城市污水处理厂设计进水水质确定和出水水质评价

以广州市各污水处理厂的进出水水质的实测数据为例,通过概率分析,进行了城市污水处理厂设计进水水质确定和出水水质评价的尝试。这些实测数据,经过适当变换,可以与标准正态分布曲线良好符合,说明它们基本遵从正态分布规律,并更加遵从对数正态分布规律。按照保证概率确定了该地区或类似地区的城市污水处理厂的设计进水水质,并利用达标概率评价了广州市各污水处理厂的出水水质。     

Nutrients removal in MBRs for municipal wastewater treatment.

Owing to increasingly stringent effluent quality requirements, intensifications of the conventional activated sludge process (ASP) are required. Due to high biomass concentrations employed, higher metabolic rates and better nutrient removal are possible in membrane bioreactors (MBRs). Decoupling of hydraulic and solids residence times offers additional possibilities for process design and optimisation. Recently, unconventional concepts like post-denitrification and enhanced biological phosphorus removal in MBRs have emerged. The objective of this paper is to present current knowledge on nutrients removal in MBRs and trends in process optimisation in comparison with conventional ASP.     

化学除磷在城市污水处理中的应用

阐述了城市污水处理中除磷的重要性和迫切性,而在普遍采用的生物除磷技术不能满足出水磷的排放标准时可考虑采用化学除磷技术.系统分析了化学除磷的原理、方法、工艺、研究进展及应用前景,并指出了现阶段化学除磷技术研究与发展的目标.     

On-site evaluation of the removal of 100 micro-pollutants through advanced wastewater treatment processes for reuse applications

The next challenge of wastewater treatment is to reliably remove micro-pollutants at the microgram per litre range in order to meet reuse applications and contribute to reach the good status of the water bodies. A hundred priority and relevant emerging substances were measured to evaluate at full-scale the removal efficiencies of seven advanced treatment lines (one membrane bioreactor process and six tertiary treatment lines) that were designed for reuse applications. To reliably compare the processes, specific procedures for micro-pollutants were applied for sampling, analysis and calculation of removal efficiencies. The membrane bioreactor process allowed to upgrade the removal efficiencies of about 20% of the substances measured, especially those that were partially degraded during conventional processes. Conventional tertiary processes like high rate clarification, sand filtration and polishing pond achieved significant removal for some micro-pollutants, especially for adsorbable substances. Advanced tertiary processes, like ozonation, activated carbon and reverse osmosis were all very efficient to complete the removal of polar pesticides and pharmaceuticals; metals and less polar substances were better retained by reverse osmosis.     

市政污水生物除磷效能和功能微生物分布特征

调研了4座市政污水处理厂的除磷效能、污泥活性以及微生物分布特征。结果表明出水总磷均达到《城镇污水处理厂污染物排放标准》(GB18918—2002)一级标准,但污泥性能差异显著。活性污泥厌氧释磷率和好氧聚磷率范围分别是0.224～7.77mg/(gVSS.h)和0.386～7.9mg/(gVSS.h)。聚磷假丝酵母菌(Accumulibacter)比例较低,为3.8%～8.7%,聚糖假丝酵母菌(Competibacter)为3.2%～9.1%。进水乙酸含量和乙酸吸收率,厌氧释磷率和好氧聚磷率间都存在很好的线性相关性,表明污水中可利用碳源的数量和磷素的比例极大影响污泥除磷性能。故控制工业废水排入,适当添加碳源,或设置独立的前置反硝化池有望增加污水处理厂的除磷效能。     

