预氧化协同混凝去除嘉陵江水中有机污染物研究

预氧化协同混凝去除嘉陵江水中有机污染物研究重庆大学硕士学位论文(学术学位)学生姓名：谢家山指导教师：高旭教授专业：环境工程学科门类：工学重庆大学城市建设与环境工程学院二O一二年十二月Pre-oxidationcollaborativecoagulationtoremoveorganicpollutantsfromtheJialingriverwaterAThesisSubmittedtoChongqingUniversityinPartialFulfillmentoftheRequirementfortheMaster‟sDegreeofEngineeringByXieJiashanSupervisedbyProfessorGaoXuSpecialty：EnvironmentalEngineeringFacultyofUrbanConstruction&EnvironmentalEngineeringofChongqingUniversity,Chongqing,ChinaDecember2012中文摘要I摘要重庆嘉陵江春季和夏季原水水质各有特点：春季时由于地表经过冬季沉积的腐殖质被冲入江中，水中含有腐殖质等天然有机物浓度较高，水质复杂；夏季水浊度则较高，两类水均存在一定处理难度。为解决单一工艺水厂处理以上两类水的困难，需寻求强化现有工艺的方法。本课题基于预氧化工艺对混凝的强化作用，考察上述两种水样经高锰酸钾、臭氧、过氧化氢三种氧化剂预氧化协同混凝的性能和效果。在三种聚合氯化铝PAC投量下(5.0,7.5,10.0mg/L)，高锰酸钾、臭氧、过氧化氢预氧化可以提高混凝除浊和除有机物的效果。高锰酸钾对混凝除浊的效果最好，可以使水体浊度降低1.0～3.9NTU；高锰酸钾对TOC去除效果也优于其它两种氧化剂，使TOC去除率提高了7.7～8.1个百分点；过氧化氢和臭氧作用效果相当。三种氧化剂对混凝去除UV254作用效果都较明显，其中以臭氧作用效果最好，使UV254去除率提高了12.1～14.2百分点。氧化剂的投量对混凝效果有显著的影响。随着三种氧化剂的投量的增加，混凝对浊度、TOC、UV254的去除率都增加。对于本试验水质，高锰酸钾较优的投加量为0.9mg/L左右，过氧化氢较优的投加量为1.2mg/L左右，臭氧较优的投加量为2.0mg/L左右。运用分子膜切割法，研究原水经单独氧化、预氧化联合混凝处理前后各个分子段有机物的变化。结果表明，嘉陵江原水以小分子有机物为主；分子量小于3k(3000Dalton)的有机物占有机物总量的一半以上；分子量大于10k的有机物只占总有机物的30%左右。预氧化前后有机物分布数据对比表明，三种氧化剂可以改变有机物的分布状态，预氧化后分子量大于3k有机物的量呈减小的趋势，分子量小于3k的有机物的量呈增加的趋势；尤其是非溶解性有机物减少较为明显。三种氧化剂预氧化后都可以提高混凝对分子量大于3k有机物的去除效果；但是对于分子量小于3k的有机物则呈出不同的结果，高锰酸钾预氧化可以提高这部分有机物的去除，而过氧化氢和臭氧却降低了这部分有机物的去除。根据试验结果,建议在处理嘉陵江原水时，采用高锰酸钾作为氧化剂较为适宜，投加量为0.6～0.9mg/L,预氧化时间选择5min,可以较好地提高混凝对有机物的去除。针对具有臭氧制备、输送和曝气设备且有后续生物处理的水厂，可以采用臭氧作为氧化剂；当采用臭氧作为氧化剂时，臭氧投加量可选择2.0mg/L，预氧化时间为5min。关键词：预氧化剂，天然有机物，分子量，强化混凝重庆大学硕士学位论文II英文摘要IIIABSTRACTSpringandsummerrawwaterqualityinChongqingJialingriverhavedifferentfeatures:Becausewintersedimentaryorganicmatterisflushedintoriver,thespringrawwatercontainshighconcentrationoforganiccompounds;Summerwaterturbidityishigher,thetwotypesofwatertreatmentisdifficult.Inordertosolveasinglewatertreatmentprocessdifficultywhentreatmentabovetwokindofwater,needtoseekingstrengthenexistingprocessofmethod.Thissubjectbasedonpre-oxidationprocessoncoagulationofreinforcement,inspectspotassiumpermanganate、hydrogenperoxide、ozonecollaborativecoagulationperformanceandeffectwhentreatmenttheabovetwokindsofwatersample.Inthreekindsofpolyaluminiumchloridedosingdoses(5.0,7.5,10.0mg/L),threekindofoxidantoxidationcanenhancedcoagulationtoremoveturbidityandorganicmatter.otassiumpermanganateshowbesteffectoncoagulationremovingturbidity,canmakethewaterresidualturbidityreductionof1.0~3.9NTU.FortheremovalofTOC,potassiumpermanganatehavethebesteffecttocoagulationinthreekindsofoxidants,TOCremovalrateisimprovedby7.8～8.1percentagepoints;FortheremovalofUV254,threekindsofoxidanteffectsaremoreobvious,theozoneeffectisbest,sothattheUV254removalrateincreasedby12.1～14.2percentagepoints.Oxidantdosagehassignificantinfluenceonenhancecoagulationeffect.Withthreekindsofoxidantdosageincreases,turbidity、TOC、UV254removalratecanbeimproved.Fortheexperimentalwater,potassiumpermanganateoptimumdosageis0.9mg/L,hydrogenperoxideoptimumdosageis1.2mg/L,ozoneoptimumdosageis2.0mg/L.Usingultrafiltrationmembraneseparationorganicmethod,studiesthewaterorganicmolecularchanges.Theresultsshowsthat,theJialingRiverRawWaterisgivenprioritytosmallmoleculeorganiccompounds;Molecularweightlessthan3korganicmatterhavehalfinthetotalorganic;molecularweightgreaterthan10khave30%inthetotalorganic.Afterpre-oxidation，molecularweightdistributionofdatacomparisonshows,threekindsofoxidantscanchangethedistributionoforganicmatter,molecularweightgreaterthan3korganicvolumeisdecreased,molecularweightlessthan3korganicvolumeshowedatendencytoincrease;especiallydissolvedorganicmatterdecreasedobviously.Differentoxidantsonorganicmatterremovalofdifferentmolecularsegmentshavedifferenteffectsincoagulation;threeoxidantscanincreasethemolecularweightgreaterthan3korganicsremoval;butformolecularweightlessthan重庆大学硕士学位论文IV3korganicmattershoweddifferentresults,potassiumpermanganatepre-oxidationcanincreasetheorganicmatterremoval,hydrogenperoxideandozonereducethispartoforganicmatterremoval.Accordingtothetestresults,itissuggestedthatusingpotassiumpermanganateastheoxidantsisrelativelyappropriateinthetreatmentoftheJialingriverwater;Potassiumpermanganateasanoxidantwhentheequipmentissimple,theinvestmentissmall,energysaving.Whenusingpotassiumpermanganateastheoxidants,potassiumpermanganatedosingquantityis0.6~0.9mg/L,pre-oxidationtimechoose5min,canbetterenhancedcoagulationtoremovetheorganicpollutants.Whenwatertreatmentplanthaspreparation,deliveryandaerationequipmentandasubsequenttothebiologicaltreatmentofwater,canuseozonepre-oxidation.whenusingozoneasoxidant,ozonedosingquantityis1.5~2.0mg/L,pre-oxidationtimefor5min.Keywords:Pre-oxidation,Naturalorganicmatter,Molecularweight,Enhancedcoagulation.目录V目录中文摘要..........................................................................................................................................I英文摘要.......................................................................................................................................III1绪论............................................................................