Nitrate Removal from agricultural wastes using modified zeolite

In recent decades, consumption of nitrogenous fertilizers has increased environmental pollution. Using low ab cost effective sorbents such as zeolite has been more considered in recent years. In this study, the performance of natural and modified Semnan zeolite, using HDTMA-Br, for nitrate removal was evaluated. The results showed that the modified zeolite had a good performance in nitrate adsorption from laboratory solution and from an agricultural wastewater. By increasing the concentration of solution from 10 to 200 mg/lit, the amount of adsorption increases from 0.2 to 1.4(mg/g)as well. Initial kinetic experiments showed that 150 minutes is needed for reaching equilibrium condition. Furthermore, the amount of adsorption in shaking mode is more than stationary mode and with increasing nitrate concentration from 10 to 200 mg/lit, the difference between their adsorption will increase from 0.05 to 0.37 mg/g.the investigating governing isotherm in shaking and stationary mode showed that Langmuir isotherm has a good agreement for describing nitrate adsorption by zeolite. Modified zeolite by removing 56 percent of nitrate from agricultural waste water showed a good performance in nitrate removal.