Laboratory of Environmental Technology, INET, Tsinghua University, Beijing, 100084, China; Beijing Key Laboratory of Radioactive Wastes Treatment, Tsinghua University, Beijing, 100084, China.
Laboratory of Environmental Technology, INET, Tsinghua University, Beijing, 100084, China; Beijing Key Laboratory of Radioactive Wastes Treatment, Tsinghua University, Beijing, 100084, China.
Chemosphere. 2024 Sep;364:143000. doi: 10.1016/j.chemosphere.2024.143000. Epub 2024 Aug 3.
Nitrogen-doped biochar as Fenton-like catalysts has been widely used to remove emerging pollutants in wastewater. However, the effect of in-situ and ex-situ nitrogen doping on the Fenton-like catalytic activity of biochar is unclear. In this study, the nitrogen-doped biochar was prepared by in-situ (NBC) and ex-situ (BC-N) nitrogen doping, and the Fenton-like catalytic activity of NBC and BC-N was compared for activating hydrogen peroxide (HO), peroxydisulfate (PDS) and peroxymonosulfate (PMS). The results showed that NBC had higher Fenton-like catalytic activity than BC-N, because the formation of carbon quantum dots (CQDs) significantly increased the adsorption capacity to HO, PDS and PMS. NBC could activate HO, PDS and PMS for degradation of sulfamethoxazole (SMX), but showed different catalytic activity and degradation mechanism. In the systems of NBC/HO and NBC/PDS, CQDs played a key role in the activation of HO and PDS, and surface-bound reactive species were mainly responsible for SMX degradation. In the system of NBC/PMS, NBC acted as both electron mediator and activator, direct electron transfer between PMS and SMX and surface-bound reactive species contributed to SMX degradation. This study provides an insight into the catalytic activity of NBC for HO, PDS and PMS.
氮掺杂生物炭作为类芬顿催化剂已被广泛应用于去除废水中的新兴污染物。然而，原位和异位氮掺杂对生物炭类芬顿催化活性的影响尚不清楚。本研究通过原位（NBC）和异位（BC-N）氮掺杂制备了氮掺杂生物炭，并比较了 NBC 和 BC-N 对活化过氧化氢（HO）、过二硫酸盐（PDS）和过一硫酸盐（PMS）的类芬顿催化活性。结果表明，NBC 具有比 BC-N 更高的类芬顿催化活性，因为碳量子点（CQDs）的形成显著提高了对 HO、PDS 和 PMS 的吸附能力。NBC 可以激活 HO、PDS 和 PMS 来降解磺胺甲恶唑（SMX），但表现出不同的催化活性和降解机制。在 NBC/HO 和 NBC/PDS 体系中，CQDs 在 HO 和 PDS 的活化中起关键作用，表面结合的活性物质主要负责 SMX 的降解。在 NBC/PMS 体系中，NBC 既作为电子介体又作为活化剂，PMS 和 SMX 之间的直接电子转移以及表面结合的活性物质有助于 SMX 的降解。本研究深入了解了 NBC 对 HO、PDS 和 PMS 的催化活性。
