STUDYING THE POSSIBILITY OF REMOVING SOME CHEMICAL CONTAMINANTS FROM SOLUTIONS USING SELECTED AGRICULTURAL RESIDUES

Abstract

This paper explores the feasibility of using the seeds of the Leucaena leucocephala in the preparation of activated carbon in view of the advantages that the plant can provide in terms of abundance, low cost and product quality. Activated carbon was prepared using Leucaena seeds and activated by H3 PO4 chemical activation process using H3 PO4 : char ratios (w/w) of (1:1), (1:2) and (1:3) at (400°C). Surface properties were determined using FT-IR and FE-SEM techniques. Cadmium and PNP, PPD dyes were chosen as the prominent chemical pollutants to study the ability of the prepared carbon to adsorb them. The adsorption process was controlled and the factors affecting it were studied, which are: Mass of the adsorbent, Temperature, pH, Contact time, Initial concentration of the adsorbed material. It was found that the adsorption capacity increases with decreasing temperature for cadmium and dyes. The optimum PH value was between (pH=6, pH=5) for the mentioned adsorbents, Recorded (180 hours) as the best contact time. Positive value of ∆H (J\mole) indicate that the reaction is exothermic, negative value of ∆S (J\mole.K) indicate that the reaction is spontaneous and negative value of ∆G (J\mole) indicate that the reaction occurs spontaneously.