缺氧/好氧和协同控制DO/HRT工艺对亚硝化的影响比较

为比较协同控制DO/HRT和缺氧/好氧两种运行方式对亚硝化的影响,在常温(18~22℃)下,采用两组2级连续搅拌反应器(CSTR),1#采取协同控制DO/HRT的启动和运行方式,2#采取缺氧/好氧的方式,分别比较两种方式在亚硝化的启动时间、稳定运行效果、曝气能耗、对进水NH4+-N质量浓度下降的适应性以及污泥沉降性能上的差异.结果表明:1#、2#分别用了26和41 d实现了亚硝化;在以原水经AO除磷出水为进水时(NH4+-N质量浓度35~43 mg/L),两种运行方式亚硝化效果均较好,但缺氧/好氧的运行方式节省了约20%的曝气能耗.当进水NH4+-N质量浓度由43 mg/L下降到27 mg/L时,1#亚硝化失稳,最终亚硝化率下降到67.39%,而2#亚硝化较稳定,亚硝化率保持在88%以上;1#和2#在整个过程中污泥沉降性能良好.利用协同控制DO/HRT的方式启动亚硝化,随后转变为缺氧/好氧运行,有助于亚硝化的快速启动和稳定运行,并能节省曝气能耗.     

3DBER-S-Fe深度脱氮除磷效果

为强化三维电极生物膜(3DBER)工艺深度脱氮除磷性能,提高污水厂尾水质量,将硫磺和海绵铁作为混合填料,构建硫铁复合填料三维电极生物膜(3DBER-S-Fe)脱氮除磷工艺;在不同ρ( C)/ρ( N)、I和水力停留时间( HRT)运行条件下,探究工艺深度脱氮除磷效果.分别从反应器填料和阴极上取生物膜,通过Miseq高通量测序,构建细菌16S rRNA基因克隆文库.结果表明：在运行条件为ρ(C)/ρ(N)=2、I=150 mA和HRT=4 h时,3DBER-S-Fe对总氮和总磷的去除率分别可达85.59%和97.43%;适当增加ρ( C)/ρ( N)、I和HRT均能不同程度提高系统脱氮除磷效率.在填料和阴极上丰度最大的均为具有硫自养反硝化功能的Thiobacillus,分别占40.62%和44.75%;具有氢自养反硝化功能的Rhodocyclaceae在阴极的分布明显多于填料.因此,3DBER-S-Fe具有较高的脱氮性能主要是硫自养反硝化和氢自养反硝化共同作用的结果,且氢自养反硝化过程主要发生在阴极.     

MBR-CANON工艺处理生活污水的快速启动及群落变化

为研究全程自养脱氮工艺(CANON)处理生活污水的可行性,在常温膜生物反应器（MBR）中,保持进水氨氮不变,采用逐渐缩短水力停留时间(HRT)的策略在限氧条件下快速富集氨氧化菌(AOB),之后减小曝气量并进一步缩短HRT富集厌氧氨氧化菌(anammox),并通过DGGE技术分析不同阶段的种群变化．结果表明：CANON工艺在78 d内成功启动,总氮去除率达80％,总氮去除负荷RNR达0.95 kg·m-3·d-1;将该工艺应用于生活污水的处理,实现了COD和氨氮的同时高效去除;微生物群落发生了较大变化,稳定运行的反应器中氨氧化细菌为亚硝化单胞菌属(Nitrosomonas),厌氧氨氧化菌为Candidatus Kuenenia stuttgariensis．MBR-CANON工艺可以有效应用于常温生活污水的脱氮．     

后曝气池HRT对双泥生物膜亚硝化反硝化除磷工艺的影响

目的 研究双泥生物膜亚硝化反硝化除磷工艺的最佳后曝气池水力停留时间(HRT).方法 通过改变后曝气池出水口位置的方法调节后曝气池HRT,研究不同后曝气池HRT条件下,双泥生物膜工艺的脱氮除磷性能和COD去除率的变化.结果 在后曝气池HRT为2.4h的条件下,系统COD平均去除率为66.68％,NH4-N平均去除率为88.41％,出水NH4+-N平均质量浓度为6.26 mg/L,大部分NH4-N都在前段反应中去除,同步亚硝化反硝化不受COD质量浓度的限制;TP平均去除率在94.88％左右,厌氧释磷率稳定在45.24％左右,缺氧吸磷率最大,维持在54.59％.HRT为4.8h时,TP平均去除率降至59.48％,可利用的COD质浓度逐渐减少,使运行后期的NH4-N氧化率下降.结论 对于长期运行的双泥生物膜亚硝化反硝化除磷工艺,保持后曝气池HRT为2.4h,系统出水COD值可满足排放标准,脱氮效果稳定,除磷效果最好.     

