Fluorescence as a surrogate measurement of MIEX treatment efficiency
Fluorescence as a Surrogate Measurement of MIEX Treatment Efficiency<br />Pedro A. Palomino and Treavor H. BoyerUniversity of Florida, Department of Environmental Engineering Sciences<br />Peak Location<br />Drive<br />DOC vs. Intensity<br />SUVA vs. FI<br />Growing populations are stressing water supplies in many parts of the world. As a result, alternative water sources must be incorporated to meet demand. Dissolved organic matter (DOM) is a major concern in alternative water sources because of the formation of disinfection by-products. With the development of new treatment technologies, such as magnetic ion exchange (MIEX) resin, detailed monitoring is important to understand the treatment efficiency of DOM. <br />In practice, dissolved organic carbon (DOC) and specific ultraviolet absorbance at 254 nm (SUVA) are measured to determine MIEX treatment efficiency. Fluorescence spectroscopy has been shown to be an effective technique to characterize DOM, while its use in drinking water processes is an active research area. (Figure 1)<br />Several waters were studied to explore the differences among the source characteristics and treatability. The goal of this work is to better characterize DOM to improve treatability. The specific objectives are to (1)understand the shift in fluorescence peak location, (2)compare DOC to fluorescence intensity, and (3) compare the SUVA to fluorescence index (FI).<br />Microbial<br />Terrestrial<br />FI = 1.6<br />FI = 2.1<br />IHSS Isolate of NOM from Suwannee River<br />Ichnetucknee Spring<br />Figure 4 – Fluorescence standards<br />Rayleigh Line<br />Figure 5 – Fluorescence peak location shift after MIEX treatment <br />Figure 1 – Location of EEM peaks based on literature review <br />(Chen, W.; Westerhoff, P.; Leenheer, J.A.; Booksh, K. Environmental Science and Technology. 2003, 37, 5701 – 5710)<br />Sampling and Analysis<br />Samples were collected between 2/09 and 1/10 from landfills, surface water bodies and a groundwater aquifer. (Figure 2) They were analyzed on a F-2500 Fluorescence Spectrophotometer. (Figure 3) MatLab programs were developed in house to analyze fluorescence data.<br />Sample Cell<br />Figure 6 – DOC and fluorescence peak intensity for microbial and terrestrial regions of both raw and treated samples<br />Figure 7 – SUVA and FI of both raw and treated samples <br />Syn2-4<br />L4<br />Syn1<br />Photo Detector<br />L5<br />L1<br />Impact<br />SW2<br />GW1<br />SW1<br />Emission Monochromator<br />SW1: Lake Jesup<br />SW2: St. Johns River<br />Syn1: Santa Fe River<br />Syn2-4: St. Mary’s River<br />GW1: Cedar Key GW<br />L1: Alachua SW Landfill<br />L2-3: Polk Landfill<br />L4: New River Landfill<br />L5: Putnam Landfill<br />L2-3<br />Excitation Monochromator<br />Peak Location <br /><ul><li>MIEX treatment alters DOM chemistry</li></ul>DOC vs. Intensity<br /><ul><li>Raw
Microbial peak intensity is better correlated (Table 1)
MIEX preferentially removes the terrestrial component </li></ul>SUVA vs. FI<br /><ul><li>Raw SUVA: Synthetic < Surface < Ground < Waste
SUVA and FI are negatively correlated (Table 2)</li></ul>Fig 3 – Fluorescence Spectrophotometer<br />Table 1 – Correlation between microbial and terrestrial peak intensities versus the raw and treated DOC values <br />Xenon Lamp<br />Figure 3 – Fluorescence Spectrophotometer Schematic<br />Table 2 – Correlation between SUVA and FI value for raw and treated samples<br />Figure 2 – Florida Sampling Map<br />Acknowledgements<br />Thanks to all the students (Stephanie, Sara, Katie, Troy, Paul, Katie, Chris, Krystal, and Jennifer) in Dr. Treavor Boyer’s research group for sample and data collection.<br />Fluorescence measurements could be a better alternative for monitoring MIEX treatment efficiency. <br />
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