Microbial electrochemical systems outperform fixed-bed biofilters in cleaning up urban wastewater

Abstract

Water impact: MET biofilters outperform gravel biofilters in wastewater treatment and will reduce the surface for CW, selecting certain genera of bacteria reported to be electroactive.

Microbial Electrochemical Technologies for Wastewater Treatment: Principles and Evolution from Microbial Fuel Cells to Bioelectrochemical-Based Constructed Wetlands

“…Conceptual illustration of METland set-upMETland system has been tested for the removal of organic matter and nitrogen with horizontal subsurface flow (HSSF) coke biofilters at laboratory scale at different hydraulic loading rates (HRT), ranging from 4 to 0.5 days[102]. The coke based biofilter showed removal rates of 91% for COD and for 96% for BOD5 at the lowest HRT (0.5 d), and 97% for NH4 and 69% for TN at 3.5 d HRT results that suggest that METland system can enhance biodegradation rates, thus allowing the reduction of the area requirements of classical CWs.Conceptually this new system operates similarly to a microbial electrochemical snorkel -MES[90,91,120], which is composed of a single conductive material that allows the connection between anoxic zones (performing as anode) and oxic zones (performing as cathode).…”

Electrodes boost microbial metabolism to mineralize antibiotics in manure

“…Our electrode-assisted treatment performs bioremediation by avoiding chemicals consumption or manure manipulation with negative environmental consequences providing an endless, low priced and sustainable terminal electron sink showing minimal environmental disturbance [46]. Furthermore, we believe that electrobioremediation shows a great potential for solving a environmental problem by minimizing antibiotic discharge into natural landscape; so our next strategy will be to integrate this electrode-assisted approach into bioelectrochemicallyassisted constructed wetland (so-called METlands) for in situ pollutant degradation [47]. Such a configuration will facilitate the scaling-up to rural environments where manure and METlands may perfectly coexist.…”

Microbial Electrochemical Technologies for Wastewater Treatment: Principles and Evolution from Microbial Fuel Cells to Bioelectrochemical-Based Constructed Wetlands

“…In a METland system, the EAB are stimulated to generate and transfer electrons to an electro-conductive material that act as an unlimited acceptor ( Figure 10) maximizing substrate consumption instead of leaving free electrons for methane generation, and consequently to a decrease of microbial metabolism rates (as in an anaerobic system) due to the limited number of electron acceptors [103]. The METland system has been tested for the removal of organic matter and nitrogen with horizontal subsurface flow (HSSF) coke biofilters at laboratory scale at different hydraulic loading rates (HRT), ranging from 4 to 0.5 days [104]. The coke-based biofilter showed removal rates of 91% for COD and for 96% for BOD5 at the lowest HRT (0.5 d), and 97% for NH4 and 69% for TN at 3.5 d HRT results that suggest that the METland system can enhance biodegradation rates, thus allowing the reduction of the area requirements of classical CWs.…”

“…Additional limiting factors that must be considered include i) the internal resistance of a CW-MFC, which increases linearly as the size and distance between electrodes increase [24]; ii) the overpotential during activation and the insufficient electrical contact between bacteria and anode [124]; iii) competition among EAB and other microorganisms (e.g., methanogenic bacteria) for electrons or The METland system has been tested for the removal of organic matter and nitrogen with horizontal subsurface flow (HSSF) coke biofilters at laboratory scale at different hydraulic loading rates (HRT), ranging from 4 to 0.5 days [104]. The coke-based biofilter showed removal rates of 91% for COD and for 96% for BOD 5 at the lowest HRT (0.5 d), and 97% for NH 4 and 69% for TN at 3.5 d HRT results that suggest that the METland system can enhance biodegradation rates, thus allowing the reduction of the area requirements of classical CWs.…”