UV和UV/过硫酸盐工艺降解安替比林的对比研究

Comparative study of antipyrine degradation by UV and UV/persulfate system

针对紫外(UV)和紫外/过硫酸盐(UV/PS)法降解药物安替比林,选取底物浓度、氧化剂投量、pH、光照强度和腐植酸(HA)5个影响因素进行研究。结果表明:安替比林浓度随时间的变化符合准一级动力学模型(R2>0.95)。准一级反应速率随安替比林AP初始浓度增加而降低,UV/PS系统平均反应速率大于UV系统。增加PS投量、提高溶液pH及提升光照强度可增大反应速率。增加PS投量可使UV/PS系统准一级速率常数kobs从2.46×10-2min-1([PS]0=0 mmol/L)增加至2.76×10-2 min-1([PS]0=0.52 mmol/L)。考察pH的影响,各系统最大去除率均发生在pH=11.5,分别为76.0%(UV)和85.7%(UV/PS)。各系统kobs均与光强呈线性关系(R2>0.95),光强从414 mJ/cm2降至69 mJ/cm2时,两者的kobs分别从2.43×10-2 min-1降至5.42×10-3 min-1(UV)及从2.64×10-2 min-1降至5.20×10-3min-1(UV/PS)。适当的HA投入使得2个系统的反应速率增加,UV系统kobs在ρ0(HA)=7.5 mg/L达最大值2.53×10-2min-1;UV/PS系统kobs在ρ0(HA)=2.5 mg/L时达最大值3.28×10-2 min-1,过多HA投加会因其与AP竞争和活性自由基反应而导致AP去除受抑制,kobs分别降至2.01×10-2 min-1和2.80×10-2 min-1。

The degradation of antipyrine（AP） in UV and UV/persulfate system was evaluated with several influencing factors including original AP dosage, persulfate（PS） dosage, pH, UV irradiance and humic acid dosage discussed. The results show that AP degradation fits the first-order kinetics well（R^2〉0.95）. The degradation rates decrease in two systems when the AP dosage increases. The persudo-first-order-constant（kobs） in UV/PS system is higher than that in UV system. Degradation can be accelerated by enhancing oxidant persulfate, raising pH and increasing UV light intensity. PS dosage causes kobs to increase from 2.46×10^-2 min^-1（[PS]0=0 mmol/L） to 2.76×10^-2 min^-1（[PS]0=0.52 mmol/L）. When pH=11.5, AP degradation（76.0%（UV） and 85.7%（UV/PS）） reaches the maximum. kobs decreases from 2.43×10^-2 min^-1 to 5.42×10^-3 min^-1（UV） and from 2.64×10^-2 min^-1 to 5.2×10^-3 min^-1（UV/PS） when light intensity reduces from 414 mJ/cm2 to 69 mJ/cm2. In UV system, kobs reaches the top of 2.53×10^-2 min^-1 with 7.5 mg/L HA（UV） and 3.28×10^-2min^-1 with 2.5 mg/L HA（UV/PS）. Excessive HA addition has a suppression effect because of the competitive reactions with radicals. kobs decreases to 2.01×10^-2 min^-1（UV） and 2.80×10^-2 min^-1（UV/PS）.