Wei Jing, Liu Yi-Han, Tu Chen, Deng Shao-Po, Hao Dan-Dan, Xiao Liang, Mao Meng
State Environmental Protection Key Laboratory of Soil Environmental Management and Pollution Control, Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing 210042, China.
Guangdong Provincial Key Laboratory of Environmental Health and Land Resource, Zhaoqing University, Zhaoqing 526061, China.
Huan Jing Ke Xue. 2023 Feb 8;44(2):965-974. doi: 10.13227/j.hjkx.202203011.
Biochar has a range of advantages including large porosity, high specific surface area, and strong adsorption capacity. It has been widely used in environmental pollution remediation, soil improvement, and carbon sequestration and emission reduction. Arsenic (As) is a highly toxic pollutant widely distributed throughout the soil. In typical surface soils, the most common forms of As are arsenite (AsO) and arsenate (AsO). Since most biochar surfaces are negatively charged, the adsorption efficiency of biochar to arsenic is usually low, and the biochar material needs to be modified to enhance its As adsorption performance. Iron-based materials, such as zero valent iron and iron oxide, are excellent As adsorption materials with wide environmental sources. They can be loaded to biochar to form iron-modified biochar via precipitation, pyrolysis, ball-milling, and micro-biological methods. The combined advantages of the iron-modified biochar will expand the application of biochar materials in environmental remediation. Based on a systematic analysis of the literature on iron-modified biochar in recent years, this study reviewed the common preparation methods of iron-modified biochars; analyzed biochar substrates, iron-modified biochar, and their synergistic mechanisms on As adsorption; and briefly expounded the application status of iron-modified biochar in soil pollution remediation. The prospects of the future research direction of iron-modified biochar were put forward as a reference for the large-scale application of biochar materials in the future.
生物炭具有一系列优点，包括孔隙率大、比表面积高和吸附能力强。它已广泛应用于环境污染修复、土壤改良以及碳固存与减排。砷（As）是一种剧毒污染物，广泛分布于土壤中。在典型的表层土壤中，砷最常见的形态是亚砷酸盐（AsO）和砷酸盐（AsO）。由于大多数生物炭表面带负电荷，生物炭对砷的吸附效率通常较低，需要对生物炭材料进行改性以提高其对砷的吸附性能。铁基材料，如零价铁和氧化铁，是具有广泛环境来源的优良砷吸附材料。它们可以通过沉淀、热解、球磨和微生物方法负载到生物炭上，形成铁改性生物炭。铁改性生物炭的综合优势将扩大生物炭材料在环境修复中的应用。基于对近年来铁改性生物炭文献的系统分析，本研究综述了铁改性生物炭的常见制备方法；分析了生物炭载体、铁改性生物炭及其对砷吸附的协同机制；并简要阐述了铁改性生物炭在土壤污染修复中的应用现状。提出了铁改性生物炭未来研究方向的展望，为生物炭材料未来的大规模应用提供参考。
