This study focused on the adsorptive behaviors of humic acid onto freshly prepared hydrous MnO_(2)(s)(δMnO_(2)),and investigated the feasibility of employingδMnO2 for humic acid removal from drinking water.Effects o...This study focused on the adsorptive behaviors of humic acid onto freshly prepared hydrous MnO_(2)(s)(δMnO_(2)),and investigated the feasibility of employingδMnO2 for humic acid removal from drinking water.Effects of such parameters as molecular mass of humic acid,kinds of diva-lent cations on adsorptive behaviors and possible mechanisms involved were investigated.This study indicated that humic acid with higher molecular mass exhibited more tendency of adsorbing ontoδMnO2 than that with lower molecular mass.Ca^(2+)facilitated more humic acid adsorption than Mg^(2+);UV-Vis spectra analysis indicated higher capabilities of Ca^(2+)coordinating with acidic functional groups of humic acid than that of Mg2+.Additionally,ζpotential characterization indicated that Ca^(2+)showed higher potential of increasingζpotential ofδMnO_(2) than Mg^(2+).Ca^(2+)of 1.0 mmol/L increasedζpotential ofδMnO2 from−37 mV(pH 7.9)to+7 mV(pH 7.2),while 1.0 mmol/L Mg^(2+)^increased to lower value as−9 mV(pH 6.5),correspondingly.Fourier transform infrared(FTIR)spectra demonstrated the adsorption of humic acid ontoδMnO_(2),showing the important roles of-COO−function-al groups and surface Mn-OH in the adsorption of humic acid ontoδMnO_(2).展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant No.50678007).
文摘This study focused on the adsorptive behaviors of humic acid onto freshly prepared hydrous MnO_(2)(s)(δMnO_(2)),and investigated the feasibility of employingδMnO2 for humic acid removal from drinking water.Effects of such parameters as molecular mass of humic acid,kinds of diva-lent cations on adsorptive behaviors and possible mechanisms involved were investigated.This study indicated that humic acid with higher molecular mass exhibited more tendency of adsorbing ontoδMnO2 than that with lower molecular mass.Ca^(2+)facilitated more humic acid adsorption than Mg^(2+);UV-Vis spectra analysis indicated higher capabilities of Ca^(2+)coordinating with acidic functional groups of humic acid than that of Mg2+.Additionally,ζpotential characterization indicated that Ca^(2+)showed higher potential of increasingζpotential ofδMnO_(2) than Mg^(2+).Ca^(2+)of 1.0 mmol/L increasedζpotential ofδMnO2 from−37 mV(pH 7.9)to+7 mV(pH 7.2),while 1.0 mmol/L Mg^(2+)^increased to lower value as−9 mV(pH 6.5),correspondingly.Fourier transform infrared(FTIR)spectra demonstrated the adsorption of humic acid ontoδMnO_(2),showing the important roles of-COO−function-al groups and surface Mn-OH in the adsorption of humic acid ontoδMnO_(2).
