Biochar Appended Semi Natural Polymer Composites A Sustainable Root for the Effective Decontamination of Wastewater

Abstract

The disposal of multipollutant wastewater continues to threaten life on Earth. According to WHO (2022), 2.2 billion people lack access to safely managed drinking water, while 17 20% of water contamination arises from textile dyeing industries. Antibiotics further intensify global pollution across terrestrial and aquatic systems due to frequent consumption; India ranks among the largest consumers, driven by poorly regulated non-prescription sales. newlineThis thesis reports the development of bioinspired adsorbents derived from natural and semi-natural sources. Biochar was synthesized from Kigelia Africana fruit fibers, palmyra palm hydrogel, and 1D bacterial cellulose microfilaments via a low-cost, eco-friendly process. Surface modification was achieved by acid oxidation and functionalization using curcumin, melamine, and layered double hydroxide (LDH). newlineTwo fabrication routes were adopted: (1) embedding curcumin- and amino-functionalized biochar into a polyacrylic acid hydrogel via in situ polymerization, and (2) employing palmyra palm biochar, bacterial cellulose microfilament, hydrochar, and LDH-grafted versions as reinforcing and crosslinking agents in chitosan/polyethyleneimine/PVA semi-natural sorbent beads. Characterization (FTIR, TGA, SEM, EDX, BET, XPS, TEM, surface charge) confirmed high porosity and functionality. Owing to the abundance of functional groups, high porosity, and pH sensitivity, the synthesized adsorbents exhibited exceptional adsorption capacities: 3168 mg·gand#8315;¹ (CR), 1795 mg·gand#8315;¹ (LFX), 741 mg·gand#8315;¹ (Rho), 691 mg·gand#8315;¹ (MET), 960 mg·gand#8315;¹ (TET), 711 mg·gand#8315;¹ (SO), 1845 mg·gand#8315;¹ (AZM), and 2182 mg·gand#8315;¹ (VAN). newlineIsothermal and kinetic analyses revealed that chemisorption or physisorption depended on surface heterogeneity and adsorbate structure. The mechanism involved hydrogen bonding, electrostatic attraction, anion exchange, complexation, and and#960; and#960; stacking, demonstrating the potential of these bioinspired adsorbents as sustainable, high-performance materials for water purification. newline