污水再生工艺去除病原体效果的评价

为考察常用城市污水再生回用工艺去除病毒的效果,采用柯萨奇B3型病毒(CoxB3)作为肠道病毒示踪剂进行试验.首先向污水厂二级处理出水中人工投加已知浓度的病毒,然后分别采用混凝/沉淀/过滤、超滤、氯消毒和臭氧消毒对其进行处理,并分析处理前后病毒的组织培养半数感染剂量(TCID50).结果表明,混凝/沉淀/过滤对大肠菌的去除率为2-lg～3-lg,对柯萨奇病毒的去除率约为1.83-lg;氯消毒和臭氧消毒可以有效杀灭大肠菌,在消毒剂浓度为1～10mg/L、余氯浓度为1～6 mg/L、pH为6～7的条件下,氯消毒对柯萨奇病毒的去除效果不佳,臭氧消毒对柯萨奇病毒的去除率则随臭氧浓度的不同而在1.33-lg～3.83-lg变化;超滤可有效去除大肠菌,对柯萨奇病毒的去除率为2.33-lg.     

城镇污水处理厂次氯酸钠消毒效果的影响因素研究

次氯酸钠消毒是目前我国城镇污水处理厂应用最广泛的一种消毒方式,但行业内对次氯酸钠的运行参数如投加量等及其消毒效果尚未达成共识。为此,以执行《城镇污水处理厂污染物排放标准》(GB 18918—2002)一级A标准的某城镇污水处理厂二沉池出水为研究对象,开展了以次氯酸钠为消毒药剂的加氯消毒试验。结果表明,二沉池出水的粪大肠菌群对数去除率与消毒工艺中的有效氯投加量、接触时间以及水温均呈正相关,消毒后出水的氧化还原电位(ORP)可间接表征消毒效果,CT值(接触时间T×接触时间结束时消毒剂残留浓度C)可指导消毒药剂的投加量。在保持接触时间为12 min的前提下,当有效氯投加量为3. 67 mg/L时,粪大肠菌群对数去除率可达到2. 5-lg以上,确保消毒后出水的粪大肠菌群数达到一级A排放标准,此时,ORP为578m V,总氯CT值为7. 6 mg·min/L,游离氯CT值为3. 3 mg·min/L。     

氯化消毒条件及污水水质对生成THMs、HAAs的影响

系统地研究了消毒务件和水质在城市污水氯化消毒过程中对生成三卤甲烷和卤乙酸的影响。结果表明，投氯量对三卤甲烷和卤乙酸生成量的影响最大，投氯量为40mg／L时的生成量分别约是投氯量为5mg／L时的30倍和70倍。三卤甲烷浓度随反应时间和温度无明显变化，而卤乙酸浓度在反应2h后达到峰值并在之后逐渐降低，且随温度的升高呈下降趋势。pH对两类副产物生成的影响几乎相反，近中性条件下的三卤甲烷生成量最多而卤乙酸生成量最少。水中氨氮浓度的增加会导致三卤甲烷生成量略有下降，而卤乙酸浓度却大幅上升。溴离子浓度升高将导致三卤甲烷和卤乙酸生成量显著增加，其中三氯甲烷浓度下降，三溴甲烷浓度显著上升，混合取代的三卤甲烷浓度先增加后减少。与此类似，二氯乙酸和三氯乙酸浓度随溴离子浓度的增加而减少，含溴卤乙酸浓度则有不同程度的增加。反应温度、反应时间、pH和氨氮对污水消毒副产物生成的影响与已报道的饮用水消毒中的作用规律存在显著差异，甚至截然相反，这为有针对性地选取消毒工艺参数提供了依据。     

Synergistic effect of the sequential use of UV irradiation and chlorine to disinfect reclaimed water

