城市供水管网水源切换模拟及黄水控制措施研究

针对Z市未来水源切换期间可能发生的黄水现象,通过建立小区试验模型,研究了管网中总铁、溶解氧和硫酸盐等水质参数在换水期间的变化规律。研究结果表明:硫酸盐浓度可以作为整个水源切换过程的指示性指标,该市主要管网水源切换过程的终点时间约30h,小区管道在换水期间将发生铁超标现象,通过增大管道内余氯浓度至0.4mg/L以上,控制管网溶解氧水平在4.50mg/L以上,可在换水7d后有效缓解黄水现象。     

千岛湖水源对余杭区供水的影响

为配合杭州市第二水源千岛湖配水工程通水调试及水源切换,研究水厂进水水质波动和对出水水质影响的问题,以宏畔水厂及其供水区域为研究对象,收集3个月的运行数据,分析了水源切换前后宏畔水厂水源、出厂水、管网水水质及水厂制水成本方面的变化.结果表明,千岛湖水源水质稳定,浊度在1～2 N T U,耗氧量、氨氮等多项指标达到《地表水环境质量标准》(GB 3838-2002)中的Ⅰ类;与切换前相比,水厂运行中絮凝剂单耗可以降低约62％,消毒剂(次氯酸钠)单耗可以降低约33％;管网水质切换为千岛湖水后,拉森指数显著降低,且未出现黄水现象;管网水质也明显改善.     

水厂-管网协同控制提升管网供水水质的策略与实践

充分考虑管网输配过程中水质稳定性对水厂工艺条件、出厂水水质指标的要求,从水厂-管网协同控制的水质安全保障理念,通过优化水厂布局、改善管网水力条件、构建应对多水源和季节性高藻的强适应性净水体系、强化出厂水水质化学稳定性和生物稳定性控制、持续管网及老旧小区更新改造等工程技术措施,提高南水北调水源进京后管网水质的稳定性.根据2014-2019年全市252个管网监测点的水质监测数据,发现管网水浊度整体呈季节性周期变化趋势,且逐年降低;构建的管网水质评价模型进一步证明了管网水浊度一级监测点数量显著增加,2019年一级和二级监测点数量达到总数的94％,管网监测点的浊度指标得到显著改善,水厂-管网协同控制技术的实施切实保障了北京市供水水质的稳定达标.     

水水厂厂-管网协同控制提升管网供水水质的策略与实践

充分考虑管网输配过程中水质稳定性对水厂工艺条件、出厂水水质指标的要求,从水厂-管网协同控制的水质安全保障理念,通过优化水厂布局、改善管网水力条件、构建应对多水源和季节性高藻的强适应性净水体系、强化出厂水水质化学稳定性和生物稳定性控制、持续管网及老旧小区更新改造等工程技术措施,提高南水北调水源进京后管网水质的稳定性。根据2014—2019年全市252个管网监测点的水质监测数据,发现管网水浊度整体呈季节性周期变化趋势,且逐年降低;构建的管网水质评价模型进一步证明了管网水浊度一级监测点数量显著增加,2019年一级和二级监测点数量达到总数的94%,管网监测点的浊度指标得到显著改善,水厂-管网协同控制技术的实施切实保障了北京市供水水质的稳定达标。     

管网水质影响因素分析及改善措施

由于城市水源的污染,不少供水企业努力采取措施提高出厂水的水质,但有一种情况一直被不少供水企业所忽视:合格甚至优质的出厂水输送到用户终端时,水质往往已经恶化.根据对国内50个城市的调研可知,管网水浊度比出厂水增加0.38NTU、色度增加0.45度,铁增加0.04mg/L、锰增加0.02mg/L、细菌增加18个/mL、管网末端余氯下降到0.015mg/L、大肠菌增加0.4个/L.现对自来水输送过程中影响管网水质的因素进行分析并提出一些改善措施.     

