Pesticide removal from drinking water by adsorption

The aim of this study is to remove pesticides such as endrin from organochlorine pesticides and atrazine, a herbicide from triazine class, which are toxic and persistent micropollutants that may adversely affect the environment and human health, from water resources by adsorption method. The removal of endrin and atrazine from drinking water by adsorption method was investigated by batch adsorption experiments using modified with iron (FeZ) adsorbent material. Clinoptilolite, which is used as an adsorbent material, has been modified by using iron in order to increase its adsorptive capacity and to enable it to have different surface properties. The endrin and atrazine adsorption capacity of the FeZ material increased with the increase of contact time, and the required equilibrium time for endrin and atrazine was 5 hours and 10 hours, respectively. The adsorption capacity of the FeZ material at the equilibrium times was calculated as 57.89 μg/g for endrin and 55.80 μg/g fot atrazine. According to the response surface functions obtained as a result of the experiments carried out using the Box-Behnken statistical experiment design method, the optimum pH value was found as 6 for endrin adsorption on FeZ, and the optimum pH value was found as 4 for atrazine adsorption on FeZ. At the determined pH value, the optimum amount of adsorbent was found to be 0.08 g for endrin and 0.09 g for atrazine. The maximum adsorption efficiency obtained at the optimum operating conditions and initial endrin and atrazine concentrations of 500 ppb were found as 95.96% and 96.12%, respectively. It was determined that the adsorption of endrin and atrazine on FeZ material conformed to the Freundlich isotherm. In addition, it was observed that the pseudo-second-order kinetic model provided a very good correlation in the adsorption of endrin and atrazine on FeZ.