Removal of some wastes from wastewaters by natural adsorbents

Today, removal of heavy metals which has toxic effects on living organisms from waste waters and the environment is an important issue. Therefore, many methods are used such as extraction, coprecipitation, electrolytic deposition and ion exchange. This study is based on the adsorption of Cu(II), Fe(III), Cd(II) and Pb(II) ions on natural bentonite, sepiolite and dolomite, synthetic zeolite, modified dolomite and zeolite using batch-type and column methods. Effects of parameters such as amount of adsorbent, stirring time, initial concentration, pH, interfering ions on adsorption were investigated using batch-type method and parameters such as flow rate, eluent type, eluent volume, preconcentration factor, column capacity, column reuse were studied in column. The equilibrium experimental data were investigated by Freundlich and Langmuir isotherm models. Optimum conditions of the batch-type method in which natural and modified clays used as adsorban were found 0,2 g clay, 30 minutes stirring time, 10 mg/L initial concentration. However, optimum conditions of the column method in which modified dolomite and zeolit used as adsorban were found 1 mL/min. flow rate and 15 mL eluent volume. The results obteined showed that natural clays performed well for the removal of metal ions. And also compared to natural clays, modified clays showed a higher performance for removal and recovery of metal ions.