Release of toxic substances into public waterways continues unabated, despite concerted efforts to minimize environmental pollution. In particular, heavy metals and dyes are problematic due to their toxicity and persistence in the environment. As a consequence, remediation technologies such as biosorption have been designed, but biosorption applications have rarely been used at industrial levels. More recently, research has sought to harness the unique properties of nanotechnology by developing biosorbents at nanoscale, e.g. nano-biosorbents. Here I review principles and applications of nano-biosorbents. The major points are the following: (1) nano-biosorbents offer unique properties such as high surface area, which boosts the chemical activity and adsorption capacity, increase surface binding energy, and reduce internal diffusion resistance; (2) performances of nano-biosorbents are improved by encapsulation of nano-biosorbents in materials such as alginate polymers, chemical and biological modification of the raw biomass, and magnetic modification by incorporating materials such as magnetite; (3) use of nanoparticles with magnetic properties allows for rapid and efficient separation by using an external magnetic field, thus presenting a possibility for online separation and point-of-use water purification as well as sorbate and biosorbent recovery; (4) green engineered nanoscale zero-valent metals such as zero-valent iron and zero-valent silver have shown greater potential due to their high reducibility and large specific surface area; and (5) nano-biosorbents have shown great potential for the removal of dyes and heavy metals, and for the recovery of precious metals.

尽管为减少环境污染作出了共同努力，向公共水道中释放有毒物质的情况仍未减弱。特别地，重金属和染料由于其毒性和在环境中的持久性而成为问题。结果，已经设计了诸如生物吸附的修复技术，但是在工业水平上很少使用生物吸附应用。最近，研究试图通过开发纳米级生物吸附剂，例如纳米生物吸附剂，来利用纳米技术的独特性质。在这里，我回顾了纳米生物吸附剂的原理和应用。要点如下：（1）纳米生物吸附剂具有独特的特性，例如高表面积，可提高化学活性和吸附能力，增加表面结合能，并降低内部扩散阻力；（2）通过将纳米生物吸附剂封装在诸如藻酸盐聚合物之类的材料中，对原始生物质进行化学和生物改性以及通过掺入诸如磁铁矿之类的磁性改性来改善纳米生物吸附剂的性能；（3）使用具有磁性的纳米颗粒可以通过使用外部磁场进行快速有效的分离，从而提供了在线分离和使用点水净化以及吸附剂和生物吸附剂回收的可能性；（4）绿色工程纳米级零价金属，例如零价铁和零价银，由于其高还原性和较大的比表面积而显示出更大的潜力；（5）纳米生物吸附剂具有去除染料和重金属以及回收贵金属的巨大潜力。