Ozone generation mechanism

Plasma-Chemical Ozone Generation Mechanisms and Kinetics... 

The mechanism for ozone generation is the exeitation and aeceleration of stray eleetrons within the high-voltage field. The alternating eurrent causes the electron to be attracted first to one electrode and then to the other. As the electrons attain sufficient velocity, they beeome capable of splitting some oxygen moleeules into free radical oxygen atoms. These atoms may then eombine with Oj moleeules to form O3. 

The mechanism for ozone generation is the excitation and acceleration of stray... 

Since reaction mechanisms and experimental observations are not independent of the system in which they are made, the experimental set-up and how the experiment is run affect the outcome. That means that it must be clear how equipment and procedures affect the outcome when they are chosen. It also means that experimental set-ups and procedures from drinking water treatment cannot be applied on waste water without appropriate evaluation and vice versa. In general, an experimental set-up consists of an ozone generator, reactor, flow meters and on-line analysis of at least the influent and effluent ozone gas concentrations and ambient air monitor (Figure 2-1). Each set-up will be tailored to the experimental goals and the resources available. 

Boron-doped diamond is electrically conducting and has found applications as electrode material in waste-water treatment, ozone generation, electroanalysis, and trace metal detection [ii]. Due to their exceptional chemical inertness and mechanical strength, diamond electrodes have been proposed for applications in extremely aggressive media such as strong acids or plasmas. See also -> carbon electrodes. 

Ozonation system consists of the following sections a. feed-gas treatment b. ozone generation c. ozone-water contact mechanism and d. destruction unit (Lin S.H., 1993). The use of ozonation in preliminary treatment is not economic effective even it can decrease the soluble organic. Therefore, it is better to implement Ozonation in tertiary treatment for effectively colour removal of the residual dyes. 

All experiments were carried out in a 500 mL cylindrical contact tower (300 mm x 170 mm ID), as shown in Figure II. The ozone was generated from the ozone generator Dwyer Model-2001 (manufactured by the Jelight Co. Ltd. CA, USA) and driven by an air pump with adjustable flow rates. The ozone-oxygen mixture was then ted into the contact tower through a porous plate gas sparer located at the tower s base. 500 mL of dye solution was used during each batch ozonation. A mechanical stirrer worked with the gas diffuser to achieve sufficient recirculation of the dye solution, so a favorable gas transfer rate was expected (Lin S.H., 1993). 

It is very important to be aware that the toxicity of ozone applies to humans as well as fish. Breathing in ozone gas will injure the lungs and a high concentration is directly toxic. An alarm system that monitors the ozone concentration in the air should therefore be used, preferably with an automatic close down mechanism on the ozone generator. 

Diamond is a promising electrode material for electrochemical ozone generation because of its mechanical durability and chemical inertness. Diamond electrodes are suitable for water electrolysis under quite high current conditions, with no need for concern regarding dissolution. 

The continuous evolution of bubbles accompanying water electrolysis can lead to considerable mechanical damage to conventional electrode materials. Mechanical durability is an additional requirement for the ozone-generating anode, which is sufficiently satisfied by diamond electrodes. 

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