Study On O₃/H₂O₂+K₂FeO₄ Coupling System For Treatment Of RO Concentrated Water In Coal Chemical Industry

The components of coal chemical industry wastewater are relatively complex and have high organic content.After being treated by membrane technology,the produced reverse osmosis concentrated water has the characteristics of high COD,high salinity,complex composition,poor biodegradability,etc.It is a highly concentrated organic wastewater.Ozone can remove organic matter in water,but the effect of ozone oxidation treatment alone is not good,so it is necessary to establish a new advanced oxidation system to overcome this shortcoming.This paper takes RO concentrated water of coal chemical industry as the research object,explores the degradation process of RO concentrated water by O₃/H₂O₂and O₃/H₂O₂+K₂Fe O₄systems,and takes COD removal rate and UV254 removal rate as investigation objects to explore and study The interaction and influence of various factors,and determine the optimal conditions of the system reaction process.The oxidation mechanism of the coupling system O₃/H₂O₂+K₂Fe O₄was analyzed,and the kinetic analysis was carried out.Through a series of comparative experiments,and from multiple angles of analysis such as COD removal,biodegradability changes,p H changes of wastewater in the reaction process,and ozone utilization rate,The effect of potassium ferrate on the oxidation effect was investigated through experiments,and it was reformed on the basis of traditional ozone oxidation,which has important guiding significance for ozone oxidation RO concentrated water treatment technology.the experimental results show that:The factors affecting the degradation of RO concentrated water in the O₃/H₂O₂system are analyzed:the increase of ozone dosage is conducive to the degradation of COD,but excessive dosage will cause waste.The reaction has the best effect under weak alkaline conditions.The study of this system found that the removal effect of organic matter was the best when p H=8.5.There is an optimal value for the amount of hydrogen peroxide added.If the amount is too high or too low,it will affect the treatment effect.The higher the temperature,the better the organic removal effect,but the temperature has little effect on the reaction.Under the optimal conditions,the treatment effect of UV254 was examined.After 80 min of reaction,the removal rate of UV254 reached 54.2%.In the O₃/H₂O₂+K₂Fe O₄system,the effects of initial p H,potassium ferrate and hydrogen peroxide dosage on COD removal were investigated.The results showed that at a p H of 11,potassium ferrate and hydrogen peroxide were added at 40 mg/L and 56 mg/L.The effect is best when the temperature is 40℃.Under the optimal conditions,when the reaction proceeds to 80 min,the removal rate of UV254 is close to 80%;after adding different concentrations of tert-butanol to the solution,the higher the concentration of tert-butanol added,The better the oxidation effect,which also shows that the O₃/H₂O₂+K₂Fe O₄system mainly relies on hydroxyl radicals for oxidation during the reaction.By analyzing the kinetics of COD degradation of wastewater,it is found that the reactions of the O₃/H₂O₂+K₂Fe O₄system and the O₃/H₂O₂system to degrade RO concentrated water are in accordance with the quasi-first-order reaction kinetic model.Through the discussion of the effects of ions on the oxidation effect in water,it was found that Cl^-and CO₃^2-have a certain inhibitory effect on the oxidation effect,while SO₄^2-has little effect on the oxidation effect.Through comparative experiments between different advanced oxidation systems,the COD removal rate was used as the evaluation index of the oxidation effect.Judging the order of oxidation capacity:O₃/H₂O₂+K₂Fe O₄﹥O₃/K₂Fe O₄﹥O₃/H₂O₂﹥O₃﹥H₂O₂/K₂Fe O₄﹥K₂Fe O₄﹥H₂O₂,O₃/H₂O₂+K₂Fe O₄system has a COD removal rate of 63.62%,The COD degradation rate of the O₃/H₂O₂+K₂Fe O₄system is greater than the sum of the COD degradation rates of the O₃/H₂O₂system and the H₂O₂/K₂Fe O₄system,and there is a synergistic effect between the O₃,H₂O₂,and K₂Fe O₄.Through the study of wastewater biochemical properties,the B/C value of the O₃/H₂O₂+K₂Fe O₄system is higher than that of O₃and O₃/H₂O₂,indicating that the addition of K₂Fe O₄is beneficial to the later biochemical treatment,and the B/C value will increase with p H Large and enlarged.O₃/H₂O₂+K₂Fe O₄system and O₃system during the reaction process p H of the wastewater changes with the reaction time is different,the former wastewater p H decreased first and then increased,the latter wastewater p H has been declining.In the course of the reaction,the ozone utilization systems.