螯合沉淀联合微滤法脱除电镀废水中的低浓度络合金属严苹方

112Vol．11No．220172ChineseJournalofEnvironmentalEngineeringFeb．201720162016A0404030682014KTSP022－2015A0303080082015－10－132015－11－241989—。[e-mail]*[e-mail]*510006-Fe、Cu、ZnCr。pHEDTCEDTCPACFe、Cu、ZnCrEDTC。pH7EDTC60mg·L－11minPAC20mg·L－12minPAM2.5mg·L－12minCu0.020mg·L－1＜0.3mg·L－1Fe0.43mg·L－1＜2.0mg·L－1Zn0.37mg·L－1＜1.0mg·L－1Cr0.45mg·L－1＜0.5mg·L－1《GB21900-2008》。Fe、Cu、ZnCrEDTCFe、ZnCr。EDTCFe、Cu、ZnCrEDTCEDTC。-X703A1673-9108201702-0769-09DOI10.12030/j．cjee．201510087Ｒesearchonlow-concentrationmetalsremovalsimultaneouslyfromelectropla-tingwastewaterbythemethodofchelateprecipitation-microfiltrationYANPingfangYEMaoyouSUNShuiyu*XIAOXiaoLINXiajunDAIWencanSchoolofEnvironmentalScienceandEngineeringGuangdongUniversityofTechnologyGuangzhou510006ChinaAbstractWhentreatingwastewatercontainingmetalcomplexesusingconventionalapproachese．g．sulfideprecipitationitisconsideredtobedifficulttobringdowntheconcentrationofmetalstolevelsthatmeetthedischargestandard．Toaddressthisprobleminthisstudyachelatingprecipitation-microfiltrationmethodwaschosentoremovelowconcentrationmetalcomplexesincludingFeCuZnandCrdeeplyandsimultaneouslyforitsbettertreatmenteffect．TheinfluenceofpHdosageofthecaptureagentEDTCreactiontimedosageofflocculantPACandcoexistingmetalionsontheremovalofmetalsFeCuZnandCrwasstudied．Inaddi-tionthereactionmechanismsofEDTCandthemetalsFeCuZnandCrwerecomparedforthefirsttime．TheexperimentalresultsshowedthatEDTChadahighmetalremovalefficiencyunderthefollowingorderofcon-ditionspH760mg·L－1ofEDTC1minofreactiontime20mg·L－1ofPAC2minofreactiontime2.5mg·L－1ofPAMand2minofreactiontimeleadingtoaresidualmetalconcentrationofCu0.020mg·L－1＜0.3mg·L－1Fe0.43mg·L－1＜2.0mg·L－1Zn0.37mg·L－1＜1.0mg·L－1andCr0.45mg·L－1＜0.5mg·L－1whichallmettheemissionstandardsofpollutantsforelectroplatingGB21900-2008．ThemetalionsaffectedeachotherwhencombinedwithEDTCinsolution．FeCuZnandCrcompetedforchelationwithEDTCwhileFeandZnpromotedtheEDTCremovalofCr．Theinfraredspec-trumshowedthatthemechanismsofEDTCremovalofallthemetalsFeCuZnandCrweresimilar．EDTC11andthemetalunderwentchelationreactions．ThesulfurofthethiolofEDTCcapturedthemetalionandtendedtobondwiththeinsolublechelateproduct．Keywordschelatingprecipitation-microfiltrationelectroplatingwastewatermetalscoexistingmetalreactionmechanisms、、。1-2、3-4、5-6、7-8。、。EDTA910。DTC11。dithiocarbamateDTC19DTC。DTC。DTCDTC。ZHEN12DTC-TABEDTA-CuCu。pH3-5DTC-TAB/Cu1.2∶1Cu2+99%0.37mg·L－1。FU13135-HTDCpH3～9Cu100mg·L－1EDTC-CuCu0.5mg·L－1。14ＲDTCCuCA、NiCA、NiTAPbCACu2+0.033mg·L－1Ni2+0.043mg·L－1Pb2+0.071mg·L－1。