氮/磷缺乏对污泥沉降性能及丝状菌生长的影响

在4个序批式反应器中,分别考察了氮磷正常供给、磷缺乏、氮缺乏及氮磷同时缺乏对污泥沉降性能和丝状菌生长的影响。结果显示：磷缺乏会导致聚磷菌流失,限制菌胶团菌对碳源的贮存和利用,导致胞外聚合物中蛋白质的含量减少,SVI达到200～250 ml·g^-1;氮缺乏对聚磷菌生长及菌胶团菌贮存利用碳源的影响较小,能刺激菌胶团菌大量分泌蛋白质,SVI低于100 ml·g^-1;短期内氮磷同时缺乏会导致污泥沉降性能恶化,但经长期驯化后微生物种群结构会发生较大改变,丝状菌数量减少,且会滋生大量球状菌胶团菌,SVI在120 ml·g^-1左右。进水磷缺乏的优势丝状菌为N. limicola Ⅱ;进水氮缺乏的优势丝状菌为Type 0092;进水氮磷同时缺乏的优势丝状菌为N. limicola I。氮磷缺乏所滋生的丝状菌种类对污泥沉降性能均只能产生有限的影响。     

城市污水自养脱氮系统中有机物与磷的回收

厌氧氨氧化的发现使开发低能耗城市污水处理技术成为可能,可通过生物吸附实现污水能源与资源的回收。强化除磷系统污泥龄(SRT)仅为2 d,系统抗冲击性强,污泥沉降性良好,污泥体积指数(SVI)低于50,可为自养脱氮系统提供稳定的进水,但系统污泥碳含量仅为37%。将反应器内好氧水力停留时间(HRT)降至 40 min后,实现有机物去除序批式反应器(SBR)的稳定运行,厌氧段COD去除率占总COD去除率的93.8%,这表明系统对有机物的去除主要为生物吸附作用,同时污泥碳含量提升至48%。由于异养菌对有机物的消耗利用与除磷菌的吸磷过程同时进行,若试验废水C/P比较低,可降低系统水力停留时间、提升碳的回收率并辅助少量的化学除磷手段,对系统厌氧搅拌时间、曝气时间及污泥龄进行优化,从而实现C与P的高效回收。     

耐冷氨氧化功能菌群的富集及其对A2/O系统的生物强化

为提高北方地区冬季污水生物处理系统的脱氮效果,利用序批式反应器(SBR)和选择性培养基在(14±1)℃下驯化并富集耐冷氨氧化功能菌群,并采用软性填料进行固定,对(14±1)℃运行的A²/O系统好氧段进行生物强化。结果表明,连续运行5个周期后,SBR中的活性污泥逐渐演替为氨氧化功能菌群,在进水NH₃-N为205～236 mg·L^-1时,SBR的NH₃-N去除率可达79.5%;将组合式纤维填料置于SBR中并继续运行5个周期,可将氨氧化功能菌群以生物膜的形式固定于填料表面。以固定化氨氧化功能菌群对A²/O系统进行生物强化,在投加量为3.24%(污泥干重)的条件下,A²/O系统的氨氮平均去除率由投加前的65%提高到78%,COD和总氮去除率也有明显提高。在生物强化后的持续运行中,A²/O系统的氨氮去除效能有缓慢下降趋势,其长期强化效果有待进一步探讨。     

腐殖土强化SBR工艺除磷效果及污泥性能

将普通SBR和腐殖土SBR反应器进行除磷效果对比。结果表明,腐殖土SBR工艺好氧吸磷量、利用单位PHA吸磷量、VFAs吸收速率都比SBR工艺明显提高,腐殖土强化了SBR工艺PAOs优势,提高了PAOs含量,抑制了GAOs的代谢活动,有利于生物除磷。腐殖土还改善了SBR工艺污泥沉降性能,SVI值比普通SBR工艺降低20%以上,VSS/MLSS比值降低8.9%,污泥性能改善是化学和生物共同作用的结果 。     

