Today, high consumption and increasing use of pesticides and chemical fertilizers to control pests of agricultural products, and the entry of these pollutants into the environment, is one of the most important environmental and health problems. Their non-biodegradability, as well as their toxicity and carcinogenicity, have generally made these compounds one of the most dangerous pollutants that cause inevitable pollution of the environmental. Among the various methods used to remove agricultural pesticide residues from the water sources, the adsorption method has received more attention due to its simplicity, cost and higher efficiency. In this research, nanocomposite of Co/Ni/Al-LTH@ZIF-8 was synthesized by in-situ growth of ZIF-8 on the Co/Ni/Al-LTH and used for the removal of diazinon (DIZ) pesticide from aqueous solution. Characterizations of the nanocomposite were performed by various techniques, including Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX) and thermal analysis. Statistical evaluation was studied by BOX-Behnken design. In addition, the response surface methodology was used to optimize the factors affecting on the adsorption process. Parameters such as adsorbent dose (mg), pH, and contact time (min) were considered in this experiment. The results showed that the removal efficiency of diazinon is improved significantly (from 64 to 84%) by loading ZIF-8 on Co/Ni/Al-LTH. Statistical studies showed the optimum conditions achieved under pH = 6.9, adsorbent dosage 25 mg, and contact time 12 min.
