טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentPeleg Anna
SubjectPesticides Removal by Activated Carbon Fibers
DepartmentDepartment of Chemical Engineering
Supervisor Professor Emeritus Raphael Semiat
Full Thesis textFull thesis text - English Version


Abstract

The main objective of the research was to study the removal of cholinesterase inhibiting pesticides from aqueous solution using KYNOLTM Activated Carbon Fibers (ACF) with high specific area (2000 m2/g). The pesticides concentration was monitored using HPLC coupled with using Ascentis C18 column 25 cm x 4.6 mm column. Adsorption isotherm and kinetics of Methamidophos, Methomyl, Propoxur, Oxamyl, Monocrotophos and Parathion were studied. Equilibrium data were fitted to the Langmuir and Freundlich isotherm models and the data best represented by Freundlich model. The adsorption processes were found to follow the pseudo-first order or the pseudo-second order kinetics models over a period of ~60 min with no clear preference to either model. The effects of physiochemical properties of the adsorbate, solution pH and temperature on pesticides adsorption were investigated. The adsorption enthalpy (ΔHads) and entropy of adsorption, (ΔSads) for Methomyl and Methamidophos were calculated. Fixed bed experiment was conducted, and a breakthrough curves obtained. The total adsorbed contaminant for both pesticides were calculated and compared with the adsorption per unit weight for complete monolayer obtained from Langmuir isotherm. The competitive adsorption onto ACF was investigated. Experimental data were modeled by extended Langmuir-based equations and Freundlich Type multicomponent adsorption isotherm for both systems.