Background and purpose:Diazinon is an organophosphorus insecticide, which is classified as a relatively dangerous product by the World Health Organization. Entrance of this pollutant into water resources can have detrimental effects on human health and environment. The aim of the present study was to evaluate the performance of pulsed alternative current and the electrocoagulation-flotation (ECF) processes in removal of diazinon from aqueous solutions.

Materials and methods:An applied laboratory-scale experiment was designed. Diazinon removal was performed using ECF and pulsed alternative current in a 750 ml borosilicate glass intermittent flow reactor, equipped with a magnetic stirrer, an electrical source, a pulsar, and four aluminum electrodes. The optimized operating conditions were also assessed using 10-500 mg/L of diazinon.

Results:According to the results, the removal efficiency of diazinon was found to range between 5% to 85%. Investigation of ­the operational parameters demonstrated significance of the initial concentration of diazinon, current density, the number of pulses, and electrical conductivity in efficiency of ECF process. The maximum removal efficiency of diazinon was found to be 85% (213 mg of diazinon), which was achieved in an operating condition with pH=7, current density of 46.7 A/m², electrical conductivity of 600 μS/cm, and process time of 45 min.

Conclusion:According to this study, ECF method could be used along with pulsed alternative current for removal of high concentrations of diazinon from wastewater.Additional processes are needed to meet the standards of drinking water.