Wastewater Treatment Plant Transformation

Wastewater Plants: Can They Become Energy Neutral?

Rhea Morgan in Climate & Environment December 2025 • 4 min read.

"Deammonification and other strategies are paving the way for energy-neutral wastewater treatment, reducing costs and environmental impact."

Wastewater treatment, an essential service for public health and environmental protection, is also an energy-intensive process. Traditional wastewater treatment plants (WWTPs) consume significant amounts of electricity, contributing to operational costs and carbon footprints. However, innovative approaches are transforming these facilities from energy consumers into potential energy producers.

The concept of energy-neutral wastewater treatment is gaining traction, driven by the need for sustainable and cost-effective solutions. This involves minimizing energy consumption while maximizing the recovery of energy from wastewater. By implementing advanced technologies and optimizing treatment processes, WWTPs can significantly reduce their reliance on external energy sources and even generate surplus energy.

This article explores the strategies and technologies enabling wastewater treatment plants to achieve energy neutrality, focusing on the deammonification process and its integration with other energy-efficient practices. Learn how these innovations not only reduce energy consumption but also contribute to a more sustainable and circular economy.

Unlocking Energy Neutrality: The Deammonification Advantage

Wastewater Treatment Plant Transformation

Deammonification is a biological process that removes nitrogen from wastewater, particularly from side streams rich in ammonia. Unlike traditional nitrification-denitrification, deammonification requires less energy and fewer resources, making it an attractive option for WWTPs aiming for energy neutrality. By treating side streams with deammonification, plants can reduce the overall nitrogen load and optimize downstream processes for further energy savings.

A case study simulation of a medium-sized Polish WWTP (115,000 p.e.) demonstrates the potential of deammonification. The simulation explored various scenarios, including the implementation of deammonification and the optimization of mainstream reactor operations. The results indicated significant energy savings and cost reductions through reduced sludge retention time and optimized oxygen concentration in the main stream reactors.

Reduced Energy Consumption: Deammonification lowers the energy demand for nitrogen removal, a major energy-consuming process in WWTPs.
Cost Savings: Lower energy consumption translates directly into reduced operational costs for the plant.
Optimized Mainstream Processes: Lower nitrogen loads allow for the optimization of mainstream reactors, further reducing energy consumption.

Another strategy for achieving energy neutrality involves chemically assisted primary sedimentation (CAPS). CAPS enhances the removal of carbon from wastewater during the primary treatment stage. This diverted carbon can then be used for sludge anaerobic digestion to produce methane. The methane can then be used for energy production in combined heat and power (CHP) units, further reducing the plants need for external energy.

The Future is Neutral: A Sustainable Path for Wastewater Treatment

Achieving energy neutrality in wastewater treatment plants is not just an aspirational goal but a practical and achievable objective. By implementing strategies like deammonification, CAPS, and sludge anaerobic digestion, WWTPs can significantly reduce their energy consumption, lower operational costs, and contribute to a more sustainable future.

The Polish WWTP simulation highlights the potential for substantial savings and environmental benefits. While the optimal approach may vary depending on the specific characteristics of each plant, the underlying principles remain the same: minimize energy consumption, maximize resource recovery, and embrace innovative technologies.

As the demand for sustainable solutions continues to grow, energy-neutral wastewater treatment is poised to become the new standard. By investing in these advanced technologies and optimizing treatment processes, communities can transform their WWTPs from costly burdens into valuable resources, paving the way for a cleaner, more sustainable future.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1051/e3sconf/20172200070, Alternate LINK

Title: Towards Energy Neutrality Of Wastewater Treatment Plants Via Deammonification Process

Subject: General Medicine

Journal: E3S Web of Conferences

Publisher: EDP Sciences

Authors: Kamil Janiak, Andrzej Łojek, Mateusz Muszyński-Huhajło

Published: 2017-01-01

Everything You Need To Know

What does it mean for a wastewater treatment plant to be 'energy-neutral'?

Energy-neutral wastewater treatment aims to minimize energy consumption while maximizing energy recovery from wastewater. This involves implementing advanced technologies such as deammonification and optimizing treatment processes like sludge digestion. The goal is for wastewater treatment plants (WWTPs) to significantly reduce their reliance on external energy sources and even generate surplus energy, transforming them from energy consumers into potential energy producers.

What is deammonification, and how does it help wastewater treatment plants become more energy-neutral?

Deammonification is a biological process used to remove nitrogen from wastewater, especially from side streams rich in ammonia. It's advantageous because, unlike traditional nitrification-denitrification, deammonification requires less energy and fewer resources. By treating side streams with deammonification, wastewater treatment plants can reduce the overall nitrogen load, which then allows for the optimization of downstream processes and further energy savings. This directly contributes to the goal of energy neutrality.

How does chemically assisted primary sedimentation (CAPS) contribute to energy neutrality in wastewater treatment?

Chemically assisted primary sedimentation (CAPS) enhances the removal of carbon from wastewater during the primary treatment stage. This diverted carbon is then used for sludge anaerobic digestion to produce methane, a biogas that can be harnessed as a renewable energy source. The methane can then be used for energy production in combined heat and power (CHP) units, significantly reducing the plant's need for external energy and contributes to energy neutrality.

What did the simulation of the Polish wastewater treatment plant reveal about the benefits of deammonification?

The simulation of a medium-sized Polish wastewater treatment plant (WWTP) with 115,000 p.e. demonstrated the potential of deammonification. By exploring scenarios that included implementing deammonification and optimizing mainstream reactor operations, the simulation revealed significant energy savings and cost reductions. These benefits were achieved through reduced sludge retention time and optimized oxygen concentration in the main stream reactors. This simulation highlights that deammonification reduces energy consumption and optimizes mainstream processes.

What are the broader implications and benefits of achieving energy neutrality in wastewater treatment plants?

Achieving energy neutrality in wastewater treatment plants offers numerous benefits. Besides reducing operational costs through lower energy consumption, it significantly reduces the carbon footprint, contributing to environmental protection. Furthermore, by embracing technologies like deammonification, CAPS, and sludge anaerobic digestion, wastewater treatment plants move towards a circular economy model, where waste is viewed as a resource for energy production, promoting sustainability and resilience.