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Phsicochemical Treatment of Hazardous Wastes - Chapter 7

Tia cực tím / hydrogen peroxide quá trình (UV/H2O2) có thể được áp dụng để loại bỏ một loạt các chất độc nguy hại từ nước ngầm, nước uống và nước thải, thành phố trực thuộc Trung ương và công nghiệp. Sau khi Koubek (1975) tại Học viện Hải quân Hoa Kỳ đã được trao bằng sáng chế cho công việc của mình vào "quá trình oxy hóa các chất hữu cơ vật liệu chịu lửa trong các dòng thải dung dịch hydrogen peroxide và ánh sáng tia cực tím," các ứng dụng thương mại đầu tiên của UV/H2O2 quá. | 7_ Ultraviolet Hydrogen Peroxide 7.1 Introduction Ultraviolet hydrogen peroxide process UV H2O2 can be applied to remove a wide range of toxic hazardous substances from groundwater drinking water and municipal and industrial wastewaters. After Koubek 1975 at the U.S. Naval Academy was awarded a patent for his work on oxidation of refractory organics in aqueous waste streams by hydrogen peroxide and ultraviolet light the first commercial application of UV H2O2 processes emerged in 1977. Since then the UV H2O2 process has been successfully applied for groundwater remediation and wastewater treatment. This chapter discusses four major topics of the UV H2O2 process 1 fundamental principles involved in the process 2 degradation kinetics and mechanisms of major classes of organic pollutants 3 QSAR models for different classes of organic compounds and their treatability and 4 engineering applications as impacted by water quality and various operation parameters. Table 7.1 briefly summarizes the major research areas of the past several decades. 7.2 Fundamental Theory Ultraviolet light without hydrogen peroxide is not very effective for the degradation of organics. When UV light and H2O2 are combined the overall oxidative reaction potential is greatly enhanced even under ambient temperature and pressure. The efficiency of direct photolysis depends on 1 UV absorbance by substrates 2 quantum yield of photolysis 3 presence of other competitive UV absorbents and 4 intensity of UV sources. UV H2O2 process may degrade organic contaminants either directly by photolysis or indirectly by hydroxyl radicals. If the photon wavelength is greater than 254 nm hydroxyl radicals are largely responsible for initiating oxidation reactions. The hydroxyl radical is a short-lived extremely potent 2004 by CRC Press LLC TABLE 7.1 Historical Aspects in UV H2O2 Research Period Description of Study 1950s Hydrogen peroxide photolysis was studied Baxendale and .