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1.
亚硝酸盐对聚磷菌厌氧代谢的影响 总被引:1,自引:0,他引:1
以2种强化生物除磷(EBPR)系统中的活性污泥为研究对象,考察亚硝酸盐对聚磷菌厌氧代谢的影响,结果表明:不同EBPR系统中的聚磷菌对于亚硝酸盐的耐受能力不同。人工配水富集聚磷菌的活性污泥,当亚硝态氮浓度超过10 mg/L时,聚磷菌吸收VFA受到抑制, PHA的合成减少,磷酸盐的释放增加;处理生活污水的SBR短程脱氮除磷活性污泥,亚硝酸盐的浓度高达30 mg/L时,未对聚磷菌的厌氧代谢造成抑制,但引起异养反硝化菌与聚磷菌竞争VFA,导致PHA合成量和释磷量的减少。富集聚磷菌的活性污泥投加亚硝酸盐后P/VFA 相似文献
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叙述了生物法利用聚磷菌和反硝化聚磷菌除磷原理,研究了不同运行方式、有机物浓度及其种类、厌氧段NO3-浓度和污泥龄等因素对生物除磷产生的影响,并指出现阶段生物除磷存在的问题,以期对生物除磷的试验和实际生产提供帮助。 相似文献
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对强化生物除磷机理与工艺认识误区的剖析 总被引:9,自引:4,他引:5
结合国际上生物除磷机理与工艺的最新进展,分析了目前我国在污水生物除磷工艺研发和运行中存在的一些认识误区。基于成熟的生物除磷生化代谢机理,指出反硝化除磷菌(DPB)是一种广泛存在于一些强化生物除磷(EBPR)工艺中的聚磷菌(PAOs),无需特殊培养;对于市政污水,EBPR工艺中出现的聚糖原茵(GAOs)一般不会成为聚磷茵(PAOs/DPB)的竞争者而严重影响系统的除磷功能。针对强化生物除磷工艺的认识误区,指出污泥龄(SRT)是设计的关键参数,在最不利细菌生长的冬季,控制SRT〉12 d即可使EBPR保持较好的硝化与脱氮除磷效果;在污水生物处理除磷工艺选择上,“厌氧池+氧化沟”只是污水处理升级而演变出的一种被动型工艺,并非最佳的EBPR工艺选择;此外倒置A^2/O工艺由于忽略了聚磷菌所需的进水碳源及DPB的作用,并不一定能改进EBPR的生物除磷效果。 相似文献
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生物除磷系统中聚磷菌与聚糖菌代谢模型比较 总被引:1,自引:1,他引:1
基于国内外学者对生物除磷代谢机理的最新研究成果,介绍了生物除磷系统中聚磷菌与聚糖菌的代谢模型,并对两者进行了比较。指出有必要对聚磷菌与聚糖菌的代谢机理与生理特性进行进一步研究,以提高系统的运行效率和稳定性。 相似文献
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污水生物除磷的糖控制(CHC)工艺 总被引:8,自引:0,他引:8
活性污泥糖类物质(Carbohydrate)的代谢已被证明是除磷脱氮工艺中活性污泥的一个普遍的主导性代谢活动,对其研究也成为污水除磷领域的焦点。实际运行证明,进水特征对生物除磷效率影响很大,在厌氧段,污泥每释放1mg磷需吸收7.5mg挥发性有机酸(V... 相似文献
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以西安市采用不同工艺的三个污水处理厂为研究对象,对其除磷效果进行测定,利用荧光原位杂交技术(FISH)对污泥中的聚磷菌、聚糖菌和总细菌的数量和分布特征进行分析。结果表明,厌氧释磷速率为2.81~11.03 mgP/(gVSS·h),厌氧过程中吸收单位质量乙酸的释磷量为0.098~0.345 mg。好氧吸磷速率为3.03~13.58 mgP/(gVSS·h),缺氧吸磷速率为1.93~4.48mgP/(gVSS·h),缺氧、好氧吸磷速率的比值为33.02%~71.91%。污泥中聚磷菌占总细菌的比例为0.43%~5.34%,聚糖菌的比例为0.16%~10.08%。聚磷菌和聚糖菌在活性污泥絮体中的分布状态存在明显差异,聚磷菌主要以菌胶团形式存在,而聚糖菌则均匀分布于絮体中。 相似文献
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以一营养物去除工艺——BNR为研究对象,分别采用试验与模拟,研究了通过厌氧上清液侧流磷回收和外加碳源方式对低碳源污水生物除磷的强化作用。试验结果与模拟预测双双显示,对COD/P值=50的实际生活污水实施30%的厌氧上清液旁路磷沉淀可明显强化生物除磷作用,使出水TP浓度从碳源抑制时的1.8 mgP/L下降至0.5 mgP/L以下。侧流磷回收不仅可回收40%的进水磷负荷,亦可节省27%的外加碳源。因此,厌氧上清液侧流磷回收与外加碳源对强化生物除磷作用有着异曲同工之处。模拟预测与试验结果几乎一致的演示表明,数学模拟技术可取代传统试验进行相关问题研究。 相似文献
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聚磷菌PAO1-1的筛选及除磷特性 总被引:9,自引:1,他引:9
从运行稳定的以生活污水为碳源的生物除磷污泥中筛选出一株聚磷菌PAO1-1,该菌株对普通活性污泥系统具有很好的强化作用,驯化10 d后可使除磷率由投菌前的44%提高到90%以上。对该菌株的形态、生理生化特征及16S rDNA序列进行分析后,鉴定该菌株为产碱杆菌属。该菌株对磷的平均吸收速率为13.8 mg/(g.h),处于“磷酸盐饥饿期”时对磷的吸收速率为19.2 mg/(g.h),比“非饥饿期”提高了39.1%。处于对数期的PAO1-1在厌氧条件下的无磷培养基中的释磷速率为11.8 mg/(g.h),稳定期释磷速率为7.0 mg/(g.h),释磷速率下降了40.7%。 相似文献
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Advanced sewage treatment process with excess sludge reduction and phosphorus recovery 总被引:33,自引:0,他引:33
An advanced sewage treatment process has been developed, in which excess sludge reduction by ozonation and phosphorus recovery by crystallization process are incorporated to a conventional anaerobic/oxic (A/O) phosphorus removal process. The mathematical model was developed to describe the mass balance principal at a steady state of this process. Sludge ozonation experiments were carried out to investigate solubilization characteristics of sludge and change in microbial activity by using sludge cultured with feed of synthetic sewage under A/O process. Phosphorus was solubilized by ozonation as well as organics, and acid-hydrolyzable phosphorus (AHP) was the most part of solubilized phosphorus for phosphorus accumulating organisms (PAOs) containing sludge. At solubilization of 30%, around 70% of sludge was inactivated by ozonation. The results based on these studies indicated that the proposed process configuration has potential to reduce the excess sludge production as well as to recover phosphorus in usable forms. The system performance results show that this system is practical, in which 30% of solubilization degree was achieved by ozonation. In this study, 30% of solubilization was achieved at 30 mgO(3)/gSS of ozone consumption. 相似文献
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厌氧/跌水充氧接触氧化/人工湿地处理农村污水 总被引:17,自引:1,他引:17
为了使太湖地区农村污水处理达到占地面积小、除磷脱氮效率高、管理简单、运行和建设费用低的目标,采用厌氧/跌水充氧接触氧化/人工湿地组合工艺进行了工程规模的试验研究。结果表明,在厌氧池水力停留时间为2d、5级跌水充氧接触氧化池总水力停留时间为2h、并采用50cm/d的高水力负荷人工湿地的条件下,该组合工艺对COD和TN的平均去除率分别为81%和83%,对TP的平均去除率在进水TP〉1.5mg/L时达82%,在进水TP〈1.5mg/L时为72%。 相似文献
