Oxidation of methyl methacrylate from semiconductor wastewater by O3 and O3/UV processes

Treatment of methyl methacrylate from semiconductor wastewater by catalytic wet oxidation

“…In a study on the oxidation of MMA by O 3 and O 3 /UV processes, a decomposition pathway of MMA was reported by Shang et al (2007). The intermediates of methyl formate, formaldehyde, acetic acid and formic acid were formed before being further oxidized into CO 2 and H 2 O.…”

“…Thus, it exhibits the aquatic toxicity. Other health effects of MMA reported include (1) rapid absorption in the oral or inhalatory uptake of human beings and (2) potential for induction of mutagenic effects, particularly clastogenicity (USEPA, 1998;Shang et al, 2007). Hence, the MMA-containing wastewater needs to be treated adequately because of environmental and health concerns.…”

“…The MMA due to its toxicity and bioresistance is difficult to be properly treated via the common wastewater treatment processes designed for general purposes. Shang et al (2007) employed sole ozonation (OZ), direct photolysis with UV and combined OZ and UV (OZ/UV) processes to treat the MMA-containing solution. The OZ and OZ/UV belong to advanced oxidation processes (AOPs), which have been widely applied in water and wastewater treatment (Alborzfar et al, 2000;Beltran and Alvarez, 1996;Bila et al, 2005;Chang et al, 2009;Chen and Masten, 2005;Chen et al, 2006;Hautaniemi et al, 1998;Hong et al, 2008;Huang et al, 2007;Langlais and Reckhow, 1991;Oh et al, 2006;Peyton and Glaze, 1988).…”

“…The OZ and OZ/UV belong to advanced oxidation processes (AOPs), which have been widely applied in water and wastewater treatment (Alborzfar et al, 2000;Beltran and Alvarez, 1996;Bila et al, 2005;Chang et al, 2009;Chen and Masten, 2005;Chen et al, 2006;Hautaniemi et al, 1998;Hong et al, 2008;Huang et al, 2007;Langlais and Reckhow, 1991;Oh et al, 2006;Peyton and Glaze, 1988). The study of Shang et al (2007) conducted the experiments with the following conditions: initial concentration of MMA (C MMA0 or C 0 ) = 505.3 mg/L, flow rate of feed gas (Q G ) = 1.78 L/min, concentration of ozone in feed gas (C O 3 ) = 10 mg/L, intensity of UV irradiation (I UV ) = 35.96 W/m 2 . For the three AOPs examined, the OZ/UV process offers the highest removal of MMA and COD.…”

Inhibiting the regeneration of N-nitrosodimethylamine in drinking water by UV photolysis combined with ozonation

“…A large amount of H 2 O 2 will decrease the effectiveness of NDMA removal in the UV/H 2 O 2 system, and residual H 2 O 2 becomes a problem. By comparison, the combination of ozonation with UV irradiation is considered a more effective process for removing organics [28][29][30]. Hydroxyl radicals ( • OH) that are generated in the UV/O 3 process are non-selective and vigorous oxidants.…”