Larouk Safa, Ouargli Rachida, Shahidi Dariush, Olhund Leanne, Shiao Tze Chieh, Chergui Nacira, Sehili Tahar, Roy René, Azzouz Abdelkrim
Nanoqam, Department of Chemistry, University of Quebec at Montreal, H3C-3P8, Canada; Laboratory of Science and Technology of Environment, University of Constantine-1, Algeria.
Department of Materials Engineering, University of Science and Technology, Oran, Algeria; Laboratory of Materials Chemistry, Oran University, BP 1524 El M'naouer, Oran, Algeria.
Chemosphere. 2017 Feb;168:1648-1657. doi: 10.1016/j.chemosphere.2016.11.120. Epub 2016 Dec 9.
Hematite-SBA-16 mixture (HS) exhibited high catalytic activity in Orange-G (OG) ozonation in water. Total OG discoloration was achieved in half the time required with hematite or SBA-16 alone, all UV-Vis bands disappeared in less than 2 min. Liquid chromatography- Mass spectrometry (LC-MS) revealed that OG ozonation triggers via both hydroxylation and desulfonation of the aromatic rings into specific intermediates. Prolonged ozonation in the presence of hematite and SBA-16 alone resulted in different distributions of common derivatives. The latter were not detected after 25 min ozonation with HS. Stochastic modeling of the evolution in time of the UV-Vis bands of OG revealed strong binary interaction between the initial pH and catalyst concentration. This was explained in terms of reciprocal contributions of: i. the catalytic properties of hematite in spite of its low porosity; ii. the high specific surface area of SBA-16 for adsorption and surface reaction notwithstanding its low intrinsic catalytic activity. The weak basicity of SBA-16 surface seems to play a key-role in adsorption. These findings are of great interest for envisaging flexible oxidative treatments, where Fe containing soils or mixtures of sand and rust may also act as catalyst for total mineralization of various azo-dyes, regardless to their structures.
赤铁矿-SBA-16混合物（HS）在水中对橙黄G（OG）的臭氧化反应中表现出高催化活性。实现OG完全脱色所需的时间仅为单独使用赤铁矿或SBA-16时的一半，所有紫外可见吸收带在不到2分钟内消失。液相色谱-质谱联用（LC-MS）表明，OG臭氧化反应通过芳环的羟基化和脱硫反应生成特定中间体。单独在赤铁矿和SBA-16存在下进行长时间臭氧化会导致常见衍生物的分布不同。用HS进行25分钟臭氧化后未检测到后者。对OG紫外可见吸收带随时间演变的随机建模表明，初始pH值与催化剂浓度之间存在强烈的二元相互作用。这可以从以下相互作用来解释：i. 尽管赤铁矿孔隙率低，但仍具有催化性能；ii. 尽管SBA-16的固有催化活性低，但其具有高比表面积用于吸附和表面反应。SBA-16表面的弱碱性似乎在吸附中起关键作用。这些发现对于设想灵活的氧化处理具有重要意义，在这种处理中，含铁土壤或沙子与铁锈的混合物也可能作为各种偶氮染料完全矿化的催化剂，而不管其结构如何。
