【作者】 侯翠荣；

【导师】 胡文容；

【作者基本信息】 山东大学 ， 环境工程， 2008， 博士

【摘要】 由于饮用水水源受到污染,传统的水处理工艺正面临着严峻的挑战,水质成为保障城市供水安全的关键性因素。本文在对济南市两种类型受污染水库水源水的水质特征进行分析研究的基础上,从水源水水质改善、常规工艺强化、深度处理等方面对源水处理关键技术进行了探讨。主要研究内容及结果如下:1、分析评价了济南市主要饮用水源山区水库和引黄水库的常规化学指标、挥发、半挥发性有机物指标、异味物质指标和藻类污染指标,结果显示二者均受到较重的有机污染和藻污染,水质呈现高藻高有机污染特性,导致水体有明显异味。2、分析了现有给水常规处理工艺的净水能力。通过水厂出水水质指标测试分析,结果显示现有工艺对遭受藻类污染的水库水的水质净化能力有限。混凝、消毒单个工序对胞外藻毒素的去除率维持在18-44%,砂滤没有去除效果,常规工艺对胞外藻毒素的平均去除效率为28%;混凝、砂滤、消毒单元工序对总藻毒素的去除率维持在30%以内,传统工艺对总藻毒素平均去除62%。监测数据也表明现有工艺对异味物质的去除几乎没有效果。引黄水库出水经水厂处理后引起异味的主要为土味素和甲基异冰片,浓度超过生活饮用水卫生标准。南部山区水库出水经水厂处理后引起异味的主要是甲基异冰片,浓度超过生活饮用水卫生标准。水厂用户终端一溴二氯甲烷、三卤甲烷各类化合物中每种化合物实测浓度与各自限值的比值之和超过生活饮用水卫生标准(GB/T5749-2006)限值,显示由于水源水高藻有机污染的存在,加氯消毒副产物浓度升高,降低了出水的安全性。3、通过对水库一个水文年度不同深度水质指标研究,发现浅型水库内部存在随季节交替而迁移转化的活性反应带,活性带覆盖的水体水质较差。在具备形成水库水体热分层的气候条件下,能否有足够的水力停留时间和水库底部是否有能提供内源性氮磷营养的底泥是水库能否形成活性反应带的两个缺一不可的必要条件。4、基于水库活性区的研究,提出通过实施必要的工程技术措施压缩活性区厚度,改善水库水质和避开活性带分层取水可有效提高水库出水水质的建议。DDDMAC(氯化双十二烷基二甲基铵)是一种以椰树胶为原料合成的一种新型高分子絮凝剂,试验结果显示该药剂对藻类具有很强的抑制作用,1mg/L的投加量足以实现对藻类生长的抑制,因此可以考虑被用来抑制原水输水管道和水厂各制水工序中的藻类生长。5、通过对常规处理工艺各阶段蓝藻藻体形态破坏及藻毒素的释放机制研究,表明混凝处理的高渗状态虽不致使藻体破碎,但却促使藻体局部破损,释放胞内藻毒素;预氯化可直接导致藻体破坏及藻毒素的释放。6、实验室和现场运行研究证明高锰酸钾、湿式粉末活性炭均能改善混凝效果,强化藻污染的消除,提高后续净化能力。采用高锰酸钾-湿式粉末活性炭助凝工艺(KPP),克服了干炭污染重、效率低等缺陷,分别投加0.5mg/L的高锰酸钾和20mg/L的湿式粉末活性炭可显著去除藻类污染、消除嗅味物质,常规工艺的水质净化能力提高明显。7、研发获得复合混凝剂RemA,试验数据表明它是一种除藻型高效混凝剂,可用于高藻水高效混凝体系的构建。RemA强化混凝工艺对藻类的去除率在90%以上,耗氧量保持在3mg/L以下,且能解决嗅味污染问题。8、研究设计了活性炭床浮滤池净水工艺,实现了气浮与过滤一体化,高度集成了多种除污染机理,可实现藻和有机物同时去除,同时能且运行方式灵活、占地面积较省。该工艺形式由于不需单独设置完整的絮凝池,可显著降低基建投资,适用于老水厂的工艺改造。预氧化强化的浮滤池工艺拓展了源水适应性,提高了污染物消减能力,藻、藻毒素和嗅味物质的去除率超过90%,耗氧量去除率超过50%,水质全面改善。本文为自来水厂寻求高效安全的水质净化工艺提供了技术支持。更多还原

