Light-driven biohybrid for phosphorus recovery via struvite biomineralization in tetracycline-laden livestock wastewater
Shang Tian Yang, Andong Hu, Jia Zhang, Wei Yu, Xiaofeng Wu, Yuefei Huang, Shungui Zhou, Bing Li, Guangqian Wang
Abstract
Struvite biomineralization drives phosphate mineralization, playing a critical role in sustaining biogeochemical phosphorus cycling and industrial phosphorus recovery. Phosphorus-rich wastewater, however, frequently contains inhibitory tetracycline that suppresses microbial activity, diminishes recovery efficiency, and accumulates in recovered struvite. Semiconductor-mediated microbial photoelectrochemical process generate photogenerated electrons to stimulate microbial metabolism. Concurrently, photogenerated reactive oxygen species can degrade tetracycline. Despite extensive evidence of TC's inhibitory effects on biomineralization, the development of integrated photoelectrochemical-microbial process for simultaneous tetracycline degradation and phosphorus recovery remains unexplored. We develop a microbial photoelectrochemical system integrating microorganisms with nano-semiconductor materials. Light-activated carbon nitride generates electrons boosting microbial metabolism and holes degrading tetracycline. Coupling carbon nitride with S. oneidensis under illumination doubles biomineralization rates in tetracycline-laden wastewater versus conventional struvite biomineralization. The system achieves near-complete tetracycline degradation within 48 hours and full nitrate reduction. Those efforts achieve simultaneous phosphorus recovery and tetracycline removal from wastewater, converting pollutants into agriculturally viable struvite without pH adjustment. The system establishes an energy-efficient platform for coupled nutrient recovery and water purification, while creating a closed-loop framework for resource regeneration from contaminated wastewater.