DTCDTCDTC14。Cr、ZnFe。Cr、Zn、FeCu《GB21900-2008》Cu＜0.3mg·L－1、Fe＜2.0mg·L－1、Zn＜1.0mg·L－1、Cr＜0.5mg·L－115。EDTCCr、Zn、FeCu。0772EDTC。11.1EDTCPACPAMZnSO4·7H2OCuSO4·5H2OFeCl3·6H2OK2Cr2O7C10H14N2O8Na·2H2O0.45μm。Na2SpH11Cu11.42mg·L－1Fe6.22mg·L－1Zn3.01mg·L－1Cr1.09mg·L－1。EDTA-2NaFeCl3、ZnSO4K2Cr2O7CuSO41∶1pH3Cu10.99mg·L－1Fe6.42mg·L－1Zn3.48mg·L－1Cr1.33mg·L－1。1.21.2.1100mL150mLpH200r·min－1PAC70r·min－12minPAM2.5mg·L－170r·min－12min30min10mL。pH、EDTC、EDTC、EDTC。3±。1.2.22.2.110mL0.45μm。3±。1.3pHpHS-25Z20000.02mg·L－1KBrNicolet380THEＲMOFisherSci-entific4000～400cm－1。2400ⅡPerkinElmer。22.1pHEDTCEDTC16EDTCEDTCpH6～1017pHEDTCEDTCpH18pHpH7～12。Fe、Cu、ZnCr。EDTC70mg·L－1177111pHEDTCFig．1EffectsofpHonremovalofmetalsbyEDTC1minPAM2.5mg·L－12minpH1。pHFe、CuZnCrpHFe、CuZnCrpHFe、CuZn。Na2SpH＞pKapKa=3.4H+EDTAMn+EDTCMn+EDTC2EDTCEDTCFig．2EffectofEDTCdosageonremovalofmetalsbyEDTCEDTCMn+18。pHFe、CuZn。EDTA-ZnⅡ、EDTA-FeⅡ、EDTA-CuⅡEDTA-CrⅢ1.0×10－16.5、1.0×10－14.33、1.0×10－18.801.0×10－23.4CrpH。pH=7。Fe1.46mg·L－1、Cu1.57mg·L－1、Zn0.85mg·L－1、Cr1.18mg·L－176.53%、86.25%、71.76%43.54%。3EDTCEDTCFig．3EffectofEDTC'reactiontimeonremovalofmetalsbyEDTC2.2EDTCEDTCpH7EDTC1minEDTC。2EDTCFe、Zn、CuCr。EDTCFeZnFeZn0.47mg·L－1＜2.0mg·L－10.37mg·L－1＜1.0mg·L－1。EDTCCuCuCrEDTC60mg·L－1。2.3EDTCEDTCpH7EDTC60mg·L－1200r·min－10～12min。3Fe、ZnCuCr60s1minEDTC200r·min－11min1min。27722.4PACEDTC4PACEDTCFig．4EffectofPACdosageonremovalofmetalsbyEDTCpH7EDTC60mg·L－11minPAC。4PACCuFe、ZnCr。PAC20mg·L－1Cu2.08mg·L－10.16mg·L－1CrCu0.16mg·L－1＜0.3mg·L－1、Fe0.45mg·L－1＜2.0mg·L－1、Zn0.37mg·L－1＜1.0mg·L－1。EDTCCuPACPAC19PACCu。FeZnPAC。Cr。CrCrEDTC。2.5EDTC＜0.45μm。EDTC、EDTC1。CuCrCuCrFeZn。《GB21900-2008》20。1Table1Treatmenteffectofelectroplatingwastewaterbydifferentmethods/mg·L－1CuFeZnCrEDTC0.160.450.370.55EDTC+0.0200.430.370.450.32.01.00.52.6EDTCEDTA-2NaFeCl3、ZnSO4、K2Cr2O7CuSO41∶13EDTC。5Cu2+Fe3+、Zn2+Cr6+3Cu2+EDTCFe3+、Zn2+Cr6+。EDTCCu2+Fe3+、Zn2+Cr6+Cu2+100%。Fe3+Zn2+Zn2+Fe3+。Fe3+Zn2+。Cr6+Fe3+Zn2+Fe3+Zn2+Cr6+。Cr6+Fe3+Zn2+Fe3+Zn2+EDTCCr6+。EDTA-Cr9mg·L－1EDTA-FeCr6+0.730.14mg·L－180.82%4mg·L－1EDTA-ZnCr6+0.42mg·L－142.47%。377115EDTCFig．5EffectofcoexistingmetalionsonremovaloftargetmetalbyEDTC2.7EDTC2.7.1EDTCSC—S6。EDTC3421cm－1N—H2936cm－1C—H3000cm－1C—H2700cm－1－SH1672cm－1—SH1063cm－1CS1496cm－1N—CS2C—N1300cm－1CN1600cm－11476cm－1C—S982cm－1C—SEDTCSC—S。6EDTCCu、Cr、FeZn2700cm－1—SH1672cm－1S—H。EDTC—SH。—SH—S－18。2.7.2EDTCEDTC。。Cr、Fe、CuZn44Zn＞Cu＞Fe＞CrCr2+d4、Fe2+、d6Cu2+d9d1～9d54772。ZnCuZn2+d10C、NS。Irving-WilliamCr2+＜Fe2+＜Cu2+＞Zn2+21。Fe2+3d6Fe3+3d53d5F．HundFe3+Fe2+。Cr2+3d4Cr6+3p6pdCr6+Cr