Enhanced electron transfer for the improvement of nitrogen removal efficiency and NO reduction at low temperatures.

Low temperature generally restricts biological activity, slowing down electron transfer in biogeochemical cycles and causing a series of environmental problems such as nitrogen pollution. We present a strategy to boost electron transfer in microbial cell at low temperatures via stimulation with low current. It is demonstrated by establishing a constructed wetland system coupled with solar powered microbial electrolysis cell, which enhances microbial activity through external micro currents (18.

Nutrient removal in floating and vertical flow constructed wetlands using aluminium dross: An innovative approach to mitigate eutrophication.

On global scale, eutrophication is one of the most prevalent environmental threats to water quality, primarily caused by elevated concentration of nutrients in wastewater. This study utilizes aluminum dross (AD), an industrial waste, to create a value-added material by improving its operational feasibility and application for removing phosphate and ammonium from water. The operational challenges of AD such as its powdered nature and effective operation under only extreme pH conditions were addressed by immobilizing in calcium alginate to form calcium alginate aluminium dross (Ca-Alg-Al dross) beads.

Exploring the potential of graphite material in an unplanted electroactive wetland for the remediation of synthetic wastewater containing azo dye.

The current study was conducted to understand the sole role of graphite as a substrate material in a dual-chambered baffled electroactive wetland (EW) in the treatment of Methyl red dye-containing wastewater. The results obtained were compared with conventional gravel-based unplanted dual-chambered constructed wetlands (CW) at a lab scale. The highest dye decolorisation and COD removal efficiency achieved was 92.

Aluminium dross waste utilization for phosphate removal and recovery from aqueous environment: Operational feasibility development.

The need to minimize eutrophication in water bodies and the shortage of phosphate rock reserves has stimulated the search for sequestration and recovery of phosphate from alternative sources, including wastewater. In this study, aluminium dross (AD), a smelting industry waste/by-product, was converted to high-value material by encapsulation in calcium alginate (Ca-Alg) beads, viz. Ca-Alg-AD and utilized for adsorptive/uptake removal and phosphate recovery from an aqueous environment.

Development of nature-based sustainable passive technologies for treating and disinfecting municipal wastewater: Experiences from constructed wetlands and slow sand filter.

There is an urgent need to develop low-cost technology for effective wastewater treatment and its further disinfection to the level that makes it economically useful. This work has designed and evaluated the various types of constructed wetlands (CWs) followed by a slow sand filter (SSF) for wastewater treatment and disinfection. The studied CWs were, CWs with gravels (CW-G), free water surface-CW (FWS-CWs), and CWs integrated microbial fuel cell (MFC) with granular graphite (CW-MFC-GG) planted with Canna indica plant species.

A glance of coupled water and wastewater treatment systems based on microbial fuel cells.

Microbial fuel cell (MFC) is a variant of the bioelectrochemical system that uses microorganisms as biocatalysts to generate bioenergy by oxidizing organic matter. Due to its two-prong feature of simultaneously treating wastewater and generating electricity, it has drawn extensive interest by scientific communities around the world. However, the pollution purifying capacity and power production of MFC at the laboratory scale have tended to remain steady, and there have been no reports of a performance breakthrough.

Influence of aeration, plants, electrodes, and pollutant loads on treatment performance of constructed wetlands: A comprehensive study with septage.

This study reports the performance of non-aerated and aerated unplanted, planted, microbial fuel cell planted wetlands for stabilizing septage and treating the drained wastewater. The wetland systems of this study were dosed with septage for a relatively shorter period, i.e.

The race between classical microbial fuel cells, sediment-microbial fuel cells, plant-microbial fuel cells, and constructed wetlands-microbial fuel cells: Applications and technology readiness level.

Microbial fuel cell (MFC) is an interesting technology capable of converting the chemical energy stored in organics to electricity. It has raised high hopes among researchers and end users as the world continues to face climate change, water, energy, and land crisis. This review aims to discuss the journey of continuously progressing MFC technology from the lab to the field so far.

Systematizing Microbial Bioplastic Production for Developing Sustainable Bioeconomy: Metabolic Nexus Modeling, Economic and Environmental Technologies Assessment.

