Removal of Heavy Metal Ions from Aqueous Solution by Raw and Modified Diatomite

Abstract

Removal of heavy metal ions (Cu2+, Pb2+and Ni2+) from aqueous solution by raw and modified diatomite was investigated in a batch reactor. The diatomite was modified by acid-wash and base-wash, respectively. The influence of kind of diatomite, contact time and initial concentration of metal ions on the adsorption efficiency were studied. The results showed that the acid-washed diatomite showed the best adsorption capacity for all of Cu2+, Pb2+and Ni2+) among raw, acid-washed and base-washed diatomites. Metal ions adsorption amount on A-diatomite increased in the initial concentration range from 10 to 50ppm and in general kept constant after the initial concentration was higher than 60ppm. The result also indicated that Ni2+is more easily adsorbed on the surface of diatomite than Pb2+and Cu2+.

Adsorption isotherm studies of Cu (II) and Co (II) in high concentration aqueous solutions on photocatalytically modified diatomaceous ceramic adsorbents

“…The removal and addition of cations using aluminosilicates are dependent on ion exchange and adsorption mechanisms. Most recent works on the use of modified diatomaceous aluminosilicate as adsorbents are based on the removal of toxic metals from aqueous solutions at relatively low concentrations which may not always be the case in real situations (Linghu and Cui 2014;Knoerr et al 2013;Zhu et al 2012;Liu et al 2013;Irani et al 2011;Danil de Namor et al 2012;Yusan et al 2012;Sheng et al 2008Sheng et al , 2012Sprynskyy et al 2010;Pookmanee et al 2011). Also natural diatomites are contaminated with impurities, which impact negatively on their removal of heavy ions (Zhu et al 2012).…”