Unveiling mechanistic intricacies of Chlorella pyrenoidosa-mediated pathogen removal from sewage

Abstract

Amidst the global sanitation challenges of water pollution, waterborne diseases, and the alarming presence of pathogens in disinfected water, microalgal technology has emerged as a viable alternative for wastewater treatment. Recently, the ability of microalgae to remove pathogens from wastewater has been highlighted. However, a critical knowledge gap exists regarding microalgae-mediated pathogen removal mechanisms. The present study uncovers the intricate mechanisms of Chlorella pyrenoidosa-mediated Escherichia coli removal from sewage. Microalgae-induced pH increase was identified as the most crucial mechanism, followed by photooxidation and attachment, mediated by the hydroxyl group. Longer photoperiods or ultraviolet irradiation produced high oxidative stress, promoting microalgal exopolysaccharides’ production and increasing pathogen entrapment. The knowledge of crucial removal mechanisms can be harnessed for the development of more efficient, innovative, and scalable microalgal systems. Such improved systems offer a sustainable solution to address water-related issues by improving wastewater treatment, increasing access to clean water, and reducing the transmission risk of waterborne diseases.