tailieunhanh - Ozone Reaction Kinetics for Water and Wastewater Systems - Chapter 3

Động học của phản ứng Ozone trực tiếp Trong chương này, động lực học của các phản ứng ôzôn trực tiếp trình bày. Rõ ràng là ozonation trực tiếp điểm của phân tử hợp chất hữu cơ để điều trị có thể được sử dụng rộng rãi trong ozonation trực tiếp của các hợp chất vô cơ. Phản ứng Ozone trong nước và nước thải hàng loạt các phản ứng không đồng nhất song song khí chất lỏng trong đó một thành phần khí (ozone) chuyển từ pha khí (oxy hoặc không khí) giai đoạn nước nơi mà nó đồng thời. | 3 Kinetics of the Direct Ozone Reactions In this chapter the kinetics of ozone direct reactions is presented. It is evident that the direct ozonation of molecular organic compounds points to a treatment that can be used extensively in the direct ozonation of inorganic compounds. Ozone reactions in water and wastewater are heterogeneous parallel-series gas liquid reactions in which a gas component ozone transfers from the gas phase oxygen or air to the water phase where it simultaneously reacts with other substances pollutants while diffusing. The main aim of the kinetic study is to determine the rate constant of the reactions and mass transfer coefficients. This is achieved by establishing the corresponding kinetic As a difference from chemical equilibrium kinetic laws are empirical and must be determined from experiments. According to the type of experiments the ozonation kinetic study can follow two different approaches. The first one is based on experimental results of homogeneous ozonation reactions. This is the case where ozone and any compound are previously dissolved in water and then mixed to follow their concentrations with time. The kinetic law in this case relates the chemical reaction rate with the concentration of reactants and products in the case of reversible reactions . Thus for any general irreversible ozone direct reaction with a compound B zO3O3 zBB---- zPP zO3 zB and zP being the stoichiometric coefficients of ozone B and P respectively the kinetic law corresponding to the ozone or B chemical reaction rates are rO zOkCnO3Cm O3 O3 O 3 B and B B O3 B where k n and m are the reaction rate constant and reaction orders with respect to ozone and B respectively. Notice that zA and zB have negative signs due to convention rules. Both equations are related through the stoichiometric coefficients r O3 ĨP3- r b zB 1 z 2004 CRC Press LLC In most of the studies however the ratio between coefficients zB z03 z is considered so that