Identification of surrogates for rapid monitoring of microbial inactivation by ozone for water reuse: A pilot-scale study

• Published in: Journal of hazardous materials Vol. 424; no. Pt C; p. 127567
• Main Authors: Shi, Qi, Chen, Zhuo, Wei, Fanqin, Mao, Yu, Xu, Qi, Li, Kuixiao, Lu, Yun, Hu, Hong-Ying
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.02.2022
• Subjects: Adenosine tri-phosphate (ATP); Disinfection; Escherichia coli; Microbial Viability; Ozone; Ozone disinfection; Reproducibility of Results; Total fluorescence; Ultraviolet Rays; UV absorbance; Water; Water Purification; Water reclamation; Adenosine tri-phosphate (ATP); UV absorbance; Ozone disinfection; Total fluorescence; Water reclamation
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2021.127567

The complex contaminants in reclaimed water sources and delayed feedback of microbial detection have brought tremendous challenges to disinfection process control. The identification of sensitive and online surrogates for indicating microbial inactivation efficacy is vital to evaluate and optimize the disinfection technologies and processes. This study analyzes the inactivation of microbial indicators during ozone disinfection at a pilot-scale study over 5 months. It is identified that total fluorescence (TF) intensity, ultraviolet absorbance at 254 nm (UV254) and intracellular adenosine triphosphate (cATP) concentration can act as surrogates in predicting microbial inactivation by ozone. Particularly, the empirical linear correlations for log removal values (LRV) of TF, UV254 and cATP concentration are developed for the inactivation of four widely applied microbial indicators, namely the total coliforms, fecal coliforms, Escherichia coli (E. coli) and heterotrophic plate count (HPC) (R2 = 0.86–0.96). Validation analyses are further conducted to verify the robustness and effectiveness of empirical models. Notably, TF is considered as the most efficient surrogate due to its high sensitivity, accuracy and reliability, whereas cATP concentration is an efficient supplement to directly reflect total microbial counts. The study is important to provide a rapid and reliable approach for ozone disinfection efficiency evaluation and prediction. [Display omitted] •Inactivation of four microbial indicators by ozone was evaluated in pilot studies.•LRV of TF, UV254 and cATP concentration were selected as surrogate parameters.•Linear correlation models were established between inactivation and surrogates.•Bacteria concentration and water qualities of influent showed seasonal differences.•Validation results confirmed the effectiveness and feasibility of the models.