影响供水管网中余氯与浊度的因素及相关性分析

余氯与浊度是管网水质中有效反映水质状况的参数,以太仓市某小区供水管网为研究对象,通过对该小区供水管网14个取样点进行水质监测,分析供水管网中余氯与浊度之间的的相关性及其影响因素。研究结果表明:余氯在管网中总体呈下降趋势,浊度总体呈上升趋势;当管网中余氯在0.05~0.2mg/L时,余氯与浊度之间呈明显负相关,浊度越小,耗氯量越小,管网中自由余氯保持在较高浓度,消毒效果显著;当余氯高于0.2mg/L时,浊度对余氯消毒效果没有显著影响,余氯与浊度无明显相关性。     

不同聚磷酸盐投加量控制管网铁释放效果比较

研究了三聚磷酸钠和六偏磷酸钠两种缓蚀剂不同投加剂量条件下对给水管网铁释放的控制效果差异。结果表明,最佳投加量均为1.0～1.5 mg/L(以P计),当三聚磷酸钠投加量为1.0mg/L时,铁释放速率降低68%,浊度降低55%,色度降低76%,对铁释放的控制效果最好;当六偏磷酸钠投加量为1.0mg/L时,铁释放速率降低82%,浊度降低85%,色度降低88%,对铁释放的控制效果最好。六偏磷酸钠对给水管网铁释放现象的控制效果要优于三聚磷酸钠。投加1.0mg/L聚磷酸盐的主要经济费用约为0.033元/m3水,可作为突发性管网"黄水"问题的应急控制技术。     

臭氧预处理-常规处理-深层过滤组合工艺的生产性试验

针对广东饮用水源的水质特点,采用臭氧预处理—常规处理—深层过滤组合工艺对微污染水源水进行生产性试验,结果表明:当进水浊度、CODMn、氨氮、铁、细菌总数和大肠菌群等分别为8.44～112.09NTU,1.13～2.98mg/L,0.07～0.31mg/L,0.65～9.74mg/L,3.2×103～3.6×103CFU/mL和1.6×103CFU/100mL时,出水各指标分别为0.09～0.68NTU,0～0.79mg/L,小于0.02mg/L,小于0.01mg/L,未检出和小于3CFU/100mL;年平均去除率分别为99.15%,80.33%,84.89%,94.17%,100%和近100%。该工艺出水水质好,抗冲击负荷能力强,运行平稳。     

臭氧-活性炭-超滤联用技术处理高寒地区微污染原水的工程应用

高寒地区Z水厂以L水库作为水源,近年来L水库水质变差,为轻度有机污染水体,原有常规处理工艺无法满足出厂水水质要求,出水CODMn最高值为6mg/L。通过采用臭氧-活性炭-超滤联用的升级改造技术,使水厂出水浊度小于0.05NTU,贾第鞭毛虫和隐孢子虫未检出,全面满足《生活饮用水卫生标准》(GB 5749-2006)的要求。     

某市供水管网水质问题及对策

对湛江市供水管网的水质进行了调查研究,发现管网水的浊度、色度、铁和CODMn都比出厂水的略有增加,原水为地下水的管网水浊度及铁合格率比出厂水有较大的下降。从出厂水稳定性、管材和管网水停留时间等方面,对影响管网水质的原因进行了分析,提出了相应的对策。     

氯离子浓度和碱度对给水管网管垢重金属锰释放的影响

通过静态释放实验,研究了水源切换造成原水中不同浓度的氯离子和碱度对管网管垢中重金属锰释放的影响。选取郑州市给水管网管段,设计模拟释放反应装置,配制不同浓度氯离子(5 mg/L、23.1 mg/L、60 mg/L、90mg/L)和碱度(52.5mg/L、125mg/L、200mg/L)的实验用水,比较分析氯离子浓度和碱度变化对管垢重金属锰释放的影响。根据实验结果初步推断:氯离子浓度和碱度与管垢中金属锰的释放浓度有较高相关性,且实验中氯离子浓度是影响管网管垢锰释放的首要因素。当氯离子浓度为30 mg/L,停留时间60h,锰的释放量达到最大为108mg/L,之后释放浓度趋于平稳。在氯离子浓度促进锰释放的条件下,碱度与管垢中锰的释放量表现出明显相关性。实验结果可为水源切换引起的水质差异对给水管网管垢锰释放问题提供一定参考。     

配水管网中水质变化规律及主要影响因素分析

安全输配是饮用水水质保障的关键。在对中国南方 S 市配水管网水质大量调查的基础上,分析了余氯、浊度、铁、三卤甲烷、卤乙酸、AOC 等主要水质指标在管网中的变化规律,发现余氯沿管线逐渐降低,浊度和铁基本沿管线逐渐增加,其主要影响因素有管道属性、温度及水力条件等;三卤甲烷在管网中表现出增加的趋势,而卤乙酸则在管网中表现出降低的趋势,其主要影响因素有余氯浓度、水质条件、温度条件及水力条件等;供水系统中 AOC 以 AOC-P17为主要组分,沿供水系统有逐渐增加的趋势,其浓度、组成以及在管网中的变化规律呈现明显的季节性。     

Impact of RO-desalted water on distribution water qualities.