The effectiveness of UV and chlorination, used individually and sequentially, was investigated in killing pathogenic microorganisms and inhibiting the formation of disinfection by-products in two different municipal wastewaters for the source water of reclaimed water, which were from a microfilter (W1) and membrane bioreactor (W2) respectively. Heterotrophic plate count (HPC), total bacteria count (TBC), and total coliform (TC) were selected to evaluate the efficiency of different disinfection processes. UV inactivation of the three bacteria followed first-order kinetics in W1 wastewater, but in W2 wastewater, the UV dose-response curve trailed beyond approximately 10 mJ/cm² UV. The higher number of particles in the W2 might have protected the bacteria against UV damage, as UV light alone was not effective in killing HPC in W2 wastewater with higher turbidity. However, chlorine was more effective in W2 than in W1 for the three bacteria inactivation owing to the greater formation of inorganic and organic chloramines in W1 wastewater. Complete inactivation of HPC in W1 wastewater required a chlorine dose higher than 5.5 mg/L, whereas 4.5 mg/L chlorine gave the equivalent result in W2 wastewater. In contrast, sequential UV and chlorine treatment produced a synergistic effect in both wastewater systems and was the most effective option for complete removal of all three bacteria. UV disinfection lowered the required chlorine dose in W1, but not in W2, because of the higher chlorine consumption in W2 wastewater. However, UV irradiation decreased total trihalomethane formation during chlorination in both wastewaters.     

城镇污水处理厂消毒设施运行调研与优化策略

我国《城镇污水处理厂污染物排放标准》(GB 18918—2002)将粪大肠菌群数列为出水基本控制指标之一,要求污水处理过程中必须进行消毒,以降低病原微生物对人畜产生的健康风险。为了解污水处理消毒设施运行的效果,对全国56座城镇污水处理厂进行了调研,分析了消毒单元存在的问题并提出应对措施。调研结果表明,采用次氯酸钠和二氧化氯作为消毒剂的污水处理厂数量占调研总量的91. 6%。次氯酸钠和二氧化氯消毒的优势在于持久性效果较好以及运行管理相对简单。但调研数据显示,72%的污水处理厂有效氯投加量为1～4 mg/L,14%的污水处理厂有效氯投加量过高,超过了6 mg/L;消毒接触时间≥30 min的污水处理厂仅占43%,消毒接触时间≤10 min和≤2 min的污水处理厂分别占28%和17%;此外,50%的污水处理厂未对消毒后的总余氯含量进行测试,在已检测该指标的污水处理厂中,总余氯浓度≥0. 20 mg/L的占70%。针对调研中发现的问题,结合文献报道以及试验数据,提出了污水处理厂消毒设施优化运行建议,并展望了未来的主要研究方向,以期为城镇污水处理厂更合理地设计、运行消毒设施提供理论依据和技术指...     

化学生物絮凝/悬浮填料床工艺出水深度处理研究

化学生物絮凝/悬浮填料床是一种新型、高效的组合工艺,中试结果表明其出水TP为0.89 mg/L、浊度为9.7 NTU、氨氮为8.8 mg/L、COD为37.3 mg/L.采用流砂微絮凝过滤工艺、复合二氧化氯消毒对其出水进行了深度处理的试验研究,运行结果表明：在微絮凝剂PAFC投量为3.1 mg/L的条件下,出水TP、氨氮和COD浓度分别下降到0.38、7.2和26.6 mg/L,浊度也降至2.2NTU;当复合二氧化氯消毒接触时间≥30 min、游离余氯＞0.5 mg/L时,消毒后出水总大肠菌群≤3CFU/L.该系统维护简单、运行稳定,出水水质优良,各项指标均达到国家〈生活杂用水水质标准〉（CJ/T 48-1999）.     

Study on chlorine disinfection of pond effluent

Chlorine disinfection experiments were conducted to investigate the die-off patterns of the fecal coliforms when present in waste stabilization pond effluents containing from 100 to 400 mg l⁻¹ algae. The fecal coliform inactivation was observed to occur at two rates, i.e. an initial rapid kill followed by a slower kill. The magnitude of inactivation was found to be proportional to the initial chlorine dose and contact time and inversely proportional to the algal concentration. A mathematical model was developed to predict the fecal coliform survival ratio during the chlorination of the pond effluent. When compared with the experimental data, the predicted results had a correlation coefficient of 0.981.     

