低溶解氧条件下分段进水对SBR工艺脱氮除磷效果的影响研究

针对传统生物法处理低C/N生活污水存在曝气量过饱和、有机碳源不足和脱碳效率低等问题,开展了低溶解氧(DO)条件下分段进水SBR运行模式的试验研究,对比分析4种低DO条件下传统SBR工艺与分段进水SBR运行模式的脱氮除磷效果。结果表明:传统SBR工艺中,CODCr去除率达到90%以上,而二段进水方式下其去降率下降了20%;采用4种不同DO条件下,一段进水方式下SBR反应器的脱氮效率较低,出水中TN分别为17.4mg/L、19.5mg/L、18.6mg/L、21.6mg/L,其中当DO为1.0mg/L时SBR反应器的脱氮效率最高,TN去除率达到45%,而TP去除率分别为19%、25%、22%、21%;对于二段进水,同样的DO条件下,其中当DO为1.0mg/L时SBR反应器的脱氮除磷效果最佳,脱氮除磷去除率分别提高了17%、20%。通过分段进水,提高了进水中反硝化细菌和聚磷菌对原有有机物的利用率,从而提高了SBR反应器的脱氮除磷效率。     

不同运行方式下低溶解氧污泥微膨胀的可行性研究

污泥微膨胀是一种利用低溶解氧（DO）引发丝状菌繁殖来实现污水节能处理的新方法.为分析该方法的可行性,采用4个间歇式反应器（SBR）模拟不同的工艺,考察了低DO下（DO=0.5 mg/L）各反应器的污泥沉降性、絮体结构、污染物去除特性及曝气能耗.结果表明,全程好氧运行方式易引发恶性膨胀;而前置缺氧运行方式下进水时间在60...     

常温SBR亚硝化快速启动及优化试验研究

采用SBR反应器,在高、低氨氮浓度(245.28 mg/L与58.08 mg/L)交替进水及低DO浓度(0.15～0.40 mg/L)的条件下,经过33周期(20 d)的连续运行亚硝化率基本维持在85%左右,成功抑制了亚硝酸盐氧化菌的生长,从而实现了亚硝酸盐氮的大量积累,并考察了低氨氮浓度进水条件下,5个不同DO浓度对...     

AOA系统厌氧时间和溶解氧对内源反硝化脱氮速率的影响

为了探索提升基于内源反硝化的厌氧/好氧/缺氧(Anaerobic/Oxic/Anoxic,AOA)工艺脱氮效率的方法,本研究分别考察了前置厌氧时间和好氧阶段溶解氧(DO)对内源反硝化脱氮速率的影响.结果表明:在进水COD浓度为155.1mg/L时,厌氧时间为60min,缺氧阶段内源反硝化速率(EDNR)最高;在不同的进水COD条件下,控制适当的厌氧时间,当内碳源中的聚羟基烷酸酯(PHAs)积累量达到峰值时,EDNR最高;EDNR受到好氧阶段DO过量或不足的影响,当DO控制为1mg/L时,EDNR最高.通过厌氧时间优化与DO控制可将EDNR分别提高31.7%,18.4%.本研究为AOA工艺提高后置缺氧阶段EDNR提供了可行策略,有利于AOA工艺设计与运行策略优化.     

SBR亚硝化快速启动过程中影响因子研究

在低DO条件下对SBR反应器实现快速亚硝化的途径及影响因素进行研究.控制反应器主要参数为：DO 0.15～0.40mg/L,pH值7.52～8.30,温度22.3～27.1℃,曝气时间为8 h.通过高、低氨氮浓度（245.28 mg/L与58.08 mg/L）交替进水的方式,经过57个周期（36 d）的稳定运行成功实现...     

