ANALYSES OF FAT, OIL AND GREASE IN WASTEWATER OR RECEIVING WATER USING FOURIER TRANSFORM INFRA-RED SPECTROSCOPY (FTIR)

The insoluble component of wastewater consisting of a mixture of various natural and petroleum organic oils and fats, typically referred to as Fats, Oils and Grease (FOG), interferes with facility processes and becomes a regulatory issue when it enters a receiving stream. Typically, the concentration of FOG in influent wastewater and effluent is estimated gravimetrically by extracting 1 liter of water sample with an organic solvent followed by the subsequent evaporation of all of the solvent. The mass of the remaining residue is measured gravimetrically and corrections are applied to produce a concentration estimate; no other information about the nature of the FOG is provided by this method. Gravimetric protocols also result in (1) the release of significant amounts of organic solvent to the atmosphere and (2) a relatively inaccurate mass estimate because of the error introduced by measuring a small mass change in a relatively massive container.A method was developed by our laboratory that utilizes Fourier Transform Infra Red (FTIR) spectroscopy to analyze FOG in water/wastewater samples. Advantages of this procedure include:The ability to quantify a wide range and low levels of FOG (400 toReducing analytical sample size toThe ability to characterize the chemical nature of the sample extracted from wastewater and water samples.For quantifying FOG in influent and effluent samples, FTIR provides a method that is more sensitive and/or precise than gravimetric methods. FTIR also permits the identification of FOG components, including determining whether an observed ambient slick is produced by FOG from a wastewater facility or another source.