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The objective of this research was to advance a fundamental understanding of a unique post-anoxic denitrification process for achieving biological nutrient removal (BNR), with an emphasis on elucidating the impacts of surface oxygen transfer (SOT), variable process loadings, and bioreactor operational conditions on nitrogen and phosphorus removal. Two sequencing batch reactors (SBRs) were operated in an anaerobic/aerobic/anoxic mode for over 250 days and fed real municipal wastewater. One SBR was operated with a headspace open to the atmosphere, while the other had a covered liquid surface to prevent surface oxygen transfer. Process performance was assessed for mixed volatile fatty acid (VFA) and acetate-dominated substrate, as well as daily/seasonal variance in influent phosphorus and ammonia loadings. Results demonstrated that post-anoxic BNR can achieve near-complete (>99%) inorganic nitrogen and phosphorus removal, with soluble effluent concentrations less than 1.0 mgN L−1 and 0.14 mgP L−1. Observed specific denitrification rates were in excess of typical endogenous values and exhibited a linear dependence on the glycogen concentration in the biomass. Preventing SOT improved nitrogen removal but had little impact on phosphorus removal under normal loading conditions. However, during periods of low influent ammonia, the covered reactor maintained phosphorus removal performance and showed a greater relative abundance of polyphosphate accumulating organisms (PAOs) as evidenced by quantitative real-time PCR (qPCR). While GAOs were detected in both reactors under all operational conditions, BNR performance was not adversely impacted. Finally, secondary phosphorus release during the post-anoxic period was minimal and only occurred if nitrate/nitrite were depleted post-anoxically. 相似文献
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《Water research》1996,30(10):2323-2328
A full-scale sewage treatment plant designed for biological phosphorus removal may experience short- or long-term shortage in potassium of the influent. In this study, using an anaerobic-aerobic sequenced batch reactor system, inoculation sludge from laboratory-, pilot- and full-scale phosphorus removal plants was exposed to different potassium-phosphorus ratios in the influent. By simulating the conditions which may occur in practice, it was shown that potassium is an essential factor in biological phosphorus removal processes. When the system was exposed to severe shortage of potassium in the influent: (a) phosphorus removal was absent, (b) polyphosphate concentration in the biomass decreased exponentially due to sludge wasting and (c) the anaerobic phosphorus release and the related acetate uptake was only affected after several days of potassium absence, likely due to insufficient content of polyphosphate in the biomass to allow full acetate uptake under anaerobic conditions. In contrast, the system achieved complete phosphorus removal when potassium was present in excess amounts. 相似文献
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Interactions between calcium precipitation and the polyphosphate-accumulating bacteria metabolism 总被引:3,自引:0,他引:3
A sequencing batch reactor that is operated for biological phosphorus removal has been operated under different influent calcium concentrations to study the precipitation process and the possible effects of phosphorus precipitation in the biological phosphorus removal process. Four experiments were carried out under different influent calcium concentrations ranging from 10 to 90 g Ca m(-3). The experimental results and the equilibrium study, which are based on the saturation index calculation, confirm that the process controlling the calcium behaviour is the calcium phosphate precipitation. This precipitation takes place at two stages: initially, precipitation of the amorphous calcium phosphate, and later crystallization of hydroxyapatite. Also the accumulation of phosphorus precipitated was observed when the influent calcium concentration was increased. In all the experiments, the influent wastewater ratio P/COD was kept constant. It has been observed that, at high calcium concentration, the