Nature-Based Technologies for Wastewater Treatment and Bioenergy ProductionOpen Access
An accessible ePub edition is available here
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.
ISBN: 9781789064094 (paperback)
ISBN: 9781789064100 (eBook)
ISBN: 9781789064117 (ePub)
Chapter 7: Open and closed photobioreactors for microalgal cultivation and wastewater treatment Open Access
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Published:February 2025
S. A. Laizu, L. H. S. Hassan, I. Ahmad, 2025. "Open and closed photobioreactors for microalgal cultivation and wastewater treatment", Nature-Based Technologies for Wastewater Treatment and Bioenergy Production, Imran Ahmad, Norhayati Abdullah
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Abstract
The utilization of microalgae in wastewater treatment (WWT) witnesses a global interest. From this sector, there are two main cultivation systems that can be used for microalgae cultivation, either open or closed systems; the choice of which of these cultivation systems to be used depends on the purpose of the produced biomass. Use of closed photobioreactors (PBRs) is better than open systems because they can provide uncontaminated monoalgal culture. Design of PBR allows controlling light intensity, light penetration ratio, with good gas exchange sectors, air/carbon dioxide supply, and mixing strategy. Different configurations of PBRs, including aerobic, horizontal tube, moving tank, and tubular aerobic PBRs, are studied in terms of their design, operation, and performance, with emphasis on their efficiency in generating microalgae biomass. Airlift pressure-feedback PBRs are energy-efficient and improve mass transfer in both internal and external loop configurations. Horizontal tube PBRs maximize light exposure but face biofouling and uneven distribution. Stirred tank PBRs have good mixing efficiency but limited light penetration and high energy requirements. PBRs are preferred for continuous cultivation systems due to their superior light penetration and high biomass productivity. The most common PBRs are flat panel reactors, tubular, and bubble column PBRs. Microalgae cultivation technology using PBRs depends on cultivation mode, factors that control the optimal growth, and harvesting techniques. PBRs are used in WWT, with suspended systems offering economical alternatives. Fixed systems, such as PBRs, improve separation but struggle with accurate biomass measurement. Hence, this chapter emphasizes the need for engineering improvements and optimization techniques to overcome operational and economic limitations of open and closed PBRs. This provides an overview of commercial WWT using microalgae, highlighting growth factors, different types and designs, and their applications.