Synthesize of polypyrrole nanocomposite and its application for nitrate removal from aqueous solution

The aim of this research work is to investigate sorption characteristic of polypyrrole coated on the sawdust (PPy/SD) for the removal of NO3− from aqueous solutions and wastewater. The sorption of NO3− is carried out by batch method. The optimum conditions of sorption were found to be: a sorbent dose of 0.6 g in 100 ml of NO3− solution, contact time of 20 min and pH = 5. In optimum condition, removal efficiency was 84.2% for the NO3−. Three equations, i.e. Morris–Weber, Lagergren and pseudo second order have been tested to track the kinetics of removal process. The Langmuir, Freundlich and D–R are subjected to sorption data to estimate sorption capacity. It can be concluded that PPy/SD has potential to remove NO3− ions from aqueous solutions at different concentrations. Also the effect of temperature on the process was investigated. It was found that the temperature has positive effect on the process and the negative ΔG values indicated thermodynamically feasible and spontaneous nature of the sorption. The positive value of ΔS reveals the increased randomness at the solid–solution interface during the fixation of the ion on the surface of the sorbent.