Combined photolysis and catalytic ozonation of dimethyl phthalate in a high-gravity rotating packed bed.
In this study, a high-gravity rotating packed bed (HGRPB) was used as a catalytic ozonation reactor to decompose dimethyl phthalate (DMP), an endocrine disrupting chemical commonly encountered. The HGRPB is an effective gas-liquid mixing equipment which can enhance the ozone mass transfer coefficient. Platinum-containing catalyst (Pt/-Al2O3) of Dash 220N and ultra violet (UV) lamp were combined in the high-gravity ozonation (HG-OZ) system to enhance the self-decomposition of molecular ozone in liquid to form highly reactive radical species. Different combinations of HG-OZ with Dash 220N and UV for the degradation of DMP were tested. These include HG-OZ, HG catalytic OZ (HG-Pt-OZ), HG photolysis OZ (HG-UV-OZ) and HG-UV-Pt-OZ. The result indicated that all the above four ozonation processes result in significant decomposition of DMP and mineralization of total organic carbon (TOC) at the applied ozone dosage per volume of liquid sample of 1.2gL(-1). The UV and Pt/gamma-Al2O3 combined in HG-OZ can enhance the TOC mineralization efficiency (eta(TOC)) to 56% (via HG-UV-OZ) and 57% (via HG-Pt-OZ), respectively, while only 45% with ozone only. The process of HG-UV-Pt-OZ offers the highest eta(TOC) of about 68%.
Chang
Chia-Chi
CC
Graduate Institute of Environmental Engineering, National Taiwan University, Taipei 106, Taiwan.
Chiu
Chun-Yu
CY
Chang
Ching-Yuan
CY
Chang
Chiung-Fen
CF
Chen
Yi-Hung
YH
Ji
Dar-Ren
DR
Yu
Yue-Hwa
YH
Chiang
Pen-Chi
PC
D002384:Catalysis; D002623:Chemistry Techniques, Analytical / Q000295:instrumentation* / Q000379:methods*; D006112:Gravitation; D008903:Minerals / Q000737:chemistry; D010126:Ozone / Q000737:chemistry*; D010782:Photolysis; D010795:Phthalic Acids / Q000032:analysis* / Q000737:chemistry*
D008903:Minerals; D010795:Phthalic Acids; C024629:dimethyl phthalate; D010126:Ozone