Adsorptive removal of organochloride pesticide in water using surfactant modified aluminum hydroxide nanoparticles

In the present study, an anionic surfactant, sodium dodecyl sulfate (SDS) was used to modify aluminum hydroxide nanoparticles to form a novel adsorbent (SMAH) for removal of an organochloride pesticide, Dichlorodiphenyltrichloroethane (DDT) in water environment. The DDT removal using α-Al(OH)3 and SMAH nanoparticles were 35.5, and 96.1 %, respectively indicated the high removal efficiency of SMAH compared with α-Al(OH)3. The effective conditions for adsorptive removal of DDT using SMAH were optimized and found as pH 8, contact time 30 min and SMAH dosage 25 mg/mL. The maximum adsorption capacity of DDT on SMAH calculated by a two-step model was found to be 2500 µg/g. After five regenerations, the DDT removal was still higher than 80 %. Adsorption isotherms of DDT on SMAH and the surface charge change of SMAH after adsorption demonstrate that hydrophobic interactions in the presence of SDS bilayer of admicelle is the main driving force to control DDT adsorption on SMAH.