Surrogate Parameters for Monitoring Organic Matter and THM Precursors

Abstract

IJV absorbance at 254 nm is an excellent surrogate parameter for estimating the raw water concentrations of organic carbon (NPTOC-nonpurgeable total organic carbon) and THM precursors (TTHMFP-total trihalomethane formation potential) in the Grasse River (highly colored water) and the Glenmore Reservoir (protected, upland source). The raw water surrogate equations developed from the Grasse River data were tested successfully on other waters. Direct filtration pilot-plant data demonstrated that IJV can be used to monitor pilot-plant performance for removals of NPTOC and THM precursors. For two plants studied, UV was an excellent predictor of plant performance for removals of NPTOC and THM precursors. Instantaneous TTHMs of the finished waters can be predicted from raw water UV, finished water pH, chlorine consumption, and temperature data. Particular attention should be given to the selection of sampling locations and to the sample-handling conditions.

Enhanced coagulation using a magnetic ion exchange resin

“…This is consistent with the findings of other researchers (e.g. [5,6,17,19]). Some investigators have shown that hydrophobic carbon is more readily removed by certain treatment processes, e.g.…”

“…This is consistent with the published literature which indicates that UV254 is a good surrogate for THM formation potential (e.g. [17,18]). Similar trends were observed for THM and HAA formation potential in the other waters, although not all graphs showed as strong a trend as Figs.…”

“…Furthermore, whereas alum coagulation has been shown to preferentially remove UV-absorbing material and THM precursors compared to TOC (e.g. [5,17,19]), MIEX tended to show little preference for removal of UV-absorbing material or THM precursors relative to removal of TOC. Instead, the percent removals of TOC, UV254, and THMFP tended to be similar for each water treated with MIEX and subsequently with alum.…”

THMs precursor removal by an integrated process of ozonation and biological granular activated carbon for typical Northern China water

“…The NOM is quite complicated in nature since it contains a variety of chemical components with a large distribution of molecular weights. The source waters with a high SUVA are generally enriched in hydrophobic and high molecular weight NOM, such as ionization of carboxyl groups and humic substances [35,36]. The ozone can cleave the unsaturated bonds in the aromatic moieties that are found in humic materials, which makes the organic molecules smaller, more oxidized, and more biodegradable; however, it cannot mineralize the organic carbon into inorganic carbon.…”

Natural organic matter (NOM) removal in a typical North-China water plant by enhanced coagulation: Targets and techniques

“…3b shows that not only the hydrophobic acid but also the hydrophilic have higher THMFP. The result shows that if the organic is hydrophilic and low molecular weight organic pollution is very likely to have higher THMFP, thus it could pose health issue of the formation of DBPs in disinfection process with Cl 2 [11,12].…”