Evaluation of coconut husk carbon for the removal of arsenic from water

The adsorption isotherm of As(III) on copper impregnated activated carbon was obtained in a batch reactor. Various parameters such as reaction time, adsorbent dose, initial concentration of adsorbate, pH, and temperature were studied to establish optimum conditions. Maximum adsorption capacity was observed at pH 12.0. The adsorption isotherm was also affected by temperature since the adsorption capacity was increased by raising the temperature from 30 to 60°C. The experimental adsorption data fitted reasonably well to the Langmuir isotherm. The mass transfer coefficients as a function of initial sorbate concentration have been determined. Arsenic(III) can be successfully removed from synthetic and industrial wastewaters. Desorption studies revealed that spent adsorbent can be regenerated and reused by 30% H2O2 in 0.5 M HNO3.