School of Environmental and Chemical Engineering, Shanghai University, No. 99, Shangda Road, Shanghai 200444, China; Centre of Green Urban Mining and Industry Ecology, Shanghai University, No. 99, Shangda Road, Shanghai 200444, China.
School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia.
Bioresour Technol. 2018 Dec;270:223-229. doi: 10.1016/j.biortech.2018.09.027. Epub 2018 Sep 6.
In this study, lignin was selected as the main component of waste biomass to synthesise carbonaceous adsorbents with environmentally persistent free radicals (EPFRs) through hydrothermal carbonisation (HTC) under different conditions. The HTC method with Fe(III) doping was superior for promoting dehydration and decarboxylation of lignin hydrochar than that with HTC Cu(II) doping. The deconstruction of oxygen-containing groups of lignin was reduced while esterification was enhanced by Fe(III). The Fe(III) addition was conducive to the formation of EPFRs as carbon-centred radicals with an adjacent oxygen atom and oxygen-centred radicals. A comparison of lignin with cellulose and d-xylose suggests that the formed EPFRs on lignin hydrochar were derived from their phenolic hydroxyl groups. A high removal efficiency of bisphenol A by lignin hydrochar was observed owing to oxygen-centred radicals, which activated HO to produce OH. These results will facilitate the design and application of novel hydrochar materials with EPFRs.
在这项研究中，选择木质素作为废生物质的主要成分，通过水热碳化（HTC）在不同条件下合成具有环境持久性自由基（EPFRs）的碳质吸附剂。与 HTC Cu(II) 掺杂相比，Fe(III) 掺杂的 HTC 方法更有利于促进木质素水热炭的脱水和脱羧。Fe(III) 的添加减少了木质素中含氧基团的解构，同时增强了酯化作用。Fe(III) 的添加有利于形成以相邻氧原子和氧中心自由基为中心的碳中心自由基的 EPFRs。将木质素与纤维素和 D-木糖进行比较表明，木质素水热炭上形成的 EPFRs来自其酚羟基。木质素水热炭对双酚 A 的去除效率很高，这是由于氧中心自由基激活 HO 产生 OH。这些结果将有助于设计和应用具有 EPFRs 的新型水热炭材料。
