Surfactant modified kaolinite (MK-BZK) as an adsorbent for the removal of diazinon from aqueous solutions

This paper presents the adsorption potential of natural kaolinite (NK) and kaolinite modified with benzalkonium chloride (MK-BZK) for the removal of the diazinon pesticide from contaminated water. Batch experiments were carried out with various experimental conditions such as pH (3, 7, and 11), adsorbent dosage (1, 5, and 10 g/L), initial diazinon concentration (5-100 g/L) and contact time (0-40 min). Based on the experimental data, the removal efficiency of MK-BZK was slightly higher (97%) than that of NK (93%) operating at pH 3 and optimum contact times of 10 and 15 min, respectively. The adsorption rate followed a pseudo-second-order kinetics model and the equilibrium adsorption fitted well the Freundlich adsorption isotherm model. The maximum adsorption capacity of diazinon on NK and MK-BZK was 0.86 and 2.25 mg/g, respectively. Overall, MK-BZK has potential as a local and cost-effective adsorbent to remove diazinon from aqueous solutions.