医院污水的紫外线消毒研究

对医院污水采用紫外线消毒所需的剂量进行了研究,结果表明:当紫外线剂量为 15mJ/cm2 时,对粪大肠菌的杀灭率可达 99. 999%;未经处理的医院污水,直接采用紫外线消毒的效果不稳定,而经二级处理后的医院污水采用紫外线消毒时可确保出水粪大肠菌稳定在 500个 /L的一级排放标准内。     

重庆城市污水粪大肠菌污染源调查

对重庆市几个主要区县的城市污水排放口及医院污水排放口进行了抽样调查,结果显示未经处理的城市污水粪大肠菌值主要处于106~107个/L数量级,最大值与最小值之间相差4个数量级。医院污水处理系统虽设计安装有消毒装置,但运行管理不当,出水粪大肠菌严重超标,主要处于104~105个/L数量级,低于城市生活污水。比较了安装与未安装消毒装置的污水处理厂出水中粪大肠菌值,技术经济比较结果显示,氯法、紫外光和臭氧消毒技术在城市污水排放消毒和回用水消毒、医院污水排放消毒方面各有优缺点,宜根据实际情况单独或组合使用。     

再生水用于地下回灌的加氯消毒研究

针对城市污水厂二级出水用于地下回灌的两种深度处理工艺,确定了达到消毒要求的加氯量,并且研究了加氯消毒对有关水质参数DOC、AOX、CHCl3、CCl4、UV254等的影响。研究发现,有效氯投加量在8mg/L左右时,水中细菌总数与总大肠菌群数均能达到我国饮用水卫生标准。加氯后水的DOC值变化不大,AOX值则有较明显的增大,CHCl3浓度略有增加,CCl4基本维持在加氯前的水平,UV254值也较加氯前有所增大。研究结果还表明,粒状活性炭处理工艺在污水深度处理流程中对去除消毒副产物（AOX）及其前驱物发挥着重要的作用。     

ClO_2和Cl_2对城市污水再生水消毒效果的比较

采用Cl02和C12对西安市的城市污水再生水进行消毒,中试结果表明:当Cl02投加量>7.67mg/L时,经30min接触消毒后,出水中未检出总大肠菌群,以氯代有机物为代表的消毒副产物(DBPs)较进水没有明显增加,出水的COD和浊度分别平均降低了13.2%和17.9%,色度平均减少了5倍当Cl2投加量>6mg/L时,经30min接触消毒后,出水中未检出总大肠菌群,出水中的二氯甲烷和三氯甲烷浓度是进水中的2-3倍,三卤甲烷含量则达到进水的4-6倍,同时生成少量的二氯一溴甲烷,出水的COD和浊度分别平均降低了17.8%和8.75%,色度减少了5-10倍.     

Hazards associated with the use of chlorinated oxidation pond effluents for irrigation

Eight milligrams per litre chlorine applied to oxidation pond effluents caused no algal kill within the first 2 h of contact. The available chlorine attacks bacteria causing coliform count to drop from 10⁵ 100 ml⁻¹ to a few tens. Enterovirus counts dropped from about 80 100 ml⁻¹ before chlorination to 37 100 ml⁻¹ (after chlorination). Vibrio cholerae (El-Tor) were killed under these adverse conditions, and MPN dropped from 10³ 100 ml⁻¹ in the influent wastes to 2 100 ml⁻¹ in the effluents. A 5 mg l⁻¹ dose of chlorine at 1 h contact time killed these sensitive bacteria decreasing MPN to less than 2 100 ml⁻¹.Differences between the efficiency of chlorination experiments under laboratory and field conditions would necessitate the application of 15 mg l⁻¹ chlorine for 2 h of contact.     

二氧化氯、氯胺顺序投加联合消毒工艺的研究

以天津市某自来水厂的滤后水为研究对象,采用二氧化氯、氯胺顺序投加联合消毒工艺对其进行消毒处理。运用化学分析和生物学试验的方法,考察了经不同投量的组合消毒后消毒剂残余量的变化,以及联合工艺的消毒效果和持续消毒能力。试验结果表明,经不同投量组合的二氧化氯、氯胺顺序投加联合消毒后,出水中的细菌总数及总大肠菌群均达到《生活饮用水卫生标准》的要求。氯胺投量对总余氯和二氧化氯残余量的影响显著,而二氧化氯的投加量对其残余量的影响不大。二氧化氯、氯胺顺序投加联合消毒工艺在低投量组合下就能达到良好的消毒效果,且持续消毒能力强。     

