| China's dye industry has developed for more than 100 years and has reached the international leading level.It is an industry that is related to the national economy and people's livelihood.However,a large amount of pollutants such as wastewater.waste gas and waste residue are generated in the dye production process.Dye production wastewater treatment is difficult,costly,and toxic.The feasibility of developing and treating this type of wastewater and clarifying its toxic effects and mechanisms have important theoretical and practical value for environmental and human health protection and environmental management.Ozone oxidation overcomes the difficulties encountered by traditional physical,chemical and biological processes in the treatment of dye production wastewater,and is an effective means of treating dye production wastewater.In this paper,the ozone dyeing treatment is used to treat the dye production wastewater,and the efficiency and mechanism of the wastewater treatment are studied.The human serum albumin(HSA)is used as the research object to evaluate the toxic effect of wastewater from the molecular point of view;through the combination of ozone and various technologies,Study ways to improve the efficiency of wastewater treatment.First,the efficiency and mechanism of ozone oxidation treatment of dye production wastewater were studied.The results show that the aromatic organic compounds and azo bonds in the wastewater are more easily removed under alkaline conditions(pH=10),and the benzisothiazole organics are more easily removed under weakly acidic conditions(pH=5.5);in alkaline conditions The ozone oxidation process is divided into two stages.In the first stage,HO· plays a major oxidation,and in the second stage,O3 plays a major oxidation.The oxidation rate of HO for wastewater characteristic substances is about 22,7.5 and 180 times of O3,and the removal rate of COD is 19 times that of O3,and the removal of TOC is basically completed by HO·.Therefore,wastewater decolorization and mineralization are mainly completed by HO·.The main components in the wastewater are aniline and benzisothiazole.During the oxidation process,the chromophore and chromogenic group of the organic matter are detached,the structure is destroyed,and intermediate products such as p-nitrophenol and nitrotoluene are formed,which are further produced.Organic acids,alcohols,and finally mineralized to CO2 and H2O.Secondly,the effects of dye production wastewater on the structure and activity of HSA were studied by means of spectroscopy and esterase activity determination.The results showed that the organic matter in the wastewater caused the structural change of HSA,the structure of the protein skeleton was loose,and the hydrophilicity was enhanced.The microenvironment of tyrosine residues in HSA molecules was affected by wastewater,and the microenvironment gradually became hydrophobic and colored.There was no obvious change in the microenvironment of the residue of the acid residue,indicating that the action of organic matter and HSA in the wastewater is closer to tyrosine;the wastewater can inhibit the esterase activity of HSA.Ozone oxidation can destroy the complex structure of organic matter in wastewater,and oxidize it into organic acids and alcohols with simple structure to reduce the toxic effects of wastewater.Third,through the use of ozone and a variety of technologies,research to improve the treatment efficiency of wastewater treatment.The results show that ozone oxidation can significantly accelerate the start-up time and gas production rate of anaerobic bioreactor with wastewater as substrate,and increase the cumulative gas production,but has no significant effect on the aerobic biological treatment effect.For disperse dye production wastewater,the optimum mass ratio of ozone to hydrogen peroxide is 15:1.By adjusting the optimum ratio of ozone to hydrogen peroxide in the oxidation process by adding hydrogen peroxide in stages,the treatment effect can be improved.The final COD removal rate is 29%,which is 2.03 times higher than that of single ozone oxidation.It shows that the combined use of ozone hydrogen peroxide technology can improve the efficiency of wastewater treatment. |
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