预处理及深度处理改造后D水厂消毒副产物跟踪分析

W市D水厂于2011年和2012年完成了深度处理和预处理改造,形成了预臭氧-曝气氧化-沉淀-砂滤-后臭氧-活性炭-消毒工艺,运用了多点加氯技术.通过跟踪调研改造前后D水厂太湖水净化过程中臭氧消毒副产物和液氯消毒副产物情况,发现改造后D水厂出厂水中臭氧消毒副产物溴酸盐检出率为1.18％,达标率为100％,出水甲醛无检出;...     

次氯酸钠消毒技术在自来水厂中的应用

近年来,次氯酸钠消毒工艺正广泛应用于水厂消毒工艺改造中。介绍了次氯酸钠消毒技术、工艺、应用情况,并以实际工程为例对液氯消毒和次氯酸钠消毒进行了比较,结果表明次氯酸钠消毒具有投加安全、可靠、运维方便等优点,并对改造成本作了简要分析。     

桐乡水务集团次氯酸钠投加系统改造情况介绍

针对液氯消毒存在的安全性问题,桐乡市水务集团有限公司下属果园桥水厂和运河水厂对消毒工艺进行了改造,由液氯投加改为次氯酸钠投加。结果表明,改造后的次氯酸钠投加系统安全系数高,设备故障率低,出厂水水质良好,可节约大量压力水和用电,同时药剂存储安全可靠,可较大程度地降低重大节日、重要会议期间的供水安保压力。     

沉淀—气浮联用技术在高藻水处理中的工程应用

C市给水厂的原水水质随季节交替变化为低温低浊水、高温高浊水和高藻低浊水,给水厂原有处理工艺在高藻期间无法满足现有的生活饮用水标准.为了解决高藻低浊水处理效果差的问题,采用溶气气浮工艺对原有平流沉淀池进行改造,实现沉淀-气浮联用技术.对原水、沉淀出水、气浮出水以及出厂水的长期监测结果表明,沉淀-气浮联用技术对水中有机物、藻类、浊度、臭味都有很好的去除效果,并且解决了改造前出现的混凝剂投加量大幅增加、余铝超标、滤池运行周期短、反冲洗频繁、出水臭味严重等问题.     

水厂液氯消毒系统技改工程设计

通过对液氯和次氯酸钠消毒方式的比较和成本分析,在水厂液氯消毒系统技改工程中,采用了电解法现场制备次氯酸钠消毒系统替代原有的液氯消毒系统。介绍了次氯酸钠制备系统的工作原理、系统组成和工作流程,分析了改造工程的主要设计参数、设施和设备选型、系统布置以及改造实施步骤等,提出了设计、实施和运行中需要注意的问题。     

净水厂消毒技术升级改造调研分析与启示

作为一种较为廉价且消毒效果理想的消毒剂,液氯消毒多年来一直在我国供水行业被广泛使用.近年来,为消除液氯在城市运输及使用过程中带来的重大安全隐患,武汉市从2018年开始对净水厂消毒系统实施升级改造工程,采用次氯酸钠消毒替换原有液氯消毒.从水质安全、生产运营、运维管理、成本控制等方面对采用次氯酸钠消毒的水厂进行了充分调研及...     

次氯酸钠发生器在南方某水厂的运行研究分析

次氯酸钠消毒工艺作为传统液氯消毒工艺的优质替代,已经在自来水厂中得到了广泛的研究和应用,但目前对于自来水厂发生器制备的次氯酸钠溶液质量控制方面的研究较少.以南方某水厂在线次氯酸钠消毒改造为例,对发生器的调试、运行、产品检验进行了研究分析.结果显示,在线次氯酸钠溶液具有较好的卫生安全性和溶液稳定性,但需要关注有效氯检测方...     

高藻引黄水库水常规工艺强化集成技术研究与示范

针对黄河下游地区引黄水库水夏季高藻高臭味、冬季低温低浊、小分子有机物含量高等水质特征,采用强化常规处理工艺的技术路线,研发了曝气生物流化池预处理—强化混凝工艺、基于藻及藻毒素同时去除的强化混凝—浮沉池—活性过滤组合工艺、水厂气浮藻渣无害化处置与再利用等关键技术,经过中试验证及优化集成,研究成果用于两座引黄水厂的示范建设,可有效解决引黄水库原水中的藻及二甲基异莰醇等问题,工艺运行稳定可靠,出水水质满足《生活饮用水卫生标准》(GB 5749-2006),为黄河下游地区常规工艺水厂提标改造提供了可借鉴的工程范例.     

