Bayberry tannin (BT), a typical plant tannin, was grafted onto chitosan microfibers (CF) through the Mannich reaction to synthesize biosorbent (BT-CF) that was effective for adsorptive removal of Pb²⁺ from aqueous solutions. The adsorption capacity of Pb²⁺ on the BT-CF was pH-dependent, which increased from 4.5 mg/g to 21.7 mg/g along with increasing solution pH from 2.5−5.5. The adsorption capacity increased with the increase of temperature from 303 K to 323 K, and thermodynamic calculations indicated that the adsorption of Pb²⁺ on the BT-CF was an endothermic process. The adsorption isotherms were well described by the Langmuir isotherm model with correlating constant (R²) higher than 0.980. The adsorption kinetics were well described by the pseudo-second-order rate model. The Pb²⁺ adsorbed on the BT-CF was desorbed using diluted acid solution. Column adsorption experimental results confirmed that the BT-CF was applicable for continues adsorptive removal of Pb²⁺ at the low concentration of 2.0 mg/L.

杨桃单宁（BT）是一种典型的植物单宁，通过曼尼希（Mannich）反应接枝到壳聚糖微纤维（CF）上以合成生物吸附剂（BT-CF），该吸附剂可有效地从水溶液中吸附去除Pb ²⁺。BT-CF对Pb ²⁺的吸附能力是pH依赖性的，随着溶液的pH从2.5-5.5增加，Pb ²⁺的吸附能力从4.5 mg / g增加到21.7 mg / g。吸附量随温度从303 K增加到323 K而增加，热力学计算表明Pb ²⁺在BT-CF上的吸附是一个吸热过程。Langmuir等温线模型很好地描述了吸附等温线，相关常数为（R ²）高于0.980。准二级速率模型很好地描述了吸附动力学。使用稀酸溶液解吸吸附在BT-CF上的Pb ²⁺。柱吸附实验结果证实，BT-CF适用于在2.0 mg / L的低浓度下继续吸附去除Pb ²⁺。