High-performance size exclusion chromatography with a multi-wavelength absorbance detector study on dissolved organic matter characterisation along a water distribution system.
This study examined the associations between dissolved organic matter (DOM) characteristics and potential nitrification occurrence in the presence of chloramine along a drinking water distribution system. High-performance size exclusion chromatography (HPSEC) coupled with a multiple wavelength detector (200-280nm) was employed to characterise DOM by molecular weight distribution, bacterial activity was analysed using flow cytometry, and a package of simple analytical tools, such as dissolved organic carbon, absorbance at 254nm, nitrate, nitrite, ammonia and total disinfectant residual were also applied and their applicability to indicate water quality changes in distribution systems were also evaluated. Results showed that multi-wavelength HPSEC analysis was useful to provide information about DOM character while changes in molecule weight profiles at wavelengths less than 230nm were also able to be related to other water quality parameters. Correct selection of the UV wavelengths can be an important factor for providing appropriate indicators associated with different DOM compositions. DOM molecular weight in the range of 0.2-0.5kDa measured at 210nm correlated positively with oxidised nitrogen concentration (r=0.99), and the concentrations of active bacterial cells in the distribution system (r=0.85). Our study also showed that the changes of DOM character and bacterial cells were significant in those sampling points that had decreases in total disinfectant residual. HPSEC-UV measured at 210nm and flow cytometry can detect the changes of low molecular weight of DOM and bacterial levels, respectively, when nitrification occurred within the chloraminated distribution system.
School of Chemical Engineering, The University of Adelaide, Adelaide, SA 5005, Australia.
Huiping
H
Huang
Australian Water Quality Centre, SA Water Corporation, 250 Victoria Square, Adelaide, SA 5100, Australia.
Emma
E
Sawade
Australian Water Quality Centre, SA Water Corporation, 250 Victoria Square, Adelaide, SA 5100, Australia.
David
D
Cook
School of Earth and Environmental Sciences, The University of Adelaide, Adelaide, SA 5005, Australia; Australian Water Quality Centre, SA Water Corporation, 250 Victoria Square, Adelaide, SA 5100, Australia. Electronic address: chris.chow@sawater.com.au.
Christopher W K
CWK
Chow
Australian Water Quality Centre, SA Water Corporation, 250 Victoria Square, Adelaide, SA 5100, Australia.
Mary
M
Drikas
School of Chemical Engineering, The University of Adelaide, Adelaide, SA 5005, Australia.
Bo
B
Jin
D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D004784:Environmental Monitoring / Q000295:instrumentation* / Q000379:methods; D006812:Humic Substances / Q000032:analysis*; D008970:Molecular Weight; D014873:Water Pollutants / Q000032:analysis*
D006812:Humic Substances; D014873:Water Pollutants
DOM; Distribution system; HPSEC-UV; Sum of nitrate and nitrite concentration