ADSORPTION OF POLLUTANTS FROM AQUEOUS ENVIRONMENT BY ACID CITRIC MODIFIED RICE HUSK ASH

Abstract

  Rice husk ash residue with high surface area has been modified by citric acid with anappropriate concentration. The resulted materials have large absorption capacity ofCu(II) ion and other pollutants in aqueous environment. Investigation on theadsorption of Cu (II) ion with concentration from 30 ppm to 100 ppm showed that theadsorption followed the second-order kinetics with an average rate constant of2,36.10-1 (g.mg-1.min-1) and the isotherm fitted the Freundlich equation. Theadsorption capacity at equilibrium qe was found to be 72.74 mg/g at the concentrationof 100 ppm. The efficiency of the absorption Cu (II) ion at concentrations of 30, 50, 70and 100 ppm was 83.20%, 78.66%, 74.37% and 72.74%, respectively. In addition, thematerial could be used for surface water treatment with DO, COD, BOD5, totalnitrogen, and total phosphorus standards. The average efficiency of water treatmentwas over 70%. The water after treatment met the standard to use for domestic watersupply and for conservation of aquatic flora and fauna.

Keyword: rice husk ash, adsorption, acid citric modified