Reuse of agro-wastes to treat wastewater containing dyestuff: sorption process with potato and pumpkin seed wastes

The extent of study is to evaluate the adsorption performance of potato (Solanum tuberosum L.) and pumpkin seed (Cucurbita pepo L.) shells as agro-industrial waste materials to remove methylene blue dye from aqueous solutions. The process mechanism was determined by kinetic models and adsorption isotherms. It was observed that the best conformity fitted to pseudo second order kinetic model (R-2 > 0.999) and Freundlich isotherm (R-2 > 0.982). The maximum adsorption capacities were determined as 161.4 mg/g and 277.8 mg/g for pumpkin seed shells and potato shells, respectively. The thermodynamic data express that the adsorption of methylene blue with potato peels was reversible, spontaneous, exothermic, controlled by chemical interactions while the feasibility, randomness, spontaneous, and endothermic nature on pumpkin seed shell. From results, it was determined that potato and pumpkin seed shells can be used effectively as a cheap and viable alternative adsorbent.