废弃虾壳制备改性甲壳素凝胶球及其对金属离子的吸附性能

以虾壳酶解残渣为原料，经5%盐酸脱钙处理4 h后，用45%氢氧化钠和460 W微波辅助脱乙酰处理10 min，得到脱乙酰度为40.4%的改性甲壳素。将改性甲壳素加入海藻酸钠水溶液中混合均匀，挤压滴入氯化钙水溶液中固化12 h，制备得到直径为1.5~3.2 mm的凝胶小球，研究了该凝胶球对Pb²⁺、Cr³⁺、Ni²⁺、Cu²⁺、Co²⁺和Zn²⁺的吸附效果。结果表明：凝胶球对Cu²⁺、Co²⁺和Zn²⁺的吸附效果最好，300 mg/L重金属离子溶液吸附处理8 h是较适宜的吸附条件，此条件下，Cu²⁺、Co²⁺和Zn²⁺的吸附率分别达到94.2%、75.6%和57.3%。在Cu²⁺-Co²⁺-Zn²⁺共存溶液体系中，凝胶球对3种离子的吸附率均有所提高，Cu²⁺、Co²⁺和Zn²⁺的吸附率分别为95.1%、82.5%和67.5%。

Preparation of Modified Chitin Gel Bead from Waste Shrimp Shell and Its Adsorption Properties for Metal Ions

Modified chitin with 40.4% deacetylation degree was obtained from enzymatic hydrolysis residue of shrimp shell,which was treated by 5% HCl for 4 h and 45% NaOH coupled with 460 W microwave for 10 min,and then prepared into gel beads with diameter of 1.5-3.2 mm by adding sodium alginate,mixing evenly,and squeezing in calcium chloride solution for 12 h.The adsorption performances of the gel beads to metal ions (Pb²⁺,Cr³⁺,Ni²⁺,Cu²⁺,Zn²⁺ and Co²⁺) were investigated.The adsorption rates of Cu²⁺, Co²⁺ and Zn²⁺ were found to be 94.2%,75.6% and 57.3% in 300 mg/L ion solutions by treating for 8 h,and 95.1%, 82.5%, 67.5% in the Cu²⁺, Zn²⁺ and Co²⁺ coexisting system,respectively.