fulltext.study @t Gmail

Elucidating bacterial regrowth: Effect of disinfection conditions in dark storage of solar treated secondary effluent

Paper ID Volume ID Publish Year Pages File Format Full-Text
26938 43988 2014 11 PDF Available
Title
Elucidating bacterial regrowth: Effect of disinfection conditions in dark storage of solar treated secondary effluent
Abstract

•240 solar disinfection experiments were performed, focusing on regrowth.•The effects treatment conditions on bacterial dark repair were evaluated.•No regrowth was observed in samples with null counts.•Regrowth was more intense in low-temperature treatment.•The alive fraction at the end of treatment influences short and long-term regrowth.

In this study, we systematically investigate solar disinfection of synthetic secondary wastewater, with the effort to decrypt the effects disinfection conditions have on post-irradiation bacterial regrowth in the dark. A full factorial design of 240 experiments was employed to investigate the effects of (i) exposure time (1, 2, 3 and 4 h), (ii) treatment temperature (20, 30, 40, 50 and 60 °C), (iii) initial bacterial concentration (103, 104, 105 and 106 CFU/mL) and (iv) sunlight intensity (0, 800 and 1200 W/m2) on Escherichia coli survival for a subsequent 48-h dark control period. The decisive implications treatment temperature inflicted in regrowth were monitored and interpreted within two temperature ranges, from 20 to 40 °C and 40 to 60 °C. In dark tests, bacterial populations presented initial moderate growths at 20–40 °C range, followed by intense regrowth. At 40–60 °C range, acute thermal inactivation without long-term regrowth predominated at 50 °C and was total at 60 °C, within the 4-h treatment period. Introduction of light resulted in higher removal rates or permanent inactivation for 800 and/or 1200 W/m2, respectively. No post-treatment regrowth in the dark was observed after 24 and 48 h, in completely inactivated samples, and its demonstration, when observed, was well correlated to the bacterial numbers at the end of the disinfection period. Statistical observations on the transferred bacterial populations from day to day are also discussed in this paper.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide

Keywords
Solar disinfection; Wastewater; Full factorial design; E. coli; Regrowth; Dark repair
First Page Preview
Elucidating bacterial regrowth: Effect of disinfection conditions in dark storage of solar treated secondary effluent
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us
Publisher
Database: Elsevier - ScienceDirect
Journal: Journal of Photochemistry and Photobiology A: Chemistry - Volume 290, 15 September 2014, Pages 43–53
Authors
, , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us