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1、摘要氰化物为剧毒产品,在生产和使用过程中会产生含氰废水,该废水不经处理直接排放会对环境造成严重污染。本文对氰化物进行了风险评价计算,并采用液膜萃取法处理含氰废水。包括含氰废水生态风险评价和人体健康风险评价。考察了微乳液的配方及其稳定性,乳水比,乳水接触时间,NaOH浓度,Span-80用量,三正辛胺(TOA)用量,液体石蜡用量,油内比等因素的改变对萃取率的影响,以及乳液循环使用情况。通过风险评价,废水中氰化物含量为166μg/L时,对整体生态风险不存在生态风险;氰化物的暴露剂量限值应低于0.1mg/kg
2、•d,可保证氰化物对人体无不可接受风险;在保证对人体无不可接受风险时,皮肤渗入途径的浓度限值为10-5~10-6mg/L,呼吸吸入途径的浓度限值为0.001~0.009mg/m3。研究发现采用废水pH值为4、Span-80用量为3%、TOA用量为2%、液体石蜡用量为1%、NaOH浓度为2%、制乳转速为2300r/min、乳水比为1:7、乳水接触时间为15min,转速250r/min,油内比为1:1时,萃取率能达到95%以上。液膜性能稳定,萃取周期短,萃取效率高,乳液可循环使用,经济效益高,可进行工业推广
3、。关键词:含氰废水;液膜萃取;风险评价;三正辛胺(TOA)第I页AbstractDuetothetoxicityofcyanide,itproduceswastewatercontainingofcyanogenintheprocessofindusty.Dischargingthewastewaterdirectlywithouttreatmentcouldcauseseriousenvironmentalpollution.Thisexperimentmakesriskassessmentofcya
4、nidewaste,andusesliquidmembraneextractionmethodtohandlecyanidewastewater.Inarticleriskassessmentincludesecologicalriskassessmentandhumanhealthriskassessment.Theeffectoftheformulaandthestabilityofthemicroemulsion,volumeratioandcontacttimeofmilkphaseandwat
5、erphase,NaOHconcentration,uselevelofSpan-80,TOA,atolinandratiovolumeofoilphasetointernalphasefortheextractionratewereinvestigated.Emulsionrecycledconditionwasalsodiscussed.Throughtheriskassessment,thereisnoriskforecologicalwhenthecontentofcyanideisbelow1
6、66μg/L.Astheamountofexpoesdcyanideisbelow0.1mg/kg•d,thereisnoriskforhumanbeings.Concentrationlimits10-5~10-6mg/Lforpenetrationforskinand0.001~0.009mg/m3forbreathin.Theextractionratecanreachabove95%whenwastewaterpHvaluewas4,Span-80was3%,TOAwas2%,NaOHwas2%
7、,emulsifyingstirringspeedwas2300r/min,volumeratioofmilkphaseandwaterphaseiswas1:7,contacttimeofmilkphaseandwaterphasewas15min,thespeedwas250r/min,ratiovolumeofoilphasetointernalphasewas1:1.Theindustrilizationcanbepromotedforstableliquidmembraneperformanc
8、e,shortextractionperiod,highextractionefficiency,recyclableemulsionandhigheconomicbenefit.Keywords:thecyanidewastewater;liquidmembraneextraction;riskassessment;threeoctylamine(TOA).第IV页目录摘要I1绪论11.1含氰废水来源与危害11.2含氰废水的风险评价11.