生物除磷颗粒污泥去除Pb2+的效能机制

以好氧颗粒污泥的吸附作用和磷酸盐对重金属的螯合作用为基础,采用富含磷酸盐的生物除磷颗粒污泥作为吸附剂来处理含铅废水,考察了不同吸附条件（pH、Pb²⁺的初始浓度、吸附反应时间）下,颗粒污泥对Pb²⁺的去除效果。结果表明,除磷颗粒污泥在pH为4,初始Pb²⁺浓度为150 mg·L^-1时,对铅的去除率最高（为99.9%）;在吸附反应20 min时即可达到吸附平衡。生物除磷颗粒污泥对Pb²⁺的吸附可以用Langmuir模型拟合（R²=0.993）,最大吸附量为49.5 mg·g^-1。其中离子交换和磷酸盐与Pb²⁺的螯合作用对除磷颗粒污泥去除Pb²⁺起到重要作用;傅里叶变换红外光谱（FTIR）测定表明-COOH、-OH、磷酰基等多种官能团也参与了除磷颗粒污泥除Pb²⁺过程。     

苯酚对污水生物脱氮系统亚硝积累及污泥性能的影响

采用SBR缺氧/好氧反应工艺,研究了不同苯酚浓度对脱氮过程中亚硝积累与污泥性能的影响。结果表明,苯酚浓度在0~90 mg·L^-1变化时系统出现2次明显亚硝酸盐积累,最终稳定维持在70%±5%,低浓度(0~30 mg·L^-1)系统亚硝酸盐积累恢复是微生物改变自身结构及分泌胞外聚合物导致;高浓度(60~90 mg·L^-1)苯酚条件下亚硝积累是由于苯酚对AOB(ammonia-oxidizing bacteria,氨氮氧化细菌)和NOB(nitrite-oxidizing bacteria,亚硝酸氧化细菌)抑制作用引起的微生物种群改变形成。氨氮氧化速率和氮氧化物生成速率由10.85 mg N·(g MLSS)^-1·h^-1和10.12 mg N·(g MLSS)^-1·h^-1降低至2.79 mg N·(g MLSS)^-1·h^-1和2.32 mg N·(g MLSS)^-1·h^-1,亚硝酸盐积累率和氮氧化物生成速率呈现负相关性,与苯酚浓度呈正相关;荧光原位杂交表明苯酚的抑制使得硝化菌群结构发生了变化,AOB 相对数量由2.80%增加为9.30%。苯酚的可降解性使得系统污泥浓度由2500 mg·L^-1左右上升至5870 mg·L^-1。当EPS(extracellular polymeric substances,胞外聚合物)总量由67.20 mg·(g VSS)^-1减少至32.10 mg·(g VSS)^-1时,SVI从165 ml·g^-1降到50 ml·g^-1。亚硝酸盐积累、丝状菌和胞外聚合物是引起活性污泥系统SVI变化的原因,其中NAR影响最大,丝状菌次之。     

生物除磷的电场强化作用及其规律研究

本课题通过对比试验对生物除磷的电场强化作用及其规律进行了初步研究,结果表明,在试验条件下(电流密度:i=0．04-0．08mA／cm2),无论那个反应时段(厌氧段、好氧段)施加电场,对提高、稳定生物除磷效率都有积极的作用;对比研究发现,在相同的电流密度下,好氧段电场强化对除磷效果的促进作用更明显,在最佳工况(好氧段强化,i=0．08mA／cm2),电场强化反应器TP平均去除率高达92％,比对照组普通生物反应器高出15％。另外,试验分析了剩余污泥的含磷量,数据显示,电场强化生物反应器剩余污泥含磷率达5．04％(干重),比对照组普通生物反应器高0．68％,进一步表明了电场可强化活性污泥的超量吸磷能力。     

SBR中曝气强度对除磷颗粒的影响

在3个SBR反应器(R1、R2和R3)中,好氧段分别控制气体流量为0.5、1.0和1.5 L·min^-1,研究了不同曝气强度对除磷颗粒的特性、处理性能和生物量等的影响。3个反应器在不同的曝气强度下30 d均实现了除磷污泥颗粒化,而后稳定运行30 d。试验结果表明,曝气强度对除磷颗粒的粒径、形态、含水率、沉淀性、处理效果、生物量等有着重要的影响。颗粒成熟后,R1、R2和R3中颗粒的平均粒径分别为900、1000和1150 μm,含水率分别为95.6%、94.2%和93.4%,沉淀速度分别为24～144、29～162和33～178 m·h^-1。在40 d后的运行中,R1、R2和R3中COD的平均去除率分别为95%、96%和98%,TP的平均去除率分别为97%、98%和99%。可见,曝气强度较大的反应器中形成的颗粒具有较好的沉淀性、较大的粒径、较低的含水率、较好的处理效果,且形状规则、外表光滑,而较大的生物量及较密实的结构是这些颗粒具有较优性能的主要原因。同时,测定并计算了3个反应器中第51天除磷颗粒的MLVSS/MLSS和生物活性层的厚度,高曝气强度反应器中聚磷颗粒的生物活性层厚度比较大,生物量比较高;并通过计算厌氧阶段P释放量与COD消耗量的比值,证实了本试验除磷颗粒系统中富集了大量的聚磷菌。     

