Enhanced effectiveness of medium-pressure ultraviolet lamps on human adenovirus 2 and its possible mechanism

2009 ◽  
Vol 60 (4) ◽  
pp. 851-857 ◽  
Author(s):  
Gwy-Am Shin ◽  
Jung-Keun Lee ◽  
Karl G. Linden

There has been growing concern over human exposure to adenoviruses through drinking water due to their apparent high resistance to UV irradiation and the anticipated widespread use of ultraviolet (UV) disinfection in drinking water treatment processes. However, most inactivation studies on adenoviruses were performed using only one type of UV technology—low-pressure (LP) UV, and little is known about the effectiveness of different UV technologies such as medium- pressure (MP) UV or other polychromatic UV technologies. In this work, the kinetics and extent of inactivation of a human adenovirus (adenovirus 2 (Ad2)) by both monochromatic LP and polychromatic MP UV were evaluated to determine the effectiveness of these UV technologies on human adenoviruses. Inactivation of Ad2 by LP UV was very slow and only 0.87 and 2.17 log10 inactivation was achieved with UV doses of 30 and 90 mJ/cm2, respectively. However, inactivation of Ad2 by MP UV was much faster and 2.19 and 5.36 log10 inactivation was observed with the same UV doses (30 and 90 mJ/cm2, respectively). It appears that MP UV is more effective against Ad2 than LP UV and the enhanced effectiveness of MP UV on Ad2 is likely due to its ability to inhibit the repair process in UV-irradiated Ad2.

2010 ◽  
Vol 56 (7) ◽  
pp. 606-609 ◽  
Author(s):  
Gwy-Am Shin ◽  
Jung-Keun Lee

In an effort to reduce human exposure to adenoviruses through drinking water, we determined the effectiveness of sequential disinfection with an alternative ultraviolet (UV) technology (medium-pressure (MP) UV) and monochloramine. The results of this study showed that MP UV was much more effective than traditional UV technology (low-pressure (LP) UV) against human adenovirus 2 (Ad2). Specifically, an inactivation of ~3 log10 was achieved by a dose of 40 mJ/cm2 of MP UV compared to ~1 log10 by the same dose of LP UV. However, because of the ineffective inactivation of Ad2 by monochloramine, a very high dose (40 mJ/cm2) of MP UV and a very large Ct99 value (~1200 mg/L·min) was still needed to achieve a significant inactivation (e.g., 4 log10) of Ad2. Also, it appears that the inactivation of Ad2 by monochloramine is not enhanced by prior exposure to MP UV. Overall, the results of this study indicated that, in spite of the enhanced effectiveness of alternative UV technologies on human adenoviruses, sequential disinfection with an alternative UV technology (MP UV) and monochloramine still may not provide adequate inactivation of human adenoviruses — especially at high pH and low temperature — in drinking water treatment processes.


2013 ◽  
Vol 47 (16) ◽  
pp. 5955-5976 ◽  
Author(s):  
Jessica Benner ◽  
Damian E. Helbling ◽  
Hans-Peter E. Kohler ◽  
Janneke Wittebol ◽  
Elena Kaiser ◽  
...  

2009 ◽  
Vol 60 (3) ◽  
pp. 709-715 ◽  
Author(s):  
Kim van Schagen ◽  
Luuk Rietveld ◽  
Alex Veersma ◽  
Robert Babuška

Owing to the nature of the treatment processes, monitoring the processes based on individual online measurements is difficult or even impossible. However, the measurements (online and laboratory) can be combined with a priori process knowledge, using mathematical models, to objectively monitor the treatment processes and measurement devices. The pH measurement is a commonly used measurement at different stages in the drinking water treatment plant, although it is a unreliable instrument, requiring significant maintenance. It is shown that, using a grey-box model, it is possible to assess the measurement devices effectively, even if detailed information of the specific processes is unknown.


2006 ◽  
Vol 6 (4) ◽  
pp. 17-25 ◽  
Author(s):  
A. Ried ◽  
J. Mielcke

The use of ozone and/or UV for water treatment processes is often a combination of an ozone and/or UV-step with additional treatment steps, e.g. biological treatment, flocculation, filtration and activated carbon. Therefore, it is necessary to develop an optimized combination of these different steps. This article will demonstrate the advantages presenting two examples for drinking water treatment and two examples for municipal wastewater treatment.


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