Article

Development of chlorine dioxide-related by-product models for drinking water treatment.

Acres and Associated Environmental Limited, Toronto, Ont, Canada.
Water Research (Impact Factor: 5.32). 02/2002; 36(1):330-42. DOI: 10.1016/S0043-1354(01)00194-4
Source: PubMed

ABSTRACT Factorial experiments were conducted using source waters from seven drinking water treatment plants in Ontario, Canada to develop statistically based model equations capable of predicting chlorine dioxide consumption and chlorite and chlorate formation upon chlorine dioxide application. The equations address raw water quality and operational parameters including pH, temperature, chlorine dioxide concentration, reaction time and water organic content (as described by non-purgeable organic carbon x ultraviolet absorbance measured at 254 nm, NPOC x UV254). Terms describing two-factor interaction effects were also included, improving the accuracy of the predictive equations in fitting measured response concentrations as evaluated through internal and external validations. Nearly 80% of the predictions for chlorine dioxide consumption and chlorite formation were observed to be within 20% of the measured levels. Over 90% of the predicted chlorate levels were within +/- 0.1 mg/L of the measured levels. Chlorine dioxide concentration and NPOC x UV254 were key parameters when developing the predictive models.

1 Follower
 · 
99 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: The presence of zooplankton in drinking water treatment system may cause a negative effect on the aesthetic value of drinking water and may also increase the threat to human health due to they being the carriers of bacteria. Very little research has been done on the effects of copepod inactivation and the mechanisms involved in this process. In a series of bench-scale experiments we used a response surface method to assess the sensitivity of copepod to inactivation when chlorine dioxide (ClO2) was used as a disinfectant. We also assessed the effects of the ClO2 dosage, exposure time, organic matter concentration and temperature. Results indicated that the inactivation rate improved with increasing dosage, exposure time and temperature, whereas it decreased with increasing organic matter concentration. Copepod inactivation was more sensitive to the ClO2 dose than that to the exposure time, while being maintained at the same Ct-value conditions. The activation energy at different temperatures revealed that the inactivation of copepods with ClO2 was temperature-dependent. The presence of organic matter resulted in a lower available dose as well as a shorter available exposure time, which resulted in a decrease in inactivation efficiency.
    Environmental Technology 11/2014; 35(22):2846-2851. DOI:10.1080/09593330.2014.924566 · 1.20 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Chlorine dioxide gas has an excellent ability for sterilization and deodorization, and is harmless to humans. However, it is very unstable and explosive as it is highly concentrated, thus its use in the air clean fields has been limited. Therefore, there is need to control chlorine dioxide gas at a low concentration for a long time. Chlorine dioxide gas could be produced slowly and sustainedly since the release of acetic acid from the polymer hydrogels delayed the reaction between acetic acid and sodium chlorite. In addition, as the amount of both acetic acid sodium chlorite loaded within the hydrogel and on the membrane increased, respectively, the generation amount of chlorine dioxide gas increased. The result shows that the use of polymer hydrogels has the potential to control the generation of chlorine dioxide gas.
    Polymer Korea 09/2013; 37(5). DOI:10.7317/pk.2013.37.5.553 · 0.43 Impact Factor
  • Source

Preview

Download
1 Download
Available from