Trends in Biotechnology
ReviewWaste or Gold? Bioelectrochemical Resource Recovery in Source-Separated Urine
Section snippets
The Potential of Urine for Resource Recovery
An accelerating human population and consumption growth rate mean that the global demand for food will not decrease anytime soon. To make matters worse, this booming competition for water, nutrients, and energy will affect the global capacity to produce enough food. Moreover, the need to control the negative impacts of human activity, including food production, on the environment will also increase [1].
There is no simple solution to meeting the ever-increasing food expectations of ~8 billion
Bioelectrochemical Systems: MFCs and MECs
BESs (see Glossary) are emerging technologies that have been developed as different reactor setups (Box 2) following the discovery that some microorganisms (Box 3) can catalyze various anodic or cathodic reactions (Box 4). Source-separated urine could be a suitable influent for BESs to recover nutrients, energy, fuel, and valuable compounds. Figure 1 provides an overview of the basic working principles in BESs and centers around the most common BESs: MFCs and MECs.
The growing number of recent
Bioelectrochemical Systems Fed with Source-Separated Urine
Key BESs, including MFCs and MECs, with applications envisaged for the treatment of wastewater streams, have been in the spotlight for the past two decades. Unfortunately, there are two main obstacles to their use: low ionic conductivity and low buffering capacity of most wastewater streams [21]. However, source-separated urine overcomes these obstacles with an average ionic conductivity of 20 ms.cm–1 and a buffering capacity of 660 mM because of its urea concentration of 20 g.l–1 [23].
Concluding Remarks and Future Perspectives
Given its high energy and macronutrient content. including N, P, and K, source-separated human urine is an ideal candidate for sustainable nutrient and energy recovery. Numerous technical approaches have been introduced throughout the recent decades, yet they all have drawbacks that limit their widespread implementation. The production of electrical power and value-added products, COD removal of >90% [40,47,49,62], and P and N recoveries of >90% [33] and >50% [35], respectively, over the past
Acknowledgments
The authors would like to acknowledge the Iran National Science Foundation (INSF) and Razi University for the full financial support provided for this research work.
Glossary
- Bioelectrochemical systems (BESs)
- systems capable of converting the chemical energy of organic waste into electricity, hydrogen, or other useful chemicals.
- Chemical oxygen demand (COD)
- indicative measure of the oxygen required to oxidize organic matter in a water sample.
- Coulombic efficiency (%)
- fraction of charge output to charge input by which the electrons are transferred and an electrochemical reaction is facilitated.
- Current density (A.m–2)
- amount of charge generated or applied to a
References (119)
Three perspectives on sustainable food security: efficiency, demand restraint, food system transformation. What role for life cycle assessment?
J. Clean. Prod.
(2014)The story of phosphorus: global food security and food for thought
Glob. Environ. Chang.
(2009)A study of a urine separation system in an ecological village in northern Sweden
Water Sci. Technol.
(1997)Urea hydrolysis and precipitation dynamics in a urine-collecting system
Water Res.
(2003)Phosphate and potassium recovery from source separated urine through struvite precipitation
Water Res.
(2007)Low-cost struvite production using source-separated urine in Nepal
Water Res.
(2011)- et al.
Struvite precipitation from urine with electrochemical magnesium dosage
Water Res.
(2013) A design of experiments to assess phosphorous removal and crystal properties in struvite precipitation of source separated urine using different Mg sources
Chem. Eng. J.
(2016)Source-separated urine opens golden opportunities for microbial electrochemical technologies
Trends Biotechnol.
(2015)Hydrogen production and ammonium recovery from urine by a Microbial Electrolysis Cell
Int. J. Hydrog. Energy
(2014)
Energy efficient reconcentration of diluted human urine using ion exchange membranes in bioelectrochemical systems
Water Res.
Ammonia recovery from urine in a scaled-up Microbial Electrolysis Cell
J. Power Sources
Influence of carbon anode properties on performance and microbiome of Microbial Electrolysis Cells operated on urine
Electrochim. Acta
Anaerobic biological fermentation of urine as a strategy to enhance the performance of a microbial electrolysis cell (MEC)
Renew. Energy
Ammonium recovery and energy production from urine by a microbial fuel cell
Water Res.
