With 80% of wastewater globally discharged untreated and non-renewable energy resources rapidly depleting, the call for sustainable solutions has never been louder.Nature-Based Technologies for Wastewater Treatment and Bioenergy Production explores the groundbreaking integration of natural systems and advanced technologies to address critical global challenges in wastewater management and renewable energy. This book delves into nature-based technological approaches such as constructed wetlands, bio-aided filtration systems, and photobioreactors for microalgae cultivation, showcasing their potential to transform wastewater into a valuable resource while significantly reducing the environmental footprint.Rooted in innovative research, the book emphasizes advanced techniques for nutrient recovery, pollutant removal, and carbon capture. It examines the role of emerging technologies, such as high-rate algal ponds and hybrid treatment systems, in achieving cost-effective and energy-efficient wastewater treatment. Highlighting the science behind microalgae-based biodiesel production, the book also explores the potential of algae-derived bioproducts such as biofertilizers, bioplastics, and animal feed supplements, underscoring the role of these innovations in building a sustainable bioeconomy.Rich in real-world applications, this reference work provides practical insights for academia, researchers, students, industry professionals, scholars, practitioners, and policymakers. It addresses critical issues such as wastewater management, rising energy demands, and carbon footprint while demonstrating scalable solutions for global implementation.Nature-Based Technologies for Wastewater Treatment and Bioenergy Production envisions a future where nature-inspired technologies lead to a thriving circular bioeconomy. By combining natural processes with advanced technologies, this book lays the roadmap for transforming environmental challenges into sustainable opportunities and fostering cleaner and more resilient planetary health.