THMs removal from aqueous solution using hydrochar enhanced by chitosan nanoparticles: preparation, characterization, kinetics, equilibrium studies

Abstract

In this study, novel green and economical techniques were established to synthesize modified banana peel hydrochar (HBP) through hydrothermal carbonization. Chitosan nanoparticles, a green adsorbent with multiple features, were prepared, characterized, and used to enhance the performance of the hydrochar in THMs removals. The optimal method for hydrothermal carbonization was determined based on previously cited methods. The dried banana peels and HBP were characterized using Fourier transform infrared spectrometer (FTIR), pH, zero point of charge, and bulk density. The prepared chitosan nanoparticles were characterized using scanning electron microscope (SEM), transmission electron microscope (TEM), and zeta potential techniques. The average size of chitosan nanoparticles was 12.1 nm, and a 1:1 mixture of HBP and chitosan nanoparticles was used for the removal of THMs from an aqueous solution. The concentrations of THMs were measured using gas chromatography, and the effect of THMs’ initial concentrations, adsorbent doses, temperature, and pH value on the adsorption capacity was studied. The results showed that the 1:1 mixture of HBP and chitosan nanoparticles was an efficient adsorbent for removing THMs from aqueous solutions. This adsorbent was found to be effective in removing THMs from the aqueous solution, even at low temperature and pH values, with an estimated maximum sorption capacity (qm) of 588.23 g g−1, exceeding numerous other adsorbents previously studied, and the regression coefficient (R2 = 0.9959) for data fitting with the Freundlich isotherm. This research has the potential to offer a great avenue for future development and implementation in water treatment. It could lead to improved methods of treating water, which would be beneficial for both environmental protection and economic growth. The developed adsorbent had high adsorption affinity toward the THMs compounds, making the adsorption method efficient and viable technique for treating water containing such contaminants.