黑曲霉菌丝体-壳聚糖的制备及对Cr(Ⅵ)的吸附性能研究

Preparation of Aspergillus niger Mycelium-chitosan Biosorbent and Its Adsorption Characteristics for Cr (VI)

摘要:

研究了黑曲霉菌丝体-壳聚糖对Cr(Ⅵ)的吸附特性。以废弃黑曲霉菌丝体、壳聚糖作为吸附剂制备原料，采用环氧氯丙烷进行交联，三聚磷酸钠进行固化，制备成黑曲霉菌丝体-壳聚糖复合型吸附剂。探究了pH值、黑曲霉菌丝体-壳聚糖的投加量对Cr(Ⅵ)的吸附影响。实验结果表明，黑曲霉菌丝体-壳聚糖的用量为0.5 g时对Cr(Ⅵ)吸附率最高达到92.30%，pH=6时对Cr(Ⅵ)吸附率最高达84.32%。动力学数据分析表明黑曲霉菌丝体-壳聚糖生物吸附剂对Cr(Ⅵ)的吸附过程符合准二级动力学模型（R2=1）。同时该吸附过程符合Freundlich等温线模型，最大吸附量为108.23 mg/g；扫描电镜和红外光谱证实吸附反应发生吸附剂的颗粒表层，主要活性基团为-OH，-COOH。上述结果表明，黑曲霉菌丝体-壳聚糖对Cr(Ⅵ)吸附性能良好，绿色环保，应用前景广泛。

Abstract:

The adsorption characteristics of Aspergillus niger mycelium-chitosan for Cr(VI) were studied. The waste Aspergillus niger mycelium and chitosan were used as raw materials for the preparation of Aspergillus niger mycelium-chitosan composite biosorbent for Cr(VI), through cross-linking with epichlorohydrin and then immobilizeation with sodium tripolyphosphate. The effects of pH and loading amount of Aspergillus niger mycelium-chitosan on the adsorption of Cr(VI). The experimental results showed that the adsorption rate of Cr(VI) was up to 92.30% when the loading amount of Aspergillus niger mycelium-chitosan was 0.5 g, and reached 84.32% when pH=6. Analysis of kinetic data revealed that the adsorption process of Aspergillus niger mycelium-chitosan biosorbent on Cr(VI) conformed to the quasi-secondary kinetic model (R2=1), and in the meantime, the Freundlich isotherm model (with the maximum adsorption capacity reaching 108.23 mg/g); Scanning electron microscopy (SEM) and infrared spectroscopy (IR) confirmed that the adsorption reaction occurred on the surface layer of the Aspergillus niger mycelium-chitosan adsorbent, involving mainly -OH and -COOH functional groups; The above results showed the good performance of Aspergillus niger mycelium-chitosan towards Cr(VI), which is environmentally friendly and has broad application prospects.