河北应急水源工艺适应性研究与工艺优化

南水北调的应急工程是从河北四水库调水进京,为了保证净水厂运行稳定,进行了适应性研究,并采用层次优化法对中试工艺进行选优。结果表明:第九水厂工艺运行方案为采用粉末活性炭预处理(20mg/L),混凝剂投加量为20～25mg/L;当原水藻类较高时可采用"氯+粉末活性炭"联合预处理方式;在剑水蚤数量较多时,建议砂滤池和炭池的反冲洗水不回收。第三水厂、田村山水厂采用混凝—沉淀—过滤—O3—炭池工艺,主臭氧投加量为0.5～1.5mg/L,混凝剂投加量为20～25mg/L。剑水蚤数量较少时,混凝沉淀能够将其去除,或通过主臭氧将剑水蚤杀死去除。在调水过程中,应跟踪原水MIB的变化,并加强活性炭出水的臭味检测,适时调整工艺运行参数。     

谈二氧化氯预处理对常规净水工艺的强化

1二氧化氯的选择临沂市自来水公司东北园水厂是临沂市驻地兰山区内唯一的一座城市净水厂,设计规模为15万t/d,于1999年9月在原有简易水厂基础上改扩建后投入使用,净水工艺为常规工艺(反应—沉淀—过滤—消毒)。水源引自山东省第二大水库——岸堤水库,     

金门水厂原水中臭味物质去除的中试研究

金门地区水库富营养化严重影响饮用水水质。夏天藻类所产生的臭味以土霉味为主。土霉味主要来自于藻类代谢物二甲基异冰片和土臭素。利用活性炭处理工艺分别使二甲基异冰片、土臭素及嗅值的去除率达92%、83%及72%;而利用臭氧一生物活性炭工艺则可使二甲基异冰片、土臭素及嗅值的去除率分别达96.3%、100%及96.7%。组合工艺可有效去除臭味物质,但清水池加氯消毒所产生的氯臭味,使嗅值无法达到台湾地区的饮用水水质标准,因此要特别注意控制加氯量。     

佛山新城区优质水厂设计与运行分析

广东佛山新城区优质水厂原水为自来水,采用浸没式超滤膜水处理工艺,供水设计生产能力5000 m3/d.根据新城区优质水厂的工艺设计特点、实际运行情况以及运行过程中出现的问题,对新城区优质水厂的工艺流程、生产运行工况和水质处理效果进行了分析与评价.结果表明:采用活性炭-浸没式超滤膜处理工艺和臭氧-二氧化氯联合消毒技术,处理效果良好,CODMn去除率为44.96%,浊度去除率为70.55%,各项指标均达到了佛山市新城区优质供水水质要求,有效提高了供水水质安全性,改善了口感.     

Sensory evaluation of the odors produced during bromophenol formation using a multi-level statistical model.

In response to reports of medicinal taste and odor problems in suburban Paris, a lab scale study was conducted to investigate the contribution of different water quality parameters--pH, phenol, bromide, chlorine, temperature and dissolved oxygen levels--on bromophenol medicinal odor formation using the Flavor Profile Analysis (FPA) method. A study of six parameters at 2 levels (64 experiments) analyzed by the FPA method suggests that chlorine at high concentration is more important as a controlling agent than phenol under similar conditions and the ratio of HOBr:Phenol and the time for reaction will control subsequent brominated products of reaction. Results from a three-level statistical model indicate that high pH was associated with lower odor intensities, whereas high levels of chlorine, phenol and temperature were associated with high odor intensities. Potential worst case scenarios of water quality conditions were determined for evaluation by chemical identification and kinetics.     

Application of HACCP principles as a management tool for monitoring and controlling microbiological hazards in water treatment facilities.

