Efficient Degradation of Dyes in Water by a Novel Inorganic Cation Exchanger Cerium(IV) arsenomolybdate

An advanced inorganic cation exchange material of the class of tetravalent metal acid salt, cerium(IV) arsenomolybdate has been synthesized by co-precipitation method. The chemical composition was determined from EDS and other physio-chemical analyses carried out are TGA, FTIR and X-ray diffraction studies. Its ion exchange capacity was found to be 2.19 meqg-1.The distribution coefficient(Kd) has been determined for transition metal ions ( Co2+, Ni2+, Cu2+, Zn2+ and Mn2+ ), heavy metal ions( Cd2+, Hg2+, Pb2+ and Bi3+) and alkaline earth metals( Mg2+ and Ca2+ ) using cerium(IV) arsenomolybdate. Distribution studies showed that the selectivity of the exchanger towards various metal ions was in the order Pb2+ > Co2+> Cu2+> Mn2+> Bi3+> Cd2+> Mg2+> Zn2+> Ni2+> Ca2+> Hg2+. The analytical importance of the material has been established by studying degradation of various dyes (methylene blue, methyl orange, congo red and crystal violet) in water using UV-Visible diffuse reflectance spectrophotometer. The remarkable change in intensity of absorption of aqueous solution of these dyes, before and after the treatment with the exchanger showed clearly that these dyes are significantly degradable by cerium(IV) arsenomolybdate. The efficiency of the exchanger towards the removal of methylene blue, methyl orange, congo red and crystal violet from aqueous solution indicates its promising use in waste water treatment for the removal of these dyes.