Effects and mechanism of constructed wetland microbial fuel cell (CW-MFC) in the treatment of freshwater fish aquaculture wastewater

Mechanism involved in the treatment of sulfamethoxazole in wastewater using a constructed wetland microbial fuel cell system

Constructed wetland – Microbial fuel cell (CW-MFC) packed with suspended fillers to enhance denitrification with Acorus calamus biomass addition

Greywater reuse through decentralized and low-cost treatment systems emerges as an opportunity to tackle the existing demand for water. In recent years, constructed wetlands (CW) systems and microbial fuel cells (MFCs) have emerged as attractive technologies for sustainable wastewater treatment. In this study, constructed wetland microbial fuel cells (CW-MFCs) planted with Phragmites australis were tested to evaluate the potential of combining these two systems for synthetic greywater treatment and energy recovery. Open (CW) and closed circuit (CW-MFCs) reactors were operated for 152 days to evaluate the effect of energy recovery on the removal of soluble chemical oxygen demand (sCOD), nutrients and total suspended solids (TSS). Results indicate no significant differences for sCOD and phosphate removal efficiencies. CW-MFCs and CW reactors presented sCOD removal efficiency of 91.7 ± 5.1% and 90 ± 10% and phosphate removal efficiencies of 56.3 ± 4.4% and 61.5 ± 3.5%, respectively. Nitrate removal efficiencies were higher in CW: 99.5 ± 1% versus 86.5 ± 7.1% in CW-MFCs, respectively. Energy generation reached a maximum power density of 33.52 ± 7.87 mW m−3 and 719.57 ± 67.67 mW m−3 at a poised anode potential of −150 mV vs. Ag/AgCl. Thus, our results suggest that the incorporation of MFC systems into constructed wetlands does allow energy recovery while providing effective greywater treatment.

Simultaneous removal of coexisting sulfadiazine and copper oxide nanoparticles with constructed wetland-microbial fuel cell.

Performance assessment of constructed wetland-microbial fuel cell for treatment of mariculture wastewater containing heavy metals

Roles of external circuit and rhizosphere location in CH4 emission control in sequencing batch flow constructed wetland-microbial fuel cell

Decomposition of pollutants from domestic sewage with the combination systems of hydrolytic acidification coupling with constructed wetland microbial fuel cell

Endogenous metabolism and electricity conversion of organic clogging substances in constructed wetland microbial fuel cell.

Over the past few decades, there has been a growing concern regarding the fate and transport of pharmaceuticals, particularly antibiotics, as emerging contaminants in the environment. It has been proposed that the presence of antibiotics at concentrations typically found in wastewater can impact the dynamics of bacterial populations and facilitate the spread of antibiotic resistance. The efficiency of currently-used wastewater treatment technologies in eliminating pharmaceuticals is often insufficient, resulting in the release of low concentrations of these compounds into the environment. In this study, we addressed these challenges by evaluating how different influent ibuprofen (IBU) concentrations influenced the efficiency of a laboratory-scale, integrated constructed wetland-microbial fuel cell (CW-MFC) system seeded with Eichhornia crassipes, in terms of organic matter removal, electricity generation, and change of bacterial community structure compared to unplanted, sediment MFC (S-MFC) and abiotic S-MFC (AS-MFC). We observed that the addition of IBU (5 mg L−1) resulted in a notable decrease in chemical oxygen demand (COD) and electricity generation, suggesting that high influent IBU concentrations caused partial inhibition for the electroactive microbial community due to its complexity and aromaticity. However, CW-MFC could recover from IBU inhibition after an acclimation period compared to unplanted S-MFC, even though the influent IBU level was increased up to 20 mg L−1, suggesting that plants in CW-MFCs have a beneficial role in relieving the inhibition of anode respiration due to the presence of high levels of IBU; thus, promoting the metabolic activity of the electroactive microbial community. Similarly, IBU removal efficiency for CW-MFC (i.e., 49–62%) was much higher compared to SMFC (i.e., 29–42%), and AS-MFC (i.e., 20–22%) during all experimental phases. In addition, our high throughput sequencing revealed that the high performance of CW-MFCs compared to S-MFC was associated with increasing the relative abundances of several microbial groups that are closely affiliated with anode respiration and organic matter fermentation. In summary, our results show that the CW-MFC system demonstrates suitability for high removal efficiency of IBU and effective electricity generation.

