硅藻精土在污水处理中的应用与分析

对硅藻精土水处理技术的原理特点和应用情况做了分析和总结.工程实践表明硅藻精土能够提高生化系统的效率,与A/O工艺相结合出水所有指标均稳定达到<城镇污水处理厂污染物排放标准>(GB 18918-2002)一级A标准,具有投资省、运行费用低、占地少、出水水质优等特点,尤其适合于中小城镇的污水处理工程.     

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.     

水质变化对循环水系统排污水回用的影响及对策

针对循环水系统调整运行工艺后水质变化对排污水回用的影响进行了研究,认为水中Ca2+浓度的增加和总碱的降低是导致排污水回用装置出水硬度超标的主要原因,并提出了通过加入直接成垢因子的方法来去除水中的硬度。对三种软化方法的考察结果表明,对于永硬较高的循环水系统排污水,纯碱烧碱法的软化效果优于纯碱法和纯碱石灰法。在排污水中分别加入与其Ca2+和Mg2+浓度相同当量的纯碱和烧碱,可以使处理出水的Ca2+浓度和总硬度达到回用水的标准。反应时间对絮体的形成和沉降效果有一定影响,加药后的反应时间宜控制在30min以内。对于稳定运行的循环水系统,以固定的适当加药量进行投加,可获得良好的软化效果。     

标准化水厂建设工程造价模型

基于回归分析法构建标准化的自来水厂工程造价模型,包括单元构筑物建筑工程费用模型和自来水厂设备购置费用模型。同时结合自来水厂取水头部、其他类型建筑物及总平面布置费用造价分析,工程建设其他费用及预备费估算水厂造价。根据实际工程,对获得的模型进行校验。单元构筑物各自的建筑工程费用估算误差均控制在30%以内,符合项目建议书阶段的精度控制要求;自来水厂工程部分,实际设备购置费用估算误差为-11.30%;自来水厂造价整体造价估算误差率为4.03%。基于回归分析构建的自来水厂造价模型,能够应用于自来水厂的快速造价估算,并保证较好的估算精度。     

气力输送在石灰软化工艺中的调试及运行研究

结合某电厂中水回用工程,将气力输送应用于石灰投加系统,研究石灰、絮凝剂和助凝剂的最佳用量,并考察振荡器和通过高压气体扰动两种辅助下灰方式的效果,探讨该系统在设计和运行中应注意的问题。正交试验结果表明,在满足出水硬度和浊度的条件下,各药剂的最佳用量为石灰350 mg/L、PAM 2 mg/L、氯化铁80 mg/L,搅拌时间15 min。工程调试、运行结果表明,气力输送系统运行稳定,容易实现自动化,机械加速搅拌澄清池出水水质稳定,出水硬度和碱度明显降低,满足设计要求。     

Investigation of opportunistic pathogens in municipal drinking water under different supply and treatment regimes.

Changing regulations to lower disinfectant byproducts in drinking water is forcing utilities to switch disinfection from chlorine to monochloramine. It is generally unknown whether this will impact positively or negatively on the microbiological quality of drinking water. A utility in Florida, using water with relatively high organic carbon levels from deep wells in several wellfields, made the decision to change its disinfection regime from chlorine to chloramine in order to meet the new regulations. To assess the impacts of such a change on the microbiology of its water supplies, it undertook a number of studies before and after the change. In particular, the presence of the opportunistic pathogens Legionella and Mycobacterium, and also the composition of drinking-water biofilms, were examined. A preliminary synthesis and summary of these results are presented here. Legionella species were widely distributed in source waters and in the distribution system when chlorine was the disinfectant. In some samples they seemed to be among the dominant biofilm bacteria. Following the change to monochloramine, legionellae were not detected in the distribution system during several months of survey; however, they remained detectable at point of use, although with less species diversity. A variety of mycobacteria (21 types) were widely distributed in the distribution system when chlorine was the disinfectant, but these seemed to increase in dominance after chloramination was instituted. At point of use, only four species of mycobacteria were detected. Other changes occurring with chloramination included (a) an altered biofilm composition, (b) increased numbers of total coliforms and heterotrophs and (c) nitrification of water storage tanks. The results suggested that consideration should be given to the microbiological effects of changing disinfection regimes in drinking-water and distribution system biofilms.     

