Sustainable sludge management through circular economy solutions for resource recovery and carbon footprint reduction

Every city relies on wastewater treatment plants to process wastewater from industrial, agricultural, and domestic sources. The byproduct of these processes is sludge, a biosolid substance rich in chemical properties. While sludge has various potential uses, improper handling can lead to significant environmental risks. This paper investigates how the Circular Economy idea might be applied to handle sludge efficiently, with the goal of reducing waste and minimizing carbon impact. The main topic of discussion is the recovery principle of the circular economy, particularly focusing on the recovery of nutrients and energy from sludge. The data for this study is drawn from sludge produced at a water treatment plant in Dubai, where it is currently disposed of in landfills. The findings reveal that 2% of the sludge can be used for nutrient extraction, 19% can be processed for energy recovery through anaerobic digestion, and the remaining portion can be incinerated to generate electricity for the entire treatment process. Further research and analysis are needed to fully understand the long-term ecological and economic advantages of this approach.<i>Implications</i>: This study demonstrates the potential for integrating Circular Economy principles into wastewater sludge management, with significant implications for environmental policy and sustainable urban planning. By recovering nutrients and energy from sludge currently sent to landfills, Dubai could reduce waste, lower carbon emissions, and contribute meaningfully to its 2030 emission reduction targets. The research provides a compelling case for policymakers to support investment in resource recovery technologies such as anaerobic digestion and incineration. Adopting these sustainable practices not only promotes energy efficiency and climate action but also strengthens the city's resilience in managing urban waste, aligning with broader regional and global sustainability goals.