• Journal of Korean Society on Water Environment
• /
• v.25 no.4
• /
• pp.547-552
• /
• 2009

Because of refractory property of light, the travel path of UV light becomes longer than the straight line and shorter solely in water as UV light passes sequentially through air, quartz and water. Note that water significantly absorbs UV light. Hence, UV intensity shall be estimated to be lower when refraction is neglected than it is considered. Reflection is also critical for the design of UV radiation system. While the reflection at the interface of air and quartz is low enough to ignore, it is too high to be ignored at the interface of quartz and water. Assuming constant power, smaller length to width ratio of UV reactor is beneficial and single-lamp system is preferred to multi-lamps. Under the given cross section, optimal lamp positions could be decided. For example of an elliptical reactor with dual lamps, the optimal lamp locations shall be the 1/3 and 2/3 position of the longer axis.

• Journal of Environmental Science International
• /
• v.14 no.3
• /
• pp.327-333
• /
• 2005

The performance of ozone contactor in ozone-BAC advanced water treatment process was evaluated by the degree of decomposition of organic matters. The degree was measured by the analyses of $UV_{254}$ absorbance and the concentrations of DOC and BDOC for the sand filtered water and the ozone treated water, respectively. In addition, the ozone concentration in the contactor, required for the maximum BDOC concentration, was selected as the optimum concentration, and the appropriate residential time of ozone treated water in a reservoir was recommended based on the residual ozone concentration in the treated water. The following results were obtained from the pilot scale experiments. By ozonation $UV_{254}$ absorbance was decreased, and BDOC concentration was increased. The change of DOC concentration by ozonation was negligible, but the excess input of ozone resulted in the removal of the small amount of BDOC by complete oxidation. The optimum ozone concentration was 0.58mg $O_3/mg$ DOC. In order to remove residual ozone, 20minutes of the residential time were enough after ozonation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.15 no.1
• /
• pp.70-77
• /
• 2001

This paper present a fuzzy mxlel of describing reacton features for ozon contactor in advanced water treatn-ent systems. Input and output variables are chosen by considenng the object of ozon processing and several parameters related to management of water quahty. Dissolved organic carbon concentration, $UV_{254}$ absorptIon and $KM_NO_4$ consumption are proposed as common variables in input and outp.lt variables. Furthermore own concentration, raw water's temperature and contact time are suggested as input variables, Membership hmctions for input variables have triangular type share and the grades in each lrembership function are determined by investigating process data gathered at pilot planl The decision parts of fuzzy model have linear combination form of input variables and coefficients included in such linear equations are computedd with process clata in the sense of least square error Also fuzzy trodel suggested in this paper is partitioned by 3 independent fuzzy rnxlels using the characteristics of having no interactions armng output variables. As a result, such fuzzy mxlel has rrerits in computation and comprehension. According to simulatIon results, fuzzy moIel's outputs give almost similar data to process output under same input conditions.