The presence of toxic and hazardous substances in aquatic environments poses an enormous risk to ecosystems and human health. Recent years have witnessed a substantial rise in the utilization of biochar (BC) as an adsorbent for the remediation of water contamination. To augment the adsorption capability of pristine BC, a multitude of BC composites have emerged. Natural polysaccharides (NP), such as chitosan, sodium alginate, β-cyclodextrin, starch, and other substances, can act as modifiers for BC, enabling the incorporation of the benefits of both NP and BC. Generally, the formed composites demonstrate significant improvements in functional groups, specific surface area, adsorption sites, stability, and adsorption efficacy. Significantly, NP-BC demonstrates notable attributes as a green adsorbent while also being cost-effective in synthesis. Over the past five years, there has been a growing corpus of investigations on the topic of water pollutant adsorption, with a particular emphasis on the application of NP-BC. Nevertheless, a comprehensive evaluation of NP-BC remains absent, specifically regarding its modification techniques and characterization methodology. Furthermore, there is a notable absence of a systematic summary of research methodology concerning adsorption mechanisms. Consequently, the present study investigates the synthesis, characterization, and mechanism of NP-BC, along with its use in adsorbing water contaminants, including metal ions, organic pollutants, and inorganic ions. On this basis, this paper presents a comprehensive overview of the challenges that necessitate attention and the potential research directions worth exploring for NP-BC in removing water pollutants. According to the current dual-carbon policy, it is anticipated that NP-BC will have significant potential in water pollution remediation.

中文翻译：

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天然多糖改性生物炭吸附废水污染物的最新进展：制备、表征、机理和应用

水生环境中有毒有害物质的存在对生态系统和人类健康构成巨大风险。近年来，生物炭（BC）作为水污染修复吸附剂的使用大幅增加。为了增强原始BC的吸附能力，出现了多种BC复合材料。天然多糖（NP），如壳聚糖、海藻酸钠、β-环糊精、淀粉和其他物质，可以作为BC的改性剂，从而能够结合NP和BC的优点。一般来说，形成的复合材料在官能团、比表面积、吸附位点、稳定性和吸附效率方面表现出显着改善。值得注意的是，NP-BC 表现出作为绿色吸附剂的显着属性，同时在合成中也具有成本效益。在过去的五年中，关于水污染物吸附主题的研究不断增多，特别是 NP-BC 的应用。然而，对 NP-BC 的全面评估仍然缺乏，特别是在其修饰技术和表征方法方面。此外，明显缺乏对吸附机制研究方法的系统总结。因此，本研究调查了 NP-BC 的合成、表征和机理，及其在吸附水污染物（包括金属离子、有机污染物和无机离子）方面的用途。在此基础上，本文全面概述了NP-BC去除水污染物需要关注的挑战和值得探索的潜在研究方向。根据目前的双碳政策，预计NP-BC在水污染修复方面将具有巨大潜力。