The discharge of toxic heavy metals including zinc (Zn), nickel (Ni), lead (Pb), copper (Cu), chromium (Cr), and cadmium (Cd) in water above the permissible limits causes high threat to the surrounding environment. Because of their toxicity, heavy metals greatly affect the human health and the environment. Recently, better remediation techniques were offered using the nanotechnology and nanomaterials. The attentions were directed toward cost-effective and new fabricated nanomaterials for the application in water/wastewater remediation, such as zeolite, carbonaceous, polymer based, chitosan, ferrite, magnetic, metal oxide, bimetallic, metallic, etc. This review focused on the synthesis and capacity of various nanoadsorbent materials for the elimination of different toxic ions, with discussion of the effect of their functionalization on the adsorption capacity and separation process. Additionally, the effect of various experimental physicochemical factors on heavy metals adsorption, such as ionic strength, initial ion concentration, temperature, contact time, adsorbent dose, and pH was discussed.

中文翻译：

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使用纳米材料有效去除水中重金属的研究进展

在水中排放超过允许限值的有毒重金属，包括锌（Zn），镍（Ni），铅（Pb），铜（Cu），铬（Cr）和镉（Cd）会对周围环境造成严重威胁。由于它们的毒性，重金属会极大地影响人体健康和环境。最近，使用纳米技术和纳米材料提供了更好的修复技术。注意力集中在用于水/废水修复的具有成本效益的新型纳米材料上，例如沸石，碳质，聚合物基，壳聚糖，铁氧体，磁性，金属氧化物，双金属，金属等。各种纳米吸附材料的合成及其消除各种有毒离子的能力，讨论了它们的功能化对吸附容量和分离过程的影响。此外，还讨论了各种实验理化因素对重金属吸附的影响，例如离子强度，初始离子浓度，温度，接触时间，吸附剂剂量和pH。