Feng Dongqing, Shou Jianxin, Guo Sen, Ya Mengna, Li Jianfa, Dong Huaping, Li Yimin
College of Chemistry and Chemical Engineering, Shaoxing University Shaoxing Zhejiang 312000 China
College of Life Science, Shaoxing University Shaoxing Zhejiang 312000 China
RSC Adv. 2022 Jun 10;12(27):17237-17248. doi: 10.1039/d2ra01647h. eCollection 2022 Jun 7.
Activation of hydrogen peroxide (HO) with biochar is a sustainable and low-cost approach for advanced oxidation of organic pollutants, but faces the challenge of a low yield of hydroxyl radical (˙OH). Herein, we hypothesize that the activation efficiency of HO can be enhanced through co-catalysis of trace dissolved iron (Fe) with biochar. Two biochar samples derived from different feedstock, namely LB from liquor-making residue and WB from wood sawdust, were tested in the co-catalytic systems using trace Fe(iii) (0.3 mg L). The cumulative ˙OH production in [Fe(iii) + LB]/HO was measured to be 3.28 times that in LB/HO, while the cumulative ˙OH production in [Fe(iii) + WB]/HO was 11.9 times that in WB/HO. No extra consumption of HO was observed in LB/HO or WB/HO after addition of trace Fe(iii). Consequently, the reaction rate constants ( ) for oxidation of pollutants (2,4-dichlorophenoxyacetic acid and sulfamethazine) were enhanced by 3.13-9.16 times. Other iron species including dissolved Fe(ii) and iron minerals showed a similar effect on catalyzing 2,4-D oxidation by biochar/HO. The interactions involved in adsorption and reduction of Fe(iii) by biochar in which the defects acted as electron donors and oxygen-containing functional groups bridged the electron transfer. The fast regeneration of Fe(ii) in the co-catalytic system resulted in the sustainable ˙OH production, thus the efficient oxidation of pollutants comparable to other advanced oxidation processes was achieved by using dissolved iron at a concentration as low as the concentration that can be found in natural water.
生物炭活化过氧化氢（HO）是一种可持续且低成本的有机污染物高级氧化方法，但面临着羟基自由基（˙OH）产率低的挑战。在此，我们假设通过痕量溶解铁（Fe）与生物炭的共催化可以提高HO的活化效率。使用痕量Fe(iii)（0.3 mg L）在共催化体系中测试了两种源自不同原料的生物炭样品，即来自酿酒残渣的LB和来自木屑的WB。测得[Fe(iii) + LB]/HO体系中˙OH的累积产量是LB/HO体系中的3.28倍，而[Fe(iii) + WB]/HO体系中˙OH的累积产量是WB/HO体系中的11.9倍。添加痕量Fe(iii)后，在LB/HO或WB/HO体系中未观察到HO的额外消耗。因此，污染物（2,4-二氯苯氧乙酸和磺胺二甲嘧啶）氧化反应的速率常数（）提高了3.13 - 9.16倍。其他铁物种，包括溶解的Fe(ii)和铁矿物，对生物炭/HO催化2,4-D氧化也有类似效果。生物炭对Fe(iii)的吸附和还原过程中的相互作用，其中缺陷充当电子供体，含氧官能团桥接电子转移。共催化体系中Fe(ii)的快速再生导致˙OH的持续产生，因此通过使用浓度低至天然水中可发现浓度的溶解铁，实现了与其他高级氧化过程相当的污染物高效氧化。
