毛木耳(Auricularia polytricha)对水中铬的去除特性研究

BIOSORPTION OF Cr IN AQUEOUS SOLUTIONS BY AURICULARIA POLYTRICHA

以毛木耳子实体(Auricularia polytricha)为生物吸附材料,通过批量实验研究起始pH值、反应时间、生物量、Cr浓度等因素对毛木耳子实体吸附去除水中铬的影响及吸附特性。结果表明:铬的生物吸附过程明显受溶液pH影响,其中总Cr和Cr(Ⅵ)的最佳去除pH分别为2.0和1.0;48 h后生物吸附达到平衡,生物吸附剂的最佳浓度为4 g/L;A.polytricha对Cr的最大吸附容量为113.8 mg/g;在整个吸附过程中伴随着Cr(Ⅵ)转化为Cr(Ⅲ)。生物吸附剂的X射线光电能谱显示:吸附在生物吸附剂表层的Cr大都呈+3价。在等温实验中Freundlich模型能较好地模拟毛木耳子实体对Cr的等温吸附过程,同时准二级模型很好地拟合了生物吸附Cr的过程。毛木耳(A.polytricha)子实体在去除水体中的Cr方面具有很强的潜力。

Using Auricularia polytricha as a biosorbent,the paper studied the effects of different factors including pH,contact time,biomass dose and concentrations of Cr on adsorption of Cr by the biosorbent. pH dramatically affected the biosorption and the optimum initial pH for maximum adsorption of total Cr and Cr（ Ⅵ） were 2. 0 and 1. 0,respectively. The equilibrium time for the biosorption process was 48 h,and the optimal biomass of biosorbent was 4 g/L. The maximum adsorption capacity of Cr（ Ⅵ） by A. polytricha was 113. 8 mg/g. Reduction of Cr（ Ⅵ） to Cr（ Ⅲ） coexisted with in the whole biosorption process.The XPS spectra of biosorbent revealed that most of the chromium loaded on the surface of biomass was in the trivalent form.The Freundlich isotherm model fit better for the biosorption than Langmuir isotherm model. The pseudo-second-order kinetics could characterize the biosortion process of Cr. The results suggested that A. polytricha was a promising biomaterial for chromium removal from aqueous solutions.