Carbon-Neutral Wastewater Treatment and Resource Recovery

Dear Colleagues,

The accelerating global demand for sustainable and energy-efficient wastewater treatment has brought carbon neutrality and resource recovery to the forefront of environmental engineering research. This Special Issue gathers cutting-edge advances aimed at minimizing carbon footprints, recovering valuable resources, and developing next-generation treatment systems aligned with circular economy principles. We warmly invite high-quality contributions that expand scientific understanding and provide innovative technological solutions in this rapidly evolving field.

Introduction,

Carbon neutrality has become a central objective in modern wastewater treatment and environmental resource management. Conventional biological and physicochemical treatment processes often involve significant energy consumption, excessive sludge production, and greenhouse gas (GHG) emissions, including CO₂, CH₄, and N₂O. Recent progress in bioelectrochemical systems, microbial-based nitrogen removal, anaerobic carbon recovery, and energy-positive treatment technologies is reshaping the paradigm of wastewater management.

Furthermore, the growing emphasis on circular bioeconomy encourages the recovery of energy, nutrients, water, bio-polymers, and high-value bioproducts from waste streams. These approaches not only mitigate climate and environmental impacts but also provide pathways for transforming wastewater treatment plants into resource recovery facilities (WRRFs).

Given the scientific and societal importance of this research area, more comprehensive studies are required to elucidate underlying mechanisms, assess carbon emission dynamics, integrate omics-based tools, and develop scalable, low-carbon process configurations.

We are pleased to invite you to submit your latest research findings, reviews, and perspectives to this Special Issue.

This Special Issue aims to promote interdisciplinary discussion and disseminate scientific advances that contribute to environmentally sustainable and carbon-efficient wastewater treatment across municipal, industrial, and emerging waste streams.

Suggested themes and article types for submissions:

In this Special Issue, original research articles, reviews, and short communications are welcome. Research areas may include, but are not limited to, the following:

1. Carbon-neutral and low-energy wastewater treatment processes

-Anaerobic treatment, shortcut nitrogen removal, anammox-based systems, PN/A, DAMO, DNRA

-Low-carbon process optimization and GHG mitigation strategies

2. Electrochemical and bioelectrochemical systems (BES/EBR/MFC/MEC)

- Electron-transfer mechanisms, CO₂ conversion, energy recovery

- Integrated BES with nutrient removal or resource recovery

3. Resource recovery and circular bioeconomy applications

-Recovery of nutrients (N, P), biogas, VFAs, biopolymers, biominerals

-Water reuse, carbon capture, and valorization of waste streams

4. Omics-driven insights and microbial ecology

- Metagenomics, metatranscriptomics, metabolomics, and isotopic tracing

- Microbial community dynamics in carbon-efficient treatment systems

5. Carbon footprint assessment and environmental modeling

- LCA of wastewater processes

- AI-based modeling, digital twins, and carbon-emission forecasting

6. Innovative hybrid or modular systems

- Membrane-aerated systems, dynamic membrane bioreactors, photobioreactors

- Combined physical–biological carbon-neutral treatment systems

We look forward to receiving your contributions to this Special Issue and hope it will serve as a valuable platform for advancing sustainable and carbon-neutral wastewater treatment technologies.

Prof. Dr. Jaecheul Yu
Dr. Kyung-Yup Hwang
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Applied Sciences is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• carbon-neutral wastewater treatment
• resource recovery
• greenhouse gas mitigation
• bioelectrochemical systems
• electroactive biofilms
• shortcut nitrogen removal
• anammox processes
• circular bioeconomy
• omics-based microbial analysis
• life cycle assessment (LCA)