Characterization and identification of antiestrogenic products of phenylalanine chlorination

Recent studies have reported that chlorination increased the antiestrogenic activity of wastewater, suggesting that disinfection by-products (DBPs) formed during chlorination is a potential and important source of endocrine-disruptor. However, antiestrogenic DBPs have not been identified. In this study, the antiestrogenic activity after aqueous chlorination of phenylalanine solution was evaluated by yeast two-hybrid assay and antiestrogenic DBPs were also identified and characterized. For the first time, aqueous chlorination of phenylalanine was found to form antiestrogenic DBPs when the antiestrogenic activity of chlorinated phenylalanine solution (0.5 mmol L^?1) increased from undetectable to 57 μmol-tamoxifen (TAM) L^?1 with the increase in chlorine doses from 0 to 0.5 mmol-Cl₂ L^?1. This level decreased sharply when chlorine addition went over 0.5 mmol-Cl₂ L^?1. By fractionating DBPs of chlorinated phenylalanine solution into different fractions via semipreparative liquid chromatography, a key fraction with high antiestrogenic activity was discovered and collected. Based on analyses of mass spectrometry (MS) and nuclear magnetic resonance (NMR), the compound involved in this fraction (21 mg) was determined to be 2,4-diphenylcrotonaldehyde, which is newly identified as a relatively high antiestrogenic chemical.     

Naproxen removal from water by chlorination and biofilm processes

Naproxen is an anti-inflammatory pharmaceutical that has been detected in natural and engineered aquatic environments. The primary aim of this research was to study chemical transformations of naproxen following chlorine oxidation, which is common in water and wastewater treatment systems. Synthetic waters containing elevated concentrations of naproxen were oxidized by free chlorine at naproxen:chlorine molar ratios of 0.02-3:1 and pH values of 5-9. The formation of naproxen products was dependent on pH, chlorine dosage and contact time. This study demonstrates that naproxen readily reacts with free chlorine and forms disinfection products. The formation of specific reaction products can vary depending on the characteristics of the water or wastewater and treatment operating conditions. More research is needed to identify intermediate and chemical reaction end products and to understand the reaction kinetics of naproxen chlorination for a range of water and wastewater treatment conditions. A secondary aim of this research was to study effects of naproxen and its chlorination products on biofilm processes, which are common in water and wastewater treatment systems and natural aquatic environments. A bioreactor was fed a naproxen solution and then fed a solution at the same naproxen concentration following contact with free chlorine. Results indicate that naproxen was not degraded biologically for the conditions of this study. In contrast, the naproxen solution containing products of chlorination caused an adverse response by discharging biomass from the bioreactor. Results therefore demonstrate that naproxen products of chlorination can adversely affect a biofilm process, which potentially can impact the performance of biofilm processes in natural and engineered aquatic environments. More research is needed to study naproxen chlorination reactions at low concentrations and in complex matrices, and to understand the toxicological relevance of naproxen and its products of chlorination in natural and engineered aquatic environments.     

污水氯化/脱氯消毒副产物的生物毒性

利用发光细菌法考察了氯化／脱氯消毒后污水的生物毒性及余氯形态、氨氮浓度和有机物含量等对消毒后污水生物毒性的影响。研究发现,经氯化／脱氯消毒后污水的生物毒性显著增强;当余氯呈化合态时污水的生物毒性随投氯量的增大而增强,污水对发光细菌的发光抑制率与投氯量的对数有较好的线性关系;当余氯呈游离态时,污水的生物毒性随投氯量的变化出现了峰值,继续增大投氯量后生物毒性有所减小;氨氮有削弱消毒后污水生物毒性的倾向,而有机物则有增强消毒后污水生物毒性的倾向。     

Lagooned, secondary effluents as water source for extended agricultural purposes

Chlorination of trickling filter effluents at 40 mg l⁻¹ chlorine for 4 h and 20 mg l⁻¹ for 4 and 6 h showed very limited coliform survival. The number of viruses decreased from a few hundred in 100 ml before chlorination to 0 after chlorination. A 70,000 m³ pond (4 m deep) was used for holding non-chlorinated secondary effluents for 73 days. Bacterial and viral counts were performed every few days. In addition BOD, TC, pH and solar radiation were monitored. After this, the water was pumped out and chlorinated in a pipeline with 8 or 20 mg l⁻¹ chlorine. After chlorination the coliform count was reduced by from 3 to 5 orders of magnitude. After storage for 43 days the non-chlorinated secondary effluents viral count was nil. After chlorination these effluents were also virus-free.