铁碳微电解—A/O组合工艺处理精细化工废水

嘉兴某精细化工厂采用铁碳微电解—A/O组合工艺处理生产废水.运行结果表明,出水水质稳定,COD去除率可达79.12％,出水可稳定达到《污水综合排放标准》(GB 8978-1996)三级排放标准,工艺处理成本为1.1元/m3.该工艺具有处理效果好、耐冲击负荷能力强、经济效益高等特点,在精细化工废水的处理中具有很好的应用价值.     

Improving Consumer Satisfaction in Water Distribution Networks Through Optimal Use of Auxiliary Tanks (A Case Study of Kashan City,Iran)

Temporal and spatial variations in pressure may lead to consumer dissatisfaction and distrust of water distribution networks when it comes to reliable performance. Pressure management is a set of programs and operations conducted in water distribution networks to adjust the pressure. Constructing new auxiliary tanks in proper locations at the best height for the area they serve minimizes the pressure fluctuations. Additionally, chlorine is often injected in the reservoirs and tanks to improve the water quality. The goal of this research was to improve the condition of the network by adding auxiliary tanks with appropriate locations, heights and chlorine concentration. An optimization model is prepared to optimize consumer satisfaction, water quality and the relevant costs as objective functions. The performance of the models are evaluated by a selected case study; and the objectives are optimized in three scenarios. Using the proposed model in a water distribution network, a trade-off diagram of reliability and costs is obtained, that lets the decision makers select the proper options considering the available fund. A new indicator, the consumer satisfaction index, is also proposed as a way to evaluate the performance of water distribution networks.     

人工湿地污水处理系统优化设计模型

针对污水处理厂进水水质和水量的不确定性,考虑进水水量、TSS、BOD5、TN、TP的区间变化,以出水时TSS、BOD5、TN、TP的质量浓度标准为约束条件,单元面积为决策目标,以费用最小为目标函数,建立基于一级动力学污染物去除模型的人工湿地污水处理系统区间数优化设计模型。该模型包含初沉池、人工湿地床(表面流和潜流式)两个单元,考虑了设计中的不确定性因素。实例计算表明,模型适用性较好。     

Evaluation of Chlorine Decay in Drinking Water Systems for Different Flow Conditions: From Theory to Practice

An intensive study was developed to assess the influence of different flow conditions in the chlorine decay of drinking water systems based on a series of experiments tested on a loop pipe linked to the Lisbon water distribution system. Water samples and chlorine measurements were taken under three distinct flow conditions: (1) steady-state regimes; (2) combined flow situations—an initial steady-state period, followed by successive transient events and a new steady-state period; (3) isolated flow tests—steady-state flow regimes and transient flow regimes performed independently. All the tests were replicated for a typical range of Reynolds numbers in real water distribution systems. More specifically, pressure and velocity variations associated with hydraulic transients or water hammer conditions may degrade water quality. The series of results obtained in steady-state flow conditions confirmed the rate of chlorine decay increases with the Reynolds number and provided evidence that hydraulic transients have a slowing-down effect on chlorine decay rates.     

红河南沙电站水轮机筒阀液压控制系统

以天津大学研制的南沙电站水轮机筒阀液压控制系统为对象，重点对水轮机筒阀启闭速度控制、多接力器同步控制的模块如控制阀组、液压分流马达组成的分流模块和配油模块等进行了介绍，并研究了水轮机简阀在不同工况下控制系统的工作原理。通过在云南红河南沙水电站的实际应用，表明了该控制系统的各项功能和性能指标均满足设计要求。     

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.     

