Department of Civil & Environmental Engineering, Universiti Teknologi PETRONAS, 32610, Seri Iskandar, Perak Darul Ridzuan, Malaysia.
Department of Civil & Environmental Engineering, Universiti Teknologi PETRONAS, 32610, Seri Iskandar, Perak Darul Ridzuan, Malaysia; Centre for Urban Resource Sustainability, Institute of Self-Sustainable Building, Universiti Teknologi PETRONAS, Seri Iskandar, 32610, Perak, Malaysia.
Environ Res. 2022 Sep;212(Pt A):113138. doi: 10.1016/j.envres.2022.113138. Epub 2022 Mar 29.
Recent trends in adsorption of Chromium (Cr), Copper (Cu), Lead (Pb) and Mercury (Hg) in wastewater using (i) carbonaceous materials including activated carbon (AC) and biochar (BC), and (ii) nanomaterials including nano zero-valent iron (nZVI) and MXenes have been discussed in this paper. It has been found that adsorption capacity depends largely on the adsorbent modification technique, initial pH of wastewater, dosage of adsorbent, contact time and initial concentration of the pollutants. The pH value ranges for maximum removal of Cr, Cu, Pb and Hg have been reported as 2-4, 5-6, 5-8 and 3-8, respectively. Up to 99% removal of metals has been reported using AC, BC, nZVI and MXene. The mechanism involves the reduction and chemical adsorption of metals. AC and BC have a higher surface area (up to 5000 m/g) compared to nZVI (up to 500 m/g) and MXene (up to 67.66 m/g). However, the higher reactivity and regeneration capacity of nZVI and MXene make them suitable adsorbents. From a practical point of view the application of adsorbents for real effluents, cost analysis, regeneration capability and reuse of heavy metals are some aspects that need attention in future studies. The removal efficiencies of AC and BC are comparable to the nZVI and MXene. The cost analysis may be an attractive aspect to decide the future application of these adsorbents at large scale.
本文讨论了近年来利用（i）包括活性炭（AC）和生物炭（BC）在内的碳质材料，以及（ii）包括纳米零价铁（nZVI）和 MXenes 在内的纳米材料，在废水处理中对铬（Cr）、铜（Cu）、铅（Pb）和汞（Hg）的吸附的最新趋势。研究发现，吸附能力在很大程度上取决于吸附剂的改性技术、废水的初始 pH 值、吸附剂的用量、接触时间和污染物的初始浓度。报道的 Cr、Cu、Pb 和 Hg 的最大去除 pH 值范围分别为 2-4、5-6、5-8 和 3-8。使用 AC、BC、nZVI 和 MXene 已报告可达到高达 99%的金属去除率。该机制涉及金属的还原和化学吸附。与 nZVI（高达 500m/g）和 MXene（高达 67.66m/g）相比，AC 和 BC 的比表面积（高达 5000m/g）更高。然而，nZVI 和 MXene 的更高反应性和再生能力使它们成为合适的吸附剂。从实际的角度来看，对于实际废水的应用、成本分析、再生能力和重金属的再利用等方面，都是未来研究中需要关注的问题。AC 和 BC 的去除效率可与 nZVI 和 MXene 相媲美。成本分析可能是决定这些吸附剂在大规模应用的一个有吸引力的方面。