ABR反应器对垃圾渗滤液的处理试验研究

ABR工艺在处理垃圾渗滤液中具有其他厌氧生物反应器所达不到的优点。尤其是对B/C低、氨氮浓度高、COD浓度高的废水处理,通过调节回流比、HRT、碱度等参数后,可以取得很好的处理效果。在本次实验中,HRT控制在18h后明显提高的垃圾渗滤液的可生化性及C/N,使ABR出水CODcr去除率达到75%,C/N为6.72,对后续好氧反应起到了重要作用。在调控一定回流比后,为提供厌氧氨氧化所需的电子受体NO-3和NO-2实现脱氮。反应器在经过120d的培养驯化,氨氮进水为460mg/L,ABR对氨氮的去除率稳定在80%。不同格室的厌氧颗粒污泥都得到很好的驯化并在其合适的环境中发挥各自的功能。     

Treatment of Domestic Sewage by Two-Stage-Bio-Contact Oxidation Process

Effects of hydraulic retention time (HRT) and gas volume on efficiency of wastewater treatment are discussed based on a simulation experiment in which the domestic swage was treated by the two-stage-bio-contact oxidation process. The result shows that the average CODcr, BOD5 , suspended solid (SS), and ammonia-nitrogen removal rate are 94.5 %, 93.2 %, 91.7 % and 46.9 %, respectively, under the conditions of a total air/water ratio of 5 : 1 , an air/water ratio of 3:1 for oxidation tank 1 and 2:1for oxidation tank 2 and a hydraulic retention time of 1 h for each stage. This method is suitable for domestic sewage treatment of residential community and small towns as well.     

HRT与有机负荷对ABR各隔室净化功能的影响分析

以ABR反应器为研究对象，在不同HRT和有机负荷条件下，对各隔室的净化功能进行了分析。试验结果表明：1)固定进水COD浓度，减小HRT的过程中，各隔室从前到后的去除效果是由低-高-低的变化，HRT降低会导致水力负荷的过度增加，使隔室沟流、短流严重产生，影响去除效果；2)固定HRT，增加进水COD浓度时，l#隔室COD去除负荷与COD的有机负荷呈正相关，COD去除率稳定在40％以上，其余隔室COD去除负荷与COD的有机负荷先呈正相关，随后呈下降趋势，进水浓度过高会引起反应器酸化，1#隔室的酸化一经发生，VFA组分发生变化，产生丙酸、丁酸等中间产物，对后续隔室的微生物产生抑制，COD去除负荷就会明显下降；3)ABR反应器运行操作方便灵活，在以高浓度时的相同负荷的条件下，采用不同的运行方式，COD去除率由98．6％降为89％，仅降低10％左右，在低浓度下实现的高负荷易产生水力负荷的提高而降低处理效果，表明ABR适宜于高浓度的有机废水处理。     

Strategies for improvement of biohydrogen production from organic-rich wastewater: A review

Biohydrogen can be produced from organic wastewater but the process is limited by low production yields. The aim of this review is to summarize the production strategies which are recently researched for enhancing biohydrogen yield and productivity from organic wastewater. The survey of published work indicates that the dark hydrogen fermentation is the most promising production mode. Current strategies geared towards improving biohydrogen production include: microbial culture immobilization, bioreactor modifications, the optimization of process conditions (temperature, pH, OLR and HRT), culture selection and enrichments, substrate choice, and the metabolic engineering of biohydrogen specialists. Comparative analysis of energy recovery from anaerobic digestion using vinasse-related substrates indicates that the production of methane has a higher energy yield than production of hydrogen. A sequential combination of biohydrogen and biomethanation production phases has the potential for even higher bioenergy recovery from organic wastewater.     

MBBR中HRT与pH对短程硝化反硝化的影响

为了开发经济高效的生物脱氮工艺,在MBBR中进行了短程硝化反硝化的研究,考察了HRT与pH对短程硝化反硝化的影响。结果表明,在短程硝化反硝化过程中,在室温、不控制溶解氧的条件下,NH_4~+-N与COD去除率随着HRT的延长而增大,出水NO_2~--N随着HRT的延长先增大后减少,当HRT为8h时出水NO_2~--N最高;当pH由5增加到10时,COD去除率的变化较小,NH_4~+-N去除率和出水NO_2~--N则随着pH的增大先增大后减小,pH在8~9时对NH_4~+-N的处理效果最好,出水NO_2~--N最高。     

Effects of hydraulic retention time,temperature, and effluent recycling on efficiency of anaerobic filter in treating rural domestic wastewater

With rural population expansion and improvement of the socio-economic standard of living, treatment of rural domestic wastewater has rapidly become a major aspect of environmental concern. Selection of a suitable method for treatment of rural domestic wastewater depends on its efficiency, simplicity, and cost-effectiveness. This study investigated the effects of hydraulic retention time(HRT), temperature, and effluent recycling on the treatment efficiency of an anaerobic filter(AF) reactor. The first round of experimental operations was run for three months with HRTs of one, two, and three days, temperatures of 18℃, 21℃, and 24℃, and no effluent recycling. The second round of experimental operations was conducted for another three months with HRTs of three and four days; temperatures of 30.67℃, 30.57℃, and 26.91℃; and three effluent recycling ratios of 1:1, 1:2, and 2:1. The first round of operations showed removal rates of 32% to 44% for COD, 30% to 35% for TN, 32% to 36% for +4NH-N, 19% to 23% for 3NO-N-, and 12% to 22% for TP. In the second round of operations, the removal rates varied from 75% to 81% for COD, 35% to 41% for TN, 31% to 39% for +4NH-N, 30% to 34% for 3NO-N-, and 41% to 48% for TP. The average gas production rates were 6.72 L/d and 7.26 L/d for the first and second rounds of operations, respectively. The gas production rate increased in the second round of operations as a result of applied effluent recycling. The best removal efficiency was obtained for an optimum HRT of three days, a temperature of 30℃, and an effluent recycling ratio of 2:1. The results show that the removal efficiency of the AF reactor was affected by HRT, temperature, and effluent recycling.