In this work, the calcined chitosan (CS)-supported layered double hydroxides were prepared, characterized, and further applied to remove organic contaminants in aqueous solution. The chitosan-supported layered double hydroxide calcined at 400 °C (CSLDO400) was found to be effective for the adsorption of azo dye and antibiotic. CSLDO400 showed excellent adsorption performance at a wide pH range from 5 to 9 for methyl orange (MO) while the adsorption of tetracycline (TC) was most efficient at a pH of 9, and the optimal CSLDO400 dosages were 0.175 g L^–1 for MO and 0.375 g L^–1 for TC. The divalent and trivalent anions have a great effect on removal efficiency of MO and TC, while the effect of monovalent anions adsorption can be neglected. The adsorption kinetics indicated that the MO and TC removal followed the pseudo-second-order model. In addition, it can be fitted well with both the Langmuir and Freundlich model for MO and TC at 298 K, respectively. The adsorptions of MO and TC on CSLDO400 were both spontaneous and endothermic. After five adsorption–desorption cycles, CSLDO400 still showed high efficiency with an adsorption capacity of 60.72 mg g^–1 for MO and 21.92 mg g^–1 for TC. Therefore, the CSLDO400 are promising for use in the treatment of drinking water and wastewater contaminanted by organic matters.

中文翻译：

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用可循环煅烧的壳聚糖负载的层状双氢氧化物吸附剂去除典型的有机污染物：动力学和平衡等温线

在这项工作中，制备，表征了煅烧的壳聚糖（CS）负载的层状双氢氧化物，并进一步应用于去除水溶液中的有机污染物。发现在400°C下煅烧的壳聚糖负载层状双氢氧化物（CSLDO400）对偶氮染料和抗生素的吸附有效。CSLDO400在5至9的宽pH范围内对甲基橙（MO）表现出优异的吸附性能，而四环素（TC）在pH为9时的吸附效率最高，MO的最佳CSLDO400剂量为0.175 g L ^–1和0.375 g L ^–1对于TC。二价和三价阴离子对MO和TC的去除效率有很大的影响，而一价阴离子的吸附作用可以忽略。吸附动力学表明，MO和TC的去除遵循伪二级模型。此外，它还可以分别与适用于298 K的MO和TC的Langmuir和Freundlich模型拟合。CSLDO400上MO和TC的吸附是自发的和吸热的。经过五个吸附-解吸循环，CSLDO400仍然显示出高效率，对MO的吸附容量为60.72 mg g ^–1，对TC的吸附容量为21.92 mg g ^–1。因此，CSLDO400有望用于处理饮用水和有机物污染的废水。