Background & Objective: Nitrate is one of the hazardous contaminants in the aquatic environment that causes health problems. The nitrate concentrations higher than permitted potable water limit(10 mg/l) cause Methemoglobinema disease, Nitrosamine production, intestinal cancer, and etc. In the present study, removal of nitrate from aquatic solution using the nano-magnet chitosan was investigated.

Materials and methods: Magnetic chitosan was prepared by co-precipitation method.  Effects of parameters such as pH(4-8), initial concentrations of nitrate and contact time(0,5,10,15,10,30,45,60,90,120,min) on nitrate removal from aqueous solution was studied. For nitrate removal mechanism study, Langmuir and freundlich isotherms and first order and second order kinetics were used.

Results: The structure of the synthesis materials was characterized by SEM,XRD  and FTIR. According to the SEM method, the nano-magnet chitosan was about 50-100nm. The FTIR analysis show that nano-magnet chitosan is able to absorb nitrate and according to the XRD, there is iron at absorbent compound. The optimum nitrate adsorption occurred at pH 7, 6 g/l of adsorbent and 100 mg/l of initial nitrate concentration that higher of adsorption capacity was also attained at contact time 60 min, it was found high adsorption capacity (141/92 mg/g) and removal percentage (85/16%) for removal of nitrate anion.

Conclusion: The results of the present study showed that nano-magnet chitosan adsorbent can be used as an suitable adsorbent for removing nitrate anions from aquatic environments.