State Key Lab of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, PR China.
State Key Lab of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, PR China.
Environ Pollut. 2022 Dec 1;314:120296. doi: 10.1016/j.envpol.2022.120296. Epub 2022 Sep 28.
Fe-N co-doped biochar is recently an emerging carbocatalyst for persulfate activation in situ chemical oxidation (ISCO). However, the involved catalytic mechanisms remain controversial and distinct effects of coexisting water components are still not very clear. Herein, we reported a novel N-doped biochar-coupled crystallized Fe phases composite (Fe@N-BC) as efficient and low-cost peroxydisulfate (PDS) activators to degrade bisphenol A (BPA), and the underlying influencing mechanism of coexisting inorganic anions (IA) and humic constituent. Due to the formation of graphitized nanosheets with high defects (AI index>0.5, I/I = 1.02), Fe@N-BC exhibited 2.039, 5.536, 8.646, and 23.154-fold higher PDS catalytic activity than that of Fe@N-BC, Fe@N-BC, N-BC, BC. Unlike radical pathway driven by carbonyl group and pyrrolic N of low/mid-temperature Fe@N-BCs. The defective graphitized nanosheets and Fe-Nx acted separately as electron transfer and radical pathway active sites of Fe@N-BC, where π-π sorption assisted with pyrrolic N and pore-filling facilitated BPA degradation. The strong inhibitory effects of PO and NO were ascribed to competitive adsorption of phosphate (61.11 mg g) and nitrate (23.99 mg g) on Fe@N-BC via electrostatic attraction and hydrogen bonding. In contrast, HA competed for the pyrrolic-N site and hindered electron delivery. Moreover, BPA oxidation pathways initiated by secondary free radicals were proposed. The study facilitates a thorough understanding of the intrinsic properties of designed biochar and contributes new insights into the fate of degradation byproducts formed from ISCO treatment of micropollutants.
Fe-N 共掺杂生物炭是近年来新兴的过硫酸盐活化原位化学氧化（ISCO）的碳催化剂。然而，所涉及的催化机制仍存在争议，共存水成分的不同影响尚不清楚。本文报道了一种新型的 N 掺杂生物炭结合结晶 Fe 相复合材料（Fe@N-BC）作为高效、低成本的过一硫酸盐（PDS）活化剂来降解双酚 A（BPA），以及共存无机阴离子（IA）和腐殖质组成的潜在影响机制。由于形成了具有高缺陷的石墨化纳米片（AI 指数>0.5，I/I=1.02），Fe@N-BC 比 Fe@N-BC、Fe@N-BC、N-BC、BC 具有 2.039、5.536、8.646 和 23.154 倍更高的 PDS 催化活性。与由羰基和中低温 Fe@N-BCs 的吡咯 N 驱动的自由基途径不同。缺陷石墨化纳米片和 Fe-Nx 分别作为电子转移和自由基途径的活性位点，π-π 吸附辅助吡咯 N 和孔填充促进 BPA 降解。PO 和 NO 的强抑制作用归因于磷酸盐（61.11 mg g）和硝酸盐（23.99 mg g）通过静电吸引和氢键在 Fe@N-BC 上的竞争性吸附。相比之下，HA 竞争吡咯-N 位并阻碍电子传递。此外，还提出了由次级自由基引发的 BPA 氧化途径。该研究有助于深入了解设计生物炭的固有特性，并为理解 ISCO 处理微污染物过程中形成的降解副产物的命运提供了新的见解。