A large-scale pilot distribution study was conducted to investigate the impacts of blending different source waters on distribution water qualities, with an emphasis on metal release (i.e. corrosion). The principal source waters investigated were conventionally treated ground water (G1), surface water processed by enhanced treatment (S1), and desalted seawater by reverse osmosis membranes (RO). Due to the nature of raw water quality and associated treatment processes, G1 water had high alkalinity, while S1 and RO sources were characterized as high sulfate and high chloride waters, respectively. The blending ratio of different treated waters determined the quality of finished waters. Iron release from aged cast iron pipes increased significantly when exposed to RO and S1 waters: that is, the greater iron release was experienced with alkalinity reduced below the background of G1 water. Copper release to drinking water, however, increased with increasing alkalinity and decreasing pH. Lead release, on the other hand, increased with increasing chloride and decreasing sulfate. The effect of pH and alkalinity on lead release was not clearly observed from pilot blending study. The flat and compact corrosion scales observed for lead surface exposed to S1 water may be attributable to lead concentration less than that of RO water blends.     

引黄济青工程渠首水质变化研究

2011年4月至2012年3月从引黄济青工程渠首取样并分析水质变化情况。结果表明，渠首黄河水含沙量和浊度年平均值分别为0．83kg/m3、754NTU；总氮（TN）含量变化范围为3．43~6．84mg／L，平均值为4．70mg／L；硝酸盐氮（N03-N）是TN的主要形式，占TN的58．5％-90．2％；氨氮（NH3-N）、亚硝酸盐氮（N02-N）、总磷（TP）含量较低；叶绿素a（Chla）变化范围为1．10-7．60mg／m2，平均值为3．96mg／m3。除泄洪、流量低等特殊情形外，不同季节间含沙量、浊度及其他水质指标没有明显差异。     

Impacts of water quality variation and rainfall runoff on Jinpen Reservoir,in Northwest China

The seasonal variation characteristics of the water quality of the Jinpen Reservoir and the impacts of rainfall runoff on the reservoir were investigated. Water quality monitoring results indicated that, during the stable stratification period, the maximum concentrations of total nitrogen, total phosphorus, ammonia nitrogen, total organic carbon, iron ion, and manganese ion in the water at the reservoir bottom on September6 reached 2.5 mg/L, 0.12 mg/L, 0.58 mg/L, 3.2 mg/L, 0.97 mg/L, and 0.32 mg/L, respectively. Only heavy storm runoff can affect the main reservoir and cause the water quality to seriously deteriorate. During heavy storms, the stratification of the reservoir was destroyed, and the reservoir water quality consequently deteriorated due to the high-turbidity particulate phosphorus and organic matter in runoff. The turbidity and concentrations of total phosphorus and total organic carbon in the main reservoir increased to 265 NTU, 0.224 mg/L, and 3.9 mg/L, respectively.Potential methods of dealing with the water problems in the Jinpen Reservoir are proposed. Both in stratification and in storm periods, the use of measures such as adjusting intake height, storing clean water, and releasing turbid flow can be helpful to safeguarding the quality of water supplied to the water treatment plants.     

