The main function of pre-ozone is to kill algae, improve the effect of flocculation and sedimentation, remove some organic matter,

advantage：The ozone-biological activated carbon filter process integrates the four technologies of activated carbon physical and chemical adsorption, ozone chemical oxidation, biological oxidation degradation and ozone sterilization and disinfection. Compared with the traditional water treatment process, it has obvious advantages, mainly reflected in:

① The Ames mutagenicity test results of tap water treated by conventional chlorination process are mostly positive, while those treated by ozone-biological activated carbon process are negative;

② The removal rate of organic pollutants by ozone-activated carbon process is more than 50%, which is 15-20% higher than that of conventional treatment;

③ Improve the removal rate of chroma and odor, and improve sensory indicators;

④ Improve the removal rate of iron and manganese;

⑤ Ammonia nitrogen can be removed to about 90%, and ammonia nitrogen and nitrite in water can be biologically oxidized to nitrate, thereby reducing the amount of chlorine input for post-chlorination and reducing the generation of disinfection by-products such as trihalomethane;

⑥ Effectively remove AOC and protein ammonia nitrogen, improve the biological stability of the treated water, and improve the water quality of the pipe network.

In addition, the combined use of ozone and activated carbon can also prolong the operating life of activated carbon and reduce operating costs.

shortcoming：Although ozone-biological activated carbon filter advanced treatment technology has played a good role in controlling pollution of drinking water and improving water quality, it also has limitations. Mainly in:

① Ozone oxidation treatment of drinking water has defects such as low ozone utilization rate and insufficient oxidation capacity;

② Ozone can effectively degrade organic pollutants containing unsaturated bonds or some aromatic organic pollutants, but it is difficult to oxidatively degrade some stable organic pollutants (such as pesticides, halogenated organic compounds and nitro compounds, etc.). The degradation of some organic compounds by ozone is only limited to changes in the structure of the parent compound, and may generate intermediate oxidation products that are more toxic and not easily degraded by biological activated carbon;

③ Ozone can oxidize macromolecular organic matter into small molecular organic matter, and studies have shown that activated carbon adsorption has a good removal effect on organic matter with a molecular mass of 500-3000Da, but has a poor removal effect on macromolecular and small molecular organic matter. After ozone oxidation, the molecular weight of organic matter becomes smaller, which is not conducive to the adsorption of activated carbon;

④ When the water contains bromide (Br-), ozone oxidation will generate harmful by-products such as bromate (BrO3-) and bromotrihalomethane (Br-THM), which have a great impact on human health.