FACTORS AFFECTING THE REMOVAL OF A BASIC AND AN AZO DYE FROM ARTIFICIAL SOLUTIONS BY ADSORPTION USING ACTIVATED CARBON

Abstract

Decolourisation of wastewater, particularly from texti le industries, is one of the major environmental concerns these days. Current methods for removing dyes from wastewater are costly and cannot effectively be used to treat wide range of such wastewater. This work describes the use of commercial ly avai lable granular activated carbon (GAC) as an efficient adsorbent material for dyes' removal. Aqueous solutions of various concentrations of the basic dye Methylene Blue (MB) and the azo-dye Tartrazine at 5-20 mg.L1 and 10-100 mg.L1 , respectively, were shaken with certain amount of GAC to determine the adsorption capacity and removal efficiencies. The effects of adsorbent dose, initial pH, initial dye concentration, agitation speed, and contact time on dyes' removal efficiencies have been studied. Maximum dye concentration was removed from the solution within 60-90 min. after the beginning of every experiment. Adsorption parameters were found to fit wel l into Langmuir and Freundl ich adsorption isotherm models with correlation coefficient (R 2 > 0.99) in the concentration range of MB and TZ studied.