典型城市污水处理工艺微生物气溶胶逸散研究

污水处理过程中产生微生物气溶胶,其对人体健康和环境的影响与其组成、浓度和粒径有关。采用6级撞击式空气微生物采样器分别对采用氧化沟和A2/O工艺的两座城市污水处理厂的细菌和真菌气溶胶浓度与粒径进行检测分析,结果显示,空间相对封闭的污泥脱水间内细菌和真菌气溶胶浓度最高;曝气方式对细菌气溶胶的产生量影响较大,而对真菌气溶胶产生量的影响较小;两座污水处理厂内最高浓度的细菌气溶胶和真菌气溶胶的粒径都出现在2.1～3.3μm,但粒径分布的范围受曝气方式的影响而略有差异。为污水处理工艺设计时控制微生物气溶胶逸散方法的选择提供了科学依据。     

Occurrence and fate of heavy metals in large wastewater treatment plants treating municipal and industrial wastewaters.

This paper deals with a detailed study on the occurrence and fate of heavy metals (plus As, Fe and Al) in five Italian large wastewater treatment plants treating municipal and industrial wastewaters. The study showed that some of the compounds (As, Hg and Cd) were present at trace levels, while others were dispersed in a broad range of concentrations and were sometimes under the detection limit. The occurrence followed the order Hg = As < Hg < Pb < Ni < Cu < Cr < Fe < Zn < Al. Metals were mainly present bound to particulate organic matter in municipal wastewaters while they were often present in soluble phase in industrial wastewaters. Some heavy metals, like Hg and Pb, showed clear correlations with Al and Fe, therefore the last could be used as control parameters. Metals were removed with good efficiency in the treatment works, with the order As < Cd = Cr = Zn < Pb < Hg < Ni = Al < Cu < Fe. Metals then concentrated in waste activated sludge and accumulated after sludge stabilisation because of volatile solids degradation, therefore some problems may arise with limit for agricultural application, in particular for Hg, Cd and Ni.     

城市污水处理厂运行除磷效果影响因素分析

针对西安市第四污水处理厂倒置A2/O工艺实际运行除磷效果差、出水TP不能达标排放的问题,通过监测污水处理厂实际进出水水质和生化反应池运行参数,分析除磷效果差的主要原因,并研究其解决措施,寻求最优的运行参数和工程改造措施,提出优化厌氧区水力停留时间、强化污泥处理系统污泥水的处理,以及启动污水处理厂已建成的化学除磷系统等措施。     

城镇污水处理领域的碳减排

温室气体增加导致的气候变化正在对人类社会产生日益明显的影响,减少温室气体排放、控制气候变化已经成为国际社会的共识,绝大部分行业都在进行碳排放评价研究及碳减排对策的制定.城镇污水处理虽然是人类社会活动中一个很小的行业,但却是一个重要的碳排放源,发达国家已经越来越重视城镇污水处理行业的碳减排.碳排放是关于温室气体排放的一个总称或简称.能在大气中吸收红外线产生温室效应的气体有30多种,京都议定书确定需对其中的二氧化碳(CO2)、甲烷(CH4)、一氧化二氮(N2O)、氢氟碳化物(HFCs)、全氟碳化物(PFCs)及六氟化硫(SF6)六种气体进行消减,以有效控制气候变化.     

可持续发展的新型、高效城市污水处理技术探讨

对国内外城市污水处理工艺的发展进行了回顾,提出我国目前所采用的以氧化沟技术和SBR反应器为主体的城市污水处理技术是西方发达国家在一定历史时期和技术发展水平下的产物,与西方国家的自然条件和经济发展水平是相适应的。从可持续发展方面进行考察认为这些技术(特别是延时曝气)是不适合我国国情的高物质消耗和高能耗的污水处理技术。同时,提出我国城市污水可持续发展的处理技术的关键是要在新工艺开发方面进行不断的探索,同时解决污泥处理技术方面的问题。并就工艺创新、技术创新和体制创新对城市污水处理厂降低投资和运行管理费用的作用进行了分析。对沉淀和分离性能改进,生物的量和质的提高以及充氧性能的改善是高效反应器发展的要点。     

