Natural organic matter (NOM) from five water sources was fractionated using XAD
resins and ultrafiltration membranes into different hydrophobicity and molecular weight
(MW) groups. The disinfection byproduct (DBP) formation from each fraction during
chlorination and chloramination was studied. In tests using chlorination, hydrophobic and
high MW (e.g. >3kDa) precursors produced more trihalomethanes (THMs), trihaloacetic
THAA) acids and unknown total organic halogen (UTOX) than corresponding
transphilic, hydrophilic and low MW (e.g. <3kDa) precursors. However, the formation of
THMs and THAA was similar among different fractions for a water with low humic
content. Hydrophilic and MW<0.5k fractions gave the highest dihaloacetic acid yields.
No significant difference was found for the dihaloacetic acid and UTOX formation
among different fractions during chloramination. It appears that chloramination DBP
precursors are more evenly distributed among NOM fractions. High pH favors the
formation of THMs and HAAs over UTOX. Increasing pH also led to lower TOX
formation for hydrophobic and high MW fractions, but had little impact on TOX yields
from hydrophilic and low MW fraction. Bromine and iodine were found to be more
reactive with hydrophilic and low MW fractions as measured by THM and HAA
formation than their corresponding hydrophobic and high MW fractions. However,
hydrophobic and high MW fractions produced more UTOX when reacting with bromine
and iodine. Includes 39 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 1.8 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 20 |
| Published : | 06/17/2005 |
