Bioelectrochemical Systems for Removal of Selected Metals and Perchlorate from Groundwater: A Review

Abstract

Groundwater contamination is a major issue for human health, due to its largely diffused exploitation for water supply. Several pollutants have been detected in groundwater; amongst them arsenic, cadmium, chromium, vanadium, and perchlorate. Various technologies have been applied for groundwater remediation, involving physical, chemical, and biological processes. Bioelectrochemical systems (BES) have emerged over the last 15 years as an alternative to conventional treatments for a wide variety of wastewater, and have been proposed as a feasible option for groundwater remediation due to the nature of the technology: the presence of two different redox environments, the use of electrodes as virtually inexhaustible electron acceptor/donor (anode and cathode, respectively), and the possibility of microbial catalysis enhance their possibility to achieve complete remediation of contaminants, even in combination. Arsenic and organic matter can be oxidized at the bioanode, while vanadium, perchlorate, chromium, and cadmium can be reduced at the cathode, which can be biotic or abiotic. Additionally, BES has been shown to produce bioenergy while performing organic contaminants removal, lowering the overall energy balance. This review examines the application of BES for groundwater remediation of arsenic, cadmium, chromium, vanadium, and perchlorate, focusing also on the perspectives of the technology in the groundwater treatment field.

Operation of a 2-Stage Bioelectrochemical System for Groundwater Denitrification

“…Very similar systems could also be applied to solve contamination problems related to the presence of different harmful contaminants at the same time (e.g., arsenic) in aquifers, potentially achieving simultaneous removal of both pollutants; BES have already proved to be able to remove a wide variety of contaminants from groundwater: besides nitrate, sulfate, perchlorate, aromatic hydrocarbons and metal ions have also been removed or recovered through BES so far [63,64].…”

Bioelectrochemical Systems for Groundwater Remediation: The Development Trend and Research Front Revealed by Bibliometric Analysis

“…However, great concern has been raised about the deterioration of groundwater quality related to rapid industrialization and civilization in the last decades [2,[6][7][8][9], and groundwater pollution events caused by human activities (the application of fertilizer and manure [10][11][12][13], the discharge of industrial effluents [14][15][16][17][18], and the leakage of landfill sites [19,20] have been reported round the world. Thus, the invention and implementation of groundwater remedial technologies is a hotspot issue for environmental experts nowadays [21][22][23][24], and numerous technologies involving physical, chemical, physical-chemical, biological and biochemical aspects have been invented and applied [25,26], e.g., the pump and treat method (contaminated groundwater is pumped by abstracted wells and further treated) [27][28][29][30], permeable reactive barriers (a subsurface barrier is constructed by reactive materials, and the polluted groundwater is remediated during flowing through the barrier) [31][32][33][34][35], soil vapor extraction (a vacuum is applied to the vadose zone to induce the controlled flow of air and remove volatile and some semi-volatile organic contaminants) [36][37][38], and monitored natural attenuation (based on efficient monitoring, pollutants are degraded to acceptable levels by natural physical, chemical and biochemical reactions) [39][40][41].…”

Controlled Layer-By-Layer Deposition of Carbon Nanotubes on Electrodes for Microbial Fuel Cells

“…Microbial fuel cells (MFCs) are a type of bioreactor, which directly harvests electricity from chemical energy by exoelectrogens (i.e., microorganisms transferring electrons to an electrode). Recently, they have been widely used in power generation, wastewater treatment and biosensors [1][2][3][4][5][6][7]. In particular, the electron transfer occurs between: Redox-active outer membrane c-type cytochromes (OM c-Cyts) of the microbe, or redox-active mediators secreted by the cells/added outside, or microbially generated nanowires and the electrode surface [8].…”