Miniature microbial fuel cells and stacks for urine utilisation
Int. J. Hydrog. Energy
Towards effective small scale microbial fuel cells for energy generation from urine
Electrochim. Acta
Current generation in membraneless single chamber microbial fuel cells (MFCs) treating urine
J. Power Sources
Power generation and contaminant removal in single chamber microbial fuel cells (SCMFCs) treating human urine
Int. J. Hydrog. Energy
Urine transduction to usable energy: a modular MFC approach for smartphone and remote system charging
Appl. Energy
PEE POWER® urinal II–Urinal scale-up with microbial fuel cell scale-down for improved lighting
J. Power Sources
A novel anode fabricated by three-dimensional printing for use in urine-powered microbial fuel cell
Biochem. Eng. J.
Resource recovery microbial fuel cells for urine-containing wastewater treatment without external energy consumption
Chem. Eng. J.
Electricity production from human urine in ceramic microbial fuel cells with alternative non-fluorinated polymer binders for cathode construction
Sep. Purif. Technol.
Urine microbial fuel cells in a semi-controlled environment for onsite urine pre-treatment and electricity production
J. Power Sources
Investigation of ceramic MFC stacks for urine energy extraction
Bioelectrochemistry
Enhanced MFC power production and struvite recovery by the addition of sea salts to urine
Water Res.
Removal of a cannabis metabolite from human urine in microbial fuel cells generating electricity
Bioresour. Technol. Reports
How to avoid pharmaceuticals in the aquatic environment
J. Biotechnol.
Treatment processes for source-separated urine
Water Res.
A comprehensive review of microbial electrolysis cells (MEC) reactor designs and configurations for sustainable hydrogen gas production
Alex. Eng. J.
Reactor concepts for bioelectrochemical syntheses and energy conversion
Trends Biotechnol.
Characterization of microbial current production as a function of microbe–electrode-interaction
Bioresour. Technol.
Bioanode performance in bioelectrochemical systems: recent improvements and prospects
Trends Biotechnol.
Electricity generation from starch processing wastewater using microbial fuel cell technology
Biochem. Eng. J.
Effectiveness of domestic wastewater treatment using microbial fuel cells at ambient and mesophilic temperatures
Bioresour. Technol.
Electricity generation and modeling of microbial fuel cell from continuous beer brewery wastewater
Bioresour. Technol.
Electricity generation using chocolate industry wastewater and its treatment in activated sludge based microbial fuel cell and analysis of developed microbial community in the anode chamber
Bioresour. Technol.
The Feeding of the Nine Billion: Global Food Security for the 21st Century
Food security: the challenge of feeding 9 billion people
Science
Closing the loop: recycling nutrients to agriculture
Waste design and source control lead to flexibility in wastewater management
Water Sci. Technol.
Impact of separate urine collection on wastewater treatment systems
Water Sci. Technol.
A new planning and design paradigm to achieve sustainable resource recovery from wastewater
Environ. Sci. Technol.
Swedish experiences with urine separating systems
Wasser und Boden
Peer reviewed: re-engineering the toilet for sustainable wastewater management
Environ. Sci. Technol.
High acceptance of urine source separation in seven European countries: a review
Environ. Sci. Technol.
Biologically induced precipitation in urine-collecting systems
Water Sci. Technol. Water Supply
Nitrogen and phosphorus recovery from human urine by struvite precipitation and air stripping in Vietnam
CLEAN–Soil Air Water
Cited by (37)
Integrated processes for simultaneous nitrogen, phosphorus, and potassium recovery from urine: A review
2024, Journal of Water Process EngineeringHarnessing Pseudomonas putida in bioelectrochemical systems
2024, Trends in BiotechnologyRecovery of reactive nitrogen from wastewater using bioelectrochemical systems
2023, Separation and Purification TechnologyCurrent scenario and challenges in recycling of human urine generated at source in rail coaches as resource
2023, Current Opinion in Green and Sustainable ChemistryNutrients in a circular economy: Role of urine separation and treatment
2023, DesalinationMicrobial electrochemical technologies assisted nitrogen recovery from different wastewater sources: Performance, life cycle assessment, and challenges
2023, Resources, Conservation and Recycling