The excessive usage of non-renewable resources to produce plastic commodities has incongruously influenced the environment's health. Especially in the times of COVID-19, the need for plastic-based health products has increased predominantly. Given the rise in global warming and greenhouse gas emissions, the lifecycle of plastic has been established to contribute to it significantly.

Organic media-based two-stage traditional and electrode-integrated tidal flow wetlands to treat landfill leachate: Influence of aeration strategy and plants.

Landfill leachate treatment employing normal and electrode-integrated constructed wetlands is difficult due to the presence of significant amounts of organic compounds, which frequently impede the progression of microbial-based aerobic pollutant removal pathways. As a result, this study examines the effect of supplementary air availability via intermittent and continuous aeration strategies in improving organic, nutrient, and coliform removals of the unplanted, planted (normal and electrode-integrated) two-stage tidal flow constructed wetlands designed to treat landfill leachate. The constructed wetlands were filled with coal and biochar media and planted with Canna indica.

Ozone based inactivation and disinfection in the pandemic time and beyond: Taking forward what has been learned and best practice.

The large-scale global COVID-19 has a profound impact on human society. Timely and effectively blocking the virus spread is the key to controlling the pandemic growth. Ozone-based inactivation and disinfection techniques have been shown to effectively kill SARS-CoV-2 in water, aerosols and on solid surface.

Binder-free NiO/MnO coated carbon based anodes for simultaneous norfloxacin removal, wastewater treatment and power generation in dual-chamber microbial fuel cell.

Norfloxacin (NFX) is a commonly consumed synthetic antibiotic drug to cure many adverse infectious diseases of humans worldwide, but their presence in almost all aquatic environments has grown into severe global health concerns. In this study, the power performance of dual-chamber microbial fuel cells (MFCs) with two different types of base anodes (graphite felt and activated carbon cloth) were tested with a coating of NiO/MnO for removal of NFX in wastewater. As transition metal oxides have excellent electrochemical stability and a higher specific capacitance, their application in MFC for antibiotic removal and wastewater treatment would be an interesting study.

Performance assessment of normal and electrode-assisted floating wetlands: influence of input pollutant loads, surface area, and positioning of anode electrodes.

This study reports the design and development of microbial fuel cell (MFC) assisted floating wetlands and compares treatment removal performance with a normal (without electrodes) floating wetland. Both types of floating wetlands were planted with Phragmites plant and evaluated for real municipal wastewater treatment. The effective volume of each floating wetland was 0.

Development of electrodes integrated hybrid constructed wetlands using organic, construction, and rejected materials as filter media: Landfill leachate treatment.

This study developed microbial fuel cell (MFC)-based hybrid constructed wetland systems using different filter media, i.e., organic (biochar), construction (sand), and rejected (iron particle, concrete particle, and stone dust) materials, and evaluated the performance of the developed systems for treating landfill leachate.

A comparative landfill leachate treatment performance in normal and electrodes integrated hybrid constructed wetlands under unstable pollutant loadings.

This study provides a comparative pollutant removal performance assessment between organic or construction materials-based four hybrid wetland systems that received landfill leachate. The hybrid systems included vertical flow (VF) followed by horizontal flow (HF)-based unplanted and planted systems, and planted electrodes incorporated microbial fuel cell (MFC) integrated hybrid wetlands systems. All the systems were run in free-draining mode.

Towards a more labor-saving way in microbial ammonium oxidation: A review on complete ammonia oxidization (comammox).

In the Anthropocene, nitrogen pollution is becoming an increasing challenge for both mankind and the Earth system. Microbial nitrogen cycling begins with aerobic nitrification, which is also the key rate-limiting step. For over a century, it has been accepted that nitrification occurs sequentially involving ammonia oxidation, which produces nitrite followed by nitrite oxidation, generating nitrate.

Influence of applied potential on treatment performance and clogging behaviour of hybrid constructed wetland-microbial electrochemical technologies.

A two-stage hybrid Constructed Wetland (CW) integrated with a microbial fuel cell (MFC), and microbial electrolysis cell (MEC) has been assessed for treatment performance and clogging assessment and further compared with CW. The CW-MEC was operated with applied potential to the working electrode and compared with the performance of naturally adapted redox potential of the CW-MFC system. A complex synthetic municipal wastewater was used during the study, which was composed of trace metals, organics, inorganics, and dye.

