The principal objective of this study was to quantify the effectiveness of combining
UV/H<sub>2</sub>O<sub>2</sub> and biological oxidation processes for the mineralization of the antimicrobial
compound sulfadiazine (SDZ). Specific objectives included: quantification of photolysis
and UV/H<sub>2</sub>O<sub>2</sub> oxidation rates of SDZ; evaluate the effects of a lake water matrix on
photolysis and photooxidation rates of SDZ; and, quantify the mineralization
potential of 14C-labeled SDZ oxidation products as a function of UV/H<sub>2</sub>O<sub>2</sub> oxidation
conditions (UV fluence, H<sub>2</sub>O<sub>2</sub> concentration).
Photolysis and UV/H<sub>2</sub>O<sub>2</sub> oxidation rates of SDZ were quantified with a quasi-collimated
beam (QCB) apparatus (Bolton and Linden, 2003). The purpose of the QCB apparatus is
to ensure that the UV rays reaching the sample are exactly perpendicular, which allows
for accurate measurement of UV energy at the surface of the sample. Therefore, we can
accurately measure the UV fluence delivered to the sample. The QCB is equipped with
four low pressure (LP) UV lamps. The determination of the delivered UV fluence to the
sample by the LP lamps was calculated with the method described by Bolton and Linden
(2003). Tests were conducted at an initial SDZ concentration of 4 (±1) µM. Tests
conducted in the presence of natural organic matter (NOM) were performed by spiking SDZ into Lake Wheeler
water (Raleigh, NC) that had been filtered through a 0.45-µm membrane filter. The TOC
of filtered Lake Wheeler water was 5.0 mg/L, the pH was 7.85, and the total alkalinity
was 24 mg/L as CaCO<sub>3</sub>. Includes 8 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 150 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 5 |
| Published : | 11/01/2007 |
