Synthesis and Modification of Agriculture Residue-Based Sorbents for Toxic Dyes Removal from Water Synthesis and Modification of Agriculture Residue-Based Sorbents

Abstract

Elimination of dyes and pollutants from aquatic systems is crucial due to their poisonous and detrimental characteristics. The objective of the current work was to create agricultural-based adsorbents with improved adsorption characteristics derived from agricultural residues, specifically banana Peel (BP) and wheat Straw (WS). The impact of adsorbent dosage and pH on the adsorption of Orange G (OG) dye from water was assessed. The BP and SW were acquired from the Shaheed Benazirabad district in Sindh, Pakistan. Agri-waste underwent thermal transformation in an anoxic atmosphere at 400°C to provide Banana Peel Char (BPC) and Wheat Straw Char (WSC). Furthermore, the mixture of both components, char and potassium hydroxide (KOH), is referred to as Modified Banana Peel Char (KMBPC), and Modified Wheat Straw Char (KMWSC) correspondingly. The kinetic analysis demonstrated that the experimental data for the sorption process is most consistent with the kinetic models. The equilibrium data was optimally fitted to Langmuir isotherm model (R²>0.98), signifying a chemisorption process. The findings revealed that the maximum sorption capacities of OG on BPC and KMBPC were (27.89 and 37.33 mgg^-1), correspondingly, at pH 4.5, at dye conc: of 80 mgL^-1, an adsorbent dose of 2 gL^-1. Similarly, for WSC and KMWSC, the capacities were 31.81 mgg^-1and 41.4 mgg^-1, correspondingly. Sorption percentages of dye on BPC, WSC, KMBPC, and KMWSC were determined to be 66.01, 75.67, 96.10, and 98.01%, respectively. The alteration process for WSC, BPC, and KOH-modified materials was examined utilizing Uv-Vis spectra and FTIR methods. The findings demonstrated the presence of highly porous crystalline structures inside the amorphous matrix, hence enhancing the adsorbent's surface area for the removal of toxic OG dye. This findings suggest that our innovative material may provide a more effective alternative for the removal of harmful dyes from wastewater. Moreover, this will also promote further research on pollution remediation via the utilization of modified agricultural waste products.