Growth and repair potential of three species of bacteria in reclaimed wastewater after UV disinfection.
- Author:
MeiTing GUO
1
;
JingJing HUANG
;
HongYing HU
;
WenJun LIU
Author Information
- Publication Type:Journal Article
- MeSH: Bacillus subtilis; radiation effects; Dose-Response Relationship, Radiation; Escherichia coli; radiation effects; Time Factors; Ultraviolet Rays; Waste Disposal, Fluid; Water Microbiology; Water Purification
- From: Biomedical and Environmental Sciences 2011;24(4):400-407
- CountryChina
- Language:English
-
Abstract:
OBJECTIVEThe growth and repair potential of three typical microorganisms in reclaimed water after UV disinfection was investigated to assess the effects of photo-reactivation and dark repair of microorganisms, and the microbial safety of reclaimed water following this procedure.
METHODSThe growth and repair potential of Escherichia coli, a fecal coliform strain and Bacillus subtilis in the effluent of a biological wastewater treatment plant disinfected by a low-pressure UV lamp were investigated.
RESULTSAny increase in bacterial numbers in the effluent after UV disinfection was due to damage repair. Exposure to photo-reactivating light for 8-10 h after UV irradiation with a dose of 5 mJ/cm(2), the highest percentage of photo-reactivation observed for E. coli and the fecal coliform strain was 29% and 15% respectively. B. subtilis showed little photo-reactivation under these conditions. The percentage of photo-reactivation was related to the UV dose and the photo-reactivating time, and a function was developed to forecast the final concentrations of E. coli and the fecal coliform strain after UV disinfection with possible photo-reactivation.
CONCLUSIONDifferent species of bacteria displayed different responses to UV light and different repair potentials. The repair of indigenous bacteria in wastewater needs to be investigated in future work.
