Removal of Diazinon Insecticide from Aqueous Solutions by Polypyrrole onto Polyvinyl Alcohol Composite

Organophosphorus compounds are extensively used worldwide as pesticides which cause great hazards to human health and the environment. The aim of this study was to investigate the removal of diazinon insecticide from aqueous solution by using polypyrrole (PPy) onto polyvinyl alcohol (PVA) adsorbent in a batch system. Investigation of the adsorbent structure was performed by SEM and FTIR analyses. The effect of experimental parameters on adsorption such as pH, contact time, initial diazinon concentration, and initial adsorbent mass was studied. According to the experiments, the optimal pH of diazinon adsorption by PPy/PVA adsorbent at 20 °C was 6. As the contact time increased, the adsorption efficiency increased and reached equilibrium (98%) after 10 min. The adsorption capacity of diazinon increased with increasing adsorbent mass and reached its highest value in the adsorbent mass of 0.025 g in 10 ml of aqueous diazinon solution. The kinetics study showed that the data followed by Morris–Weber and pseudo-second-order equations. The equilibrium data also show good agreement with the Freundlich isotherm. Based on the results of the present study, PPy/PVA adsorbent has a high potential for diazinon pesticide removal and it can be suggested as a cheap, efficient and available adsorbent for diazinon pesticide removal from aqueous solutions. The maximum adsorption capacity of mercury by polymer composite was 23.37 mg/g.