Salehmin, Mohd Nur Ikhmal and Me, Muhammad Farhan Hil and Daud, Wan Ramli Wan and Yasin, Nazlina Haiza Mohd and Abu Bakar, Mimi Hani and Sulong, Abu Bakar and Lim, Swee Su (2023) Construction of microbial electrodialysis cells equipped with internal proton migration pathways: Enhancement of wastewater treatment, desalination, and hydrogen production. Science of the Total Environment, 855. ISSN 0048-9697, DOI https://doi.org/10.1016/j.scitotenv.2022.158527.
Full text not available from this repository.Abstract
Microbial electrodialysis cells (MEDCs) offer simultaneous wastewater treatment, water desalination, and hydrogen production. In a conventional design of MEDCs, the overall performance is retarded by the accumulation of protons on the anode due to the integration of an anion exchange membrane (AEM). The accumulation of protons reduces the anolyte pH to become acidic, affecting the microbial viability and thus limiting the charge carrier needed for the cathodic reaction. This study has modified the conventional MEDC with an internal proton migration pathway, known as the internal proton migration pathway-MEDC (IP-MEDC). Simulation tests under abiotic conditions demon-strated that the pH changes in the anolyte and catholyte of IP-MEDC were smaller than the pH changes in the anolyte and catholyte without the proton pathways. Under biotic conditions, the performance of the IP-MEDC agreed well with the simulation test, showing a significantly higher chemical oxygen demand (COD) removal rate, desalination rate, and hydrogen production than without the migration pathway. This result is supported by the lowest charge transfer resistance shown by EIS analysis and the abundance of microbes on the bioanode through field emission scanning elec-tron microscopy (FESEM) observation. However, hydrogen production was diminished in the second-fed batch cycle, presumably due to the active diffusion of high Cl over line concentrations from desalination to the anode chamber, which was detrimental to microbial growth. Enlarging the anode volume by threefold improved the COD removal rate and hydro-gen production rate by 1.7-and 3.4-fold, respectively, owing to the dilution effect of Cl over line in the anode. This implied that the dilution effect satisfies both the microbial viability and conductivity. This study also suggests that the anolyte and catholyte replacement frequencies can be reduced, typically at a prolonged hydraulic retention time, thus minimizing the operating cost (e.g., solution pumping). The use of a high concentration of NaCl (35 g L-1) in the desalination chamber and catholyte provides a condition that is close to practicality.
| Item Type: | Article |
|---|---|
| Funders: | Ministry of Education, Malaysia (FRGS/1/2020/STG05/UKM/03/2) |
| Uncontrolled Keywords: | Microbial desalination cells (MDCs); Microbial electrodialysis cells (MEDCs); Bioelectrochemical system (BES); Wastewater treatment; Desalination; Hydrogen production |
| Subjects: | T Technology > TD Environmental technology. Sanitary engineering |
| Divisions: | Faculty of Engineering > Department of Chemical Engineering |
| Depositing User: | Ms Zaharah Ramly |
| Date Deposited: | 22 Nov 2023 04:54 |
| Last Modified: | 22 Nov 2023 04:54 |
| URI: | http://eprints.um.edu.my/id/eprint/38848 |
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