In the quest for sustainable wastewater management, researchers have made a significant stride by demonstrating the potential of aerobic granular sludge (AGS) to produce high-value biopolymers. A recent study led by Manveer Kaur from the School of Engineering at the University of Northern British Columbia has shown that AGS can be engineered to recover xanthan, a valuable biopolymer, while maintaining high treatment performance. This research, published in the journal ‘Cleaner Water’ (which translates to ‘Clean Water’ in English), opens new avenues for resource recovery and circular economy principles in the wastewater industry.
The study is the first to examine xanthan biosynthesis and recovery in AGS systems, offering an alternative to conventional carbohydrate-rich fermentation methods that are often energy-intensive and costly. “Recovering high-value biopolymers from wastewater not only supports pollution control but also generates valuable resources,” Kaur explained. “This approach aligns with the principles of a circular economy and integrated water-resource management.”
The research team assessed the effects of organic loading rate (OLR), carbon-to-nitrogen ratio (C/N), and feeding strategy on xanthan yield in nine experimental runs treating synthetic wastewater. The results were promising, with maximum xanthan yields occurring at specific OLR and C/N ratios. “We found that the organic loading rate had a strong positive correlation with xanthan yield, while the carbon-to-nitrogen ratio showed a moderate, non-significant negative correlation,” Kaur noted. “The feeding strategy, however, had minimal influence on the yield.”
The study confirmed that AGS performance remained stable under all conditions, with excellent settling and high chemical oxygen demand (COD) removal. Ammonia-nitrogen and phosphorus removals were also significant, averaging around 73% and 72%, respectively. Fourier transform infrared and proton nuclear magnetic resonance spectroscopies confirmed the structural similarity between the recovered xanthan and commercial xanthan gum.
The implications of this research are far-reaching. By engineering AGS to recover xanthan, the wastewater industry can advance sustainable management practices and contribute to biopolymer production. This innovation could have significant commercial impacts, particularly in the energy sector, where biopolymers are used in various applications, including enhanced oil recovery and drilling fluids.
“Our findings demonstrate that AGS can be a valuable tool for resource recovery and sustainable wastewater management,” Kaur said. “This research paves the way for future developments in the field, potentially leading to more efficient and cost-effective biopolymer production methods.”
As the world continues to seek sustainable solutions for wastewater management, this study highlights the importance of integrating resource recovery into treatment processes. By doing so, the wastewater industry can not only mitigate pollution but also generate valuable resources, contributing to a more circular and sustainable economy. The research published in ‘Cleaner Water’ serves as a testament to the potential of AGS in achieving these goals, offering a glimpse into the future of wastewater treatment and resource recovery.