ratio between phosphate release and acetate uptake (P(rel)/Ac(uptake)) decreases. Changes in the polyphosphate-accumulating organism (PAO) population and in the glycogen-accumulating organism (GAO) population during the experimental period were ruled out by means of fluorescence in situ hybridization. These results could suggest that PAO are able to change their metabolic pathways based on external conditions, such as influent calcium concentration. The accumulation of phosphorus precipitated as calcium phosphate at high influent calcium concentration throughout the experimental period confirmed that phosphate precipitation is a process that can affect the PAO metabolism. 相似文献
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It is estimated that up to 342 wastewater treatment plants (Wwtps) in England and Wales will require a phosphorus (P) consent by 2010. Although biological P removal is considered to be the most sustainable option for P removal, it has always been problematic for plants that remove both nitrogen and P due to the inadequate concentration of organic material during wet periods. Two biological nutrient removal (BNR) configurations, the Johannesburg (JHB) process and a combined JHB and five-stage Bardenpho process, were evaluated over a period of 2 years to assess the impact of sewage strength on bio-P removal. The JHB achieved an average effluent total phosphorus (TP) of 2.4 mg/L and the combined JHB and five-stage process averaged 1.4 mg/L effluent TP. The major problems affecting the performance of both configurations were: dissolved oxygen (DO) in the recycled mixed liquor, nitrate in the return activated sludge (RAS) and low influent biological oxygen demand (BOD) concentrations. Acetate dosing proved successful as a source of volatile fatty acids (VFAs) in the anaerobic zone during periods of low-strength sewage. An acetate dosing strategy based on the influent flow rate to the plant was found to be a simple and effective technique that ensured that a consent of <1 mg TP/L could be met. 相似文献
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Impact of solids residence time on biological nutrient removal performance of membrane bioreactor 总被引:1,自引:0,他引:1
Impact of long solids residence times (SRTs) on nutrient removal was investigated using a submerged plate-frame membrane bioreactor with anaerobic and anoxic tanks. The system was operated at 10, 25, 50 and 75 days SRTs with hydraulic retention times (HRTs) of 2 h each for the anaerobic and anoxic tanks and 8 h for the oxic tank. Recirculation of oxic tank mixed liquor into the anaerobic tank and permeate into the anoxic tank were fixed at 100% each of the influent flow. For all SRTs, percent removals of soluble chemical oxygen demand were more than 93% and nitrification was more than 98.5% but total nitrogen percent removal seemed to peak at 81% at 50 days SRT while total phosphorus (TP) percent removal showed a deterioration from approximately 80% at 50 days SRT to 60% at 75 days SRT. Before calibrating the Biowin® model to the experimental data, a sensitivity analysis of the model was conducted which indicated that heterotrophic anoxic yield, anaerobic hydrolysis factors of heterotrophs, heterotrophic hydrolysis, oxic endogenous decay rate for heterotrophs and oxic endogenous decay rate of PAOs had the most impact on predicted effluent TP concentration. The final values of kinetic parameters obtained in the calibration seemed to imply that nitrogen and phosphorus removal increased with SRT due to an increase in anoxic and anaerobic hydrolysis factors up to 50 days SRT but beyond that removal of phosphorus deteriorated due to high oxic endogenous decay rates. This indirectly imply that the decrease in phosphorus removal at 75 days SRT may be due to an increase in lysis of microbial cells at high SRTs along with the low food/microorganisms ratio as a result of high suspended solids in the oxic tank. Several polynomial correlations relating the various calibrated kinetic parameters with SRTs were derived. The Biowin® model and the kinetic parameters predicted by the polynomial correlations were verified and found to predict well the effluent water quality of the MBR at 35 days SRT. 相似文献