Diazinon removal from aqueous solutions using rice husk-carbonized macromolecule

Insecticides have been recognized as the most important water pollutants. Nowadays, diazinon (DIZ) is an organophosphate pesticide that is widely used in agriculture as a pesticide. However, DIZ residues have been found in the aquatic ecosystems of Iran. In this study, the removal efficiency of the prepared adsorbents (from rice husk) was investigated upon the DIZ residues from water. To achieve the carbonized product, rice husk was mixed with polytetrafluoroethylene (PTFE) at a 1:2 weight ratio; then, it was then placed in a furnace based on the temperature-time schedule. The influence of the following parameters was investigated on the performance of carbonized rice husk: pH, contact time, adsorbent amount, and pesticide concentration. The measured DIZ concentrations were detected by high-performance liquid chromatography (HPLC). The results of this study showed that the optimum conditions for DIZ removal were achieved at pH = 9, the contact time of 40 min, and the adsorbent dosage of 0.1 gL(-1). Therefore, the maximum removal percentage of the insecticide and the adsorption process at 10 ppm were more consistent with the Langmuir isotherm (R-2 > 0.99). This study has resulted that the prepared adsorbent from rice husk can be used as an efficient adsorbent to remove DIZ from aqueous media.