In the second experiment, secondary effluents chlorinated with 20 mg l⁻¹ chlorine with a contact period of 2 h. They were then introduced to the pond. No viruses were found in the incoming water, neither during holding nor after the second chlorination, Coliform regrowth was very slow because of the temperature of the water was only 18–20°C. Identification of the M. Endo membrane filter grown isolated colonies proved that E. coli I disappeared, and all the coliforms were of non-fecal origin or that other growths were non-coliform organisms growing on the MF.

The third experiment was a repetition of the first, in spring, after the temperatures rose. The results confirmed the findings in the first experiment. Therefore, it is thought that 70 days holding of wastewater would permit its extensive agricultural use. For safety, the addition of 20 mg l⁻¹ chlorine to effluents and a short storage could be adequate from a public health point of view.     

给水厂优化消毒数学模型及其应用

水厂常采用的保守消毒方式会导致管网末梢余氯浓度>0.05 mg/L,既不经济也不安全。为此,建立了优化消毒数学模型,并采用遗传—模拟退火混合算法对其进行求解。算例结果表明,该模型可对现有给水厂不同时段的加氯量进行优化,降低了配水系统中消毒副产物的浓度。     

Evaluation of bromine substitution factors of DBPs during chlorination and chloramination

Bromine substitution factor (BSF) was used to quantify the effects of disinfectant dose, reaction time, pH, and temperature on the bromine substitution of disinfection byproducts (DBPs) during chlorination and chloramination. The BSF is defined as the ratio of the bromine incorporated into a given class of DBPs to the total concentration of chlorine and bromine in that class. Four classes of DBPs were evaluated: trihalomethanes (THMs), dihaloacetonitriles (DHANs), dihaloacetic acids (DHAAs) and trihaloacetic acids (THAAs). The results showed that the BSFs of the four classes of DBPs generally decreased with increasing reaction time and temperature during chlorination at neutral pH. The BSFs peaked at a low chlorine dose (1 mg/L) and decreased when the chlorine dose further increased. The BSFs of chlorination DBPs at neutral pH are in the order of DHAN > THM & DHAA > THAA. DHAAs formed by chloramines exhibited distinctly different bromine substitution patterns compared to chlorination DHAAs. Brominated DBP formation was generally less affected by the pH change compared to chlorinated DBP formation.     

Disinfection of advanced wastewater treatment effluent by chlorine, chlorine dioxide and ozone: Experiments using seeded poliovirus

Chlorine, chlorine dioxide and ozone were tested as chemical disinfectants against seeded poliovirus and naturally-occurring fecal coliform organisms in wastewater effluent that had received secondary treatment followed by bench scale advanced wastewater treatment (AWT). The AWT sequence consisted of chemical treatment with lime or alum followed by mixed media filtration. The resulting effluent had low suspended solids concentrations but chemical oxygen demand and nitrogen concentrations only slightly lower than those of secondary effluent. Lime treatment produced greater reductions than alum treatment in virus numbers, but not in fecal coliform organisms.

With both chlorine and chlorine dioxide, in order to reduce seeded poliovirus to less than detectable levels, it was necessary to use doses comparable to those required to disinfect secondary effluent. The required contact times of 30–60 min were also comparable. Utilized ozone doses of 2–4 mg l⁻¹ were required to reduce seeded poliovirus to less than detectable levels in AWT effluent. Naturally-occurring fecal coliform organisms were unaffected at these ozone doses, but were inactivated at higher doses. Because they were more resistant than seeded poliovirus to ozone, fecal coliform organisms show promise as indicators for ozone disinfection.