Chromium is widely used in industry, and improper disposal of wastewater and industrial residues containing excessive chromium can contaminate water and soil, endangering both environmental and human health. Natural biopolymers and their derivatives have been investigated for removal of chromium (Cr) from wastewater. Cellulose, lignin, tannin, chitin, chitosan, and polypeptides are abundant in nature, and have high potential as adsorbents due to their easy access, low cost, and the recyclability of the captured heavy metals. In order to improve their mechanical strength, recyclability, specific surface area, binding site number, and adsorption rate as adsorbents, native materials have also been modified. This review discusses the source of chromium contamination and the main species of interest, as well as their toxicity. The structures of the aforementioned biopolymers were analyzed, and the adsorption mechanism of chromium and the main influencing factors on this process are discussed. The modification methods of various adsorbents and their adsorption effects on chromium are also detailed, and the developmental direction of research on the use of biopolymer adsorption remediation to control chromium contamination is discussed.

中文翻译：

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天然生物聚合物及其衍生物作为铬吸附剂的特性：综述

铬广泛用于工业中，废水和含铬过多的工业残留物的不当处置会污染水和土壤，危害环境和人类健康。天然生物聚合物及其衍生物已被研究用于去除废水中的铬（Cr）。纤维素，木质素，单宁，几丁质，壳聚糖和多肽性质丰富，由于易于获取，成本低和捕获的重金属可回收利用，因此具有很高的吸附剂潜力。为了提高它们的机械强度，可回收性，比表面积，结合位点数和作为吸附剂的吸附速率，还对天然材料进行了改性。这篇评论讨论了铬污染的来源和主要关注的物种，以及它们的毒性。分析了上述生物聚合物的结构，并讨论了铬的吸附机理和主要影响因素。详细介绍了各种吸附剂的改性方法及其对铬的吸附作用，并探讨了利用生物聚合物吸附修复技术控制铬污染的研究方向。