Removal of Nickel onto Alkali Treated Rice Bran

Different bases were used for the pretreatment of Rice bran biomass. Pretreatment with bases such as NaOH, Ca(OH)(2) and Al(OH)(3) were found to improve biosorption capacity. But in Rice bran, treatment with 0.5 M NaOH increased its nickel selective adsorption ability very much. The main binding site of nickel in NaOH treated cells is assumed to be carboxylic, hydroxyl, sulphate, phosphate and amino groups. The maximum biosorption capacity of Rice bran biomass subjected to 0.5 M NaOH was 198.92 mg g(-1). Kinetic and isotherm experiments were carried out at the optimal pH 6.0 for nickel. The Freundlich and Langmuir models were used to describe the uptake of nickel on NaOH pretreated Rice bran. To improve the biosorption capacity for metal ions by biomass, alkali pretreatment is an effective method.