文献类型： 外文期刊

作者： 吕鹏;;黄晓雅;;李莲芳*;;焦艳

作者机构：

关键词： Modifed biochar; Aging mechanism; Arsenic fate; Freeze–thaw cycling; Soil micro-interfaces

期刊名称： Biochar

ISSN： 2524-7972

年卷期： 2026 年

页码：

收录情况： SCIE（2025版） ; ; CSCD（2025-2026年度） ; ; 农林核心（2024版）

摘要： The aging mechanisms of modifed biochar for arsenic (As) immobilization at micro/nano-interfacial scales in diverse soils remain poorly understood. Herein, we employed three aging treatments, including natural aging (NA), freeze–thaw cycles (FT), and dry–wet alternation (DW), to simulate the aging behavior of cerium-manganese modifed biochar (CMBC) in two As-contaminated feld soils. Results indicated that CMBC amendment signifcantly reduced soil pH by 7.5–16.7%, while simultaneously increasing dissolved organic carbon contents by 10–45%, available phosphorus levels by 11–43%, and the activities of four soil enzymes by 30–320% in comparison to unamended soils. These improvements proved to be most efective under FT-aging, followed by DW-aging and NA-aging. FT-aging also led to the most pronounced reduction in water-soluble As concentrations ranging from 94 to 99%, as well as a decrease in As mobilization coefcients of 38% to 59% in CMBC-amended soils when compared to DW-aging and NA-aging. The superior As immobilization under FT-aging can be attributed to adhesion mediated by Ce–Si crystal nano-bridge between soil microparticles and CMBC matrix, whereas such adhesion was not observed in NA/DW-aged samples. This unique interfacial confguration promoted Ca/Fe-oxide intercalation and morphous Ce-oxides formation within CMBC, which facilitated the development of As–Fe/Ce crystalline phases. Meanwhile, the synergistic enrich-ment of metallic and oxygen-containing groups on FT-aged CMBC surface induced the formation of stable As–Ce/Fe–O species and triggered dual redox transformations: (1) Ce/Mn reduction drove bulk As(III) oxidation to As(V), and (2) Fe(0) oxidation mediated partial reduction of As(V)/As(III) to inert As(0). Notably, CMBC-amended red soil exhibited preferential As immobilization during aging due to the tighter adhesion between nano-CMBC and soil colloids. This enhanced adhesion strengthened the bonding of Ce/Fe-oxides with As and intensifed the oxida-tion of As(III) to As(V) through increased Ce/Mn reduction. This study provides innovative microscale mechanistic insights into the aging behavior of modifed biochar for remediating diverse soils contaminated with potentially toxic elements.

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