冻融法处理垃圾渗滤液初探

第36卷第lO期2018年IO月环境工程EnvironmentalEngineeringV01．36OctNo．102018冻融法处理垃圾渗滤液初探王悦魏美娟宁夏李广科桑楠(山西大学环境与资源学院，太原‘030006)摘要：利用冻融法处理垃圾渗滤液，研究冷冻温度、稀释倍数及种冰量对冷冻、融化阶段渗滤液电导率和COD的影响，并对两个阶段污染物的变化规律进行对比分析。结果表明：冷冻阶段：在一6，一13，一20，一26℃4组冷冻温度中，一13℃为渗滤液的最佳冷冻温度，此温度下渗滤液电导率和COD的下降效果最明显；渗滤液稀释倍数对冷冻阶段电导率和COD的变化无明显影响；不同种冰量的结果表明，冰晶不分离更有利于后续产生高纯度的冰晶。融化阶段：将渗滤液原水一13℃下完全冷冻后进行融化，发现电导率和COD浓度均呈指数形式下降，6h后电导率和COD的分配系数均降到0．04。对冷冻、融化阶段渗滤液中污染物浓度变化规律进行对比分析，发现经冻融法处理后，垃圾渗滤液中电导率和COD浓度均显著下降，且融化阶段的处理效果好于冷冻阶段。因此，冻融法作为一种减量化处理方法在渗滤液预处理领域具有广阔的应用潜力。关键词：冻融法；垃圾渗滤液；电导率；CODDOI：10．13205／j．hjgc．201810007PRELIMINARYSTUDYoNTREATMENTOFLANDFILLLEACHATEBYFREEZE．THAWINGWANGYue，WEIMei-juan，NINGXia，LIGuang·ke，SANGNan(CollegeofEnvironmentandResource，ShanxiUniversity，Taiyuan030006，China)Abstract：Inthestudy，landfillleachatewastreatedbyfreeze-thawing，andtheeffectsoffreezingtemperature，dilutionratioandamountoficeonleachateconductivityandCODduringfreezing·thawingstageswereinvestigated．Moreover，thechangesofleachatepollutantsinthesetwostageswerecomparedandanalyzed．Theresultsshowedthatamongthefreezingtemperatureof一6，一13，一20and一26℃，thetreatmentefficiencyofleachatewasbetterat一13℃thanothers．Thus，一13℃wasconsideredastheoptimalleachatefreezingtemperature．However，thedilutionratioofleachatehadnosignificanteffectontheconductivityandCODduringthefreezingstage．Studiesonthetreatmenteffectofdifferentamountsoficeindicatedthatkeepingtheicecrystalsinhachatewasmorebeneficialtothesubsequentfreezingprocess．Duringthethawingprocess，therawieachatewascompletelyfrozenat—13oC．thenmeltedatroomtemperature．WefoundthatthelevelsofconductivityandCODwereexponentialdeclined，andthedistributioncoefficientofconductivityandCODbothdroppedto0．04after6h．BycomparingthechangesofconductivityandCODinfreezingandthawingprocess，itwasfoundthatthetreatmenteffectinthawingstagewasbetterthanthatinfreezingstage．Therefore，asareductiontreatmentmethod，freeze-thawingmayhaveagreatapplicationprospectinleachatepretreatment．Keywords：freeze-thawing；Iandfillleachate；conductivity；COD0引言目前，我国应用最广泛的生活垃圾处理方式是卫生填埋