What are the best ways to extract resources from wastewater?

1 Water Reuse

One of the most obvious and essential resources to recover from wastewater is water itself. Water reuse involves treating wastewater to a suitable quality for various purposes, such as irrigation, industrial processes, toilet flushing, or even drinking. Water reuse can save freshwater resources, reduce energy consumption, and mitigate water scarcity and pollution. Some of the technologies for water reuse include membrane filtration, disinfection, reverse osmosis, and advanced oxidation. However, water reuse also faces technical, economic, and social barriers, such as public acceptance, regulatory frameworks, and cost-effectiveness.

2 Energy Recovery

Wastewater contains organic matter that can be converted into energy through biological or thermal processes. Energy recovery can reduce greenhouse gas emissions, lower operational costs, and enhance energy security and resilience. Some of the technologies for energy recovery include anaerobic digestion, microbial fuel cells, hydrothermal liquefaction, and gasification. However, energy recovery also requires careful optimization, integration, and management of the processes and systems, as well as addressing potential environmental and health risks.

4 Metal Recovery

Wastewater contains metals such as copper, zinc, iron, and gold that can be recovered and recycled as raw materials or catalysts. Metal recovery can reduce mining impacts, increase resource efficiency, and generate economic value. Some of the technologies for metal recovery include biosorption, electrochemical deposition, adsorption, and solvent extraction. However, metal recovery also faces difficulties such as high variability, low selectivity, and high energy demand.

5 Resource Recovery Platforms

To achieve optimal resource recovery from wastewater, it is not enough to apply individual technologies in isolation. Rather, it is necessary to develop integrated platforms that combine multiple technologies and processes in a synergistic and holistic way. Resource recovery platforms can enhance the performance, reliability, and flexibility of wastewater treatment systems, as well as create new opportunities for innovation and collaboration. Some of the examples of resource recovery platforms include the water-energy-nutrient nexus, the circular economy, and the biorefinery concept. However, resource recovery platforms also require multidisciplinary research, stakeholder engagement, and policy support.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?