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)

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108.23mg/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。

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(R^2=1),and in the meantime,the Freundlich isotherm model(with the maximum adsorption capacity reaching 108.23mg/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.