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Military activities and the production or disposal of ammunition often lead to soil contamination with energetic compounds (ECs) such as dinitrotoluene, trinitrotoluene, and hexogen, posing significant threats to human health and the ecosystem. Biochar has emerged as a cost-effective and widely available solution for remediating contaminated sites characterized by its capacity for pollutant removal through adsorption and conversion process, along with minimal secondary pollution. This paper provides a comprehensive review of relevant literature on biochar's efficacy in eliminating ECs, including an analysis of the underlying mechanisms. The discussion addresses challenges and opportunities associated with biochar application in ECs remediation, offering insights for future research directions. In summary, the use of biochar for ECs removal presents a promising and eco-friendly approach, facilitating the remediation of contaminated sites while promoting soil function and ecosystem recovery., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

This study prepared a cetyltrimethylammonium bromide (CTAB) functionalized δ-FeOOH using the coprecipitation method to remove arsenate and phenylarsonic acid in water polluted by phenylarsonic chemical warfare agents. Under neutral conditions, the adsorption capacity for arsenate and phenylarsonic acid was 45.7 and 85.3 mg g -1 , respectively. The adsorption process conformed to the pseudo-second-order kinetics and Freundlich isothermal adsorption model, and the adsorption was spontaneous and endothermic. The CTAB-functionalized δ-FeOOH could effectively resist the interference of coexisting anions except for CO 3 2- , SiO 3 2- and PO 4 3- . Furthermore, the adsorption mechanism was proposed by combining the adsorption experimental results, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and density functional theory analyses. The results showed that the adsorption of arsenate by the CTAB-functionalized δ-FeOOH was mainly through the formation of bidentate-dinuclear inner-sphere complexes and electrostatic interactions. While for phenylarsonic acid, the formation of monodentate-mononuclear inner-sphere complexes on (100) and (110) crystal facets, and the formation of bidentate-dinuclear inner-sphere complexes on the (002) crystal facet, as well as hydrogen bonding, electrostatic interaction, and π-hydrophobic interaction between organic compounds were the primary mechanism. Moreover, the CTAB-functionalized δ-FeOOH could maintain about 60% of the adsorption capacity for the two pollutants after five cycles. Overall, CTAB-functionalized δ-FeOOH has good potential for the remediation of inorganic and organic arsenic-contaminated water bodies., (Copyright © 2021 Elsevier Ltd. All rights reserved.)