永定河流域水生态补偿标准研究

生态补偿是用水竞争激烈的流域遏制水环境恶化趋势,实现向可持续开发利用转变的重要手段。生态补偿标准的核算是实施生态补偿的关键环节。针对流域水生态补偿实施中的不足,借鉴国内外在理论体系、管理体制、运行机制相关层面的研究成果,构建了完善补偿标准的理论框架。以永定河流域为研究对象,给出了流域水生态补偿标准的实施依据。并根据水量水质不可分割特性,给出了跨区域的水量、水质补偿标准测算方法,探讨了基于污染物处理水平的补偿标准计算过程。最后针对补偿标准测算中出现的问题,给出了完善流域水生生态补偿机制的建议。     

抽水蓄能电站运行方式和电网经济效益分析

用计算机模拟法建立模拟模型，对选定的系统进行生产模拟，统计计算出电网系统投入不同抽水蓄能容量时所发生的系统运行总燃料费用（包括抽水蓄能电站的抽水费）和系统的负荷缺电力时间概率（LOLP）等指标。通过对计算结果的分析，得出不同系统在投入不同容量抽水蓄能机组和采取不同运行方式的情况下，其运行总燃料费用的边际成本和LOLP的边际值的变化规律，并且对电网的经济效益进行合理分析。从而为抽水蓄能电站的规划和投资建设提供理论依据，推动抽水蓄能电站的发展，促使我国电源结构趋向合理。     

南通狼山水厂扩建工程取水水源地水质分析

采用二维稳态混合岸边排放模型分析,对南通狼山水厂扩建工程的取水水源地水质进行预测。选择CODCr为预测因子,通过水源地现状分析和对区域污染源的预测排放强度分析,得出结论:狼山水厂上、下游主要入江污染源在达到设计排放规模和实现达标排放时,即使在枯水期间,其水源地水质也符合Ⅱ类水质标准。     

An experimental study for chlorine residual and trihalomethane formation with rechlorination.

Maintenance of adequate chlorine residuals and control of disinfection byproducts (DBPs) throughout water distribution systems is currently an important issue. In particular, rechlorination can be a powerful tool in controlling adequate chlorine residual in a large distribution system. The patterns of chlorine decay and formation of DBPs due to rechlorination are different from those of chlorination; chlorine decay is slower and trihalomethane (THM) formation is lower with rechlorination. The present study evaluates whether existing predictive models for chlorine residual and THM formation are applicable in the case of rechlorination. A parallel first-order decay model represents the best simulation results for chlorine decay, and an empirical power function model (modified Amy model) with an introduced correction coefficient (phi1, phi2) is more suitable to THM formation.     

CAST工艺改进削峰填谷增加处理量的研究

介绍了镇江市征润洲污水处理厂自2003年建成以来的运行效果、存在的问题.结合该厂进水水量、水质的日变化及季节变化等特性以及CAST工艺运行的特点展开研究;对设计上存在的偏差进行分析;通过工艺改进,充分利用原有氧化塘系统作为调节系统,新建调节池泵站;并灵活调整运行周期;从而充分利用CAST池容,削峰填谷、增加处理水量;同时优化控制各种工艺参数,确保各项水质指标稳定达标排放.该厂在工艺改进、运行管理等方面的经验值得借鉴.     

高坝洲水厂永久取水系统改建

高坝洲水电站竣工后,为满足高坝洲水厂取水及降低水厂运行成本的需要.将水厂从大坝下游河道取水改建为从大坝上游水库取水。详细介绍了取水系统布置及取水泵选型、改建后水厂取水系统自动化控制程度、水质量的提高以及运行成本比改建前大幅度降低的情况。     

入河排污口设置论证与有关问题探讨

以芜湖县陶辛镇污水处理厂入河排污口设置论证为例,针对受纳水域的特点,采用湖(库)均匀混合水质模型计算河流纳污能力并进行水质预测,分析综合衰减系数对水质预测结果的影响,在缺乏资料条件下,探讨确定综合衰减系数的途径与方法,以提高预测结果的可靠性。提出利用当地水体和沟渠组成的湿地对污水处理厂尾水进行降解的方案,经湿地降解后的水质满足受纳水体的水质管理目标要求;最后对入河排污口设置论证的要点和应注意的问题进行了探讨,可供入河排污口设置论证参考。     

农村集中供水厂良性运行若干问题的探讨

农村集中供水厂良性运行的标志是提供合格的产品——水,收支平衡略有盈余,支持水厂长期、稳定运行。通过对影响水厂良性运行因素的分析,提出必须加强农村集中供水厂的运行管理,特别是要合理确定供水规模。建立合理水价制度,做好成本核算,加强水源保护和水质监测等,以确保供水工程的良性运行,充分发挥投资效益。