城市污水处理中砂的影响及对策

污水处理厂在日常运行中常会受到一些外来因素的影响,污水中含砂量的增加就是其中之一。这一问题给污水处理厂的运行带来了极大的困难。1　污水处理中砂量增加对运行的影响一般城市污水的沉砂量可按10 0万m3污水沉砂30m3计算,其含水率为6 0 % ,密度为15 0 0kg/m3,但有些污水处理厂进水口水样检测中经常高于上述数值,甚至是设计含砂量的2～3倍。污水中含砂量的增加给运行中各道工序带来影响。1 1　对沉砂池前道工序的影响进水泵房前池是泵房的集水区域,且成了污水中粗颗粒的沉砂池。在进水通道中有扩散和死角处积砂更严重,使水泵进水的水量受…     

溶气气浮技术的发展及其在城市污水处理厂中的应用

介绍了溶气气浮 (DAF)技术发展的三个阶段 (早期DAF ,普通DAF ,紊流DAF) ,及各自的技术特点。通过实例分析了DAF在城市污水处理领域中几个方面的应用 :强化一级处理中的应用 ,三级处理固液分离中的应用 ,厌氧处理出水及污泥浓缩中的应用。     

Phosphorus removal from synthetic and municipal wastewater using spent alum sludge.

In the present study, phosphorus removal was studied using as coagulant spent alum sludge from a water treatment plant of EYDAP (Athens Water Supply and Sewerage Company) and compared to alum (Al2(SO4)3.18H2O), iron chloride (FeCl3.7H2O), iron sulfate (Fe2(S04).10H2O) and calcium hydroxide (Ca(OH)2) at a constant pH (equal to 6).The comparison was based on their efficiency to remove phosphorus in synthetic wastewater consisting of 10 mg/L P as potassium dihydrogen phosphate and 50 mg/L N as ammonium chloride, The experiments were carried out using a jar-test apparatus and the measurements were performed according to the Standard Methods for the Examination of Water and Wastewater. Pure alum, iron chloride and iron sulfate were much more efficient in phosphorus removal than the spent alum sludge but in the case of calcium hydroxide, phosphorus removal was very low in pH = 6. Specifically, orthophosphate were totally removed by alum using 15 mg/L as Al, by alum sludge using 75 mg/L as Al and by FeCl3.7H2O or Fe2(SO4).10H2O using 30 mg/L of Fe while in the case of calcium hydroxide P removal was actually zero. pH measurements showed that the uptake of phosphates is associated to the release of OH ions in the solution and that the end of P uptake is accompanied by the stabilization of pH. Finally this spent alum sludge was tested on municipal wastewater and proved to be effective as apart from phosphorus it was shown to remove turbidity and COD.     

Alternate anoxic/aerobic operation for nitrogen removal in a membrane bioreactor for municipal wastewater treatment

A large pilot-scale membrane bioreactor (MBR) with a conventional denitrification/nitrification scheme for municipal wastewater treatment has been run for one year under two different aeration strategies in the oxidation/nitrification compartment. During the first five months air supply was provided according to the dissolved-oxygen set-point and the system run as a conventional predenitrification MBR; then, an intermittent aeration strategy based on effluent ammonia nitrogen was adopted in the aerobic compartment in order to assess the impact on process performances in terms of N and P removal, energy consumption and sludge reduction. The experimental inferences show a significant improvement of the effluent quality as COD and total nitrogen, both due to a better utilization of the denitrification potential which is a function of the available electron donor (biodegradable COD) and electron acceptor (nitric nitrogen); particularly, nitrogen removal increased from 67% to 75%. At the same time, a more effective biological phosphorus removal was observed as a consequence of better selection of denitrifying phosphorus accumulating organisms (dPAO). The longer duration of anoxic phases also reflected in a lower excess sludge production (12% decrease) compared with the standard pre-denitrification operation and in a decrease of energy consumption for oxygen supply (about 50%).     

