AWWA ACE69118

A systematic investigation about both the formation and control of halonitromethanes (HNMs) were conducted inthis study. The disinfectants applied included ozone, chlorine, monochloramine, and ozonefollowed by chlorine or monochloramine. Raw (i.e., the influents to the treatment plants) andtreated waters (i.e., the water after conventional treatment processes but before any addition ofdisinfectants) from five drinking water treatment plants in South Carolina (Charleston,Greenville, Myrtle Beach, SJWD, and Spartanburg) were collected and investigated at differenttimes in a year. The results showed that HNMs molar concentrations (22-67 nM) and molaryields (10-40 nM/DOC) were the highest by the treatment of ozonation-chlorination, followed bychlorination, ozonation-chloramination, and chloramination treatment in both raw and treatedwaters. Higher HNMs yields were observed in the treated water than the raw water at eachtreatment plant, indicating that the conventional treatment processes did not remove majorHNMs precursors. The results suggest that the most hydrophilic NOM fractions (HPI) that arenot removed by conventional treatment processes contain the major HNM precursors. It was alsofound that HNMs yields increased with decreasing DOC/DON ratios (i.e., increasing nitrogencontent per organic carbon in water), and the nitrogenous organic compounds, such asaminosugars or amino acids, are the most likely precursors of HNMs. It appears that DOC/DONratio can be a simple method for utilities to asses the presence of HNM precursors in natural andtreated waters. Includes 13 references, table, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2008

Number of Pages:

64

File Size:

1 file , 1.5 MB