Heterogeneous electro-Fenton (hetero-EF) system was one of the most promising approaches for treating antibiotic-laden wastewater. However, the rational design of cost-effective, eco-friendly, and efficient earth-abundant electrocatalysts remains a significant challenge. This study synthesized a novel catalyst, lignin-based metal biochar (Co-L@C), from coniferous lignin via hydrothermal reaction and temperature-controlled pyrolysis. The results demonstrated that Co-L@C achieved nearly 100 % oxytetracycline hydrochloride (OTC) removal within 30 min employing the hetero-EF system, consistently exhibiting efficient OTC degradation rates across a wide pH range (3−9) and in various practical water matrices. In conjunction with the burst test and electron paramagnetic resonance (EPR) analysis, singlet oxygen (1O2) was shown to play a dominant role in OTC degradation. At the same time, further investigation revealed that hydroxyl radicals (·OH), superoxide radicals (O2·−), and dissolved oxygen (DO) all contributed to 1O2 production. This work offers a potential technology for the effective degradation of antibiotic-contaminated wastewater.

中文翻译：

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非均相 Electro-Fenton 系统中 Co-L@C 阴极对 OTC 的有效降解：单线态氧的突出作用


异质电芬顿 （hetero-EF） 系统是处理含抗生素废水的最有前途的方法之一。然而，经济高效、环保且高效的地球丰富的电催化剂的合理设计仍然是一个重大挑战。本研究通过水热反应和温控热解从针叶木质素中合成了一种新型催化剂，木质素基金属生物炭 （Co-L@C）。结果表明，Co-L@C 采用异质 EF 系统在 30 分钟内实现了近 100% 的盐酸土霉素 （OTC） 去除，在较宽的 pH 范围 （3-9） 和各种实际水基质中始终表现出高效的 OTC 降解率。结合爆破测试和电子顺磁共振 （EPR） 分析，单线态氧 （1O2） 在 OTC 降解中起主导作用。同时，进一步的调查显示，羟基自由基 （·OH）、超氧自由基 （O2·−） 和溶解氧 （DO） 都有助于 1O2 的产生。这项工作为有效降解抗生素污染的废水提供了一种潜在的技术。