AWWA ACE56323

To effectively utilize a chlorine/chloramine disinfection approach, an understanding of the decay rate of chlorine and the formation rate of disinfection byproducts (DBPs) during the short period that free chlorine is in contact with the water is needed. The impact of chlorine dose, treatment, pH, and temperature upon short-term chlorine decay and DBP formation kinetics for one source water was assessed. Short-term chlorine decay kinetics were affected by dose, treatment, and pH. Temperature did not appear to have an effect on chlorine decay in the short term. Dose did not effect the kinetics relative to the long term chlorine demand. The ratio of long term chlorine demand to total organic carbon (TOC) was a useful tool for understanding the effect of treatment on the chlorine-reactivity of the remaining natural organic matter (NOM). The application of the Michaelis - Menten did not appropriately fit the data in the short term time period for any parameter set. The immediate (~ 5-min) formation of haloacetic acid (HAA9) was greater than that for total trihalomethanes (TTHM) relative to the maximum formation (120 hrs) for all experimental runs. The short term kinetics for HAA9 formation were higher than that for TTHM for all experimental runs. This implies that for some waters using a chlorine/chloramine approach the short term HAA9 formation could be limiting. Chlorine dose changes had a greater impact upon HAA9 formation than TTHM formation for all times. However, temperature and pH changes had a greater impact on TTHM formation than HAA9 formation for all times. Treatment changes equally impacted THM formation and HAA formation for all times. Studies on additional waters are ongoing. Includes 25 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

06/16/2002

Number of Pages:

20

File Size:

1 file , 440 KB