Interrelation between sulphur and conductive materials and its impact on ammonium and organic pollutants removal in electroactive wetlands.

This investigation is the first of its kind to evaluate the interrelation of sulphate (SO) with conductive materials as well as their individual and synergetic effects on the removal of ammonium and organic pollutants in electroactive wetlands, also known as constructed wetland (CW) - microbial fuel cell (MFC). The role of MFC components in CW was investigated to treat the sulphate containing wastewater under a long-term operation without any toxicity build-up in the system. A comparative study was also performed between CW-MFC and CW, where sulphate containing wastewater (S-replete) and without sulphate wastewater (S-deplete) was assessed.

An algal assisted constructed wetland-microbial fuel cell integrated with sand filter for efficient wastewater treatment and electricity production.

In this study we report on a three-stage design of algal assisted constructed wetland -microbial fuel cell incorporated sand filter for efficient treatment of wastewater and bioelectricity generation, simulating a core of it. It aims for the complete removal of organic matter and other inorganic pollutants such as NO, NH and PO. The conductive material equipped anode region of constructed wetland (CW) performed better for organic removal, and the system efficiently removed COD up to 96.

A comprehensive review on emerging constructed wetland coupled microbial fuel cell technology: Potential applications and challenges.

Constructed wetlands (CWs) integrated with bioelectrochemical systems (BESs) are being intensively researched with the names like constructed wetland-microbial fuel cell (CW-MFC), electro-wetlands, electroactive wetlands, and microbial electrochemical technologies-based constructed wetland since the last decade. The implantation of BES in CW facilitates the tuning of redox activities and electron flow balance in aerobic and anaerobic zones in the CW bed matrix, thereby alleviating the limitation associated with electron acceptor availability and increasing its operational controllability. The benefits of CW-MFC include high treatment efficiency, electricity generation, and recalcitrant pollutant abatement.

A review on the contribution of electron flow in electroactive wetlands: Electricity generation and enhanced wastewater treatment.

In less than a decade, bioelectrochemical systems/microbial fuel cell integrated constructed wetlands (electroactive wetlands) have gained a considerable amount of attention due to enhanced wastewater treatment and electricity generation. The enhancement in treatment has majorly emanated from the electron transfer or flow, particularly in anaerobic regions. However, the chemistry associated with electron transfer is complex to understand in electroactive wetlands.

Simultaneous removal of organic matters and nutrients from high-strength wastewater in constructed wetlands followed by entrapped algal systems.

The present work designs a low-cost biological treatment strategy consisting of constructed wetlands (CWs) followed by entrapped algae (EA) for removing nutrients (PO, NO, and NH) and organic matters from high-strength wastewater. The CWs are efficient means for organic pollutant removal but face challenges in nutrient removal. Algae have a high growth rate and nutrient uptake capabilities from wastewater.

Electrode dependent anaerobic ammonium oxidation in microbial fuel cell integrated hybrid constructed wetlands: A new process.

This study provides a new approach of electrode dependent anaerobic ammonium oxidation (electroanammox) in microbial fuel cell (MFC) integrated hybrid constructed wetlands (CWs). The study was carried out in three CWs, each with a horizontal flow (HF) followed by a vertical upflow (VUF). Two of the CWs were integrated with MFC, one was operated in closed circuit (CL) mode and the other in open circuit (OP) mode to determine the influence of electron transfer through an external electrical circuit.

Performance assessment of aeration and radial oxygen loss assisted cathode based integrated constructed wetland-microbial fuel cell systems.

The present study explores low-cost cathode development possibility using radial oxygen loss (ROL) of Canna indica plants and intermittent aeration (IA) for wastewater treatment and electricity generation in constructed wetland-microbial fuel cell (CW-MFC) system. Two CW-MFC microcosms were developed. Amongst them, one microcosm was planted with Canna indica plants for evaluating the ROL dependent cathode reaction (CW-MFC dependent on ROL) and another microcosm was equipped with intermittent aeration for evaluating the intermittent aeration dependent cathode reaction (CW-MFC with additional IA).