Performance Evaluation of Modified Clay with Cationic Surfactant in Removal of Nitrate from Aqueous Solutions

Today, increasing nitrate concentrations in surface water and particularly in groundwater, due to the increase of waste production and development of agricultural activities, is one of the environmental problems in many parts of the world including Iran. Consumption of water containing high concentrations of nitrate creates some problems in the field of the environment and public health. The aim of this study was to evaluate the performance of modified montmorillonite with cationic surfactant of hexadecyltrimethylammonium bromide in nitrate removal from aqueous solutions.
This experimental-laboratory research was performed in order to remove nitrate from aqueous solutions through modified clay with cationic surfactant in a closed system (batch). The effect of various parameters including initial nitrate concentration, adsorbent dosage, pH, and contact time on removal efficiency of nitrate was investigated using Design of Experiments software (DOE 6).
Findings: Initial nitrate concentration of 200 mg/l in terms of nitrate, adsorbent dose of 7.5g/l, pH of 7, and contact time of 40 minutes were determined as optimum conditions of nitrate removal. In these conditions, nitrate removal efficiency of 71.27% and nitrate adsorption capacity of 19.06% mg/g were obtained.
Modified clay with cationic surfactant can be employed as an effective adsorbed to remove nitrate from water solution.