Adsorption of chromium (VI) by a low-cost adsorbent: Biogas residual slurry

Ability of waste biogas residual slurry (BRS) to remove Cr (VI) from aqueous solutions was investigated. The influence of various parameters such as metal ion concentration, contact time, adsorbent dosage, adsorbent particle size, temperature and pH on the removal of Cr (VI) has been studied. The adsorption followed first order rate expression. The equilibrium data fit well into Langmuir and Freundlich isotherms. Adsorption was maximum at an initial pH of 1.51. Temperature studies showed that the adsorption process was endothermic in nature.