改善反应器内部光照条件对TiO2光催化去除H2S的影响

Effects of improving internal light condition of reactor on H_2S removal by TiO_2 photocatalytic oxidation

在不同紫外光照强度和不同催化剂质量条件下,研究了TiO_2对H2S光催化氧化去除效率和特征。结果表明,H2S去除率随紫外光照强度增大而增大,而在用空白玻璃珠替代部分负载有TiO_2的玻璃珠(TiO_2-GB)后,TiO_2-GB所占比例为60%(TG60%)时具有最佳的光催化氧化效率。在H2S浓度为1 062 mg·m-3,流速100 m L·min-1条件下反应90 h后,TG60%的H2S去除率依然能达到64.79%,高于相同条件下TG100%的42.03%,产物为S6与S0。通过研究反应器内部紫外光强度分布,发现单纯增大外部紫外灯功率并不能有效增大反应器内部光强,而随空白玻璃珠所占比例增大,反应器内部光照条件得到有效改善。因此,单纯增强紫外线强度或增加TiO_2催化剂用量均不能达到最理想的光利用效率,而是要将两者综合考虑。实验结果表明,与填充物全为TiO_2-GB的情况相比,TG60%在不提高能耗的前提下,减少了催化剂的用量,而H2S的光催化去除率反而提升。

The effects of the UV irradiation intensity and ratio of TiO2-GB on efficient HzS removal were in- vestigated by photo-catalytic oxidation on TiO2. Results indicated that a higher UV irradiation intensity contribu- ted to a higher H2S removal efficiency. However, after a portion of TiOE-GB was replaced with blank glass beads, rather than TG100% （100% TiO2-GB） , TG60% exhibited a superior performance. After H2S reacted for 90 hours （1 062 mg~ m-3, 100 mL ~ min-1） , 64.79% removal efficiency was obtained, which was higher than that of TG100% （42.03%）. The main products of H2S oxidation were sulfate and sulfur. Results showed that increasing the external power of the UV light could not improve effectively the internal lighting of the reactor; thus, the internal irradiation intensity of the reactor increased with increasing proportions of blank glass beads. Therefore, simply increasing the external UV light irradiation intensity or mass of catalysts was insufficient to a- chieve an optimal utilization of UV light; integrated consideration was necessary. Compared with TG100% , TG60% not only reduced the dosage on TiO2 catalysts, but also improved the efficiency of H2S removal without extra energy consumption.