Enhancing the water desalination and electricity generation of a microbial desalination cell with a three-dimensional macroporous carbon nanotube-chitosan sponge anode

Chih-Yu Ma; Chia-Hung Hou

doi:10.1016/j.scitotenv.2019.04.174

Enhancing the water desalination and electricity generation of a microbial desalination cell with a three-dimensional macroporous carbon nanotube-chitosan sponge anode

Sci Total Environ. 2019 Jul 20:675:41-50. doi: 10.1016/j.scitotenv.2019.04.174. Epub 2019 Apr 13.

Authors

Chih-Yu Ma¹, Chia-Hung Hou²

Affiliations

¹ Graduate Institute of Environmental Engineering, National Taiwan University, No.1, Sec. 4. Roosevelt Rd., Taipei 10617, Taiwan.
² Graduate Institute of Environmental Engineering, National Taiwan University, No.1, Sec. 4. Roosevelt Rd., Taipei 10617, Taiwan. Electronic address: chiahunghou@ntu.edu.tw.

PMID: 31026642
DOI: 10.1016/j.scitotenv.2019.04.174

Abstract

Microbial desalination cells (MDCs) are promising bioelectrochemical systems that are being investigated for simultaneous seawater desalination, electricity generation, and wastewater treatment. Anode materials play an important role in determining the performance of MDCs. In this study, a three-dimensional (3D) macroporous sponge was coated with compatible and conductive carbon nanotube-chitosan (CNT-CS) as a composite electrode for MDCs. Experimental results showed that the flexible CNT-CS sponge exhibited a high capacitance (159.4F/g at 20mVs^-1), good cycling stability (96% specific capacitance retention after 1000 cyclic voltammetry cycles) and low resistance. Moreover, the MDC with a CNT-CS sponge anode generated a high power density of 1776.6mW/m² (per electrode area) and desalination rate of 16.5mgh^-1, which are significantly higher than those of commercial carbon felt electrodes under the same conditions. The improved MDC performance can be attributed to the continuous 3D macroporous structure of the sponge anode promoting the bacterial loading capacity on the electrode surface. Moreover, the presence of CNTs also further enhances extracellular electron transfer. Our results demonstrate that an MDC operating with a 3D CNT-CS sponge anode offers an effective means for manufacturing high-performance MDCs with wide applicability to bioelectrochemical systems.

Keywords: Carbon nanotube; Chitosan; Desalination; Microbial desalination cell.

MeSH terms

Bioelectric Energy Sources*
Chitosan*
Electric Conductivity
Electricity
Nanotubes, Carbon / chemistry*
Water Purification / methods*

Substances

Nanotubes, Carbon
Chitosan