Methylene Blue Removal with Activated Ermenek (Karaman-Turkey) Region Lignite

Abstract

Wastewaters frequently contain significant levels of potentially hazardous pollutants. Dye-containing effluents occurs from a wide range of industries such as paper mills, chemical, leather, textile, cosmetics, pharmaceutical industries, refineries, plastic and food-processing plants. Some residual dyes may cause water pollution and a serious threat to the environment. Various processes are used to remove dyes from wastewaters such as coagulation-flocculation, adsorption, electrochemical treatment, chemical oxidation, membrane processes and aerobic and anaerobic microbial degradation. Adsorption process has become one of the most effective and comparable low-cost method for the removal different types of dyes from aqueous solutions.

In this work, the adsorption of methylene blue (MB) dye onto activated carbon derived from Ermenek (Karaman/Turkey) region lignite (EAC) has been studied at different conditions (pH, initial dye concentration, mass of adsorbent, shaking speed, contact time). Freundlich and Langmuir isotherms for the adsorption of MB dye on EAC were measured to establish the mechanism for dye adsorption. Freundlich isotherm constants, n (Freundlich exponent related to adsorption intensity) and (Freundlich constant related to adsorption capacity of adsorbent) were determined as 2.36 and 37.62 (mg/g)(L/mg)ⁿ, respectively. Langmuir isotherm constants, (maximum possible amount of component per unit weight of adsorbent to form a complete monolayer on the surface bound) and (constant related to the affinity of the binding sites) were determined as 78.74 mg/g and 1.16 L/mg, respectively. R² values of Freundlich and Langmuir isotherms were determined as 91% and 99%, respectively.