Hydrolytic Pretreatment Of Tylosin In Pharmaceutical Wastewater By Titanium-Contained Salts And Solid Acids

Antibiotic residues in wastewater lead to the production of“superbugs”,also affect ecosystems and human health.Pharmaceutical wastewater has the most kinds and the highest concentration of antibiotics among antibiotic wastewater sources.Tylosin is a widely used typical macrolide antibiotic with large market and production demand.Tylosin pharmaceutical wastewater containing a large amount of high concentration of tylosin.Acid hydrolysis is an efficient method for this kind of wastewater.Hydrolysis can effectively reduce the concentration of tylosin by breaking the glucoside bonds,which could reduce pharmacodynamic functional groups such as glycosyl on the tylosin.In this study,tylosin was used as target to study the hydrolysis pretreatment efficiency and the influence factors by titanium-contained salts and solid acids under different conditions.The influence factors of hydrolysis were identified and the hydrolysis products were determined.Finally,according to the actual requirements,a treatment process for tylosin pharmaceutical wastewater was designed.Titanium sulfate was used as solid acid to hydrolyze tylosin.The optimum dosage and hydrolysis temperature of titanium sulfate were determined.Rapid and complete removal of100 mg/L tylosin was achieved by 10 min at a dosage of 40 mg/L Ti⁴⁺under 25 ^oC.Increasing the dosage of titanium sulfate can enhance the hydrolysis efficiency.The lower the p H,the better the hydrolysis efficiency.HPLC-Q/TOF-MS was used to identify hydrolytic products and analyze hydrolytic pathways.The results showed that in the process of hydrolysis of tylosin by titanium sulfate,the break of glycoside bond would lead to the shedding of pharmacodynamic functional groups,mycarose and mycinose,which would reduce the concentration of tylosin.SO₄^2-/Ti O₂super solid were prepared to hydrolyze tylosin,which process were optimized.Rapid and complete removal of 100mg/L tylosin was achieved by 2 min at a dosage of 1.0 g/L Ti S11.25/350 under 25 ^oC.Increasing the hydrolysis temperature and adding dosage of super solid acid can both enhance the hydrolysis efficiency.The tylosin concentration removal rate was inversely proportional to p H and positively proportional to total acidity of solid acid.The use of ultraviolet to enhance the hydrolysis of tylosin by super solid acid has no obvious effect.It is speculated that the possible reason is that the load of sulfonic acid group leads to the reduction by hydroxyl on titanium dioxide,thus reducing the photocatalytic efficiency.In this paper,the hydrolysis efficiency of tylosin by titanium-contained salts and solid acids under different conditions was investigated.Both of them can be used as pretreatment hydrolysis of tylosin in a short time.This study provides data support and technological means for the pretreatment of tylosin pharmaceutical wastewater.The process design of tylosin pharmaceutical wastewater also provide a powerful treatment program for tylosin pharmaceutical wastewater.