Synthesis of Biodegradable Polymers from Agricultural Residues for Water Treatment

Abstract

This paper investigates the synthesis of biodegradable polymers derived from agricultural residues as eco-friendly adsorbents for water purification. Agricultural wastes such as rice husk and sugarcane bagasse were processed to extract cellulose and lignin, which were then chemically modified to form biodegradable polymeric adsorbents. The synthesized materials were characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and surface area analysis. Adsorption studies were performed for removal of heavy metals (Pb²⁺, Cr⁶⁺) and organic dyes (Methylene Blue) from aqueous solutions. Results indicate high affinity of the biodegradable polymers toward contaminants, with maximum removal efficiencies exceeding 85% under optimized conditions. The findings demonstrate that agro-residue-derived biopolymers can serve as cost-effective and sustainable alternatives to synthetic adsorbents for wastewater treatment.

This study focuses on the extraction of high-purity cellulose from agro-residue-based waste paper and its conversion into biodegradable polymeric adsorbents for water purification. Waste paper fibers were pretreated using alkaline swelling followed by a bleaching/delignification step to remove lignin, hemicelluloses, dyes, and fillers. FTIR analysis confirmed the presence of characteristic cellulose functional groups, including O–H stretching (3330–3400 cm⁻¹), C–H stretching (2890–2925 cm⁻¹), and β-glycosidic linkage bands at 895 cm⁻¹. SEM micrographs revealed a morphological transformation from compact raw fibers to smooth, fibrillated, and porous micro fibrils after purification. The extracted cellulose was further utilized to synthesize biodegradable polymer adsorbents, which showed high removal efficiency for Pb²⁺, Cr⁶⁺, and methylene blue dyes. Adsorption behavior followed pseudo-second-order kinetics and exhibited increased performance at optimized pH and adsorbent dosage. The results demonstrate that agro-residue waste is a viable and eco-friendly raw material for value-added polymer production, offering a sustainable solution for water treatment applications