中试规模AAO-曝气生物滤池双污泥系统的启动运行

AAO-曝气生物滤池(BAF)是污泥龄差距较大的双污泥系统,可在低C/N条件下实现氮、磷的同步去除。本试验以低碳氮比的城市污水为处理对象,研究了处理量为40~100 m³·d^-1的大型中试级别的AAO-BAF脱氮除磷工艺的启动运行。通过先使AAO和BAF独立运行以分别培养驯化聚磷菌活性污泥和硝化细菌生物膜,待分别观察到AAO出水TP及BAF 出水NH₄⁺-N浓度稳定后,再将两部分连通运行的策略,使得在第58天时系统出水COD、 、TN、TP、浊度、SS分别小于50 mg·L^-1、5 mg·L^-1、15 mg·L^-1、0.5 mg·L^-1、5NTU、10 mg·L^-1,表明该中试系统已成功启动。与小试研究比较发现,分开运行更有利于聚磷菌的培养驯化;BAF中采用自然挂膜法较接种污泥法更方便,但增加了填料挂膜的时间。根据微生物群落多样性分析,发现AAO中的硝化细菌丰度少于3%,而BAF生物膜上的硝化细菌的丰度占到12%以上。本试验可为该工艺的实际工程应用提供一定参考。     

进水负荷交替变化对好氧污泥颗粒化的促进

在序批式活性污泥法反应器(SBR)中,接种普通絮状污泥,在交替变化的负荷下培养好氧颗粒污泥,研究分析好氧污泥颗粒化的形成过程并检测颗粒污泥形成中污染物的变化规律。结果表明,进水负荷的交替变化可以增强反应器的贫富基质促使颗粒污泥快速形成,污泥颗粒化中胞外聚合物含量呈增加趋势,其中胞外蛋白质对好氧污泥颗粒形成中起到主要作用,而胞外多糖有助于维持好氧颗粒污泥系统运行的稳定性,另外变负荷还可筛选出微生物种类丰富度高的颗粒污泥。经过105 d,反应器内颗粒污泥的粒径多数为1.0~1.25 mm,混合液MLSS的质量浓度为5.512 g/L,SVI为18.50 m L/g左右,对COD、NH4+-N、TN和PO43--P的去除率分别为96.73%、96.67%、86.63%和83.74%左右。     

Partial nitrification of sludge reject water using suspended and granular biomass

BACKGROUND: Partial nitrification–Anammox is a combined promising advanced biological process for the removal of nitrogen from wastewater, which allows important savings in energy consumption, sludge production, and organic carbon. Granular biomass appears to be an interesting alternative to conventional activated sludge, mainly because of its better settling properties. This study deals with the experimental results of a comparison between a conventional and a granular sequencing batch reactor (SBR) for the partial nitrification of reject water. RESULTS: After some days of operation, 30 days in the conventional SBR (system A) and 100 days in the granular SBR (system B), partial nitrification was achieved. Granular sludge showed much better settling properties than suspended biomass, with values of sludge volumetric index (SVI₁₀) of 130 mL g^?1 in system A and 38 mL g^?1 in system B. Consequently, the solids concentration within the granular reactor was three times higher than for the conventional system while the concentration of solids in the effluent was 10 times higher in the conventional SBR. Morphology, microstructure and microbial populations in both systems were also studied. CONCLUSION: A partial nitrification process was successfully achieved in both systems, obtaining an effluent with a NO₂^?‐N/NH₄⁺‐N ratio near 1, suitable for a following Anammox process. Granular biomass, mostly formed by round particles, showed better settling properties, leading to better sludge–effluent separation as well as higher biomass retention in the reactor. The granulation process does not affect bacterial populations, since they were the same in both systems. Copyright © 2011 Society of Chemical Industry     

