Treatment of Water Containg Chromium (VI) Using Rice Husk Carbon As a Newlow Cost Adsorbent

Abstract

Presence of heavy metals in the aquatic systems has become a serious problem. As a result, therehas been a great deal of attention given to new technologies for removal of heavy metal ions from contaminated waters. Adsorption is one of the effective methods for removal of toxic heavy metal such as chromium (VI). In the present study, adsorbent is prepared from rice husk, a low cost by product from a rice mill. The rice husk carbon is activated using H3PO4 (40%). The stock solution of Cr (VI) is prepared by dissolving 2.828 gm of potassium dichromate (Central Drug House (CDH), India) in 1 litre of demineralized water. Batch mode experiments are done. The effect of various parameters like adsorbent dose, pH and contact time are studied. The studies demonstrate that the Rice Husk Carbon (RHC) has a significant capacity for adsorption of Cr (VI) from aqueous solution. The RHC characteristics are reported as FTIR and other physical properties are tabulated average. The break through capacity for Cr (VI) (100 mg/l, pH 2) is on average 38.1 mg/g. The adsorption of chromium (VI) was found to be maximum(93-94%) at low values of pH (around 2) for the carbon dosage of 1000mg/L and nearly 100% for carbon dosage of 1200mg/L. RHC exhibits high degree of selectivity for Cr (VI) adsorption. The adsorbent prepared from rice husk carbon is efficient and it is proposed that it can be conveniently employed as a low cost alternative in the treatment of industrial waste water.