ENVR 263 |
| Total organic carbon (TOC) analysis is not only important in studying disinfection byproducts' (DBPs) precursors, but also, it can help regulate the discharge of organic chemicals into a water body. However, six dissolved organic matter (DOM) fraction concentrations is a better measure for understanding of the organic character of water than the TOC of water, which is an aggregate parameter typically used by water purveyors. The experimental procedure for TOC fractionation is lengthy and tedious; therefore, many attempts have been made toward development of faster and reliable techniques. Marhaba et al. (2000) built a model using multiple linear regression applied to spectral fluorescent signature (SFS) for predicting the six-fraction concentration in water. SFS by definition is a three-dimensional matrix that records fluorescent intensity for a range of emission and excitation wavelength co-ordinates in a pre-selected spectral window. Fluorescence is a very sensitive technique and works best only at certain wavelengths that are different for different materials. It is, therefore, difficult to quantitate a material using the fluorescence technique, especially when the entire fluorescence matrix is considered, no matter what statistical technique is used. Addressing this difficulty, this research is an attempt to build an enhanced model by combining Principal Components Analysis (PCA) with multiple linear regression. This new model first reduces the dimensionality of the input data by focusing on the specific portion of the entire matrix that contains the peak locations for all six fractions. This model provides better sensitivity and accuracy, while maintaining the advantages of the earlier model, such as rapid identification and quantification of DOM fractions. Potential use of the model is to determine the problematic organic character of source water (e.g., DBPs precursors) and to optimize water treatment processes. |
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Advances in Drinking Water Disinfection and Disinfection Byproduct Management
6:00 PM-8:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Hall A, Poster
Division of Environmental Chemistry |