جستجوی مقالات مرتبط با کلیدواژه « Advanced Oxidation Processes » در نشریات گروه « مهندسی آب »

The use of dimethyl sulfoxide (DMSO) as a solvent for organic and inorganic compounds in various industries such as pharmaceutical, electronic and acrylic fiber manufacturing process has been increased in recent years. According to the growth of these industries in recent decades, treatment of DMSO wastewaters has become a serious concern. Although DMSO itself has low toxicity, the biological treatment of wastewater containing DMSO, is known to be difficult. According to limitations of biological treatment due to production of toxic compounds, advanced oxidation processes (AOPs) is considered as a most efficient method and the best one for purifying organic compounds which are resistant to conventional physical and chemical processes. In this study, some important AOPs such as extended and hybrid Fenton processes (photo- Fenton, electro- Fenton and photo-electro Fenton), ozone-based processes (O3, O3/H2O2, O3/UV), UV/H2O2 and TiO2/UV have been studied in the treatment of wastewaters containing DMSO. The efficiencies of these processes were also evaluated and discussed. Overall, it can be concluded that hybrid Fenton processes and ozone-based processes are more effective for removal of DMSO from wastewater.

Naphthalene is released into the environment by burning such organic materials as fossil fuels and wood and in industrial and vehicle exhaust emissions. Naphthalene is used in the manufacture of plastics, resins, fuels, and dyes. The aim of this study was to evaluate the performance of UV/TiO2/H2O2 process to decompose naphthalene in aqueous solutions. For this purpose, the photocatalytic degradation of naphthalene was investigated under UV light irradiation in the presence of TiO2 and H2O2 under a variety of conditions. Photodegradation efficiencies of H2O2/UV, TiO2/UV, and H2O2/TiO2/UV processes were compared in a batch reactor using the low pressure mercury lamp irradiation. The effects of operating parameters such as reaction time (min); solution pH; and initial naphthalene, TiO2, and H2O2 concentrations on photodegradation were examined. In the UV/TiO2/H2O2 system with a naphthalene concentration of 15 mg/L, naphthalene removal efficiencies of 63, 75, 80, 88, 92, 95, 96.5, and 98% were achieved, respectively, for reaction times of 5, 10, 20, 30, 40, 50, 60, 100 and 120 min. This is while removal efficienciesof 50, 59.5, 69, 80, 85, 88, 91, and 95% were obtained in the UV/TiO2 system under the same conditions. For initial pH values of 3, 4, 5, 6, 7,9, 10, and 12, naphthalene removal efficiencies of approximately 96.8, 85.5, 86, 75.5, 68.8, 57.8, and 52.5% were acheived, respectively, with the UV/TiO2/H2O2 system. Thus, it may be claiomed that, compared to either H2O2/UV or TiO2/UV process, the H2O2/TiO2/UV process yielded a far more efficient photodegradation.