In this paper, a Co₃O₄@SiO₂ core–shell magnetic nanoparticle-nylon-6 (CSMN6) was synthesized for the first time and used for the elimination of Congo red dye from wastewater samples. The morphology and the structure of the prepared CSMN6 were studied completely and its adsorption behavior vs. Congo red dye has been investigated. The sorption performance was evaluated using batch studies at room temperature, at varying operating conditions such as solution pH, sorbent dosage, initial dye concentration and contact time. It has been found that the Elovich kinetics model and Langmuir isotherm can describe this process adequately and a maximum adsorption rate of 138.9 mg g⁻¹ is obtained which may be illustrated by homogeneous physical and chemical adsorption of Congo red on the surface of the adsorbent. Through this process of adsorption with the adsorbent dose of 1.4 g l⁻¹, more than 86% of the Congo red dye from a solution with the concentration of 50 mg L⁻¹ was eliminated. The saturation magnetization of CSMN6 was 7.8 emu g⁻¹ and shows paramagnetic properties and could be isolated from the environment using an exterior magnet. The higher temperature was more suitable for the elimination of the Congo red dye. Also, intraparticle rate constant computed for Congo red was 4.87 mg g⁻¹ min^−1/2 that indicates higher tendency of CSMN6 to remove Congo red from aqueous solutions. The used CSMN6 can be recovered simply by using ethanol and utilized again for eliminating Congo red dye from contaminated water. In these reusing processes, a high yield of 76% may be obtained up to 5 recovery cycles. These results demonstrate that CSMN6 is a considerable candidate for water treatment processes with high effective and repeatable performance.

中文翻译：

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Co 3 O 4 @SiO 2核/壳-尼龙6磁性纳米复合材料的合成作为吸附剂去除废水中的刚果红

本文首次合成了Co ₃ O ₄ @SiO ₂核-壳磁性纳米颗粒尼龙6（CSMN6），用于去除废水中的刚果红染料。全面研究了所制备CSMN6的形貌和结构，研究了其对刚果红染料的吸附行为。在室温，不同的操作条件（例如溶液pH，吸附剂剂量，初始染料浓度和接触时间）下，使用批处理研究评估了吸附性能。已经发现，Elovich动力学模型和Langmuir等温线可以充分描述该过程，最大吸附速率为138.9 mg g ^-1可以通过刚果红在吸附剂表面上的均匀物理和化学吸附来说明获得的碳酸氢根。通过以1.4 gl ^-1的吸附剂量进行的吸附过程，从浓度为50 mg L ^-1的溶液中去除了超过86％的刚果红染料。CSMN6的饱和磁化强度为7.8 emu g ^-1，具有顺磁性，可以使用外部磁体与环境隔离。较高的温度更适合消除刚果红染料。另外，对于刚果红计算的颗粒内速率常数为4.87 mg g ^-1 min ^-1/2这表明CSMN6从水溶液中去除刚果红的可能性更高。使用过的CSMN6可以简单地通过使用乙醇进行回收，然后再次用于从受污染的水中去除刚果红染料。在这些重复使用过程中，最多5个回收周期即可获得76％的高产率。这些结果表明，CSMN6是具有高效率和可重复性的水处理工艺的理想选择。