Basic Research On Thermo-photo-catalytic Degradation Of Antibiotic Wastewater Near Room Temperature

In this thsis the photocatalytic degradation reaction of antibiotics was carried out without light,thermal catalytic degradation reaction was put forward as a supplement near room temperature,and layered thermal catalyst Na Co₂O₄and Bi OBr/Na Co₂O₄ thermo-photo-catalytic composite materials were synthesized,then the Na Co₂O₄/H₂O₂ thermocatalytic system,the Bi OBr/Na Co₂O₄thermocatalytic system,the Bi OBr/Na Co₂O₄ photocatalytic system and the Bi OBr/Na Co₂O₄ thermo-photo-catalytic system which application for the degradation of antibiotic wastewater with tetracycline hydrochloride or chloramphenicol simulation were constructed.The realated results obtained were as follows:（1）Thermal sensitive catalyst Na Co₂O₄ was prepared by solid phase sintering method.The Na Co₂O₄/H₂O₂ thermal catalytic system was built.The methylene blue solution was used to simulate the organic wastewater,and the degradation effect of the thermal catalytic system was investigated.The experimental results of XRD and SEM showed that the layered catalyst of Na Co₂O₄ sintered had good thermal stability.After 340 min,the degradation rate of MB was 87.00%under the optimal condition which was 100 m L 30 mg·L^-1MB,1.00 m L H₂O₂,T=50℃.Specially,under the optimal condition,the degradation rate of MB was still above 85%after three cycle runs.It is confirmed by scavengers（isopropanol,EDTA）that hydroxyl radicals（HO·）and hole（h⁺）were the main active species in the Na Co₂O₄/H₂O₂ thermo-catalytic system.（2）The series of Bi OBr/Na Co₂O₄ composite materials was prepared by hydrothermal synthesis method.The Bi OBr/Na Co₂O₄ thermocatalytic system,the Bi OBr/Na Co₂O₄photocatalyticsystemandtheBi OBr/Na Co₂O₄thermo-photo-catalytic system were constructed.The rhodamine B solution was used to simulate the organic wastewater,and the degradation effect of all catalytic system was investigated,respectively.The analysis of structure,morphology,optical properties and others confirmed that flaky Bi OBr grew on Na Co₂O₄,and new chemical bonds were formed between Bi,O,Br and Co elements,a series of Bi OBr/Na Co₂O₄ composites materials had pore structure and had better absorption to visible light.The Bi OBr/Na Co₂O₄ thermocatalytic system,the Bi OBr/Na Co₂O₄ photocatalytic system and the Bi OBr/Na Co₂O₄thermo-photo-catalytic system showed good catalytic effect on Rh B,and the B/N-1 composite showed best performance,and the degradation rate of Rh B could be up to 100%.The degradation effect of the photocatalytic system under sunlight is better:the degradation rate of Rh B can reach 100%after 60 min;the intermediate products can be completely mineralized after 80 min;Three cycles,B/N-1 composites material used three times still had a good catalytic.When the alternating test simulated was between night and day,the B/N-1 composites materialexhibitedagoodperformanceintheBi OBr/Na Co₂O₄thermo-photo-catalytic system.After three cycles,the degradation rate of Rh B could reach more than 95%after 120 min.It is confirmed by scavengers that hydroxyl radicals（HO·）,hole（h⁺）and superoxide radical（·O₂ˉ）were the main active species in the Bi OBr/Na Co₂O₄-H₂O₂ thermocatalytic system and Bi OBr/Na Co₂O₄ photocatalytic system.（3）The Na Co₂O₄/H₂O₂ thermal catalytic system,the Bi OBr/Na Co₂O₄thermocatalytic system,the Bi OBr/Na Co₂O₄ photocatalytic system and the Bi OBr/Na Co₂O₄ thermo-photo-catalytic system showed good catalytic effect on tetracycline hydrochloride,and the degradation rate of tetracycline hyd rochloride could be up to 80%.The degradation of Bi OBr/Na Co₂O₄ photocatalytic system was mainly studied for chloramphenicol,and the degradation rate was 17%after120 min.