Circular wastewater treatment solutions

Frontiers in Science Viewpoint

From wastewater treatment to value recovery: the promise of microbial electrochemical technologies

Prof Bruce E. Rittmann and Prof César I. Torres, Arizona State University, USA—Earliest impacts of microbial electrochemical technologies may emerge as infrastructure upgrades that boost digester performance and enable real-time monitoring and process control.

Portrait of Prof Veera Gnaneswar Gude. He is looking at the camera.

Published on 18 Mar 2026

Advancing microbial electrochemical technologies for the circular economy, energy resilience, and environmental sustainability

Prof Veera Gnaneswar Gude, Purdue University Northwest, USA—Microbial electrochemical technologies must evolve through optimized electron transfer, integrated treatment-resource recovery, and AI-informed design supporting nexus-based, circular economy applications beyond conventional wastewater treatment.

POLICY OUTLOOK

Waste streams hold the key to water-related sustainable development

Prof Manzoor Qadir, United Nations University Institute for Water, Environment and Health, Canada—Scaling wastewater systems for water security, nutrient reuse, and energy production requires fit-for-purpose regulation, trusted nutrient markets, public-private investment, and cross-sector policies.

Key points

Microbial electrochemical technologies (METs) present a transformative approach to wastewater treatment by simultaneously enabling energy recovery, clean water production, and nutrient recycling.

Global wastewater could produce over 800,000 GWh of chemical energy annually, and this is currently largely untapped.

The recovery of ammonia and phosphate using METs offers a compelling route to circular nutrient management and sustainable agriculture.

Despite promising lab-scale results, METs face challenges in scalability, energy efficiency, and cost, with pilot-scale systems often underperforming due to increased resistance and complex wastewater matrices.

Integrating METs with established treatment systems (e.g., anaerobic digestion or membrane bioreactors) and novel applications (e.g., hydroponics or remote sensors) extends their viability for both centralized and decentralized sanitation solutions.

Field deployments in underserved regions demonstrate the potential of METs for low-cost, decentralized energy and sanitation infrastructure, addressing multiple Sustainable Development Goals.

For all readers

EXPLAINER

Frontiers for Young Minds

How microbe-powered tech cleans and recovers value from wastewater

A summary of the lead article in a Q&A format, with a video.

The Hidden Potential of What We Flush

A version of the lead article written for—and peer reviewed by—kids aged 8-15 years.

News

Side-by-side photos of Prof Uwe Schröder, Prof Falk Harnisch, Prof Elizabeth Heidrich, and Dr Ioannis A. Ieropoulos They are looking at the camera and smiling.

Frontiers in Science: How bacteria can reclaim lost energy, nutrients, and clean water from wastewater

Wastewater contains untapped resources that, if reclaimed, could power agriculture, global sanitation, and its own treatment to help us meet UN SDG goals. (Photos: Prof Uwe Schröder of University of Greifswald, Germany, Prof Falk Harnisch of UFZ-Helmholtz Centre for Environmental Research, Germany, Prof Elizabeth Heidrich of Newcastle University, UK, and Dr Ioannis A. Ieropoulos of University of Southampton, UK).

Microbial tech taps energy in wastewater

A review published in Frontiers in Science concludes that wastewater streams contain significant reserves of energy and nutrients that could be recovered to support agriculture, sanitation infrastructure and treatment operations.

Published on 25 Feb 2026

How bacteria can reclaim lost energy, nutrients, and clean water from wastewater

Wastewater contains untapped resources that, if reclaimed, could power agriculture, global sanitation, and its own treatment to help us meet UN SDG goals, according to a recent review published in Frontiers in Science.

Recovering lost energy, nutrients and clean water from wastewater using bacteria

Every year, we produce approximately 359 billion cubic meters of wastewater worldwide. Half of this is discarded, while the rest is expensively and inefficiently treated for reuse. Using bacteria, we could recover these resources from the sewage system, save money, and reduce environmental damage.

Microbial technology may be key to water crisis

Wastewater contains untapped resources that, if reclaimed, could power agriculture, global sanitation and its own treatment to help the world meet UN SDG goals, according to a review published in Frontiers in Science.

Bacteria could unlock untapped resources from wastewater

Scientists reveal how bacteria could help reclaim energy, nutrients and clean water from wastewater.

Published on 01 Mar 2026

Bacteria instead of power plants: is the energy revolution in our toilets?

Sewage is not just a nuisance, but a gigantic, untapped reservoir of energy and valuable minerals. Scientists suggest that with the help of special bacteria, we can turn this "dirty" problem into a net benefit for the entire planet.

Published on 03 Mar 2026

Wastewater as a source of energy and raw materials: how technology with microbes makes it possible

An international research review published in Frontiers in Science, led by the University of Greifswald, demonstrates the enormous potential of microbial electrochemical technologies (METs) for environmental and resource conservation.