Fenton试剂-太阳光催化氧化法联合处理造纸黑液

Photocatalytic Degradation of Black Liquor Using Photocatalysis and Fenton Reagents

以钛酸丁酯作为TiO_2的前驱体,利用硝酸镧和硫脲作为掺杂源,采用溶胶-凝胶法制备了La、N/S共掺杂TiO_2光催化剂,并采用紫外-可见分光光度计(UV-Vis)和X射线衍射仪(XRD)对所制备的光催化剂进行了分析表征,然后利用Fenton试剂氧化法预处理与太阳光催化氧化法联合对造纸黑液进行了降解处理,分别考察了光照时间、光催化剂用量、处理液p H值、H_2O_2加入量等各因素对光催化降解率的影响,在单因素研究的基础上进行了L9(3~4)正交试验。结果表明,所制备的共掺杂TiO_2为锐钛矿晶型,吸收带红移有较强的可见光吸收,大大提高了对太阳光能的利用率。造纸黑液经Fenton试剂氧化预处理后,在500 W氙灯(模拟太阳光)下光催化氧化降解的最佳工艺条件为:50 m L造纸黑液,H_2O_2加入量为0.6 m L;反应液p H=5;光照时间90 min;催化剂用量0.04 g,在上述工艺条件下太阳光催化降解率可达到73%,处理效果大大优于市售进口TiO_2光催化剂和单一光催化降解过程。

Using lanthanum nitrate and thiourea as the doping source, the La, N/S co-doped TiO2 photocatalyst was prepared by sol-gel method with butyl titanate as precursor of TiO2, and the as-prepared photocatalysts were characterized by UV-Vis spectrophotometer（UV-Vis） and X-ray diffractometer（XRD）. The photocatalytic degradation of papermaking black liquor was carried out by pretreatment with Fenton reagent oxidation method and solar photocatalytic oxidation method. The effect of various factors on the photocatalytic degradation rate was investigated such as the irradiation time, the amount of photocatalyst, the p H value of treatment solution and the amount of photocatalyst, respectively. L9（3~4） orthogonal test was carried out on the basis of single factor study, and results show that the prepared co-doped TiO2 is anatase crystal, and the absorption band has a strong visible light absorption, which greatly improves the utilization rate of solar energy. The optimum conditions for the photocatalytic oxidation degradation under 500 W xenon lamp（simulated solar light） were 50 m L papermaking black liquor, and the amount of H2 O2（30%）0.6 m L, and the photocatalytic degradation rate can reach 73% under the above process conditions, and the treatment effect is much better than that of the commercially available imported TiO2 photocatalyst and single photocatalytic degradation process.