potential of rice husk in methyl parathion removal: preliminary study

The concern for the removal of pesticides in water resources is grown in recent years, which justifies the search for alternative technologies to those applied in conventional water treatment processes. the use of agricultural wastes directly for the preparation of the adsorbents, is a viable method, combining removal efficiency, low cost, and biodegradability of the material applied. the present work was carried out to evaluate the employability of rice husk (rh), a waste from rice agriculture, in methyl parathion (mp) removal from aqueous solutions. to find the optimum removal yield of (mp) onto (rh), the effects of various experimental factors: adsorbent dosage, ph, and the effect of contact time were studied by using the batch experiments mode. the adsorption kinetic data were analyzed using the pseudo first order (pfo), pseudo second order (pso), and elovich models. for the kinetic study, the adsorption process fitted the pso model. three adsorption isotherms namely the langmuir, freundlich, and sips isotherms were applied to the adsorption equilibrium data. the results indicated that the parameters isotherm models are found to be suitable for fitting the present adsorption isotherms data in the following subsequent order: sips > langmuir> freundlich.  the sips isotherm exponent n is near the unity indicating that the adsorption data were more of langmuir form suggesting that the surface of rh is homogeneous for mp adsorption. the monolayer adsorption capacity, qm, was found to be 4.38 mg/g. the present study showed that rh is a promising adsorbent for the removal of mp from an aqueous solution.