Chlorella pyrenoidosa-mediated removal of pathogenic bacteria from municipal wastewater – Multivariate process optimization and application in the real sewage. Issue 2 (April 2023)

• Record Type: Journal Article
• Authors: Bhatt, Ankita; Arora, Pratham; Prajapati, Sanjeev Kumar
• Is Part Of: Journal of environmental chemical engineering. Volume 11:Issue 2(2023)
• Publication Date: 2023-04
• Subjects: Microalgae -- Pathogens -- Process optimization -- Sewage -- Wastewater treatment -- Phycoremediation; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2023.109494
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: The use of microalgae for pathogen removal from wastewater has been recently brought to the limelight. However, the optimized conditions for microalgae-mediated pathogen removal (MAPR) have not been established yet. The present work is the first attempt to employ a multivariate optimization approach, the Taguchi method, for MAPR optimization. Interestingly, Chlorella pyrenoidosa demonstrated high Escherichia coli removal rates (90.1–99.9 %) from low, medium, and high-strength synthetic municipal wastewater. Process optimization revealed that 12, 000 lux illumination and 37 °C were optimal conditions to achieve maximum E. coli removal from high-strength wastewater (600 mg L −1 biochemical oxygen demand). Results indicated that the interplay between C. pyrenoidosa and E. coli is most probably governed by photooxidation since increased illumination was associated with a 93 % reduction in the removal time. Furthermore, a substantial decline in the pathogen load (92 % decline in total bacteria count) was observed in real sewage through C. pyrenoidosa cultivation at optimized conditions . Additionally, 98 % Enterobacteriaceae removal and 96 % Salmonella sp. removal were also observed from real sewage in presence of C. pyrenoidosa . Hence, MAPR results demonstrated the robustness of C. pyrenoidosa for pathogen removal from wastewater. Overall, the present study established a set of optimized conditions that could be exploited for mechanistic investigation or scale-up studies for real-world applications. Graphical Abstract: ga1 Highlights: Efficiency of C. pyrenoidosa to remove E. coli from wastewater was investigated. Taguchi method was employed for multiparameter process optimization. C. pyrenoidosa achieved 92 % removal of total bacteria from real sewage. C. pyrenoidosa removed 98 % Enterobacteriaceae and 96 % Salmonella sp. from real sewage. Wastewater strength and illumination are crucial for pathogen removal.