Development of a membrane capacitive deionization stack for domestic wastewater reclamation: A pilot-scale feasibility study

Autor: Tsai-Hsuan Chen, Shao-Wei Tsai, Yu-Yi Shen, Chia-Hung Hou, Shih-Han Sun
Rok vydání: 2021
Předmět:
Zdroj: Desalination. 500:114851
ISSN: 0011-9164
DOI: 10.1016/j.desal.2020.114851
Popis: This study aims to scale up a membrane capacitive deionization (MCDI) stack for the reuse of domestic wastewater for industry applications. The desalination performance of the pilot-scale MCDI was investigated for the removal of ions from the effluent of a domestic wastewater treatment plant in terms of water quality, ion selectivity, water productivity and fouling/scaling phenomena. The MCDI stack was composed of 40 pairs of 20 cm × 20 cm activated carbon electrodes and operated in a single-pass mode. The MCDI stack achieved good removal efficiency of ions from the wastewater effluent (up to 94% Ca2+ and 84% NO3−). For electrode regeneration, the pump-off operation enabled a much higher water recovery of 75%. In particular, the average conductivity after the MCDI treatment was 103 μS/cm, which meets the standard for industrial reuse. For the electrosorption selectivity of cations, Ca2+ and Mg2+ were favored due to their high charge. Among the anions, NO3− had the highest electrosorption selectivity owing to its hydration ratio. Notably, the water quality of MCDI-treated effluents remained stable during consecutive charging-discharging cycles over 5 months of operation. These results provide essential data to scale up the MCDI stack with application to water reclamation.
Databáze: OpenAIRE
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