高效结晶除硬技术处理高盐废水的研究

摘要II摘要高盐废水零排放技术是环境保护的必然要求，特别是部分产业部门的高盐废水排放已经严重制约了当前企业的发展情况，是当前和今后一段时间国内外关注度极高的问题之一。在传统的高盐废水处理技术基础上充分吸收国内外先进技术，以邯郸热电厂循环冷却排污水为原水，对一套完整的废水处理工艺进行研究。主要工艺包括：药剂软化、弱酸树脂离子交换软化、反渗透浓缩、正渗透及蒸发结晶，对各工艺主要影响因素进行试验研究，确定相关技术应用研究的主要参数。论文进行了混凝沉淀预处理试验，通过投加氢氧化钙和碳酸钠对高盐废水进行软化处理。试验结果表明：在处理邯郸热电厂循环冷却排水时，最佳投药量Na2CO3为800mg/L，Ca(OH)2为700mg/L。硬度则从1380mg/L降到125mg/L，而去除率为90.585%。用D113--Ⅲ型弱酸阳离子树脂对药剂软化后的高盐水做进一步的软化，以Ca2+、Mg2+全部被吸收为平衡浓度，得出D113--Ⅲ型树脂对Ca2+、Mg2+的吸附容量为114000mg/L。用反渗透对软化后的高盐废水进行预浓缩试验，在试验条件下，随着原水水箱中含盐量的增加，出水含盐量也随着增加，并且除盐率与产水率会随着降低。除盐率从最初的99.35%降到98.54%，产水率由24.51%降至23.94%。用某研究院自制正渗透膜对反渗透试验浓水进行膜性能试验。随着汲取液浓度的增加，本试验所用正渗透膜的水通量也随着增加，水通量从5.3L/(m2·h)上升至23.1L/(m2·h)；而截盐率汲取液浓度增加会较缓慢的下降，截盐率由94.2%下降至93.8%；反向盐通量会随着增加，由3.5g/(m2·h)上升至14.9g/(m2·h)。对特殊反向盐通量无影响。随着温度缓慢上升，膜通量有明显的上升趋势，在温度达到35℃时，水通量最大为14.9L/(m2·h)，膜的截留率会有稍微的下降，反向盐通量会先随着温度的升高而增加，在30℃时，反向盐通量达到最大值11.3g/(m2·h)，然后随着温度的升高而下降。用世韩4040正渗透卷式膜做小型实验，结果表明，随着正渗透试验装置的运行，原料液电导率先增加较快后缓慢增加，最后趋于平稳。在汲取液浓度为1mol/L时，原料液电导率可浓缩至43800μS/cm；汲取液浓度为2mol/L时，原料液电导率可浓缩至69300μS/cm。水通量逐渐减小，最后趋近于零。用柱蒸馏法、吹托蒸馏法和减压蒸馏法三种作为汲取液回收与提纯方法进行比较，无论从回收率还是水的提纯方面，吹托蒸馏法和减压蒸馏法明显优于柱蒸摘要III馏法。温度控制在50至60℃之间两种方法的回收率可达60%以上。在对含有氯化钠和硫酸钠的浓盐水进行蒸发结晶时，温度控制在65到75℃之间，有利于氯化钠与硫酸钠的提纯。关键词：高盐废水；药剂软化；离子交换软化；正渗透；蒸发结晶。AbstractIAbstractZerodischargetechnologyofhighsaltwastewateristheinevitablerequirementforenvironmentalprotection,especiallythehighsaltwastewatertreatmentpartindustryhasseriouslyrestrictedtheproductionanddevelopmentofenterprises,isoneofthehighdegreeofattentiontothecurrentandfutureperiodoftimeathomeandabroad.Onthebasisoftraditionalhighsaltwastewatertreatmenttechnology,thedomesticandforeignadvancedtechnologyisfullyabsorbed,andacompletesetofwastewatertreatmentprocessisstudiedbyusingthecirculatingcoolingsewageofHandanthermalpowerplantasrawwater.Themainprocessincludes:chemicalsoftening,ionexchangeresinsoftening,reverseosmosis,forwardosmosisandevaporationcrystallization,experimentandStudyonthemainfactorsofeachprocess,determinethemainparametersofthestudyontheapplicationoftechnologydevelopment.Inthispaper,thepretreatmentofcoagulationsedimentationwascarriedout,andthehighsalinitywastewaterwastreatedbyaddingcalciumhydroxideandsodiumcarbonate.TheresultsshowedthatthebestdosageofCa(OH)2was700mg/L,Na2CO3was800mg/L.Hardnessdecreasedfrom1380mg/Lto125mg/L,theremovalratewas90.585%.FurthersofteningofhighsalinechemicalsaftersofteningwithD113--typeweakacidcationresin,Ca2+,Mg2+allhavebeenabsorbedintotheequilibriumconcentrationoftheadsorptioncapacityofD113--typeresinforCa2+,Mg2+for114000mg/L.Byusingreverseosmosis