Removal of Cu (II) and Cr (III) From Drinking Water Samples by Adsorption Using Rice Husk Ash

Chirang District of Assam, India, has been populated mostly by tribal people. Due to lack of facilities and awareness these people have been drinking water from unscientific sources. A detail analysis of 13 sources of drinking water consisting of ring wells, tara pumps, tube wells and deep tube wells covering these areas have been analyzed by standard methods. Rice husk has been used as adsorbent for adsorption of Cu (II) and Cr (III) ions from solutions containing these two ions with concentrations ten times higher than that found in these drinking water samples. Rice husk has been washed, dried and calcined and then characterized by XRF, XRD, FTIR and N₂ adsorption before use as adsorbent. Rice husk has shown remarkable activity for removal of Cu⁺² and Cr⁺³ even from solutions of these two ions with concentrations ten times higher than that found in these drinking water samples. Finally, Langmuir’s and Freundlich’s adsorption isotherms are drawn on the basis of these results.