Valorization of Raw Rice Husk for Total Dissolved Solids (TDS) Adsorption: Kinetic Study and the Effect of Compound Polarity

Abstract

Aims: The present study aims to investigate the retention of TDS by adsorption on rice husk, a very abundant adsorbent, available at all times and less expensive. Study Design: This study was conducted by using batch method in the treatment of wastewater and drinking water using adsorption chemistry. Place and Duration of Study: Chemistry laboratory of Yembila Abdoulaye TOGUYENI University, September 2024 to January 2025. Methodology: A synthetic aqueous solution is prepared from groundwater by varying the concentration from 30 to 130 mg/L. The study of the effect of contact time is carried out by varying from 10 to 120 min. The effects of adsorbent dose, initial concentration of TDS, particles size and polarity of compounds on TDS adsorption were investigated. Results: The results proved the smaller size (250-400 µm) showed better adsorption of TDS. The optimal dose of adsorbent is 2 g and the maximum saturating concentration is 130 mg/L, the equilibrium time is observed from 120 min. The effect of compound polarity showed that the glycerol did not affect the adsorption of total dissolved solids contrarily, the ionic compounds such as MB and KCl affected negatively. These compounds may compete for adsorption sites, which may increase the concentration of dissolved solids. The kinetic study also indicated that the pseudo-second-order fitted the TDS adsorption because the correlation coefficient (R²) should be close to 0.97. Conclusion: This study on the use of rice husks demonstrates that this agricultural residue can be used in the field of water decontamination and waste management conducive to an environmentally friendly system.