运转条件及营养物质对污泥沉降性能的影响

分别用石化和啤酒两种工业废水作为序批式活性污泥法 (SBR)的底物 ,来研究有机负荷 (F/M )、溶解氧 (DO)、营养物质 (N、P)和 pH值与活性污泥沉降性能的关系 .试验结果表明 ,即使在公认的不易引起污泥膨胀的SBR法中 ,低F/M条件下也能引起丝状菌膨胀 .在低DO(低于 0 .5mg/L)浓度下 ,发生丝状污泥菌膨胀 .进水中只缺乏一种营养物而另一种营养物充足的条件下 ,发生由高含水率的粘性菌胶团引起的非丝状菌膨胀 ;而两种营养物 (N和P)同步缺乏的条件下则发生非丝状菌膨胀 .pH值对污泥沉降性能的影响主要表现为活性抑制和污泥上浮 ,进水pH值低于 5 .5时 ,开始出现污泥上浮 ,进水 pH值越低 ,上浮污泥量越多     

厌/缺氧时间对好氧颗粒污泥同步硝化内源反硝化和除磷的影响

选用4组同规格SBR反应器,在A/O/A模式下以水解酸化液为进水,调整厌/缺氧时间分别为50min/170min、90min/130min、130min/90min、180min/40min,探讨颗粒污泥在不同厌/缺氧时间下脱氮除磷特性.结果表明,厌氧时间从50min延长至90min时,污泥内碳源储存量和释磷量增加,同步硝化反硝化(SND)效率提高至62.65%,TN、TP去除率分别从81.1%、 82.2%上升92.9%、98.5%.当厌氧时间从90min升至180min时,释磷量反而下降,厌氧内源性条件刺激胞外聚合物(EPS)增加造成聚羟基烷酸(PHA)合成下降,TP去除率降至88.1%;同时缺氧时间从130min降至40min,系统残留的NO_X^-较多,造成TN去除率降低至84%.机理分析表明系统中TN在好氧段由反硝化聚磷菌(DPAOs)和反硝化聚糖菌(DGAOs)利用PHA以SND方式消耗,并在缺氧段由DGAOs内源反硝化进一步去除,TP由PAOs和DPAOs去除,由批次实验估算得DPAOs占比在R2中最高,达41%,4组反应器运行期间颗粒均未发生解体,以水解酸化液为基质培养的颗粒结构完整、稳定性强.结果表明,厌/缺氧时间的适当延长有利于加强内碳源的贮存与转化,强化厌氧释磷、SND和后置内源反硝化效果,实现同步硝化内源反硝化和除磷高效稳定运行.     

污水短程脱氮工艺中亚硝酸盐积累的影响因素

采用主要由厌氧-好氧-缺氧构成的短程脱氮工艺,进行了常温条件下处理生活污水的实验.分析了DO、游离氨(FA)等因素对亚硝酸盐积累的影响.结果表明,DO是影响短程硝化的主要因素,控制好氧1区的DO在1.5~2.5mg/L、好氧2区的DO在0.5~1.0mg/L,可以实现稳定的亚硝酸盐的积累,氨氮去除率达到90%.对氨氧化菌(AOB)进行T-RFLP群落分析表明,该工艺运行中的AOB优势菌种为Nitrosomonas oligotropha culster.     

基于磷回收的低温微氧EBPR系统的表观与微观特性

在低溶解氧(DO=1mg/L)条件下启动2个厌氧/好氧交替运行的SBR(A/O-SBR),中温(22±1)℃SBR1和低温(14±1)℃SBR2,考察侧流磷回收工艺对低耗主流强化生物除磷(EBPR)系统污染物去除性能?微生物种群结构和磷回收潜能的影响.结果表明,SBR1和SBR2的脱氮及COD去除性能未受磷回收操作的影...     

