Simultaneous monitoring of the adsorption process of two organophosphorus pesticides by employing GO/ZIF-8 composite as an adsorbent

Abstract

Today, a variety of pesticides are used to combat plant pests worldwide. The entry of these resistant pollutants into water resources can have devastating effects on human health and the environment; hence their removal from the environment is a vital task. In this research, the GO/ZIF-8 composite was synthesized by the solvothermal method and used for the removal of diazinon (DIZ) and chlorpyrifos (CLP) pesticides from the aqueous solution. To determine the simultaneous concentration of DIZ and CLP in aqueous solutions after the removal with GO/ZIF-8 nanoparticles, the partial least squares method (PLS) was used. The values of the evaluation parameters such as R 2 (0.995, 0.998,), Recovery percentage (101.42, 99.90 %), and Root Mean Square Error of Prediction (0.204, 0.201) for both CLP and DIZ obtained by the PLS method were satisfying. Also, to optimize the factors affecting the adsorption process such as pH, adsorbent dose (mg), and contact time (min), the response surface methodology (RSM) was used. The optimal conditions for each variable were achieved by the desirability function approach (DFA). The results showed that the highest removal efficiencies (%) under the conditions; pH=7, adsorbent dosage 24 mg, and contact time 24 min for chlorpyrifos and diazinon were obtained 83% and 73%, respectively. • The GO/ZIF-8 composite was synthesized and used for simultaneous adsorption of chlrorpyrifos (CLP) and diazinon (DIZ) pesticides. • The partial least square (PLS) was assisted to the simultaneous determination of pesticides. • The individual effects and possible interactions between the various parameters were investigated by RSM. • The data were well fitted by freundlich model and the adsorption process follows via multilayer adsorption.