Application of UV/O3 to Mineralize Dimethyl Sulfoxide in Aqueous Solution

• Main Authors: Chih-Chun Lin, 林志忠
• Other Authors: 陳孝行
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/egrpet

碩士 === 國立臺北科技大學 === 環境規劃與管理研究所 === 97 === Organic solvent such as DMSO is known to be used as the photoresist stripper in TLC-LCD manufacturing industry. It is proven that DMSO is very difficult to be to mineralized, decomposed and removed through traditional biological wastewater treatment process. In order to find a novel treatment process for wastewater that contains DMSO, this study investigates different AOP procedures and operating conditions to evaluate the efficiency of mineralization of DMSO in synthetic water samples. The AOP procedures are O3-based and combine with UV or H2O2 in different ways. Total Organic Carbon (TOC) is the main analytical item in this study, and the analytical method used to quantify TOC is UV / Low Temperature / Persulfate / WetOxidation / NDIR (nondispersive infrared sensor) method. The results showed the efficiency of DMSO mineralization in different AOP procedures is as follows: UV/O3＞UV/H2O2＞UV/H2O2/O3＞O3＞H2O2/O3＞UV. As high as 95.5% of DMSO in 40 mL water sample can be mineralized within 60 min under UV irradiation with light intensity at 37.2mW/cm2 (Wavelength 254nm) and O3 dosage at 0.5×10–4mol/min. pH value for the water sample that lies between 3 to 8 is found no significant effect to the reactions of various procedures studied. The results indicated that the higher the influent concentration of DMSO (40, 60, 80mg/L), the lower the efficiency of TOC mineralization is observed (95.5%、75.0%、69.2%). The higher the influent concentration of Cl- (0, 10, 20, 30, 50mg/L), the lower the efficiency of TOC mineralization (95.5%、90.8%、89.0%、87.5%、74.8%) is concluded, Considering SO42- concentration as the factor, the results showed that SO42- concentration does not affect the extent of DMSO (a typical highly polar contaminant) mineralization under UV/O3 procedure. The higher the concentration of Fe2+ (0, 10, 20, 30mg/L), the lower the efficiency of TOC mineralization (95.5%、78.6%、77.4%、65.5%) is observed. This study also derived the multiple regression model for the efficiency of DMSO mineralization in water using UV/O3 process under different experimental conditions as follows:MODEL {DMSOη(%)Y=0.462＋0.015Xtime－0.007XDMSO conc.－0.006XFe2+ conc.}. The experimental data used in this model derivation include 140 set and can be classified into five categories with R2=0.822. After modification,R2=0.816, D-W=0.650 and F-statistic of the four independent variables is 208.996(under Confidence interval 95%). According to this model, the higher concentration of Fe2+, Cl- and DMSO would lower the mineralization efficiency of DMSO in water. On the other hand, the longer the reaction time sure and Fe2+ conc. are able to increase the mineralization efficiency of DMSO in water. As for the different levels of Cl- and SO42- concentration in the original water sample, it showed no obvious enhancement or inhibiting effect on the mineralization of DMSO.