Coupling Microbial Fuel Cell and Hydroponic System for Electricity Generation, Organic Removal, and Nutrient Recovery via Plant Production from Wastewater

Abstract

The world is predicted to face serious threats from the depletion of non-renewable energy resources, freshwater shortage, and food scarcity. Microbial fuel cells (MFCs) are innovative bio-electrochemical devices capable of directly converting chemical energy into electrical energy using microorganisms as a catalyst. This ability has been explored for generating electricity using wastewater as an energy source, while simultaneously treating wastewater. On the other hand, hydroponics is the cultivation of plants in water without soil. The goal of this study was to develop a novel integrated microbial fuel cell-hydroponic system (MFC-Hyp system) that possesses the ability to concurrently generate electricity while degrading organic pollutants (Chemical oxygen demand, COD) in wastewater, remove and recover nutrients (phosphorus, P and nitrogen, N) from the wastewater, and produce edible plants. The MFC-Hyp system developed in this study produced a power density of 250.7 mW/m2. The power density increased by approximately 19% and the phosphorus recovery increased to 7.5% in the presence of Allium tuberosum compared to 4.9% without the plant (e.g., in the control). The removal efficiencies of nitrate, phosphate, and COD are 32%, 11%, and 80%, respectively. The results indicate that the novel integrated MFC-Hyp system can remove COD from wastewater, generate electricity using wastewater as an energy source, and utilize nutrients for growing plants; however, this system requires further improvement for field implementation.

Integrating Microbial Fuel Cell and Hydroponic Technologies Using a Ceramic Membrane Separator to Develop an Energy–Water–Food Supply System

“…Two types of ceramic membranes were prepared according to Paucar et al [ 18 ]. The Peruvian clay ceramic membrane was made of clay obtained from the Department of Junín, Peru.…”

“…In hydroponics, carbon and nutrients are captured and stored in plants as biomass, while oxygen is generated through photosynthesis and released into the environment [ 14 , 15 ]. Hence, hydroponics is considered an environmentally friendly technology that can be applied to wastewater remediation and water quality improvement [ 14 , 16 , 17 , 18 ]. One major advantage of hydroponics is that edible plants can be grown in a soil-less environment, such as in urban areas where cultivable land is limited, or arid regions where conservation of water is vitally important.…”

“…The following supporting information can be downloaded at: , Table S1. Summary of different integrated systems for wastewater treatment, nutrient removal, and resource recovery (modified from [ 18 ]); Figure S1. pH and conductance of water in the hydroponics in the presence of A. tubersosum : (a) MFC-Hyp 1; (b) MFC-Hyp 2; (c) MFC-Hyp 3; Figure S2.…”

Energy harvesting from plants using hybrid microbial fuel cells; potential applications and future exploitation

“…A number of workers ( Khuman et al, 2020 ; Yadav et al, 2020 ; Paucar and Sato, 2022 ) have described the integration of microbial fuel cells with hydroponics ( Figure 5 ). Yadav et al (2020) described the use of a novel integrated drip hydroponics-microbial fuel cell system.…”

“…The work by Paucar and Sato (2022) was to develop a new integrated MFC-hydroponic system to generate electricity whilst concurrently degrading organic pollutants (i.e., COD) in hydroponic wastewater and simultaneously removing nitrogen (N) and phosphorus (P) as well as produce edible plants. The MFC-hydroponic system produced a power density of 250.7 mW/m 2 .…”