강도측정에 의한 비접촉식 자외선 살균 모델의 보정

Abstract

ABSTRACT

Calibration of a Non-contact type UV Disinfection Model by Intensity Measurement

Kim, Maeng Sun Advisor : Prof. Kim, Sung Hong, Ph.D Department of Civil Engineering Graduate School of Chosun University

Now a days, disinfection of effluent from wastewater treatment facility is obligation in Korea. Ultraviolet(UV) disinfection is one of the useful alternative comparing to any other disinfection technology including chlorination. UV is easy to install and maintain. But the decrease of performance accompanied with fouling on the lamp of quartz sleeve is one of the most common and fatal deficit of UV in water disinfection system. To overcome this fouling, non-contact type UV disinfection system which is fundamentally fouling-free is proposed in this study. Based on optical laws and other UV distribution models, a detailed mathematical model for a non-contact type UV disinfection system was developed. Optical properties of refraction, reflection and absorption of UV light were included in this model and reflection of ceiling wall was added. The purpose of this study is to calibrate and to verify the simulation model. Fouling on the qualtz sleeve was investigated by conducting submerged UV disinfection system. The followings were obtained as results. Fouling occurred in the submerged system whether the circulation is performed or not but the fouling rate was high when the recirculation was not performed. Without recirculation, the UV attenuation by fouling was up to 56% for 7 days of operation. An experiment using lab-scale nun-contact type of UV disinfection module was carried out to calibrate and verify the parameters using by the simulation model. Two parameters of UV lamp efficiency and UV transmittance of water were selected as calibration parameters. Based on the intensity measurements and simulation results, the calibrated values of two parameters which minimize the relative errors between the measuring intensity and simulation results are suggested in this study. The best fit UV lamp efficiency was 43% and while the UV transmittance of water was approximately 100%. The average relative error was 12.8% in this calibration. Verification was made by applying these calibrated values to the another design module which is different to that used in calibration experiment. The experimental data and the simulation results were also good correlated and the average relative error was 8.5% in this case.

Keywords : non-contact, fouling, UV lamp efficiency, UV Transmittance, calibration