HACCP (hazard analysis and critical control points) principles were applied to evaluate the effectiveness of two water treatment facilities to continually produce potable water free of microbiological health hazards. This paper reports a hazard analyses protocol (microbiological hazards based on faecal coliforms (FC) and turbidity (TBY) as indicators) for critical control points (CCPs) within each facility. The CCPs were raw resource water, sedimentation, filtration and chlorine-disinfection. The aim was to determine the effectiveness of each CCP to remove the indicators from the water under treatment. Arbitrary critical performance limit targets (CPLTs) were set up for each CCP to determine to what extent each contributed to effective removal and to predict what the effect would be if any of the CCPs should fail. Health-related water quality guideline limits for expected health effects were applied and compliance measured at the 90th percentile. The raw resource river water used at both treatment facilities complied with raw resource water extraction CPLTs. The treated potable water complied with health-related drinking water guidelines. Sedimentation removed the largest proportion of the indicators from the raw water, but showed failure potential that could overload the consequent system. Filtration effectiveness at both treatment facilities showed potential to break down the overall effectiveness of the entire treatment facility, since the filter systems failed to meet their respective CPLTs. This left the disinfection phase to remove the remaining portion of indicators. Faecal coliforms appeared to be completely removed from post-chlorination samples. This indicated that both chlorine disinfection phases were 100% effective in meeting their disinfection CPLTs, despite having to "clean up" the indicator organisms that spilt over from the upstream CCPs. This, nevertheless, implied a risk of unsafe water release into distribution. CCPs at these treatment facilities had some difficulties in reducing the health-related risks to meet their respective CPLTs. Applying a HACCP programme would minimise the risk of contaminated water distribution in cases of system component failure.     

Particle size distribution and property of bacteria attached to carbon fines in drinking water treatment

The quantitative change and size distribution of particles in the effluents from a sand filter and a granular activated carbon （GAC） filter in a drinking water treatment plant were investigated. The average total concentration of particles in the sand filter effluent during a filter cycle was 148 particles/mL, 27 of which were larger than 2 μm in size. The concentration in the GAC effluent （561 particles/mL） was significantly greater than that in the sand filter effluent. The concentration of particles larger than 2 μm in the GAC filter effluent reached 201 particles/mL, with the amount of particles with sizes between 2 μm and 15 μm increasing. The most probable number （MPN） of carbon fines reached 43 unit/L after six hours and fines between 0.45 μm and 8.0 μm accounted for more than 50%. The total concentration of outflowing bacteria in the GAC filter effluent, 350 CFU （colony-forming units） /mL, was greater than that in the sand filter effluent, 210 CFU/mL. The desorbed bacteria concentration reached an average of 310 CFU/mg fines. The disinfection efficiency of desorbed bacteria was lower than 40% with 1.5 mg/L of chlorine. The disinfection effect showed that the inactivation rate with 2.0 mg/L of chloramine （90%） was higher than that with chlorine （70%）. Experimental results indicated that the high particle concentration in raw water and sedimentation effluent led to high levels of outflowing particles in the sand filter effluent. The activated carbon fines in the effluent accounted for a small proportion of the total particle amount, but the existing bacteria attached to carbon fines may influence the drinking water safety. The disinfection efficiency of desorbed bacteria was lower than that of free bacteria with chlorine, and the disinfection effect on bacteria attached to carbon fines with chloramine was better than that with only chlorine.     

村镇饮用水不同次氯酸钠消毒模式对比研究

为探讨村镇供水工程的适宜次氯酸钠消毒模式,本文采用室内试验的方法从消毒液品质及其对水质的影响、消毒效果及运行成本三方面对不同应用模式开展对比分析。研究结果表明:离子膜法电解次氯酸钠发生器所产次氯酸钠溶液的有效氯浓度高,分别是无隔膜法、隔膜法电解设备产物和商品次氯酸钠溶液的10.75倍、4.51倍和1.41倍,其杂质氯酸盐和亚氯酸盐浓度极低,投入水体后对水质的影响程度最小;对大肠杆菌的消毒效果表明,4种次氯酸钠消毒应用模式均能在10 min内有效灭菌,采用离子膜法发生器消毒产生的副产物三卤甲烷最少;离子膜法发生器的电耗、盐耗相对较低,运行成本比无隔膜法、隔膜法、商品次氯酸钠溶液分别低46%、56%和81%。由于上述优势,在村镇供水中采用离子膜电解次氯酸钠发生器消毒具有较好的应用前景。     

Wastewater reclamation systems in small communities.

