| Electroplating industry has long been the lack of a rational layout in Harbin?However, the discharge of electroplating wastewater will have a great impact on thewater quality of Songhua River, distributed electroplating industry wastewater willbring damage to the aquatic environment, so to build a surface treatment industrywastewater treatment and reuse project is necessary. Generally, the composition ofheavy metal wastewater discharged by plating tank is complex, in addition to containingdifferent concentrations of heavy metals, also containing some organic pollutants. Inthis paper, use plating tank wastewater as research object, based the conventionalchemical precipitation pretreatment, advanced treatment of organic complex heavymetals by activated carbon and resin adsorption were studied.Wastewater Treatment for precipitation was studied. The results show, to freeheavy metal wastewater, alkali precipitated treatment is very effective, the removal ratewas close to100%. Compared the effects of non-complex saccharin sodium andcomplex EDTA on alkali precipitation, indicating the presence of sodium saccharindoes not affect the precipitation process, but EDTA has a great influence on theprecipitation process, with the increase EDTA proportion, heavy metals removalefficiency decreased accordingly. Although studies show that pre-treatment caneffectively remove free heavy metal, but can not remove the complex heavy metal,follow advanced treatment measures was required.Use wasterwater after precipitated as research object, the ability of activatedcarbon adsorsb complex heavy metal were studied. Under static conditions,theadsorption of complex heavy metals by activated carbon was effective, with the dosageamount of activated carbon increased, copper ion and nickel ion adsorption rates alsoincreased, while the zinc ion is dropped after the first improving, adsorption rate wereslightly lower with increasing temperature, optimum initial PH of the three heavymetals wastewater is7, activated carbon adsorption of copper ions and nickel ions reachto equilibrium in60min, while zinc ions in40min. The adsorption of complex heavymetal by activated carbon applies to Freundlich isotherm equation, in line with thepseudo-second-order kinetic model. The analytical performance and regeneration performance of this activated carbon were studied, desorption rate of activated carbonwas97.79%, adsorption capacity could remain no significant decline after3times ofregeneration.Beside the study of activated carbon adsorption, the effect of advanced treatmentof organic complex heavy metal wastewater by resin adsorption were alsostudied.Under static conditions, while increased the resin dosage,the removal rate alsoincreased and eventually stabilized, with the increase of ion exchange time, the removalrate also increased. Copper ions removal rate increased fastest in60min, zinc andnickel ions removal rate increased fastest in180min, the removal of the three complexheavy metals were in line with pseudo-second-order kinetics, the rise of temperaturewere in favor of the removal of the three complex heavy metals, initial PH were obviousimpact on ion exchange process, the best PH were7.On the basis of the static study, a study of the dynamic adsorption experimentswere carried out, the results show activated carbon adsorption and ion exchange methodwere all effective ways to the treatment of complex heavy metal wastewater, adsorptioncapacity of ion exchange column is much larger than the the activated carbon column,so ion exchange is more suitable for practical applications.In summary, the electroplating wastewater containing complex heavy metal bringschallenge to wastewater treatment, for traditional chemical precipitation is difficult toremove it. and activated carbon adsorption or ion exchange method to treat complexheavy metal wastewater proved to be effective, the study has some practical projectsignificance, can provide some references for the removal of complex heavy metals. |
PDF Full Text Request