Enhancement of denitrification in constructed wetlands microbial fuel cells at low temperature: performance and molecular mechanisms.

In the field of sustainable wastewater management, electroactive wetlands (EW), or constructed wetland-microbial fuel cells (CW-MFC), are an emerging technology. With the growing problem of untreated wastewater, the emphasis must shift to decentralisation of wastewater treatment infrastructure, and CW-MFC can be an excellent choice. This review provides a chronologically organized account of the design and configuration of CW-MFCs developed between 2010 and 2023. The research on CW-MFC has mainly focused on material, positioning and number of electrodes; use of electroconductive media and filler materials; flow regime; algal-based CW-MFC and multistage setups. Compared to traditional constructed wetlands (CW) and microbial fuel cells (MFC), CW-MFCs have a number of advantages, including better treatment efficiency, faster organic matter utilisation, lower capital and land requirements and a smaller carbon footprint. However, there are some limitations as well, such as upscaling and viable electricity generation, which are covered in more detail in the article. Moreover, the economics of this technology is also evaluated. The microbiology of a CW-MFC and its influence on its performance are also elaborated. Recent advancements in this field in terms of design, configuration and performance are discussed. Finally, the knowledge gaps that must be addressed before this technique can be successfully implemented on a large scale are highlighted, along with specific recommendations. This article aims to advocate for EWs as an ideal decentralised wastewater treatment technique, while also shedding light on the areas that still need to be worked on.

Electroactive constructed wetland using Fe3C as an anodic exogenous electron donor: Performance and mechanisms

Innovative pilot-scale constructed wetland-microbial fuel cell system for enhanced wastewater treatment and bioelectricity production

Three novel constructed wetland‐microbial fuel cells (CW‐MFCs), based on electrode location, were developed for wastewater treatment and sustainable electricity production by embedding a MFC into a CW system. In the three CW‐MFCs, electrodes were placed in different locations, including bottom anode‐rhizosphere cathode CW‐MFC (BA‐RC‐CW‐MFC), rhizosphere anode‐air cathode CW‐MFC (RA‐AC‐CW‐MFC), and bottom anode‐air cathode CW‐MFC (BA‐AC‐CW‐MFC), to investigate the combined effects of organic loading rates (OLRs) and reactor configurations on the electrogenesis capacity of the hybrid system. All the systems operated continuously to treat five types of synthetic wastewater with increasing OLRs: 9.2, 18.4, 27.6, 55.2, and 92.0 g chemical oxygen demand (COD) m−2 d−1. The BA‐RC‐CW‐MFC failed to produce electricity at any OLR, whereas the maximum power densities of 0.79 ± 0.01 and 10.77 ± 0.52 mW m−2 were achieved in the RA‐AC‐CW‐MFC with 18.4 g COD m−2 d−1 influent OLR and in the BA‐AC‐CW‐MFC with 27.6 g COD m−2 d−1 influent OLR, respectively. The coulombic efficiencies of the RA‐AC‐CW‐MFC and BA‐AC‐CW‐MFC decreased gradually with the increase in influent OLRs. © 2016 American Institute of Chemical Engineers Environ Prog, 36: 435–441, 2017

This work explores the effect of the ammonia concentration on the wetland synthesis of microbial fuel cell (MFC) and on the production and the efficiency of sewage purification. Four ammonia concentrations from 1 to 30 mg/L have been selected. Under the fixed condition of a chemical oxygen demand (COD) concentration of 200 mg/L, a constructed wetland microbial fuel cell (CW-MFC) could be built. The results show that by selecting the optimum ammonia concentration the production of the CW-MFC could be promoted; a higher ammonia concentration (>20 mg/L) is found to inhibit the production activity of CW-MFC. In the optimum conditions, Cathode and anode thickness is 10 cm, the ammonia concentration is 10 mg/L, the COD concentration of 200 mg/L, the maximum power density of the battery is 13.6 W/m3, the corresponding current density is 148.6 A/m3 and the battery internal resistance is 270 Ω. At the ammonia nitrogen concentration of 10 mg/L, the removal rates of ammonia nitrogen and COD were up to 89.7% and 98.47% respectively. As the ammonia nitrogen concentration increased to 30 mg/L, the ammonia nitrogen and COD removal rates decreased to 74.6% and 90.69% respectively. That is, when the ammonia nitrogen concentration is 10 mg/L, CW-MFC can exhibit the best performance.