选择纳米TiO2为催化剂,研究超声—紫外协同催化降解[艹屈]的效果。考察了不同TiO2类型、TiO2投加量、H2O2投加量、超声频率、超声强度、溶液初始pH和[艹屈]初始浓度等因素对[艹屈]降解率的影响,并对协同催化降解的机制进行了探讨。结果表明,不同类型TiO2对[艹屈]的降解效果为P25型TiO2〉锐钛矿型TiO2〉金红石型TiO2。在[艹屈]初始质量浓度为5 mg/L、P25型TiO2投加量为0.06g/L、H2O2投加量为60mmol/L、超声频率为80kHz、超声强度为0.300W/cm2、溶液初始pH为3.0的条件下,反应10min时超声—紫外协同催化对[艹屈]的降解率最高可达98.26%。超声和紫外光对[艹屈]的降解具有协同促进效应,其协同因子为2.08。机制分析表明,超声—紫外协同催化降解[艹屈]的机制是以·OH为主要自由基的高级氧化作用,1,3-二苯丙烷和对苯基苯酚为主要中间产物。
The Ultrasound (US)/Ultraviolet (UV) synergetic catalysis technology with TiO2 nanoparticles as catalyst was used to degrade dissolved chrysene. The effects of different types of TiO2 , catalyst TiO2 dosage, H2 O2 dosage, ultrasonic frequency , ultrasonic intensity ,initial pH and initial chrysene concentration on the degradation rate of chrysene were investigated, and the synergetic catalytic degradation mechanism of chrysene was discussed. The re-sults showed that the degradation rate of chrysene was P25 TiO2〉anatase TiO2〉rutile TiO2. Under the optimal conditions with initial chrysene concentration of 5 mg/L, catalyst P25 TiO2 dosage of 0.06 g/L,H2O2 dosage of 60 mmol/L,ultrasonic frequency of 80 kHz,ultrasonic intensity of 0.300 W/cm2 and initial pH of 3.0,the highest degra-dation rate of chrysene could reach up to 98.26 % after 10 min by US/UV synergetic catalysis technology. The degra-dation rate of chrysene was promoted by the combination of US and UV. The synergetic factor was 2.08, which con-firmed that the US/UV had significant synergistic effect. The synergetic catalytic degradation mechanism showed that hydroxyl radicals oxidation was mainly responsible for the degradation of chrysene. The main intermediate products were 1,3-diphenylpropane and p-hydroxybiphenyl.