Urban wastewater treatment plants as resource hubs: evaluating circularity and sustainability of nutrient recovery and water reuse.

Wastewater treatment plants (WWTPs) are evolving from pollution control facilities into resource recovery hubs, aligning with circular economy principles. However, assessing their transition requires robust methodologies that integrate environmental, economic, and circularity dimensions. This study aims to evaluate the sustainability and circularity performance of a WWTP in Cyprus upgraded with additional treatment stages to recover nutrient-rich sludge for fertilizer and treated water for irrigation.

Towards circular desalination: A new methodology for measuring and assessing resource flows and circular actions.

There is a lack of methodologies that quantitatively measure the intrinsic circularity of desalination systems, particularly focusing on resource flow traceability and circular actions. This study proposes a novel framework for assessing the circular economy performance of desalination systems. By integrating a systemic indicator selection and calculation approach, this methodology enables a comprehensive evaluation of intrinsic circularity in desalination processes.

Systematic assessment of wastewater resource circularity and sustainable value creation.

The circular use of wastewater has attracted significant attention in recent years. However, there is a lack of universal definitions and measurement tools that are required to achieve the circular economy's full potential. Therefore, a methodology was developed using three indicator typologies, namely resource flow, circular action, and sustainability indicators, to facilitate a robust and holistic circularity assessment.

Indicator based multi-criteria decision support systems for wastewater treatment plants.

Wastewater treatment plant decision makers face stricter regulations regarding human health protection, environmental preservation, and emissions reduction, meaning they must improve process sustainability and circularity, whilst maintaining economic performance. This creates complex multi-objective problems when operating and selecting technologies to meet these demands, resulting in the development of many decision support systems for the water sector. European Commission publications highlight their ambition for greater levels of sustainability, circularity, and environmental and human health protection, which decision support system implementation should align with to be successful in this region.

Tracing wastewater resources: Unravelling the circularity of waste using source, destination, and quality analysis.

Current circularity assessment terminology restricts application to wastewater processes due to the focus on technical systems. Waste stream and wastewater discharge circularity definitions lead to paradoxical assessments that generate results of little value for evidence-based decision making. Therefore, a classification approach was developed to measure inflow and outflow circularity of the main wastewater resource flows using the principle of traceability, adopting the attitude that not all waste is created equally.