Natural and H2SO4 modified plane sawdust as a low-cost adsorbent: Removal of anionic and cationic dyes from aqueous solutions

Abstract

Natural and H2SO4-modified plane (Platanus orientalis L.) sawdust were used for the adsorptive removal of cationic methylene blue (MB) and anionic indigo carmine (IC) dyes from aqueous media to suggest a new and cost-effective method for wastewater treatment applications. The influences of initial pH values, concentrations of MB and IC, period of contact, dosages of the natural and modified plane sawdust, and the presence of foreign ions on the adsorption of dyes were investigated in the experimental studies to describe the best conditions of the most efficient adsorption processes. Initial pH values were optimized to be between 6.0–8.0 for MB and 2.0 for IC. Optimum contact time to reach the equilibrium were determined as 120 and 240 min for the adsorption of MB onto NPS and MPS, respectively while IC adsorption onto both adsorbents reached the equilibrium in 240 min. By using the Langmuir isotherm model maximum MB adsorption capacities of NPS and MPS were calculated as 55.56 and 38.46 mg/g, respectively and the maximum IC adsorption capacities were 58.82 and 55.55 mg/g for NPS and MPS, respectively. Results showed that the natural and H2SO4-modified plane sawdust serve as low-cost and efficient materials in the adsorptive removal of MB and IC dyes for industrial wastewater treatment applications.