合成的沸石活性污泥改进铵离子吸附和沉降性能(英文)

Municipal wastewater treatment plants typically exhibit two classic problems： high ammonium concen- tration in water after conventional biological treatment and, in some cases, poor activated sludge sediment ability. Potential solutions to these problems were investigated by adding a synthetic zeolite obtained from coal fly ash to different steps of activated sludge treatment. The experimental results for ammonium removal fit well with the theoretical adsorption isotherms of the Freundlich model with a maximum adsorption capacity of 13.72 mg.g-＇. Utiliza- tion of this kind of zeolite to improve activated sludge sediment ability is studied for the first time in this work. It is found that the addition of the zeolite （1 g. L-1） to an activated sludge with settling problems significantly enhances its sediment ability and comoact ability. This is confirmed by the sludge volume index （SVI）, which was reduced from 163 ml.g-1 to 70 ml.g-r, the V60 value, which was reduced from 894 ml.L-1 to 427 ml.L-1, and the zeta poten- tial （0, which was reduced from -19.81 mV to -14.29 mV. The results indicate that the addition of this synthetic zeolite to activated sludge, as an additional waste management practice, has a positive impact on both ammonium removal and sludge settleability.     

Effect of Ferric Chloride on the Properties of Biological Sludge in Co-precipitation Phosphorus Removal Process

This paper studied the effect of ferric chloride on waste sludge digestion, dewatering and sedimentation under the optimized doses in co-precipitation phosphorus removal process. The experimental results showed that the concentration of mixed liquid suspended solid (MLSS) was 2436 mg稬^-1 and 2385 mg稬^-1 in co-precipitation phosphorus removal process (CPR) and biological phosphorous removal process (BPR), respectively. The sludge reduction ratio for each process was 22.6% and 24.6% in aerobic digestion, and 27.6% and 29.9% in anaerobic digestion, respectively. Due to the addition of chemical to the end of aeration tank, the sludge content of CPR was slightly higher than that of BPR, but the sludge reduction rate for both processes had no distinct difference. The sludge volume index (SVI) and sludge specific resistance of BPR were 126 ml穏^-1 and 11.7?10¹² m穔g^-1, respectively, while those of CPR were only 98 ml穏^-1 and 7.1?10¹² m穔g^-1, indicating that CPR chemical could improve sludge settling and dewatering.     

污水处理运行模式对好氧颗粒污泥特性的影响

研究了运行模式的改变对好氧颗粒污泥优势丝状菌种类,以及对污泥特性所产生的影响。结果表明,序批式活性污泥法反应器(SBR)中出现大量外伸型丝状菌Type 021N,但并未阻碍污泥的颗粒化,且随着絮体污泥颗粒化进程的推进,其对污泥沉降性的影响也在逐步减小,最终得到平均粒径为0.75 mm、污泥容积指数为43 mL/g的成熟好氧颗粒污泥。而将成熟颗粒污泥接种至连续流反应器中时,颗粒污泥开始解体,污泥特性开始恶化,同时优势丝状菌演替为另一种外伸型丝状菌Sphaerotilus Natans。分析认为,外伸型丝状菌会影响污泥在生物区与沉淀池间的循环周期及其在沉淀池的实际停留时间,是颗粒污泥解体的主要原因,而该影响在SBR运行模式下较小,在连续流态下较大。     

好氧颗粒污泥培养方法及其厌氧化研究

以葡萄糖为底物,普通絮状活性污泥为接种污泥,30目以上4 0目以下木炭颗粒为载体,在类似SBR反应器中提高反应器COD负荷、减少沉淀时间,不断洗出细小分散污泥和絮状污泥,使微生物在木炭颗粒表面附着生长,当COD负荷为3 2kg/ (m3 ·d) ,沉降时间为2 0min时,反应器污泥床中活性污泥实现颗粒化。此阶段下,污泥体积指数SVI为1 8mL/g ,MLSS 90 0 0mg/L。好氧颗粒污泥直径大多2 . 0～2 . 5mm。在好氧颗粒污泥厌氧化研究中,控制温度在30℃,pH值在7 . 5～8. 0之间,停留时间为2 4h ,COD负荷从2kg/ (m3 ·d)增加至4kg/ (m3 ·d) ,COD去除率从4 5 %增加到6 6% ,好氧颗粒污泥在厌氧条件下具有了有机物分解和去除的效果,可以认为转变成了厌氧颗粒污泥。     

