Advancing resource recovery from sewage sludge with IoT-based bioleaching and anaerobic digestion techniques

The growing global focus on sustainable waste management has recognized sewage sludge (SS) as a valuable resource rather than just a disposal challenge. This review explores the integration of Internet of Things (IoT) technologies with bioleaching (BL) and anaerobic digestion (AD) to enhance resource recovery from SS. BL employs microbial metabolism to extract heavy metals (HMs), while AD offers an efficient method for biogas production and nutrient recovery. Both processes are influenced by environmental factors such as temperature, pH, microbial activity, and substrate composition, which affect the quality and quantity of by-products. By leveraging IoT technologies, real-time monitoring and optimization of these parameters can be achieved, minimizing adverse effects and maximizing resource recovery. IoT-based solutions can also reduce operational costs, energy consumption, and environmental impacts through predictive maintenance and process automation. The HMs extracted through BL can be utilized in various industrial sectors, while the residual sludge can be integrated into AD systems for biogas production. The resulting biogas can be used for energy, and the digestate serves as an organic fertilizer, enhancing soil quality. This synergistic approach not only reduces the environmental impact of conventional SS treatment but also promotes sustainable resource management and energy recovery. By combining IoT with BL and AD, this review presents an innovative framework for addressing the challenges posed by SS and advancing circular economy practices through waste-to-value strategies.