AWWA JAW10143

In a study extending over one year at the Langford works of the Essex Water Company in England, ammonia-chlorine was compared with free residual chlorine in the pre-chlorination stage. The roles of these chemicals in trihalomethane (THM) formation, water disinfection, and zooplankton removal were investigated. Samples were taken weekly from points after chlorination and flocculation and after lime-soda softening. Tests and analyses included THM determinations, bacteriologic examination for coliforms, Escherichia coli, and fecal streptococci, and counts of the predominant zooplankton in the raw water. Disinfection with ammonia-chlorine produced significantly lower levels of haloform than free chlorine at all stages of treatment. Ammonia-chlorine also provided satisfactory disinfection and effectively reduced Copepoda. Free residual chlorine did not reduce THM levels as effectively as combined chlorine, but was more effective against Cladocera. Includes 2 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

04/01/1983

Number of Pages:

3

File Size:

1 file , 970 KB