AWWA WQTC58922

A 1 um diameter fluorescent microsphere was selected and characterized for use as aphotobleachable probe of ultraviolet (UV) fluence in a disinfection reactor. Loss of fluorescence(photobleaching) was calibrated as a function of fluence, and this relationship was found not tobe significantly affected by water quality parameters, if oxidants such as hypochlorite wereexcluded. Photobleaching was also determined to be caused by the UV portion of the mediumpressure lamp spectrum, especially wavelengths below 300 nm. Microspheres were injected intothe inlet of a pilot scale UV reactor and recovered in outlet samples for subsequent analysis byflow cytometry. Data from flow cytometry, together with the calibration data, were used toconstruct a histogram of UV fluence for the reactor, showing behavior consistent with previouspredictions in other reactors. Improvement of the sensitivity of the technique is required topermit direct measurement of the minimum UV fluence. Includes 14 references, figures.

Product Details

Edition:

Vol. - No.

Published:

11/02/2003

Number of Pages:

11

File Size:

1 file , 290 KB