AAO工艺低氧条件下的运行及其模拟

利用厌氧-缺氧-好氧(AAO)工艺探讨了在好氧池低溶解氧(DO)浓度条件下的水质指标变化情况.结果表明,当好氧池DO浓度从2.00 mg·L~(-1)降低到1.00 mg·L~(-1)和0.50 mg·L~(-1)时,系统仍然具有良好的除磷脱氮效果,出水水质指标均满足我国《城镇污水处理厂污染物排放标准》(GB 18918-2002)中的一级A标准.在此基础上,基于Bio Win 4.1软件建立了AAO工艺的活性污泥模型,对模型参数进行了灵敏度分析,并利用动态模拟对模型参数中的聚磷菌吸收乙酸或丙酸的聚羟基烷酸(PHA)产率系数(YP/PHA,seq)、聚磷菌好氧氧化PHA的储磷率(YP/PHA,aerobic)、氨氧化菌的最大单位生长速率(μmax,A)和亚硝酸盐氧化菌的最大单位生长速率(μmax,N)进行了校验.此外,对系统的曝气能耗进行了模拟评估,结果表明,与好氧池DO浓度为2.00 mg·L~(-1)时相比,好氧池DO浓度为1.00 mg·L~(-1)和0.50 mg·L~(-1)时的空气流量可分别节省23.8%和38.1%,氧转移效率可分别提高7.2%和11.7%.     

Comparative study of polyhydroxyalkanoates production from acidified and anaerobically treated brewery wastewater using enriched mixed microbial culture

The production of polyhydroxyalkanoates(PHA) from wastewaters using microbial mixed cultures(MMC) has been attracting increased interest because of PHA's biodegradability characteristics. Production of PHA by an MMC enriched with PHA-accumulating bacteria was compared using anaerobically treated and acidified brewery wastewaters under various feeding strategies, namely pulse and batch feed addition. To obtain an enriched MMC, a sequencing batch reactor was inoculated with activated sludge fed with acetate and subjected to aerobic dynamic feeding. The enriched MMC was able to accumulate PHA up to 72.6% of cell dry weight(CDW) with pulse addition of acetate controlled by the dissolved oxygen(DO) concentration in the reactor. In a batch accumulation experiment with acetate,the PHA content achieved(28.5% CDW) was less than that of the pulse feeding strategy with the same amount of acetate(～2000 mg C/L). Using anaerobically treated and acidified brewery wastewater fed in pulses, the maximum PHA accumulated by the enriched MMC was similar for both wastewaters(45% CDW), in spite of the higher volatile fatty acid concentration in acidified brewery wastewater. The pulse feed addition controlled by the DO concentration was difficult to implement for wastewater as compared to acetate because the difference in DO concentration between substrate availability and depletion was low. For the batch addition of acidified wastewater, a slightly lower PHA content(39%CDW) was obtained. These results show that both brewery wastewaters can be utilized for PHA production with a similar maximum PHA storage capacity.     

Effects of sludge retention time, carbon and initial biomass concentrations on selection process: From activated sludge to polyhydroxyalkanoate accumulating cultures

Four sequence batch reactors (SBRs) fed by fermented sugar cane wastewater were continuously operated under the aerobic dynamic feeding (ADF) mode with different configurations of sludge retention time (SRT), carbon and initial biomass concentrations to enrich polyhydroxyalkanoate (PHA) accumulating mixed microbial cultures (MMCs) from municipal activated sludge. The stability of SBRs was investigated besides the enrichment performance. The microbial community structures of the enriched MMCs were analyzed using terminal restriction fragment length polymorphism (T-RFLP). The optimum operating conditions for the enrichment process were: SRT of 5 days, carbon concentration of 2.52 g COD/L and initial biomass concentration of 3.65 g/L. The best enrichment performance in terms of both operating stability and PHA storage ability of enriched cultures (with the maximum PHA content and PHA storage yield (Y_PHA/S) of 61.26% and 0.68 mg COD/mg COD, respectively) was achieved under this condition. Effects of the SRT, carbon concentration and initial biomass concentration on the PHA accumulating MMCs selection process were discussed respectively. A new model including the segmentation of the enrichment process and the effects of SRT on each phase was proposed.     

