control in SBR is an effective method for biological nitrogen removal via nitrite from wastewater.     

好氧饥饿对膨胀污泥硝化性能及污泥特性的影响

采用SBR好/缺氧工艺,考察了好氧饥饿对于丝状菌膨胀污泥中硝化细菌活性及污泥性能的影响。结果表明,14 d的好氧饥饿过程(无外加底物,保持曝气)中,氨氧化细菌(ammonia-oxidizing bacteria, AOB)表现出更高的饥饿敏感性,其好氧衰减速率[(0.42±0.06)d^-1)高于亚硝酸盐氧化菌(nitrite-oxidizing bacteria, NOB)的好氧衰减速率[(0.34±0.05)d^-1]。恢复阶段初期,系统出现了明显的亚硝酸盐积累现象,这主要归因于AOB具有在环境发生改变时做出快速反应的能力,具体体现在AOB较NOB具有更高的活性恢复速率上。此外,好氧饥饿能够快速杀死丝状细菌,迅速改善膨胀污泥的沉降性能,使污泥的SVI由170 ml·g^-1快速下降到30 ml·g^-1。胞外聚合物(extracellular polymeric substances, EPS)和溶解性微生物产物(soluble microbial products, SMP)能够相互转化,并为饥饿污泥提供一定的碳源和能源,保证了细菌在饥饿环境中长期的细胞维持。