Institute of Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
Water Res. 2011 Oct 15;45(16):5200-10. doi: 10.1016/j.watres.2011.07.018. Epub 2011 Jul 26.
The dyeing effluent of high alkalinity, which could not be treated efficiently by traditional wastewater technologies, highlighted the need to explore a technically feasible, highly efficient and cost effective method. Thus, a fast and highly efficient method for the removal of dyes under alkaline conditions using magnetic chitosan-Fe(III) hydrogel was proposed. Firstly, chitosan-Fe(III) hydrogel was prepared by a chelation procedure with cheap and environmentally friendly chitosan and iron salts. We characterized the sorption and desorption of C. I. Acid Red 73, a common type of anionic dye, on magnetic chitosan-Fe(III) hydrogel, to understand its availability for alkaline dyeing wastewater. Sorption of dye to chitosan-Fe(III) hydrogel was fast (adsorption could reach equilibrium in less than 10 min) in a wide pH range, and agreed well to the Langmuir-Freundlich adsorption model with a high maximum adsorption capacity of 294.5 mg/g under pH = 12. Meanwhile, 1 mol/L NaOH was used to desorb the dye efficiently (desorption efficiency 94.4%) and 0.1 mol/L HCl was applied to regenerate the chitosan-Fe(III) hydrogel. The results showed that the chitosan-Fe(III) hydrogel could retain its high efficiency after the desorption and regeneration. The common coexisting ions almost had no negative effect on the dye adsorption of chitosan-Fe(III) and the removals of a variety of anionic dyes suggest that the magnetic chitosan-Fe(III) hydrogel could efficiently adsorb both the acid and reactive dyes under alkaline condition. Overall, the results reported herein indicated that magnetic chtisoan-Fe(III) with high adsorption efficiency and strong magnetic property is very attractive and implies a potential of practical application for alkaline dyeing effluent treatment.
高碱性的染料废水无法通过传统的废水处理技术进行有效处理，这凸显了需要探索一种技术可行、高效且经济实用的方法的必要性。因此，提出了一种在碱性条件下使用磁性壳聚糖-Fe(III)水凝胶快速高效去除染料的方法。首先，通过螯合程序制备壳聚糖-Fe(III)水凝胶，使用廉价且环保的壳聚糖和铁盐。我们研究了 C.I.酸性红 73（一种常见的阴离子染料）在磁性壳聚糖-Fe(III)水凝胶上的吸附和解吸，以了解其对碱性染料废水的适用性。在很宽的 pH 范围内，染料对壳聚糖-Fe(III)水凝胶的吸附速度很快（吸附可在不到 10 分钟内达到平衡），并符合 Langmuir-Freundlich 吸附模型，在 pH=12 时最大吸附容量为 294.5mg/g。同时，1mol/L NaOH 可有效解吸染料（解吸效率为 94.4%），0.1mol/L HCl 可用于再生壳聚糖-Fe(III)水凝胶。结果表明，壳聚糖-Fe(III)水凝胶在解吸和再生后仍能保持高效。常见共存离子对壳聚糖-Fe(III)的染料吸附几乎没有负面影响，对多种阴离子染料的去除表明磁性壳聚糖-Fe(III)水凝胶可在碱性条件下有效吸附酸性和活性染料。总体而言，本文的研究结果表明，具有高吸附效率和强磁性的磁性 chtisoan-Fe(III)非常有吸引力，暗示了其在碱性染色废水处理方面的潜在实际应用。
