厌氧-立体循环一体化氧化沟除磷脱氮工艺中影响厌氧释磷的因素研究

本研究考察了厌氧-立体循环一体化氧化沟工艺（AN-IODVC）中厌氧释磷效果及诸影响因素.研究结果表明,AN-IODVC除磷脱氮系统中好氧污泥的VSS/MLSS值比厌氧污泥小,好氧污泥含磷量与厌氧污泥含磷量的差值和TP去除率、厌氧磷释放率及厌氧ORP呈良好的线性相关关系.厌氧磷释放的最佳条件为：污水COD/TP＞55,维持厌氧区ORP低于-400mV.     

催化铁与生物法耦合除磷工艺特性简

为了研究催化铁与生物耦合后对生物除磷特性的影响,实验采用人工配水用厌氧/好氧间歇流式富集培养聚磷微生物。对比发现,催化铁与生物耦合组中厌氧末段ORP降低了约60 mV,pH值小幅度的上升（≤0.3）,整个培养过程中铁离子的浓度开始快速增加,之后趋于稳定（约40 mg Fe/g MLSS）。对好氧末段污泥SVI值比较发现,耦合工艺污泥沉降性能得到改善。除磷曲线比较发现,耦合组中厌氧末段磷的释放量下降,而好氧阶段磷的吸收速率增加;胞内聚合物提取表明,耦合组厌氧末段聚磷菌细胞内PHA含量有提高,好氧末段糖原含量有下降。磷形态提取分析表明,耦合组好氧末段污泥中无机态PO^3-₄-P含量更高。低浓度铁离子可以起到与生物耦合同步除磷的目的,本工艺长期运行未发现耦合体系中催化铁对除磷的抑制作用。     

催化铁与生物法耦合除磷工艺特性

为了研究催化铁与生物耦合后对生物除磷特性的影响,实验采用人工配水用厌氧／好氧间歇流式富集培养聚磷微生物。对比发现,催化铁与生物耦合组中厌氧末段ORP降低了约60mV,pH值小幅度的上升（≤0．3）,整个培养过程中铁离子的浓度开始快速增加,之后趋于稳定（约40mgFe／gMLSS）。对好氧末段污泥SVI值比较发现,耦合工艺污泥沉降性能得到改善。除磷曲线比较发现,耦合组中厌氧末段磷的释放量下降,而好氧阶段磷的吸收速率增加;胞内聚合物提取表明,耦合组厌氧末段聚磷菌细胞内PHA含量有提高,好氧末段糖原含量有下降。磷形态提取分析表明,耦合组好氧末段污泥中无机态PO3 4-- P含量更高。低浓度铁离子可以起到与生物耦合同步除磷的目的,本工艺长期运行未发现耦合体系中催化铁对除磷的抑制作用。     

富磷污泥厌氧消化磷释放与回收的研究进展

生物强化除磷(EBPR)工艺会产生大量的富磷污泥。富磷污泥中的聚磷菌(PAOs)在厌氧消化过程中吸收外界碳源并释放大量正磷,高浓度的磷会对厌氧消化系统中厌氧微生物的代谢产生影响,使得消化过程更加复杂。富磷污泥厌氧消化过程会产生磷、氮、有机物和金属离子等物质,其中磷的回收利用可以减少磷矿资源的开采,从而实现磷资源的可持续循环利用。因此,研究富磷污泥厌氧消化过程中磷的变化规律,既为厌氧消化系统的稳定运行提供理论依据,又为磷的资源化回收利用提供参考。对富磷污泥厌氧消化释磷的相关研究成果以及磷回收进行分析和总结,并提出了相应的研究方向。     

污泥厌氧消化过程中磷行为的数学模型研究进展

城市污水处理厂的剩余污泥在厌氧消化过程中会释放大量的磷,因此厌氧消化是潜在的可以实施磷回收的工艺。利用数学模型可更清楚地描述厌氧消化过程中生化和物理-化学反应过程。由国际水协会提出的厌氧消化模型1号(ADM1)没有包含对磷行为的描述。主要介绍了目前基于ADM1描述厌氧消化过程中针对磷的行为所作的修改与扩展,总结了与磷释放和沉淀有关的生化过程和物理-化学过程模型,最后在此基础上提出了相关的研究展望。     

污泥回流比对厌氧/好氧工艺除磷效果影响的研究

以长距离输送的合流制污水为进水,考察不同污泥回流比下厌氧/好氧(A/O)工艺对COD、N、P的去除效果,深入研究污泥回流比对生物除P代谢过程的影响.结果表明,污泥回流比对COD及NH+4-N的去除没有明显影响,但对TN、TP、PO3-4-P的去除影响较大.随着污泥回流比的增大,聚磷菌(PAO)的厌氧释P量逐渐减小,P的去除率逐渐降低.减小污泥回流比,可延长A/O工艺厌氧池实际HRT,增加PAO在厌氧池可有效利用的碳源,使PAO在厌氧池充分释P,从而提高除P效率.     

