摘要
以水体异味物质2-甲基异莰醇(2-methylisoborneol,2-MIB)为研究对象,在紫外光(λ<380 nm)照射下,探讨TiO2(P25)对2-MIB的光催化降解特性及光化学作用机理。结果表明,UV/TiO2光催化体系可以有效去除水体异味物质2-MIB,紫外光照射60 min,对2-MIB的降解率达95%。同时研究了光催化降解体系介质pH,共存腐殖酸(HA)和过硫酸钾(K2S2O8)对UV/TiO2光催化体系降解2-MIB的影响,发现低浓度HA([HA]≤0.5 mg/L)可以提高2-MIB降解速率,当HA浓度高于0.5 mg/L,2-MIB降解反应受到抑制;同时当加入电子受体K2S2O8后,降解体系中活性物种羟基自由基(.OH)明显增加,提高了TiO2对2-MIB的降解能力。利用苯甲酸荧光光度法和POD-DPD显色法跟踪测定降解过程中羟基自由基(·OH)和过氧化氢(H2O2)的变化,表明光催化反应涉及·OH机理。
The photocatalytic degradation characteristics and photochemical mechanism of odor 2-methyli- soborueol (2-MIB) by TiO2 (P25) under UV irradiation (A 〈 380 nm) were studied. The results showed that 2- MIB in water bodies was effectively degraded in the photocatalytie system of UV/TiO2. The degradation rate of 2- MIB reached 95% under UV illumination for 60 rain. The effects of pH, coexisting humic acid (HA) and potas- sium sulfate (K2S208) on UV/TiO2system were researched. The results demonstrated that low concentration of HA ( ~ O. 5 rag/L) improved the degradation while high concentration of HA ( 〉0.5 rag/L) inhibited the deg- radation of 2-MIB. K2S208, an electronic aceeptor, enhanced the degradation rate of 2-MIB by significantly in- creasing the concentration of hydroxyl radical ( OH) in the system. The concentration of OH and hydrogen peroxide (H202) was determined by the fluorescence method and the N, N-diethyl-p-phenylenediamine (DPD) method.
出处
《环境工程学报》
CAS
CSCD
北大核心
2012年第8期2533-2538,共6页
Chinese Journal of Environmental Engineering
基金
国家自然科学基金资助项目(20877048)
湖北省创新群体项目(2009CDA020)
催化材料科学湖北省暨国家民委-教育部共建重点实验室开放基金(chcl10007)