Abstract
The extensive use of Cr(VI) in many industries and the disposal of Cr(VI)-containing wastes have resulted in Cr(VI)-induced environmental contamination. Cr(VI) compounds are associated with increased cancer risks; hence, the detection of toxic Cr(VI) compounds is crucial. Various methods have been developed for Cr(VI) measurement, but they are often conducted offsite and cannot provide real-time toxicity monitoring. A microbial fuel cell (MFC) is an eco-friendly and self-sustaining device that has great potential as a biosensor for in situ Cr(VI) measurement, especially for wastewater generated from different electroplating units. In this study, Exiguobacterium aestuarii YC211, a facultatively anaerobic, Cr(VI)-reducing, salt-tolerant, and exoelectrogenic bacterium, was isolated and inoculated into an MFC to evaluate its feasibility as a Cr(VI) biosensor. The Cr(VI) removal efficiency of E. aestuarii YC211 was not affected by the surrounding environment (pH 5–9, 20–35 °C, coexisting ions, and salinity of 0–15 g/L). The maximum power density of the MFC biosensor was 98.3 ± 1.5 mW/m2 at 1500 Ω. A good linear relationship (r2 = 0.997) was observed between the Cr(VI) concentration (2.5–60 mg/L) and the voltage output. The developed MFC biosensor is a simple device that can accurately measure Cr(VI) concentrations in the actual electroplating wastewater that is generated from different electroplating units within 30 min with low deviations (−6.1% to 2.2%). After treating the actual electroplating wastewater with the MFC, the predominant family in the biofilm was found to be Bacillaceae (95.3%) and was further identified as the originally inoculated E. aestuarii YC211 by next generation sequencing (NGS). Thus, the MFC biosensor can measure Cr(VI) concentrations in situ in the effluents from different electroplating units, and it can potentially help in preventing the violation of effluent regulations.
Highlights
The extensive use of chromium (Cr) in many industries [1] and the disposal of Cr-containing wastes over large areas of land have resulted in the release of chromium-containing effluents into the environment [2,3]
The results indicated that Tryptic soy broth (TSB) was of the TSB concentration on the Cr(VI) removal efficiency of E. aestuarii YC211 was observed when it more suitable than LB for E. aestuarii YC211 both for Cr(VI) removal and bacterial growth
We developed a Cr(VI)-microbial fuel cell (MFC) biosensor that was inoculated with E. aestuar
Summary
The extensive use of chromium (Cr) in many industries (e.g., electroplating, steel production, and leather tanning) [1] and the disposal of Cr-containing wastes over large areas of land have resulted in the release of chromium-containing effluents into the environment [2,3]. A metal, is present in the environment in two major stable oxidation states—Cr(VI) and Cr(III) [1]. Cr(VI) compounds exist mainly as chromates and dichromates [4]. They are highly soluble and mobile and are considered. Sensors 2017, 17, 2461 as acutely toxic because they can readily cross cell membranes via the sulfate anion transport system when the ambient pH exceeds 6 [3,5]. The detection of toxic Cr(VI) compounds is of great importance in order to maintain the quality and safety of our environment
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
