Once dissolved in water, ozone reacts with organic matter in the water body, and the type of oxidation produced depends on the activity of the initial compound and the ozone reaction and the efficiency of the ozone oxidation. Ozone has two main response pathways in the water column, namely, direct ozone oxidation and indirect oxidation, which are free-based oxidation through formation of hydroxyl radicals (. Oh) and reaction to compounds, the second of which is common to advanced oxidation techniques. But hydroxyl radicals can also be generated by other means, such as advanced oxidation processes or other catalytic technologies that can facilitate hydroxyl radicals。
Direct oxidation between ozone and aquatic organic pollutants takes place mainly in two ways: on the one hand, an ad hoc response and on the other hand, a pro-electric replacement response。
Because ozone has an epipolar structure, the ozone molecule and organic matter with unsaturated keys can react by first producing a peroxide, further decomposing in water to thallium-containing compounds (e. G., formaldehyde or ketone) and to a transitional intermediate, followed by hydroxyl oxide soon and further decomposition to thallium compounds and hydrogen peroxide。
The pro-electric substitution response occurs mainly in the larger electron cloud density in the molecular structure of organic pollutants, especially aromatic compounds. Aromatic compounds (e. G. - oh, -ch3, -nh2, -oc) with electron density on adjacent carbon atoms make these carbon atoms readily react to ozone, e. G. Phenol (response velocity constant k = 1300 ± 300 l/(mol. S)). However, aromatic compounds with electrons (e. G. Containing -cooh, -no, -cl, etc.) are difficult to react to ozone, e. G. The chlorobenzene reaction velocity constant k= 0. 75 ± 0. 2 l/(mol. S) and the nitrous velocity constant k= 0. 09 ± 0. 02 l/(mol. S). In this case, the ozone function is first with the lowest degree of passivation of carbon atoms, first to form intermediates with adjacent hydroxyl radicals, then to be further oxidized to produce thallium compounds, and finally to generate fat compounds containing thallium or thallium. Advanced oxidation methods are needed for highly stable organic pollutants, such as pesticides and halogenated organic pollutants。
Relevant product recommendations
Ultraviolet ozone analyst
Ozone gas detectors
Online monitoring of ozone concentrations
Ozone concentration metrics
Multi-parameter rapid water quality detector