硝酸盐对富磷剩余污泥厌氧消化的影响试验

以某采用 A/O 生物除磷工艺水质净化厂排出的富磷剩余污泥为研究对象,利用棕色消化瓶设计了 4 组厌氧消化试验,通过向其中投加NaNO3,考察硝酸盐对污泥消化过程的影响.结果表明,硝酸盐的存在导致 VSS 平均变化速率比空白样快 28.09 mg/(L·d),并且对污泥消化过程中的产甲烷阶段有一定的抑制作用;当硝酸盐存在时,厌氧氨氧化作用的发生导致上清液中的 N-NH4 变化速率减慢,硝酸盐对污泥消化过程中磷的释放有明显的抑制作用,当硝酸盐浓度高于 60 mg/L时,抑制作用明显.     

猪场废水的厌氧消化除磷机制

采用批式厌氧消化实验,研究了猪场废水厌氧消化过程中生物、物理和化学作用对磷去除的贡献。结果表明,厌氧消化6 d,灭菌的混合液几乎没有磷被去除;未灭菌的混合液,上清液总磷去除率为57.3%,且随着混合液总磷的减少,吸收液的磷逐渐增多,说明废水中的部分磷被转化成气态磷化合物并释放。将原水在4℃、厌氧条件下静置6 d,废水TP去除率为70.7%,说明物理沉降的除磷作用显著。对厌氧消化前后的污泥进行浸提,发现没有灭菌、灭菌混合液的污泥的Ca、Mg-RP(HCl-RP)含量分别增加93.4%和50.5%。由于没有灭菌的混合液的pH不断升高,灭菌的混合液的pH不断下降,说明生物的新陈代谢活动使得环境条件改变(pH增加)而有利于磷化合物沉淀的形成。实验表明,猪场废水厌氧消化过程中磷的去除是物理、化学及生物过程共同作用的结果。     

厌氧、缺氧、好氧多级交替SBR脱氮除磷试验研究

以实际生活污水为研究对象,采用厌氧、缺氧、好氧多级交替序批式反应器(SBR)工艺,通过曝气时间、交替次数的凋整对该系统的脱氮除磷效果进行了研究,最终将工艺确定为厌氧1.5 h-好氧1.0h-缺氧1.0h-好氧20 min-缺氧 1.0 h-好氧20min.试验结果表明:该系统与传统的SBR相比节省了44%的曝气量,且对COD、TN、TP去除率分别达85%、78%、99.5%,同时发现曝气过程 NO2-N和NO3-N的累积可能会对好氧吸磷产生抑制作用.     

城市污水处理厂反硝化聚磷菌的聚磷持久性

以桂林市第四污水处理厂氧化沟活性污泥为对象,研究在具有厌氧-缺氧-好氧环境的污水处理构筑物中富集存在的反硝化聚磷菌聚磷能力的持久性问题。结果表明,在此环境中富集的反硝化聚磷菌在经过3个周期的厌氧-缺氧条件下运行,最大释磷率由0.90 mg P/（g VSS.h）下降为0.07 mg P/（g VSS.h）,反硝化聚磷率由0.17 mg P/（g VSS.h）下降为0.04 mg P/（g VSS.h）。比较而言,在厌氧-缺氧-好氧环境下最大释磷率及聚磷率降幅较小,释磷率由0.59 mg P/（gVSS.h）下降为0.37 mg P/（g VSS.h）,反硝化聚磷率由0.17 mg P/（g VSS.h）下降为0.10 mg P/（g VSS.h）,厌氧-缺氧-好氧运行条件比单纯的厌氧-缺氧运行条件更有利于维持反硝化聚磷菌的聚磷性能。     

污水生物除磷若干影响因素分析

在系统阐述污水生物除磷机理的基础上,深入分析了微生物群体平衡、城市污水水质、环境因子以及工艺运行参数和运行方式等方面对生物除磷效果的影响.分析结果表明:生物除磷系统的溶解氧浓度不宜太高,一般好氧区DO＜2 mg/L,厌氧区DO＜0.2 mg/L;厌氧段存在硝酸盐对生物释磷有负面影响,缺氧段存在一定浓度的硝酸盐有利于生物聚磷;碳源必须充分、易降解;TKN/COD＜0.1的城市污水有利于生物除磷;pH偏碱性可提高生物除磷效率;低温对生物除磷效果影响不明显.     