,theconcentrationofsaltinthewatertankwasincreasedwiththeincreaseofsaltcontentintherawwatertank.Thesaltremovalratedecreasedfrom99.35%toabout98.54%andthewaterproductionratedecreasedfrom24.51%to23.94%.Experimentalstudyontheperformanceofreverseosmosistestconcentratedwaterbyusingaself-madepositiveosmosismembrane.Learntheeffectofconcentrationonmembraneperformance:withtheincreasedconcentrationofthedraw,thisexperimentusedthewaterfluxofforwardosmosismembranealsoincreasedwiththeincreaseofwaterfluxfrom5.3L/(m2·h)upto23.1L/(m2·h);andthesaltconcentrationdecreasedwiththeincreaserateofdrawwillslow,saltrejectionAbstractIIdecreasedfrom94.2%to93.8%;thereversesaltfluxwillincrease,by3.5g/(m2·h)upto14.9g/(m2·h).Noeffectonspecialreversesaltflux.Effectoftemperatureonmembraneperformance:asthetemperaturerisesslowly,membranefluxincreased,thetemperaturereached35degrees,themaximumwaterfluxof14.9L/(m2·h),theretentateratewouldbeslightlydecreased,reversesaltfluxwillincreasewiththeincreaseoftemperature,at30degreesandthereversesaltfluxreachesthemaximumvalueof11.3g/(m2·h),andthendecreasedwithtemperatureincreasing.Effectonspecialreversesaltflux.The4040isfoundwithSaehanpenetrationrollfilmexperiment,withpositivetest,permeabilitytestdeviceoperation,rawliquidconductivityfirstincreasesslowlyincreasesrapidly,finallytendstobestable.Whentheconcentrationofis1mol/L,theconductivityoftherawmaterialcanbeconcentratedto43800μS/cm.Whentheconcentrationofthesolutionis2mol/L,theconductivityoftherawmaterialcanbeconcentratedto69300μS/cm.Thewaterfluxdecreasesgradually,andfinallyapproacheszero.Blowsupportingdistillationandvacuumdistillationthreeasdrawsolutionrecoveryandpurificationmethodswerecomparedwithcolumndistillation,andfromboththerecoveryandpurificationofwater,blowingsupportingdistillationandvacuumdistillationcolumndistillationmethodwasbetterthanthatof.Temperaturecontrolat50to60℃,therecoveryrateofthetwomethodscanreachmorethan60%.Thetemperatureiscontrolledbetween65and75℃whenevaporatingandcrystallizingtheconcentratedbrinecontainingsodiumchlorideandsodiumsulfate,whichisbeneficialtothepurificationofsodiumchlorideandsodiumsulfate.Keywords:Highsalinitywastewater;chemicalsoftening;ionexchangesoftening;forwardosevaporationcrystallization目录I目录摘要.............................................................IIAbstract............................................................I第1章绪论.........................................................11.1水资源现状...................................................11.2高盐废水来源、水质特点及危害............