Work

Evaluation of separators for potential use in microbial electrolysis cells under anaerobic digester conditions

Year: 2025

Type: article

Abstract: This study presents the successful preparation of a novel chemically modified Cellophane separator with polydimethylsiloxane (PDMS) for potential use in microbial electrolysis cells (MECs) with real anaerobic digester effluent (ADE). The modified separator was assessed against commercial materials, including anion exchange membrane (AEM), cation exchange membrane (CEM), and unmodified Cellophane. They were evaluated in a conventional two-chamber electrolysis cell, serving as a surrogate for a MEC, and in a bioreactor to assess biofouling. The modified Cellophane demonstrated potential for reducing costs and enhancing separator performance. Cellophane, Cellophane + PDMS and AEM effectively prevented pH imbalances, maintaining stable anode pH levels above 7 without cathode alkalinization. However, the CEM was unsuitable due to excessive pH splitting (Δ6 pH) and elevated resistance. The study highlighted the pronounced impact of using real ADE on overpotentials and resistances of all separators. Organic acid crossover occurred across all materials, with Cellophane exhibiting higher rates (0.16–0.2 mg m −2 s −1 ) than CEM and AEM (0.04–0.1 mg m −2 s −1 ). An extensive investigation into biofouling and degradation under anaerobic digestion conditions revealed that unmodified Cellophane degraded completely within a month, whereas PDMS modification extended its durability to two months before complete disintegration occurred. • AEM and cellophane prevent pH imbalance, stable anode pH above 7. • CEM failure is caused by high pH splitting and increased resistance. • Organic acids crossover and biofouling affect all tested separators. • Cellophane-based materials degrade within 2 months in anaerobic digester conditions. • PDMS-modification doubles bare cellophane lifespan.

Source: Journal of Membrane Science

DOI: 10.1016/j.memsci.2025.123887

Authors: Simone Colantoni, Guillaume Pillot, Sofia Cvoro, Sven Kerzenmacher, Óscar Santiago

Institutions: University of Bremen, Leitat Technological Center

Language: English

Topic: Microbial Fuel Cells and Bioremediation

Subfield: Environmental Engineering

Field: Environmental Science

Domain: Physical Sciences

SDGs: Responsible consumption and production, Affordable and clean energy, Clean water and sanitation

Open Access status: hybrid

Estimated APC paid: $4,890