Removal of heavy metals in a flow‐through vertical microbial electrolysis cell

Abstract

This work describes laboratory experiments aimed at evaluating the feasibility of removing heavy metals from metal-contaminated water in flowthrough microbial electrolysis cells (MECs) with peat moss as a source of organic carbon. MECs were assembled in upflow glass columns containing granular activated carbon (GAC) bioelectrodes preceded by a layer of peat moss. The MECs were fed with metal-contaminated surface water collected at a firing range. At hydraulic retention times (HRT) of 4-6 days, up to 99 % removal of Pb, Zn, Cu, and Fe was observed. The removal efficiency of Zn and Cu declined at an HRT of 1.7 days, while effluent Pb concentration remained below the detection limit for all of the HRTs tested. Metal extraction from MEC compartments showed an accumulation of metals in both the peat moss layer and the GAC cathode, i.e., the removal was achieved by a combination of anaerobic and bioelectrochemical pathways of metal reduction. A proliferation of sulphate reducing bacteria in the peat moss layer and electroactive species in GAC electrodes was confirmed by biomolecular analysis. The proposed flowthrough system, which combines sulphate-reducing and electroactive microbial activities to achieve near-complete metal removal, can be used for removing a broad range of heavy metals from contaminated water in a low-cost passive flow treatment system.

Mine drainage: Remediation technology and resource recovery

“…Flow‐through microbial electrolysis cells (MECs) were evaluated for the removal of heavy metals with peat moss as a carbon source in a laboratory study (Jugnia, Manno, Hendry, & Tartakovsky, 2019). High metal removal (>99% for Pb, Zn, Cu, and Fe) was obtained at hydraulic retention times of 4–6 days, representing a low‐cost passive treatment system.…”

Ion Imprinted Sodium Alginate Hydrogel Beads Enhanced with Carboxymethyl Cellulose and β-Cyclodextrin to Improve Adsorption for Cu2+

“…For example, the comprehensive sewage discharge standard GB 8978 − 1996 stipulates that the maximum acceptable emission concentration of Cu 2+ is 0.5 mg/L. The treatment methods for heavy metals in wastewater include: chemical method [6], adsorption [7,8], electro-dialysis [9,10], ion exchange method [7,11], photocatalysis methods [12,13], and etc. With the adsorption method's advantages such as economic, simple and easy to operate, and wide scope of application, the research and development of green adsorption materials with good performance and speci c selectivity is becoming an important trend of controlling heavy metal pollution and recycling of resources [14][15][16][17].…”

Dual functions of activated carbon air‐cathode: Nitrobenzene removal and electricity production in microbial fuel cells

“…[1,2] BESs of different designs and types of operation, including microbial fuel cells (MFCs), microbial electrolysis cells (MECs), [3,4] microbial desalination cells (MDCs), [5] and microbial reverse electrodialysis cell (MRCs) [6] have been successfully developed for multiple applications, including the direct harvesting of electrical energy from a variety of environmental wastes [7] and the removal of different types of pollutants. [8,9] Over the past decade, researchers have explored the factors affecting BESs, accumulating valuable data for optimizing the performance of BESs. A variety of factors, including system structure, electrode materials, operating conditions, and electrode biofilm growth state, have an impact on the performance of microbial electrochemical systems such as power output and pollutant removal.…”