A novel composite adsorbent was prepared from chitosan (Ch) and sepiolite (S) for removal of Pb(II) from aqueous solution. The Ch-S composite beads were successfully synthesized by crosslinking epichlorohydrin (ECH) and tripolyphosphate (NaTPP). A number of physicochemical parameters such as, pH, initial Pb(II) concentration, temperature, contact time and desorption have been studied during the adsorption process. Experimental data acquired from batch adsorption tests have been analyzed by three isotherm models (Langmuir, Freundlich and Dubinin–Radushkevich), and three kinetic models including the pseudo-first-order, the pseudo-second-order and intraparticle diffusion equations using nonlinear regression technique. Langmuir isotherm was the best to fit the experimental data (R² = 0.971). The maximum adsorption capacity was 0.158 mol kg⁻¹ from Langmuir isotherm model. Maximum removal efficiency was found approximately 66% for the initial Pb(II) concentration of 1000 mg/L, adsorbent dosage of 100 mg and agitation speed of 150 rpm at pH 4.5. The adsorption free energy was found as E_DR (15.8 kJ mol⁻¹), which indicated that Pb(II) adsorption process onto Ch-S composite was chemically performed. The kinetic studies have shown that the best fitted kinetic model is the pseudo-first order (R² = 0.979). Adsorption enthalpy value was determined as 18.7 kJ mol⁻¹, adsorption entropy was found as 106 J mol⁻¹ K⁻¹, and Gibbs free energy was found as 12.9 kJ mol⁻¹. The thermodynamic parameters showed that the adsorption of Pb(II) on Ch-S was endothermic, possible and spontaneous.

从壳聚糖（Ch）和海泡石（S）制备了一种新型复合吸附剂，用于从水溶液中去除Pb（II）。通过交联环氧氯丙烷（ECH）和三聚磷酸钠（NaTPP）成功合成了Ch-S复合珠。在吸附过程中，已经研究了许多物理化学参数，例如pH，初始Pb（II）浓度，温度，接触时间和脱附。通过三种等温模型（Langmuir，Freundlich和Dubinin–Radushkevich）以及三种动力学模型（包括拟一阶，拟二阶和粒子内扩散方程），使用非线性回归技术分析了从批吸附测试中获得的实验数据。 。Langmuir等温线最适合实验数据（R ² = 0.971）。朗缪尔等温线模型的最大吸附容量为0.158 mol kg ^-1。对于初始Pb（II）浓度为1000 mg / L，吸附剂剂量为100 mg，在pH 4.5下搅拌速度为150 rpm的情况，发现最大去除效率约为66％。发现吸附自由能为E _DR（15.8 kJ mol ^-1），这表明化学方法对Ch-S复合物进行了Pb（II）吸附过程。动力学研究表明，最佳拟合的动力学模型是拟一阶（R ²  = 0.979）。确定吸附焓值为18.7 kJ mol ^-1，发现吸附熵为106 J mol ^-1  K ^-1，发现吉布斯自由能为12.9 kJ mol ^-1。热力学参数表明，Pb（II）在Ch-S上的吸附是吸热的，可能的和自发的。