Time to Move on From Measuring Chlorine Residuals With Outdated Methods

The formation of nitrate and chloride as end-products of chloramination (combined chlorination) was investigated at pH ranging between 6.9 and 9.6 at 25°C. The experimental results comprised concentration-time profiles of combined chlorine residuals along with nitrate and chloride. Nitrite, if present, was always below the detectibility limit of the analytical method used (25 ppb). Mass balances on chlorine species depicted that chloride formed during the slow decay of combined chlorine residuals does not account for all the chlorine lost. This substantiates the formation of other reaction end-products which are yet to be identified. A kinetic model for chloramination is proposed based on the kinetic data obtained in this study.

Download Full-text

Detection and Estimation of Free and Combined Chlorine Residuals

Analytical Chemistry ◽

10.1021/ac60060a052 ◽

1951 ◽

Vol 23 (12) ◽

pp. 1881-1882 ◽

Cited By ~ 4

Author(s):

Isadore Nusbaum ◽

Peter Skupeko

Keyword(s):

Detection And Estimation ◽

Chlorine Residuals

Download Full-text

Modeling Chlorine Residuals in Drinking‐Water Distribution Systems

Journal of Environmental Engineering ◽

10.1061/(asce)0733-9372(1994)120:4(803) ◽

1994 ◽

Vol 120 (4) ◽

pp. 803-820 ◽

Cited By ~ 251

Author(s):

Lewis A. Rossman ◽

Robert M. Clark ◽

Walter M. Grayman

Keyword(s):

Drinking Water ◽

Distribution Systems ◽

Water Distribution ◽

Water Distribution Systems ◽

Drinking Water Distribution Systems ◽

Drinking Water Distribution ◽

Chlorine Residuals

Download Full-text

What is Behind Chlorine Residuals? - Two Plants with Two Strategies in the Same City

Proceedings of the Water Environment Federation ◽

10.2175/193864709793956680 ◽

2009 ◽

Vol 2009 (16) ◽

pp. 960-971

Author(s):

Weihua (Peter) Peng

Keyword(s):

Chlorine Residuals

Download Full-text

Colorimetric Determination of Chlorine Residuals up to 10 ppm. With Ortho-tolidine

American Water Works Association ◽

10.1002/j.1551-8833.1943.tb19871.x ◽

1943 ◽

Vol 35 (8) ◽

pp. 1065-1084 ◽

Cited By ~ 5

Author(s):

N. S. Chamberlin ◽

J. R. Glass

Keyword(s):

Colorimetric Determination ◽

Chlorine Residuals

Download Full-text

Removal Efficiencies of Indicator Micro-Organisms in Sewage Treatment Plants

Water Science & Technology ◽

10.2166/wst.1989.0088 ◽

1989 ◽

Vol 21 (3) ◽

pp. 119-124 ◽

Cited By ~ 14

Author(s):

T. Omura ◽

M. Onuma ◽

J. Aizawa ◽

T. Umita ◽

T. Yagi

Keyword(s):

Activated Sludge ◽

Sewage Treatment ◽

High Rate ◽

Coliform Bacteria ◽

Minor Role ◽

Activated Sludge Process ◽

Trickling Filter ◽

Sewage Treatment Plants ◽

Micro Organisms ◽

Chlorine Residuals

The removal of coliform bacteria, enterococcus bacteria, and coliphages in two sewage treatment plants, one using the activated sludge process and the other using a high-rate trickling filter, was investigated over a period of one year. Coliform and enterococcus bacteria were removed with equal efficiency by the two plants, but coliphages were removed more efficiently by the activated sludge process. Experiments on the mechanism of removal revealed that it was mainly due to adsorption on the activated sludge and on the slime in the trickling filter. Die-off of the micro-organisms seemed to play a minor role in the reduction in counts. The treated sewage was disinfected by chlorination prior to discharge into the receiving water. No coliforms were detected in the chlorinated effluents when they had chlorine residuals in the range of 0 to 1.521 mg/l. However, enterococci were detected when chlorine residuals dropped below 0.598 mg/l. Coliphages proved to be the most resistant organisms and they were generally detected throughout the range of chlorine residuals encountered.

Download Full-text