Study On The Oxidation Decomposition Of 2-Mercaptobenzothiazole Using Ozone

2-mercaptobenzothiazole (MBT) is a kind of high production volume chemicals and it is used in many different industrial processes. Mainly used in industrial processes such as vulcanization accelerator is mainly used in rubber industry, as flotation collector in beneficiation industry, as metal corrosion inhibitor. Nowadays MBT have been detected in the industry domestic and municipal sewage. Because of its potential carcinogenicity, mutagenicity, it exists and treatment has caused more attention. At present, foreign started research on residual MBT in waste water to remove, but less reported, and domestic research on this subject is rarely reported.In this paper, ozone was used to oxidize the MBT,and decomposition mechanism and was studied. Firstly, the MBT removal effective by ozone was studied by single factor and orthogonal experiments. Secondly, the kinetic equation of MBT oxidation by ozone was discussed. Finally, the MBT oxidation mechanism was study by GC/MS analysis the oxidation intermediate. And the main result were as follows:(1) Single factor and orthogonal experiment results show that the influences of oxidation factors followed the order of reaction time> the amount of ozone> MBT initial concentration> pH. Ozone oxidation of simulated wastewater MBT optimum conditions are as follows:the initial concentration of MBT is 50mg/L, pH is 10, the amount of ozone is 5g/h. Under this condition, ozonation 10min, the removal rate of MBT reached 100%, COD is 15%,TOC is 20%. This indicates that although the complete decomposition of MBT, but not completely mineralized, produce an intermediate product. With the extension of time of ozone, oxidation untill 60min, the removal rate of COD could reach 87.1%, it instructions that this intermediate product can be further decomposed.(2)The experimental of dynamics results show that:When the pH=10, the amount of ozone is 5g/h, change the initial concentration of MBT (50mg/L, 100mg/L,200mg/L), the reaction kinetics is justified by first-order reaction kinetic mode. The constant K was-0.1885 min-1,-0.2782 min-1,-0.1654 min-1 respectively. The correlation coefficient R2 was 0.987, 0.985,0.970 respectively. And its kinetic equation was Ct= e-01885t+3.912, Ct= e-02782t+4.605, Ct= e-0.1654t+5.298 respectively. When the initial concentration of MBT is 50mg/L, the amount of ozone is 5g/h, change the pH (4,7,10), the reaction kinetics is justified by first-order reaction kinetic model. The constant K was-0.1991 min-1,-0.2582 min-1,-0.4005 min-1 respectively. The correlation coefficient R2 was 0.969,0.998,0.993 respectively. And its kinetic equation was Ct= e-0199U+4.605, Ct= e-02582t+4.605, Ct= e-0.4005t+4605 respectively. When the pH=10, the initial concentration of MBT is 50 mg/L, change the amount of ozone (1 g/h,3 g/h,5 g/h) the reaction kinetics is justified by first-order reaction kinetic model. The constant K was-0515 min-1,-1323 min-1,-2582 min-1 respectively. The correlation coefficient R2 was 0.991,0.968,0.985 respectively. And its kinetic equation was Ct= e-00515t+4.605, G= e-0.1323t+4.605, Ct= e-0.2582t+4.605 respectively.(3) The analysis results of the intermediate productt of MBT oxidation by ozone used GC/MS show that:The ozone oxidation decomposition route of MBT as follows. Firstly, MBT decomposition of benzothiazole and 2-hydroxy benzothiazole, subsequent is oxidized to phenol, and then further oxidation of phenol to aromatic esters, finally the aromatic ring opening, oxidation of low molecular weight compound.