Application of cane bagasse adsorption on nitrate removal from groundwater sources: adsorption isotherm and reaction kinetics

摘要

Removal or reduction of nitrogen compounds in natural waters resulted from discharge of industrial and agricultural activities, which has environmental and human health problems, is necessary. In this study, the effect of initial nitrate concentration (15.5, 50, 80, 120 and 200 mg/L), pH (1-7) and contact time (4.5-36 h) on the adsorption efficiency of cane bagasse modified by ZnCl2 was investigated to remove nitrate from groundwater sources in Izeh city, Khuzestan province of Iran. Adsorption performance was evaluated using Freundlich, Langmuir and Bet isotherms and the first-order and pseudo-second order feed removal models. Results showed that for modified bagasse, the system reached equilibrium after 32 h and the maximum adsorption occurred at pH = 4. Also, the removal efficiency increased by decreasing the concentration of nitrate. The adsorption process followed the Langmuir isotherm. The results of the study showed that the modified bagasse fiber absorbent has a great potential for nitrate removal. Because of the inexpensiveness of bagasse fiber and especially bagasse abundance in Khuzestan province, it is suggested to remove nitrate from groundwater of Izeh city via cane sugar (bagasse) modified by zinc chloride.