Phosphorus release in aerobic sludge digestion.

The objectives of this study are to examine the phosphorus release in aerobic sludge digestion and to better understand its governing mechanisms. In this study, phosphorus release was examined using the secondary sludge from both conventional and biological nutrient removal processes. The experiments were carried out at room temperature (22 +/- 2 degrees C), with or without automatic control of pH (4.5 to 7.8), and under three aeration schemes: fully aerobic (dissolved oxygen [DO] at 3 to 4 mg/L), low DO (0.2 to 0.8 mg/L), and cyclic (with alternate on/off aeration). The released phosphorus concentrations were 20 to 80 mg/L for the conventional sludge and 60 to 130 mg/L for the biophosphorus sludge. Higher phosphorus release also occurred at low pH (<6.0). As for the effect of DO, fully aerobic digestion caused higher phosphorus release than the low-DO and cyclic operations. For better understanding, the solid phosphorus in sludge was conceptually categorized into three forms: inorganic phosphorus precipitates, organic cellular phosphorus, and polyphosphate (poly-P) in polyphosphate-accumulating organisms. Dissolution of inorganic phosphorus precipitates is controlled by physical and chemical conditions, with pH being the most important in this study. Lowering the pH to 4 to 6 clearly promoted the release of inorganic phosphorus. Polyphosphate hydrolysis, on the other hand, was found to be regulated biologically (sensitive to occurrence of anaerobic conditions) and was insignificant in the glutaraldehyde-fixed sludge. Phosphorus release from organic phosphorus should correlate with the volatile solid (VS) digestion, which lyses the cells and frees the phosphorus covalently bonded with the organic matters. The amounts of phosphorus released per unit VS digested (deltaP/deltaVS) were therefore calculated for experiments with long periods of constant pH (to minimize interferences from dissolution/precipitation of inorganic phosphorus). The results suggested that some poly-P was hydrolyzed and released accompanying the aerobic VS digestion, but at rates far lower than those under anaerobic conditions.     

高效聚磷菌的选育及其特性研究

从鱼塘底部污泥中分离驯化得到一株高效聚磷菌株P5,采用厌氧/好氧(A/O)方式培养,在厌氧阶段3 h的最大释磷量为17 mg/L;在好氧条件下培养16 h后,P5对总磷(PO43--P)浓度为10~30 mg/L的模拟废水的除磷率均可保持在90%,COD的去除率达到82.1%。染色实验表明,P5是革兰氏阴性球杆菌,菌体内含有异染颗粒。     

耦合回流污泥预浓缩系统的新型氧化沟工艺强化除磷

针对传统的"厌氧+氧化沟"运行模式对低碳源污水除磷能力不佳的问题,采用耦合回流污泥预浓缩系统的新型氧化沟工艺对其强化除磷进行了中试实验研究。通过采用回流污泥预浓缩系统,调试回流污泥浓缩比,提高系统的除磷能力。研究结果表明,在控制最佳回流污泥浓缩比为55%的情况下,出水TP浓度和去除率分别为0.92 mg/L和67.5%,相比于浓缩比为100%、70%、50%和30%的工况,其去除率分别增加了24.3%、27.3%、8.2%和28.6%,强化了系统的除磷效果。另外,ORP可以预示预缺氧池内无效释磷和反硝化程度,以此作为自动调整最佳回流污泥浓缩比的控制参数。     

COD对强化生物除磷系统的影响及OUR的变化规律

以实际生活污水为研究对象,在SBR系统中采用厌氧/好氧运行方式,考察强化生物除磷(EBPR)系统中好氧阶段COD浓度对聚磷菌除磷性能的影响以及不同好氧阶段COD浓度下的OUR变化规律.实验分4个阶段进行,分别为不投加外碳源、厌氧结束时投加不同体积的乙酸钠作为外碳源,使COD分别提高50、100和300mg/L.4种工况...     

(AO)_2SBR同步脱氮除磷的研究

以人工配水为研究对象,采用厌氧/好氧/缺氧/好氧交替运行的序批式反应器,研究了(AO)2SBR系统同步脱氮除磷的效果,并结合批式实验讨论了同步脱氮除磷的反应机理。研究结果表明,该系统以厌氧1.5 h、好氧1 h、缺氧3h、好氧0.5 h的方式运行,在DO=2.5 mg/L,SRT=15 d的条件下,具有良好的脱氮除磷效果,配水中的总氮、总磷、COD和总有机碳的去除率分别为96.26%、99.87%、90.46%和85.57%。批式实验表明,合成的内碳源越多,氨氮的硝化越充分,反硝化除磷越多。     

Changes in anoxic denitrification rate resulting from prefermentation of a septic, phosphorus-limited wastewater.

A preliminary bench-scale study of parallel University of Cape Town (UCT) biological nutrient removal systems showed improvement in anoxic denitrification rates resulting from prefermentation of a septic (i.e., high volatile fatty acid [VFA] content), phosphorus-limited (i.e., total chemical oxygen demand/total phosphorus [TP] ratio < 40:1) wastewater. Net phosphorus removals due to enhanced biological phosphorus removal (EBPR) were only improved marginally by prefermentation in spite of significant increases in anaerobic phosphorus release, polyhydroxyalkanoate formation, and higher anoxic and aerobic uptakes. This probably was due to the high VFA/TP ratio in the raw influent relative to the VFA requirements for EBPR because enough VFAs were already present for phosphorus removal prior to prefermentation. An additional assessment of prefermentation using parallel UCT systems with step feed of 50% of the influent to the anoxic zone was completed. This second phase quantified the effect of prefermentation in a step-feed scenario, which prioritized prefermentation use to enhance denitrification rather than EBPR. While specific denitrification rates in the anoxic zone were significantly improved by prefermentation, high denitrification in the clarifiers and aerobic zones (simultaneous denitrification) made definitive conclusions concerning the potential improvements in total system nitrogen removal questionable. The prefermented system always showed superior values of the zone settling velocity and sludge volume index and the improvement became increasingly statistically significant when the prefermenter was performing well.     

Contrast of volatile fatty acid driven and inorganic acid or base driven phosphorus release and uptake in enhanced biological phosphorus removal

Addition of an inorganic acid or base was detrimental to net phosphorus removals in short-term batch experiments, suggesting there might be system upset when pH changes. In contrast, addition of volatile fatty acids (VFAs) increased anaerobic phosphorus release and aerobic phosphorus uptake while maintaining or improving net phosphorus removals. The effect of pH change differed if the acid or base added was inorganic versus organic. Volatile fatty acids that resulted in poly-3-hydroxy-butyrate rather than poly-3-hydroxy-valerate resulted in greater net phosphorus removals, and this corresponded to differences in consumption of reducing equivalents. Acetic acid resulted in improved net phosphorus removal compared to sodium acetate, suggesting that acid forms of VFAs might be superior as supplemental VFAs. It is hypothesized that anaerobic phosphorus release following addition of inorganic acid is primarily a result of phosphorus and proton (H+) symport (excretion from the cell) for pH homeostasis, whereas addition of VFAs results in phosphorus and H+ release to maintain the proton motive force.     

酸性媒介黄GG生物降解性能的试验研究

通过试验研究酸性媒介黄GG染料在厌氧、好氧条件下的生物降解机理、降解能力及共代谢降解效果。试验结果表明，厌氧菌能够通过葡萄糖共代谢作用很快降解酸性媒介黄GG；而好氧条件下经驯化活性污泥不能降解酸性媒介黄GG，经过较长时间驯化活性污泥能降解酸性媒介黄GG，但降解效果很差。葡萄糖浓度的升高对提高酸性媒介黄GG厌氧生物降解率有利，当葡萄糖浓度为2000mg／L时，40mg／L酸性媒介黄GC的12和60h厌氧生物降解率分别达到81．5％和93．5％。酸性媒介黄GG浓度对厌氧菌的生物降解能力也有影响。当葡萄糖浓度为2000mg／L，酸性媒介黄GG（浓度为20～100mg／L）的厌氧降解率最好，降解效率达到了94％，说明厌氧菌对酸性媒介黄GG的降解能力较好。