污水短程硝化反硝化和同步硝化反硝化生物脱氮中N2O释放量及控制策略

采用SBR反应器考察了短程硝化反硝化和同步硝化反硝化脱氮过程中N_2O的释放.通过实时控制策略实现了短程硝化反硝化生物脱氮,亚硝化率可维持在90%以上.在溶解氧水平为0.5、 1.0、 1.5和2.0 mg/L条件下,考察N_2O的释放和亚硝化率的变化情况.结果表明,溶解氧1.5 mg/L时最有利于维持稳定的亚硝化率,同时N_2O逸出量最小,每去除1 g氨氮释放N_2O 0.06 g;在碳纤维填料SBR反应器中,通过维持较低溶解氧水平和分段投加碳源的运行方式成功实现了同步硝化反硝化,同步硝化反硝化率在79%以上.在溶解氧水平为0.2、 0.4、 1.0和1.5 mg/L时,考察N_2O的逸出情况.结果表明,溶解氧在1.0 mg/L时最有利于控制N2O的释放,每去除1g氨氮释放N2O 0.021 g,其N_2O释放量仅为短程硝化反硝化的1/3.     

溶解氧对短程硝化稳定性及功能菌群的影响

在常温条件下,采用序批式反应器（SBR）研究不同溶解氧（DO）浓度对短程硝化稳定性的影响.在低DO （0.5mg/L）条件下,前75个周期可以一直维持短程硝化,亚硝积累率（NAR）在80%以上,但是随着运行周期增加,NAR逐渐减少,到105个周期已完全变为全程硝化.通过接种同一污泥提高DO浓度到2.5mg/L,经过180个周期,NAR始终在90%以上,能够长期维持短程硝化的稳定运行.通过不同DO条件下AOB和NOB的氧半饱和常数对比分析及qPCR试验研究,结果表明长期低DO条件下容易使Nitrospira的生长获得优势,Nitrospira是影响短程硝化稳定的重要因素,高DO条件下,AOB对溶解氧具有更高的亲和力,通过提高供氧浓度的策略,可以维持短程硝化的长期稳定.     

自养脱氮污泥的亚硝化活性恢复策略

为考察自养脱氮污泥亚硝化活性快速恢复的策略,在3个反应器内分别采用不同的方法对经过长期冷冻保存后的污泥进行了恢复活性的研究.其中R1为MBR(膜生物反应器),采用低ρ(DO)(0.30 mg/L)连续流恢复策略;R2为SBR(序批式反应器),采用低ρ(DO)(0.30 mg/L)间歇流恢复策略;R3为SBR,采用低ρ(NH₄+-N)预培养-高曝气-低ρ(DO)运行三阶段的恢复策略.结果表明,R1的恢复时间为46 d,NH₄+-N氧化速率达到4.99 mg/(h·g)(以N计),最终ρ(MLSS)达到5.43 g/L;R2的恢复时间为39 d,NH₄+-N氧化速率达到4.61 mg/(h·g),最终ρ(MLSS)达到4.47 g/L;R3的恢复时间为48 d,NH₄+-N氧化速率达到5.64 mg/(h·g),最终ρ(MLSS)达到5.16 g/L. 3个反应器均能长期抑制亚硝酸盐氧化细菌的活性,使亚硝化稳定运行. 3个反应器中,R3恢复所需时间最长,但污泥活性最好; R1中的污泥活性较低,但是膜组件有效截留了污泥,达到了最高的ρ(MLSS).研究显示,通过厌氧预培养后转为膜生物反应器连续流运行的策略,可有助于污泥的极大保留及污泥活性的最大恢复.      

