Characterizing Ohio River NOM Variability and Reconstituted-Lyophilized NOM as a Source Surrogate

Area of Science:

• Environmental Chemistry
• Water Quality Analysis
• Organic Geochemistry

Background:

• Natural organic matter (NOM) significantly impacts water treatment processes.
• Understanding seasonal variability in NOM is crucial for effective water management.
• Standardizing NOM analysis requires reliable surrogates for complex source waters.

Purpose of the Study:

• To create a temporal library of natural organic matter (NOM) from Ohio River water.
• To assess the seasonal variability of NOM characteristics.
• To validate the use of reconstituted lyophilized NOM as a surrogate for ultrafiltered source water (UF1X).

Main Methods:

• Monthly collection, concentration, and lyophilization of NOM over 15 months.
• Fluorescence spectroscopy with parallel factor analysis to analyze spectral components.
• High-pressure liquid chromatography-size exclusion chromatography and elemental analysis for NOM characterization.

Main Results:

• A two-component fluorescence model consistently described both UF1X and reconstituted lyophilized NOM.
• Average spectral components indicated humic-like characteristics with minor seasonal fluctuations.
• Reconstituted lyophilized NOM closely matched UF1X, reverse osmosis-concentrated NOM, and source water analyses.

Conclusions:

• Reconstituted lyophilized NOM serves as a valid and stable surrogate for untreated Ohio River source water.
• Seasonal variations in NOM composition were minimal, suggesting consistent water quality characteristics.
• The established temporal NOM library aids in understanding NOM behavior and optimizing water treatment strategies.