膨胀颗粒污泥的恢复及其基质降解动力学

为实现丝状菌膨胀的好氧颗粒污泥（AGS）的修复,通过在序批式活性污泥（sequencing batch reactor activated sludge process,SBR）反应器中设置厌氧生物选择段以抑制丝状菌生长,并研究了修复过程中污泥基质降解动力学参数变化。膨胀AGS表面包裹了大量丝状菌（污泥体积指数SVI高达186.56mL/g）,但恢复过程中膨胀AGS的比例逐渐减少,表面逐渐变得清晰、规则,21d时污泥膨胀趋势已完全得到遏止,最终AGS的污泥沉降比SV₃₀/SV₅、SVI和颗粒化率分别为0.92、48.74mL/g及92.79%,并表现出良好的污染物去除效果。通过双倒数法拟合得到丝状菌膨胀AGS的饱和常数和最大比增长速率分别为75.67mg/L、0.47h^–1,该值略高于普通活性污泥,但远低于恢复稳定后AGS的354.47mg/L、1.43h^–1。因此,在厌氧生物选择段创造的高底物浓度环境下,AGS中菌胶团细胞可优先获得基质并实现增殖,而丝状菌由于生长受到抑制而逐渐被淘汰,最终在22d内实现膨胀AGS的修复。     

镉离子对塔式SBR反应器中好氧颗粒污泥性能的影响

采用塔式SBR反应器,利用城市污水处理厂剩余污泥作为接种污泥,培养出好氧颗粒污泥。实验结果表明：好氧颗粒污泥的形成分为准备期、形成期和成熟期三个阶段。当原水COD在1 500±100 mg/L范围内波动时,其COD去除率可达93.4%,出水COD稳定,污泥浓度MLSS维持在2.0~4.0 g/L之间,半小时沉降比SV可达15%~20%,沉降性能优异。COD去除效果与污泥体积指数SVI有密切关系,当SVI维持在50~60 mL/g之间时,COD去除率可达90%以上,而当SVI高于100 mL/g,其COD去除率效果不佳,出水COD在400 mg/L以上。未经驯化的颗粒污泥对高浓度镉离子比较敏感,当氯化镉浓度为50 mg/L时,COD去除率仅为36.8%,且SVI迅速增加至112 mL/g,颗粒污泥发生解絮。而当氯化镉浓度低于1.0 mg/L时,对好氧颗粒污泥的影响较小。     

Effect of coagulant‐flocculant reagents on aerobic granular biomass

BACKGROUND: Technologies based on aerobic granular biomass are presented as a new alternative application to wastewater treatment due to its advantages in comparison with the conventional activated sludge processes. However, the properties of the aerobic granules can be influenced by the presence of residual amounts of coagulant‐flocculant reagents, frequently used as pre‐treatment before the biological process. In this work the effect of these compounds on aerobic granular biomass development was tested. RESULTS: The presence of coagulant‐flocculant reagents led to a worse biomass retention capacity with a lower VSS concentration compared with a control reactor (4.5 vs. 7.9 g VSS L^?1) and with a higher SVI (70 vs. 40 mL [g TSS]^?1) and diameter (5.0 vs. 2.3 mm). These reagents also caused a decrease in the maximum oxygen consumption rate, but the removal efficiencies of organic matter (90%) and nitrogen (60%) achieved were similar to those in the control reactor. CONCLUSION: The continuous presence of residual levels of coagulant‐flocculant reagents from the pre‐treatment unit negatively affected the formation process and the physical properties of the aerobic granules; however, the removal of organic matter and nitrogen were not affected. Copyright © 2012 Society of Chemical Industry     

海绵铁生物填料对生化处理效果的影响

通过加入不同量海绵铁载体填料的SBR反应器与普通活性污泥SBR反应器处理生活污水效果的比较，考察了海绵铁用作生物处理载体填料的可行性。试验表明，海绵铁生物载体填料可以大大提高反应器的处理效果，特别是脱氮除磷的效果，且处理效果与海绵铁载体的投加量密切相关。当海绵铁加量为67g／L时COD的去除率最高，为100g／L时TN的去除率最高，海绵铁加量越大，除磷的效果越好。海绵铁生物载体填料具有广阔的开发研究前景。