AWWA WQTC69434

The distribution system exerts an influence on treated water quality. This paperfocuses on the behavior of C, N, P, Si and S. These parameters are major nutrientsfor microbiological growth. Some of them are monitored as a check on the amountsof chemical addition in water treatment. The paper also compares theresults before and after ozone is used for primary disinfection. The Massachusetts Water Resources Authority (MWRA) hasinvestigated previously the effect of ozone in the absence of biofiltration. Weeklymonitoring of TOC and TIC show that BDOC increased due to ozone. But there wasno negative impact on water quality in terms of microbiological growth. This couldbe due to the increase in chloramine target. Weekly monitoring of ammonia, nitriteand nitrate show that there is increased conversion of ammonia to nitrate. But therewere no negative impacts from nitrification. TOC is negatively correlated withcombined nitrite and nitrate levels. The increase in nitrite and nitrate is alsonegatively correlated with the level of ozone byproducts (aldehydes), as well aschlorine byproducts (haloacetic acids). There were changes in the silica and sulfurlevels between finished water and distribution samples. This can be explained bychanges in pH and surface adsorption due to pipe materials (cement lining). And itwas observed that prior treatment with zinc orthophosphate at a community haslingering impacts on zinc and phosphorus levels even though the treatment ceased forabout 10 years. Includes 4 references, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2008

Number of Pages:

17

File Size:

1 file , 1.1 MB