Circular economy through integrated industrial ecology: Innovations in resource recovery and process re-design

Industrial ecology provides systems-thinking for re-designing industrial processes with greater resource efficiency, waste reduction, and circularity. This review discusses future directions in process re-design and holistic metrics for resource recovery across key industries such as agriculture, aquaculture, desalination, mining, textiles, pulp and paper, and food processing. Emphasis is placed on the integration of life cycle assessment (LCA), molecular economy concepts, and cascading material cycles for closed-loop system design. Technologies such as anaerobic co-digestion, microbial electrochemical systems, catalytic conversion, and membrane-based separation demonstrate potential for 20-50 % increases in biogas yields60-90 % recovery of nutrients, and up to 40 % reductions in separation energy demand compared to conventional practices. Industry-specific innovations like animal waste valorization, desalination brine treatment, and recovery of organic and inorganic compounds from industrial effluent show recovery efficiencies of 70-95 % for salts and metals under optimized conditions. System-level approaches including salinity gradient power and waste heat utilization could contribute 5-15 % additional renewable energy supply within integrated industrial parks. Nonetheless, significant gaps remain in integrating metal and nutrient cycles, scaling solutions for small- and medium-scale industries, and enabling supportive policy frameworks. The paper emphasizes the need for transdisciplinary research and systems thinking to address these challenges. By integrating technological, environmental, and economic knowledge, this review provides a roadmap for advancing circular economy strategies in industrial systems and promotes adaptive, resilient process designs that turn waste into value, mitigate environmental pressures, and support sustainable industrial development.