Removal of Dye (Methylene Blue) from Wastewater Using Bio-Char Derived from Agricultural Residues in Palestine: Performance and Isotherm Analysis

The main aim of this study was to perform a parametric study for treating a model dye containing wastewater (i.e., methylene blue, MB) using locally available biomass wastes in Palestine as the adsorbent. Eight different types of biomasses were investigated in batch adsorption tests, including coffee grains, almond shells, pistachio shells, date pits, jute sticks, sunflower shells, peanut shells, and grapevine sticks. The experiments were conducted on three different phases of processing for these materials: as natural adsorbents, biochar, and activated carbon. The biochar was prepared by pyrolysis, while ZnCl2 was used to chemically activate the materials for obtaining activated carbon. The influences of pH, initial MB concentration, and adsorbent dosage on the adsorption capacity and kinetics were investigated for activated carbon obtained from sunflower shells. The results indicate that the adsorption efficiency of natural adsorbents and biochar is highly dependent on the biomass type. As a natural adsorbent, peanut hulls demonstrated the maximum efficiency (>95%) for removing MB, whereas date pits showed the lowest efficiency (20%). In terms of biochar, jute sticks provide the highest removal efficiency. After activation with ZnCl2, a considerable increase in their adsorption efficiency (>95%) was obtained for most of the adsorbents, with sunflower shells being the most efficient adsorbent. The results confirm the technical feasibility of the adsorption technology to treat dye containing wastewater using locally available biomass wastes.

Automated summary

The main aim of this study was to investigate the use of locally available biomass wastes in Palestine as adsorbents for treating wastewater containing methylene blue (MB). Eight different biomasses were tested, and the effects of pH, initial MB concentration, and adsorbent dosage on the adsorption capacity and kinetics were studied. The results showed that the efficiency of natural adsorbents and biochar varied depending on the biomass type, with peanut hulls and jute sticks demonstrating the highest removal efficiency. After chemical activation, a significant increase in adsorption efficiency was observed for most adsorbents, with sunflower shells being the most efficient. The study confirms the technical feasibility of using adsorption technology with local biomass wastes to treat dye-containing wastewater.