In-Situ Polymerization of Polyaniline on Natural Fibers for Effective Lead Ion Removal from Aqueous Solutions.

Abstract

The contamination of water with heavy metals, particularly lead (Pb²⁺), has become a critical environmental and public health issue due to increasing industrialization and urbanization. Lead pollution has contributed to severe health problems, impacting over 10,000 people in recent years. In response to this growing concern, we developed a composite material, PANI@NF, by integrating polyaniline (PANI) with agro-waste fibers from date palm leaves, palm leaves, and korai grass. Among the tested composites, PANI@P20% demonstrated outstanding performance, achieving 96.2% lead removal and a sorption capacity of 24.1 mg/g under optimal conditions (pH 6.0, 0.01 g adsorbent, 50 ppm Pb²⁺, 298 K). The adsorption process for PANI@P20% followed a pseudo-second-order kinetic model and conformed well to the Freundlich isotherm, indicating multilayer adsorption on heterogeneous surfaces. Zeta potential analysis further confirmed favourable surface charge interactions at pH 6.0. Additionally, this composite exhibited excellent reusability, maintaining high efficiency over eight adsorption-desorption cycles. This work underscores the potential of using low-cost, biodegradable natural fibers as sustainable adsorbents for effective lead removal, offering a promising solution for water treatment and environmental preservation.