August 20, 2020

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Benjamin Mejia-Tickner Coauthored an Article About Inactivation of Bacteria for Environmental Science & Technology

Benjamin Mejia-Tickner (Georgia) coauthored an article entitled "Inactivation of Bacteria by Peracetic Acid Combined with Ultraviolet Irradiation: Mechanism and Optimization" for publication in Environmental Science & Technology on July 9, 2020.

Ben's coauthors were Tianqi Zhang, Ting Wang, Jessica Kissel, Xing Xie, and Ching-Hua Huang.

Ben Mejia-Tickner is a Process and Remedial Design Engineer based in Georgia with experience in the fields of environmental engineering and environmental microbiology. His experience includes remedial technology selection and evaluation, process engineering design and optimization, data analysis and visualization, reporting, laboratory and field experimentation, and groundwater and process water sampling.

Environmental Science & Technology is an environmental science and technology research journal that aims to be transformational and direction-setting by publishing rigorous and robust papers for a multi-disciplinary and diverse audience of scientists, policy makers, and the broad environmental community. The journal advances rigorous scholarship on complex environmental phenomena, particularly with respect to fate, transport, and transformation in natural and engineered systems, while simultaneously facilitating the solution of critical environmental problems. In addition to novelty and significance of research, Environmental Science & Technology considers the relevance of submitted manuscripts to its broad readership.

Founded in 1876 and chartered by the U.S. Congress, the American Chemical Society (ACS) is one of the world's largest scientific organizations with more than 150,000 members in more than 140 countries. ACS's mission is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and its people. Its vision is to improve people's lives through the transforming power of chemistry.


Peracetic acid (PAA) is an emerging disinfectant for municipal wastewater treatment owing to good biocidal effects and limited harmful by-product formation. This study investigated the inactivation of Gram-negative Escherichia coli (E. coli) and Gram-positive Enterococcus durans (E. durans) and Staphylococcus epidermidis (S. epidermidis) by PAA combined with UV concurrently (UV/PAA) or sequentially (PAA-UV/PAA) for enhanced disinfection. Under UV/PAA, the contributions of different mechanisms (UV, PAA, reactive radicals (mainly •OH and CH3C(O)OO•), and the synergistic effect of all mechanisms involved) to the overall inactivation were quantitatively assessed. Results revealed that radicals played a moderate role in the enhanced disinfection, while the synergistic effect presented a greater contribution, which could be partially linked to the diffusion of PAA into the cells as evidenced for the first time by a fluorescence microscopic method. Taking advantage of PAA diffusion into bacteria, pre-exposure of PAA followed by UV/PAA was demonstrated to yield the highest disinfection efficiency. Indeed, compared to UV/PAA, PAA-UV/PAA could achieve additional 4.7–5.4, 4.1–5.3, and 2.9–3.4 log inactivation of E. coli, E. durans, and S. epidermidis, respectively, in clean water and secondary/tertiary wastewater effluents when the same amounts of PAA and UV doses were applied in both approaches. Bacterial regrowth tests confirmed minimal regrowth potential after the disinfection.

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