Abstract:

 In comparison to common dolomite and palygorskite clay, the effects of parameters such as pH, contact time, initial concentrationofcopperonremovalofcopperionsusingclayeydolomiteinpalygorskiteclaydepositwasinvestigatedusingstatic adsorptionexperiments.Thekineticsofcopperremovalwasdiscussedbythepseudo-first-order,thepseudo-second-orderandthe Elovichmodel,andthesorptionisothermwasanalyzedbyLangmuirandFreundlichisothermequations.Theresultsshowthatthe effectofpHontheremovalofcopper(II)ionbyclayeydolomitewaslessthantheothertwo.Morethan85%ofcopper(II)ionswere removedinthepHrangeof3to5andtheoptimumpHis5.Thekineticdataoftheremovalofcopperbyclayeydolomitefittedthe pseudo-second-orderkineticmodelverywell.Theremovalrateaswellastheefficiencywasthehighest.Theisothermdatacanbe described by the Freundlich model and the removal capacity was 186.2×10-3. The removal mechanisms were mainly surface precipitationinducedbythemineral-waterinteractionsandelectrostaticattractionbetweenpalygorskiteandthenewlyformedcolloid [Cu2CO3(OH)2].Thepresentstudyconcludesthatclayeydolomiteismoreeffectivebecauseoftheintergrowthofnanoscalepalygorskite andsub-micronporousdolomite,leadingtothehigh-efficientremovalofcopperionsthanthecommondolomiteandpalygorskiteclay, anditpossessesthepotentialfortreatingcopperwastewater.

Key words: clayeydolomite;dolomite;palygorskiteclay;copper;removal;surfaceprecipitation