【Abstract】 The traditional water treatment process is faced with severe challenge from the accelerated pollution of drinking source water. Water quality becomes the key factor for the safety of urban water supply. The water quality characteristics of different kinds of polluted reservoirs were studied in this paper, and some new technologies and processes of source water quality improvement; conventional process enforcement and advanced treatment were proposed and discussed. The followings were the major study and results.1. Such indexes as COD_Mn,TN, TP, NH₃-N, NO₃-N, VOCs, semi VOC_S, odor and algae show that both the mountain reservoir and Yellow River reservoir are polluted by organic matter and algae which cause apparent unpleasant smell. High concentrations of algae and organic matter are the common charicteristics.2. Analysis data showed the current conventional water treatment process has severe shortcomings for treating water polluted by organic matter and algae:The ability of removing algae is limited. The general removal rate of external cellular microcystins is about 28% while the removal rate of total microcystins is about 62%.Odor can hardly be removed through the current process. The major substance causing odor is GSM （geosmin） for treated mountain reservoir water, and is GSM and MIB for the treated Yellow River reservoir water. The concentrations of the odor substances exceeded the corresponding national standards.THMs of the tap water exceeded the national standard, which indicates that the DBPs pollution becomes a big issue while Cl₂ is commonly used for disinfection.3. There is an activated zone in the shallow type reservoir that changes along with the seasonal variations. Ample hydraulic retention time and substrate sludge supplying endogenous N&P nutrition at the bottom of reservoir were the indispensably essential conditions for the activated area to form.4. Based on the research on activated zone, some engineering measures to compress or remove the activated zone would reduce the concentrations of TN&TP, inhibit the excessive multiplication of algae in the water therefore improve the quality of water being drawn from the reservoir for drinking source water. Avoiding the activated area when drawing water from the reservoirs is proposed as a measure to improve the water quality for drinking water source. DDDMAC is a new kind of polymeric flocculant with coco gum as raw materials. Good results were generated on inhibiting algae growth when 1mg/L DDDMAC was added in the water. Therefore it may be used for inhibiting the growth of the algae in the source water in pipeline and that in the water purification units of the water plants.5. The characteristics of the cell breakage of cyanobacterium （M.aeruginosa） during the water treatment process respectively were investigated, and the results showed that coagulation would not cause algae cell breakage, but it would cause intracellular microcystins release in water process. Cl₂ as oxidant may cause both algae cell breakage and intracellular microcystins release.6. Both experimental and on site research showed that either potassium permanganate （KMnO₄） or wet activated powder carbon （WPAC） could remove algae and improve coagulation. KP process in which 0.5mg/L KMnO₄ and 20mg/L WPAC are added in the water at different location, could remove pollutants from algae and odor substance effectively so that the treatment effect of the conventional process was enhanced greatly.7. RemA is designed in the research and the experimental data showed it is a kind of high efficiency coagulant that could remove algae in the polluted reservoir water without breaking the algae cell. More than 90 percent of algae could be removed in the intensified coagulation process with RemA as coagulant. The COD_Mni in the effluent was below 3mg/L and the pollutants of odor were also removed.8. Floating filter tank is set up and the experimental data showed that it is an efficient unit for the treatment of water with high algae concentration. Preoxidation could improve the treatment effect of the floating filter tank greatly and expand its use for different source water as well. The removal rates of all the indexes except COD_Mn were close to or even higher than 90 percent, some of them are even as high as 100 percent. This study would provide technical support for the water plant to find an more effective and safer water purification process.更多还原