Temperature effects on biological nutrient removal system with weak municipal wastewater

The wastewater characteristics of low organic strength coupled with low temperature would be considerable variables for design and operation of biological nutrient removal (BNR) systems. But temperature studies have mostly been focused on individual process with biological phosphorus removal, nitrification and denitrification, respectively. Overall temperature effects on BNR system may not be fully represented by sum of results of separated studies on biological nutrient removal steps. The operating result of a retrofitted full scale unit along with laboratory-scale BNR unit indicated 90% of nitrification was possible at temperature as low as 8°C. However, the denitrification was turned out to be a key step to regulate the overall nutrient removal efficiencies. When the operating temperature dropped down, a rapid decrease of phosphorus removal efficiencies was observed by the nitrate in return sludge. If nitrification was not well developed, phosphorus removal returned to the normal efficiency even at low temperature of 5°C. The phosphorus removal mechanism was not influenced at this low temperature.     

城市污水脱氮除磷SBR在线控制系统研究

SBR采用进水—厌氧—好氧—缺氧—好氧—沉淀—出水的运行方式处理城市污水。反应器装备有DO、ORP和pH等在线检测传感器。DO、ORP和pH变化的一些特征点可以用来判断和控制SBR中污水脱氮除磷过程的各个步骤。这包括:厌氧时,ORP和pH的转折点对应磷的释放;一次好氧时,DO、ORP的氨肘和pH的氨谷对应硝化结束;缺氧时,ORP的硝酸盐膝和pH的硝酸盐峰对应反硝化结束;二次好氧时,DO、ORP碳肘对应剩余碳的氧化结束,pH的转折点对应聚磷结束。控制系统能进行全自动运行来完成污水的脱氮除磷。     

ANAMMOX工艺在生活污水深度处理中的应用研究

随着水环境质量的恶化,高能低耗的污水深度处理技术成为当前研究热点,尤其是对于低C/N比的城市生活污水脱氮技术的研究。试验以城市生活污水的二级出水为研究对象,采用ANAMMOX下向流生物滤池,当二级出水NH3-N=15-35mg/L,CODCr=25-45mg/L,TOC=9-12mg/L,水温=25-28℃时,ANAMMOX下向流生物滤池脱氨率达80%-100%,不仅适用于处理高氨废水,也可用于城市生活污水深度处理中。试验发现pH可以用来指示ANAMMOX反应的进行,同时也可以用来指示ANAMMOX反应进程的快慢。试验中还发现,厌氧氨氧化反应速率与NO2--N含量有关,原水中NO2--N含量的增多有利于ANAMMOX工艺处理效果。     

Biolak工艺处理城市污水的设计及运行

山东诸城市污水处理厂采用Biolak工艺,一期设计处理能力6.6万m3/d。其进水包含40%生活污水和60%工业废水,设计进水CODCr450mg/L,BOD5200mg/L,SS230mg/L,NH3-N40mg/L,TP5mg/L,设计出水达到《污水综合排放标准》(GB8976-1996)一级标准。介绍了工艺流程,主要设计参数以及Biolak工艺的特点。运行结果表明,该工艺占地小,处理效率高,出水水质达到设计要求。     

城市污水处理CASS工艺模拟与优化

以中山市大涌污水处理厂的CASS工艺为例,介绍了如何利用工艺模拟工具解决实际工程问题的方法。利用BioWin软件所构建的大涌污水处理厂模型,通过对该厂历史数据和补充采样数据进行模拟和校正。经校正后的模型用于现有污水处理厂在不同运行方案下的情景分析和优化,同时,对模型在节能降耗方面的应用也进行了探讨。     

我国城镇污水处理发展的状况和面临的挑战

1 我国城镇污水处理目前处于快速发展阶段 (1)与2000年相比,我国城镇污水排放量略有增长,过去九年增长了14%,但是同期的污水处理量大幅度增加,累计增加了140%.从国际经验来看,我国是世界上唯一一个十年内污水处理量翻番的大国.