Comparative Studies of Recirculatory Microbial Desalination Cell-Microbial Electrolysis Cell Coupled Systems

Desmond Ato Koomson; Jingyu Huang; Guang Li; Nicholas Miwornunyuie; David Ewusi-Mensah; Williams Kweku Darkwah; Prince Atta Opoku

doi:10.3390/membranes11090661

Comparative Studies of Recirculatory Microbial Desalination Cell-Microbial Electrolysis Cell Coupled Systems

Membranes (Basel). 2021 Aug 27;11(9):661. doi: 10.3390/membranes11090661.

Authors

Desmond Ato Koomson¹, Jingyu Huang¹, Guang Li², Nicholas Miwornunyuie¹, David Ewusi-Mensah¹, Williams Kweku Darkwah¹, Prince Atta Opoku¹

Affiliations

¹ Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, College of Environmental Engineering, Hohai University, No. 1 Xikang Road, Nanjing 210098, China.
² Key Laboratory of Songliao Aquatic Environment, Ministry of Education, Jilin Jianzhu University, Changchun 130118, China.

Abstract

The recirculatory microbial desalination cell-microbial electrolysis cell (MDC-MEC) coupled system is a novel technology that generates power, treats wastewater, and supports desalination through eco-friendly processes. This study focuses on the simultaneous efficient removal of Fe²⁺ and Pb²⁺ in the MEC and ammonium ions in the MDC. It also evaluates the performances of dual-chambered MEC (DCMEC) and single-chambered MEC (SCMEC), coupled with MDC with Ferricyanide as catholyte (MDCF) in heavy metals (Pb²⁺ and Fe²⁺) removal, in addition to the production of voltage, current, and power within a 48-h cycle. The SCMEC has a higher Pb²⁺ (74.61%) and Fe²⁺ (85.05%) removal efficiency during the 48-h cycle than the DCMEC due to the simultaneous use of microbial biosorption and the cathodic reduction potential. The DCMEC had a higher current density of 753.62 mAm^-2 than that of SCMEC, i.e., 463.77 mAm^-2, which influences higher desalination in the MDCF than in the SCMEC within the 48-h cycle. The MDCF produces a higher voltage (627 mV) than Control 1, MDC (505 mV), as a power source to the two MECs. Stable electrolytes' pH and conductivities provide a conducive operation of the coupled system. This study lays a solid background for the type of MDC-MEC coupled systems needed for industrial scale-up.

Keywords: ammonium ions; dual-chambered MEC; heavy metals removal; power source; recirculatory MDC–MEC coupled system; single-chambered MEC.