The demands established in the rules and regulations by the administration in Catalonia seem to exclude small communities from wastewater reclamation and reuse, due to the comparatively high costs associated with the practice at small scale. In the framework of the DRAC project (Demonstration on Wastewater Reclamation and Reuse in Catalonia) two different pre-treatment systems, one extensive (infiltration-percolation) and another intensive (ring filter), each one followed by chlorine dioxide disinfection, were tested in order to be applied for small communities wastewater reclamation and reuse. The results of this study show that infiltration-percolation systems remove very efficiently physico-chemical contaminants and microorganisms. The ring filter system does not show a significant removal rate of contaminants, The use of infiltration-percolation as a pre-treatment for advanced chemical disinfection allows reducing the dose of disinfectant and the contact time needed to achieve a specific water quality, and diminishes disinfection byproducts (DBPs) generation. Therefore, this reclamation line is suitable for small communities due to its efficiency and low cost. However, further studies are needed in relation to the removal mechanisms of microorganisms, organic compounds in IP systems and the possible DBPs formation using chlorine dioxide.     

合肥市滨湖新区塘西河再生水厂工程设计

本文介绍了合肥市塘西河再生水厂的工程设计参数、处理工艺流程及其设计特点。该工程污 水处理设计规模为3. 0万m3/d,处理工艺为预处理、AZ/0、膜生物反应池和二氧化氯消毒的一体化 联合工艺,污泥处理采用机械浓缩脱水一体机。水厂的出水水质要求同时满足《城镇污水处理厂污染 物排放标准》( GB 18918-2002)和《城市污水再生利用景观环境用水标准》( GB/T 18921-2002 )。全 厂区采用分散收集、生物和天然植物喷淋液的联合除臭技术。     

Effect of peracetic acid, ultraviolet radiation, nanofiltration-chlorine in the disinfection of a non conventional source of water (Tula Valley).

Water supply for human consumption requires certain quality that reduces health risks to consumers. In this sense, the process of disinfection plays an important role in the elimination of pathogenic microorganisms. Even though chlorination is the most applied process based on its effectiveness and cost, its application is being questioned considering the formation of disinfection by-products (DBPs). Therefore, alternative disinfectants are being evaluated and some treatment processes have been proposed to remove DBPs precursors (organic matter. This paper reports the results of disinfection of a non conventional source of water (aquifer recharged unintentionally with raw wastewater) with peracetic acid (PAA) and ultraviolet radiation (UV) as well as nanofiltration (NF) followed by chlorination to produce safe drinking water. The results showed that a dose of 2 mg/L PAA was needed to eliminate total and faecal coliforms. For UV light, a dose of 12.40 mWs/cm2 reduced total and faecal coliforms below the detection limit. On the other hand, chlorine demand of water before NF was 1.1-1.3 mg/L with a trihalomethane formation potential (THMFP) of 118.62 microg/L, in contrast with chlorination after NF where the demand was 0.5 mg/L and THMFP of 17.64 microg/L. The recommended scheme is nanofiltration + chlorination.     

RESEARCH ON MATHEMATICAL SIMULATION OF RESIDUAL CHLORINE DECAY AND OPTIMIZATION OF CHLORINATION ALLOCATION OF URBAN WATER DISTRIBUTION SYSTEM

The concentration of Residual Chlorine (RC) frequently violates the standard in situations of urban water distribution system with large water supply area and long time of distribution. If chlorine dosage increases within water treatment plant, although RC in distribution system could meet water quality standard, Disinfection By-Products (DBPs) such as hydrocarbon halide rises. In the paper, a mathematical model of chlorine allocation optimization was presented based on reaction kinetics mechanism and optimization theory to solve the problem. The model includes the objective function of minimizing annual operation cost and constraints of RC standard and rational chlorination station distribution, and solving by 0-1 Integer Programming (IP). The model had been applied to a real water distribution system. The simulation results of the model showed that adding chlorine in‘ water distribution system remarkably improved water quality and reduced the operation cost by 49.3% per year less than chlorine dosed only in water treatment plant to meet RC standard. The results prove adding chlorine in water distribution system based on the model can bring both technological and economic advancement.