高锰酸盐-聚丙烯酰胺联用强化混凝处理太湖支流原水研究

太湖B支流地表水受水土流失、水体富营养化和环境污染等因素影响,水体污染严重,水中有机物浓度和藻密度相对较高。常规的"混凝—沉淀—砂滤—加氯消毒"处理工艺难以有效地去除水中有机物、铁锰、藻类等物质。采用高锰酸盐(PPC)-聚丙烯酰胺(PAM)联用强化混凝工艺对原水进行处理。高锰酸盐投量在0.45 mg/L和聚丙烯酰胺投量在0.07 mg/L条件下联用强化混凝的静态试验结果表明:PPC-PAM联用强化混凝对浊度、色度、铁、锰和耗氧量的平均去除率为90%、73%、92%、99%和38%。PPC在0.3～0.5 mg/L投量和PAM在0.05～0.10 mg/L投量下联用强化混凝生产试验的出厂水浊度、色度、铁、锰等指标,均比历史同期水平要好。     

增效结团流化床处理春季低浊水的中试研究

以水库春季低浊水为处理对象,采用增效结团流化床工艺进行了中试研究。试验结果表明,利用增效结团流化床工艺处理水库低浊水是切实可行的,具有系统运行稳定性高,出水水质好等特点,而良好的污泥回流是系统高效稳定运行的前提。控制上升流速为20m/h时,通过优化得出适宜的工艺参数:混凝剂聚氯化铝(PAC)投量为11 mg/L左右,助凝剂(PAM)投量为0.25～0.30mg/L,污泥回流比为3%,机械搅拌转速为6r/min。在此条件下,出水浊度可控制在1.0NTU以下。     

茜坑水库水质评价及污染源解析

茜坑水库作为深圳市重要的饮用水水源,掌握其水质状况和关键污染源十分必要。选取2019年1 -12月茜坑水库水体的pH、高锰酸盐指数、氨氮、硝酸盐氮、总氮、总磷、铁、锰等8个典型指标,分析其变化规律及相互关系,通过水质综合指数评价水质现状,采用因子分析法和绝对主成分多元线性回归识别关键污染源,估算主要污染源的贡献率。结果表明：受浮游植物的影响,pH全年最高达到9.8;高锰酸盐浓度在6月份最高,为6.3 mg/L;氨氮浓度全年均小于0.1 mg/L;硝酸盐氮占总氮的71%左右,总氮浓度全年大于0.5 mg/L;总磷全年平均浓度为0.014 mg/L,水体呈现出磷限制;相关性强的铁和锰浓度全年均小于0.2 mg/L。在近年来多种治理措施的作用下,水库全年水质综合指数均值为78且呈现出向好趋势。水库水质受浮游植物的直接影响,而控制污染物引水汇入和内源释放是解决水库污染问题的关键。     

江水源热泵换热器污垢形成的关键水质因素分析

江水引起的热泵换热器结垢不仅会增大机组进出口阻力,还会导致换热器的换热效率下降。江水水质对换热器污染起决定作用。江水源热泵污垢形成的关键水质因素及相关性分析是热泵用水体评价和水处理决策的基础。通过对重庆地区长江和嘉陵江水质测试分析,并与现行允许水质指标的对比,表明含沙量和浊度是江水源热泵的重点解决问题。对江水源热泵换热器污垢的成份分析则表明,污垢是以小粒径泥沙的颗粒污垢为主。从而确定关键水质因素是含沙量和浊度。根据与实际江水泥沙配置保持一致的自配水样分析,得到了含沙量与浊度的关系方程,误差分析表明预测值与实测值能较好地吻合。     

Influence of type and dose of coagulants on effectiveness of PAH removal in coagulation water treatment

This study evaluated the influence of the type and dose of coagulants on the removal of 16 polycyclic aromatic hydrocarbons (PAHs) in the coagulation process. The effects of coagulant type and dose in reducing water turbidity, colour, and the total content of organic compounds were also assessed. The surface water samples had the turbidity of 9.3–11.2 NTU and colour of 25–35 mg/L. The content of organic compounds determined with total organic carbon (TOC) was 9.2–12.5 mg/L. For the coagulation process, pre-hydrolyzed polyaluminium chloride (PACl) coagulants with basicity values of 41%, 65%, and 85% were used. This shows that water purification performance increased as the basicity of the coagulant increased. When the coagulant with the highest basicity and a dose of 3 mg Al per litre was used, a removal efficiency of 83% in the concentration of benzo(a)pyrene was achieved, and efficiencies for the remaining 15 PAHs ranged from 80% to 91%. These values were 4%–9% higher than those achieved using other coagulants. The removal efficiencies of turbidity, colour, and TOC were 80%, 60%, and 35%, respectively. The water purification performance, including PAH removal, was improved with the increased coagulant dose. Increasing the coagulant dose had more pronounced effects on PAH removal than on the reduction of turbidity and TOC.