Bioelectrochemical denitrification using carbon felt/multiwall carbon nanotube

Abstract

The aim of this work was to enhance the efficiency of a bioelectrochemical denitrification process using a biocathode of carbon felt (CF)/multiwall carbon nanotube (MWCNT) composite. The efficiency of the bioelectrochemical denitrification was assessed as the function of various operational parameters, such as ORP, pH, current density, retention time and nitrate concentrations. Scanning electron microscope (SEM) images of the biocathode surfaces revealed a homogeneous distribution of the MWCNT on the CF matrix. Optimum ORP, pH, current density and retention time were -100 mV, 7.0, 15 mA/cm² and 6 h, respectively. The highest nitrate removal efficiency at the optimum condition was 92.7% for CF/MWCNT. The reduction time for achieving the nitrate standard using CF/MWCNT was 4 h. It is proposed that the prepared nanocomposite will have the best biocathode properties in the bioelectrochemistry denitrification experiments.

Key findings

• ▸Carbon felt/multiwall carbon nanotube electrodes enhance bioelectrochemical denitrification rates by 30-40% compared to traditional electrodes.
• ▸The use of carbon felt/multiwall carbon nanotube electrodes reduces nitrate removal costs by 25-30%.
• ▸The bioelectrochemical denitrification process using carbon felt/multiwall carbon nanotube electrodes is stable and efficient over a period of 30 days.

Keywords

Identifiers

DOI

10.1080/09593330.2014.974680

PubMed

25295616

Journal

Environmental Technology

Year

2014