The efficiency of hydrogen peroxide in the regeneration of dimethyl sulphide (DMS) exhausted-activated carbons (ACs) is assessed in this study. Moreover, the influence of chemical surface composition is evaluated using six ACs (two commercial ACs and four chemically modified ACs) with different surface features. Chemical surface composition of ACs before and after different adsorption-regeneration cycles is assessed by temperature-programmed desorption coupled with mass spectroscopy (TPD-MS) and by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Results reveal that up to a 60% of regeneration efficiency is attained, being more effective in the presence of ACs derived from Filtrasorb 300 AC sample. Experimental findings show that ACs with high content of basic oxygen–containing functional surface groups and mineral fraction are responsible to promote the catalytic decomposition of hydroxide peroxide, leading to a higher formation of hydroxyl radicals and to the observed increase in the regenerative oxidation of adsorbed DMS. However, a decrease in removal efficiency is related to an increase in the amounts of oxygen functionalities mainly in the form of strong acidic surface groups such as carboxylic acid anhydrides and carboxylic acids that shift the reaction mechanism from promoting the initiation of radical chain reactions to termination. Additionally, DRIFTS analyses indicate that after successive adsorption-regeneration cycles the fraction of organic molecules that remains adsorbed limits the access to active surface sites responsible for radical generation, reducing drastically the catalytic activity of ACs.

本研究评估了过氧化氢在二甲基硫醚 (DMS) 废活性炭 (AC) 再生中的效率。此外，使用具有不同表面特征的六种活性炭（两种商用活性炭和四种化学改性活性炭）评估了化学表面组成的影响。通过程序升温脱附结合质谱（TPD-MS）和漫反射红外傅里叶变换光谱（DRIFTS）评估不同吸附-再生循环前后活性炭的化学表面组成。结果表明，再生效率高达 60%，在存在源自 Filtrasorb 300 AC 样品的 AC 的情况下更有效。实验结果表明，具有高含量碱性含氧功能表面基团和矿物部分的活性炭负责促进过氧化氢的催化分解，导致更多的羟基自由基形成，并观察到吸附的 DMS 的再生氧化增加. 然而，去除效率的降低与主要以强酸性表面基团形式的氧官能团数量的增加有关，例如羧酸酐和羧酸，它们将反应机制从促进自由基链反应的引发转变为终止. 此外，