Preparation and performance study of N-LAC/MoS2/PVDF ion exchange membrane in microbial desalination cells

Abstract

Ion exchange membranes play a crucial role in the study of microbial desalination cells (MDC). This study introduces a novel N-LAC/MoS₂/PVDF ion exchange membrane prepared via chemical grafting, emphasizing its role in enhancing MDC efficiency. The research thoroughly assesses the membrane's microstructure, infrared spectroscopy, and water flux, revealing how the composite additives enhance hydrophilicity, alter contact angles, and improve pore structure. The incorporation of hydrophilic groups like hydroxyl, carboxyl, and carbonyl groups into the membrane significantly improves its hydrophilicity. The optimal performance is achieved with 1 wt% N-LAC/MoS₂, increasing porosity to 86.94 % (a 25.5 % increase from pure PVDF) and reducing the contact angle to 71.59° (a 14.12 % decrease from pure PVDF). It also achieves an 84.1 % desalination efficiency under set conditions. The membrane shows high removal efficiency for methylene blue (MB) and Pb²⁺, reaching up to 93–96 % for MB and 91–94 % for Pb²⁺ under different pH, concentration, temperature, and salinity conditions. Its reusability is also notably enhanced. This work presents a tailored composite material for MDCs, offering insights into its interaction mechanisms and performance contributions to the MDC system, marking a significant advancement in membrane-based desalination technology.