溶解氧对活性污泥胞内贮存物和除磷性能的影响

分别以乙酸钠和葡萄糖为碳源,通过间歇实验,考察不同溶解氧(DO)浓度对厌氧-缺氧-好氧序批式反应器中活性污泥胞内贮存物聚羟基烷酸酯(PHA)、糖原和系统除磷性能的影响。实验表明:DO对以乙酸钠为碳源培养的胞内贮存物PHA和糖原影响较大,并影响污泥的除磷性能;对以葡萄糖为碳源培养的胞内物质影响较小,可能是因为细胞内存在其他类型的胞内贮存物。     

Nitrogen removal from wastewater and bacterial diversity in activated sludge at different COD/N ratios and dissolved oxygen concentrations

The impact of the organic carbon to nitrogen ratio (chemical oxygen demand (COD)/N) in wastewater and dissolved oxygen (DO) concentration on carbon and nitrogen removal efficiency, and total bacteria and ammonia-oxidizing bacteria (AOB) communities in activated sludge in constantly aerated sequencing batch reactors (SBRs) was determined. At DO of 0.5 and 1.5 mg O₂/L during the aeration phase, the efficiency of ammonia oxidation exceeded 90%, with nitrates as the main product. Nitrification and denitrification achieved under the same operating conditions suggested the simultaneous course of these processes. The most effective nitrogen elimination (above 50%) was obtained at the COD/N ratio of 6.8 and DO of 0.5 mg O₂/L. Total bacterial diversity was similar in all experimental series, however, for both COD/N ratios of 6.8 and 0.7, higher values were observed at DO of 0.5 mg O₂/L. The diversity and abundance of AOB were higher in the reactors with the COD/N ratio of 0.7 in comparison with the reactors with the COD/N of 6.8. For both COD/N ratios applied, the AOB population was not affected by oxygen concentration. Amplicons with sequences indicating membership of the genus Nitrosospira were the determinants of variable technological conditions.     

DO浓度对EBPR耦合SND处理低C/N污水的影响

为了解厌氧/好氧运行的序批式反应器（SBR）中,强化生物除磷（EBPR）与同步硝化反硝化（SND）的耦合脱氮除磷特性,以实际低C/N （约为3.5）生活污水为处理对象,先通过调控进水C/N考察其对EBPR启动和聚磷菌（PAOs）富集情况的影响,再通过调控好氧段DO浓度考察其对系统脱氮除磷性能、SND率及碳源转化特性的影响.结果表明,DO浓度为2.0mg/L,当进水C/N由3.2提高至7.5并降至3.8时,反应器出水PO₄^3--P浓度由3.9mg/L逐渐降至0.5mg/L以下,且厌氧释磷量（PRA）由3.3mg/L逐渐升高至约30mg/L.此后,当DO浓度逐渐降至约1.0mg/L时,SND现象愈加明显,且其与EBPR耦合使得系统总氮（TN）和PO₄^3--P去除率分别提高至85%和94%.但当DO浓度约为0.5mg/L时,硝化过程进行不完全,亚硝酸盐积累较为明显,耦合系统中存在同步短程硝化反硝化现象.DO浓度为约1.0mg/L时,系统具有最高的脱氮除磷性能.此外,当DO浓度由2.0mg/L降至0.5mg/L时,PAOs较聚糖菌（GAOs）在厌氧内碳源储存中的贡献逐渐减小（P_PAO,An由30.3%逐渐降至20.2%）,PRA降低约7mg/L.DO浓度为1.0~1.5mg/L最有利于系统厌氧段内碳源PHA的合成.     

以聚羟基脂肪酸酯为固体碳源去除地下水中的硝酸盐

研究了可降解聚合物聚羟基脂肪酸酯（PHA）作为固体碳源和生物膜载体去除地下水中硝酸盐的影响因素。结果表明,低温反硝化有较大影响,5℃和10℃时的反硝化速率分别只有30℃时的5%和13%。反硝化对进水pH有较强的适应性,在pH4.5-9.5条件下,反硝化速率介于11.2-15.8mg/（Loh）之间。pH为4.5-8.5时,出水亚硝酸盐的浓度相差不大。DO对以反硝化速率影响不大,当进水DO为0.9mg/L-5.0mg/L时,反硝化速率介于12.6-15.8mg/（Loh）之间,出水NO2-N浓度的最大值为0.15 mg/L。