Removal of Methylene Blue by Adsorption Process - A Comparative Study

Abstract

Methylene blue is a heterocyclic aromatic chemical compound with the molecular formula C16H18N3SCl. It has used in the biology and chemistry field. At room temperature, it appears as a solid, odourless dark green powder that yields blue solution when dissolved in water. As a part of removal of methylene blue dye from textile and leather industrial wastes, using activated carbon as adsorbents namely, commercial activated carbon (CAC), rose apple carbon (RAC), coconut shell carbon (CSC) and saw dust carbon (SDC). The percentage of Methylene blue adsorbed increases with decrease in initial concentration and particle size of adsorbent and increased with increase in contact time, temperature and dose of adsorbents. The pH is highly sensitive for dye adsorption process. The adsorption process followed first order kinetics and the adsorption data the modeled with Freundlich and Langmuir isotherms. The first kinetic equations like Natarajan Khalaf, Lagergren, Bhattacharya and Venkobhachar and intra particle diffusion were found to be applicable. A comparative account of the adsorption capacity of various carbons has been made. These activated carbons are alternative to commercial AC for the removal dyes in General and MB is particular. These results are reported highly efficient and effective and low cost adsorbent for the MB. The thermodynamics parameters are also studied and it obeys spontaneous process. The results are confirmed by before and after adsorption process with the help of the following instrumental techniques viz., FT-IR, UV-Visible Spectrophotometer and SEM photos.