Adsorption of Cr(VI) From Aqueous Solution onto Sugar Beet Pulp and Hydrochloric Acid Modified Pulp

Abstract

In this study sugar factory by product sugar beet pulp was used as adsorbent for Cr(VI) removal. Sugar beet pulp was supplied from Eskişehir Sugar Factory. Removal efficiency of Cr(VI) ions from aqueous solutions  by adsorption onto sugar beet pulp investigated by classical batch adsorption experiments. Cr(VI) was determined by UV spectrophotometer. The effect of parameters such as time, temperature, adsorbent dosage, initial concentration on Cr(VI) removal were observed. Pseudo first order and pseudo second order kinetic models were applied to fit kinetic data. Adsorption followed pseudo second order rate kinetics. Thermodynamics parameters were also determined. The positive values of ΔH⁰ change indicate that adsorption is endothermic. The positive ΔG⁰ values indicated that adsorption was nonspontaneous thermodynamically. The positive ΔS⁰ values indicated that the randomness increase. Then sugar beat pulp was modified with hydrochloric acid (AMP) and the effects of modification on Cr(VI) adsorption has been investigated. Then adsorption isotherm studies were made for AMP. Adsorption capacities of pulp and AMP were determined as 0.837 and 3.01 mg/g respectively.