The Problem Of Water Quality Conditions In H₂O₂/O₃ Application And The Efficiency Of CaO/activated Carbon Catalytic Ozone System

The physical chemistry properties of ozone,its application and research progress were reviewed in this article.The problems of H₂O₂/O₃ in practical application were discussed,and the effect of alkaline oxide on ozonation was analyzed.The effect of CaO/AC/O₃ on the oxidation of acetic acid in water was studied by using CaO/activated carbon?AC?,and the effect of CaO/AC/O₃ on the oxidation efficiency of acetic acid was studied.Two kinds of practical wastewater were pretreated by H₂O₂/O₃ and CaO/AC/O₃.First of all,The degradation efficiency of acetic acid under different conditions was studied by using H₂O₂/O₃.The impact of common ions in water on this process was focused,At the same time,the relationship between the amount of acetic acid removed,the actual dosage of ozone?calculated by the intake air minus the exhaust method?and the consumption of H₂O₂ was analyzed.At the initial pH of 7.5,the ratio of the actual dosage of ozone to H₂O₂ consumption was 0.24.Its process efficiency was the best.The degradation rate of acetic acid was different for different water quality background conditions.The presence of sulfate ion,nitrate ion or chloride almost had no effect on the efficiency of H₂O₂/O₃.The concentration of cations can promote the oxidation efficiency of H₂O₂/O₃ process.The excess concentration of metal ions on the oxidation efficiency of the system have a certain inhibitory effect.The inhibitory effects of Br-,HCO₃-and suspended solids on the system were observed.When Br-concentration was 10 mg×L-1 and 100 mg×L-1 in solution,the removal rates of acetic acid were 51.37% and 30.67%,respectively,compared to the previous reduction of 11.27%,31.97%.When HCO₃-concentration increased from 0 to 200 mg×L-1,the removal rate of acetic acid in H₂O₂/O₃ system was reduced by 12.98%.The above results are of significance for the application of H₂O₂/O₃ process in practical wastewater treatment.Secondly,The basic oxide calcium oxide was prepared on activated carbon support,and its application in ozone degradation efficiency was investigated.The results showed that the removal rate of acetic acid was 78.28% and the removal rate of acetic acid was only 25.6% when the reaction time was 60 min at the initial pH value of 7.0 and CaO/AC catalyzed ozonation.At the same time,the effect of the catalyst on the degradation efficiency of acetic acid was analyzed in detail,and the process parameters were optimized?ozone yield,CaO/AC catalyst dosage and p H value?.And the mechanism and the stability and efficiency of Ca O/AC catalyst were also discussed.The values of O₃ and CaO/AC/O₃ were 3.55×10-8 and 1.02×10-6,respectively.The difference between the two orders of magnitude,it is shown that the CaO/AC/O₃ system can produce more efficiently in the alkaline condition,and the catalytic ozonation is more effective.The ratio of acetic acid removal to actual ozone consumption was 0.36.At last,the mineralization rate and ozone consumption of two different kinds of wastewater?a seconde effluent and an inlet wastewater?were studied by using ozone,H₂O₂/O₃ system and CaO/AC/O₃ system.The removal rates of COD for a seconde effluent were 15.1%,25.6% and 31.1%,respectively.COD removal rate of an inlet wastewater was 31.84%,84.66% and 78.28% respectively.It showed that the advanced oxidation technology based on ozone was more suitable for the deep treatment of wastewater technology,which was combined with the biological aerated filter?BAF?,which could exert its advantages in water treatment.The ratio of COD removal and actual ozone consumption in the reaction was between 0.24 and 0.32.