水源切换对给水管网水质铁稳定的影响及控制特性研究

发布时间：2018-03-09 17:44

本文选题：给水管网　切入点：铁稳定性　出处：《清华大学》2015年博士论文　论文类型：学位论文

【摘要】：南水北调和淡化海水等水源切换工程对我国城镇供水系统带来了新的挑战,可能造成给水管网中铁、浊度、色度等水质指标超标的黄水问题。本论文针对水源切换对给水管网水质铁稳定的影响及控制技术展开研究,分析了水质化学组分突变对给水管网铁释放的影响特性,提出了管网铁稳定性的水质控制指标;建立了应对水源切换引发管网黄水问题的控制技术体系,明确了水质调节技术的控制参数及作用机理;阐释了腐蚀性阴离子对管垢的侵蚀机理,揭示了水源切换引发管网铁释放的微观机理;完善了给水管网铁稳定性控制理论,为保障多水源供水管网水质稳定提供了重要的理论依据和技术支撑。主要结论如下:水源切换造成硫酸盐和氯化物浓度突然增加对管网铁稳定性的影响作用效果显著且响应迅速,1-2天即可导致水质恶化,且腐蚀性阴离子浓度越高,铁释放量越大。水源切换时,建议控制管网水中硫酸盐浓度75mg/L,Larson指数(以摩尔浓度计)0.70;淡化海水需与常规水源勾兑使用,或采取相应的后处理措施。通过实际管网用户水质跟踪监测和管段模拟反应器试验,定量研究了水源调配技术、酸碱调节技术(调节pH值和碱度)、氧化还原电位调节技术、缓蚀剂投加技术对管网铁释放的控制效果,探讨了控制机理,并评价了技术经济性。在此基础上,较全面构建了应对我国水源切换水质化学组分突变引发管网铁释放的控制技术体系。根据腐蚀管垢内外分层的理化特征和管段试验,首次发现了基于消毒剂浓度调节氧化还原电位(ORP)对铁释放的控制机制,为控制管网铁稳定性提供了新思路。维持管网水中ORP≥300mV可有效抑制铁释放,ORP300mV时,管垢会发生还原反应,铁释放程度随着离子强度的升高而显著增强。游离氯比一氯胺可维持更高的ORP值,从管网铁稳定性角度,建议水厂将氯胺消毒改为游离氯消毒,并通过更换优质水源、增加深度处理工艺、对老旧管道定期冲洗喷涂、对二次供水设施补氯等措施维持管网水高余氯,以保障管网水质铁稳定性。运用材料学分析仪器和晶体学理论,国内外首次定量分析了腐蚀性阴离子对管垢晶态矿物成分(Fe3O4和FeOOH)的侵蚀特性,从机理上阐释了水源切换引发管垢破坏及黄水问题的微观机制,初步提出了阴离子侵蚀强度经验公式,并对Larson指数进行了修正。
[Abstract]:The South North Water Diversion Project, water desalination project handover has brought new challenges to China's urban water supply system, water supply network may cause iron, turbidity, water color and other water quality indicators exceed the standard problem. This thesis focuses on the influence of iron source switching water supply network stability and control technology research, analysis of the water chemical component mutation the influence of iron release characteristics of pipe network, proposed the quality control index of iron pipe network stability; control system was established to deal with water problems caused by water pipe network switch, the control parameters and the mechanism of water quality regulation technology; explains the corrosive anions on the erosion mechanism of pipe scale, reveals the source switching mechanism the network of iron release initiation; water supply network improve the iron stability control theory provides an important theoretical support for the stability of water quality in water supply network Basis and technical support. The main conclusions are as follows: water caused by switching the sulfate and chloride concentration increased suddenly effect on Guan Wangtie stability significant and rapid response, 1-2 days can lead to the deterioration of water quality, and the corrosive anion concentration is higher, the greater the amount of iron release water. When switching control suggestions in water sulfate concentration 75mg/L, Larson the index (molar concentration) 0.70; desalination using blending with conventional water sources, or take corresponding measures. By postprocessing the actual pipe network monitoring and tracking user water pipe reactor simulation test, the quantitative study of water allocation technology, technology (acid-base regulation to adjust the pH value and alkalinity), redox potential regulation technology corrosion inhibitor dosing technology, control effect of the iron pipe network release, discusses the control mechanism, and evaluation of technology and economy. Based on this, a comprehensive construction of Countermeasures The chemical composition of water source switching control system of pipe network caused by mutation of iron release. According to the physicochemical characteristics of corrosion of pipe scale inside and outside the stratification and pipe test, first discovered the disinfectant concentration regulation of redox potential (ORP) based on the control mechanism of iron release, provides a new way to control the network. To maintain the stability of iron pipe the water ORP 300mV can effectively inhibit the release of iron, ORP300mV, pipe scale will occur the reduction reaction, iron release degree increased with the ionic strength and significantly enhanced. Free chlorine than monochloramine can maintain higher ORP value, from the iron pipe network stability angle, proposed plant will change the free chlorine chloramine disinfection disinfection, and through change of water quality, increasing the depth of processing technology, the old pipe flushing regularly spraying, two water supply facilities to supplement chlorine and other measures to maintain the high water residual chlorine, in order to ensure the water quality stable. The use of iron material Material analysis instrument and the crystallographic theory at home and abroad for the first time, quantitative analysis of corrosive anions on the tube from the crystalline mineral scale (Fe3O4 and FeOOH) the water erosion characteristics, microscopic mechanism of tube scaling problems caused by switching failure and water interpretation from the mechanism, put forward the anion erosion empirical formula of strength, and the Larson index corrected.

【学位授予单位】：清华大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TU991.33

【相似文献】