Chitosan membranes using different crosslinking agents for the removal and recovery of potentially toxic metal ions from contaminated water.

• Grant number: 24/21298-2
• Support Opportunities: Scholarships in Brazil - Master
• Start date: June 01, 2025
• End date: August 31, 2026
• Field of knowledge: Engineering - Materials and Metallurgical Engineering
• Principal Investigator: Derval dos Santos Rosa
• Grantee: Lucas Rossin Gonçalves
• Host Institution: Centro de Engenharia, Modelagem e Ciências Sociais Aplicadas (CECS). Universidade Federal do ABC (UFABC). Santo André , SP, Brazil
• Associated research grant: 20/13703-3 - Environmentally friendly porous materials for the recovery and revaluation of metals reclaimed from contaminated water, AP.TEM

Abstract

This project aims to develop chitosan-based hydrogel membranes for the removal and recovery of metal ions from contaminated water, addressing one of the growing environmental concerns: water contamination by potentially toxic metals. These elements exhibit high toxicity, resistance to degradation, bioaccumulation tendencies in living organisms, and are difficult to remove using conventional water treatment methods when present at low concentrations. Adsorption and membrane filtration techniques thus emerge as promising alternatives, offering higher efficiency and lower secondary waste generation, particularly when the membranes are biodegradable. The combination of these techniques enables contaminant retention through size exclusion, a characteristic of membranes, and metal ion adsorption, facilitated by the functional groups present in their structures. Chitosan, an abundant and biodegradable biopolymer derived from the exoskeletons of crustaceans and insects, contains amine (-NH¿) and hydroxyl (-OH) functional groups, which can act as crosslinking sites for the formation of membranes with different pore sizes and metal ion adsorption sites in aqueous media.In this context, the project explores the preparation of chitosan hydrogel membranes crosslinked with three specific agents (glutaraldehyde, epichlorohydrin, and EDTA) to evaluate their efficiency in metal ion removal and the possibility of recovering these elements. The membranes will be produced using the solution casting method, varying the concentrations of the crosslinking agents to analyze their influence on the specific properties of innovative membranes, referred to here as adsorptive-filtrating systems (i.e., hydrogel membranes that simultaneously filter physically and adsorb metal ions). These properties include mechanical properties [mechanical strength and elastic modulus (E)], selectivity for the studied metal ions, static and flow sorption capacity, water permeability, swelling degree, and porosity. The membranes will be characterized in terms of their chemical structure, morphology, thermal properties, porosity, crystallinity, mechanical properties, flow and transport properties, water absorption, and sorption/desorption capacities. Additionally, a life cycle assessment (LCA) of the prepared membranes will be conducted to compare the potential environmental impacts associated with the use of each membrane. Ultimately, the project aims to develop environmentally friendly materials with excellent sorption and filtration capabilities that can be reused, with a view toward future applications in water treatment.