黑曲霉改性沼渣对水中Pb(Ⅱ)的生物吸附

Biosorption of Pb (Ⅱ) from Aqueous Solutions by Biogas Residue Modified by Aspergillus niger

经黑曲霉改性的沼渣首次作为生物吸附剂,处理含Pb^(2+)模拟废水,并取得较高吸附量。经黑曲霉改性后,沼渣比表面积由1.524 7 m^2·g^(-1)提高到7.054 2 m^2·g^(-1);且沼渣表面长有大量气生菌丝体与孢子,表明黑曲霉改性过程具有提高沼渣吸附潜力的作用。研究选取不同p H和投加量作为影响因素探求其对生物吸附量的影响。实验结果表明,最适合p H为4～自然p H,在投加量为0.1 g、温度为30℃、自然p H条件下,沼渣和改性沼渣对于Pb^(2+)的最大吸附量分别为2.86 mg·g^(-1)、6.32 mg·g^(-1);说明黑曲霉改性沼渣的吸附能力优于沼渣,主要是由于黑曲霉菌分泌的酶和产生的孢子与气生菌丝体提高了沼渣表面的吸附特性。改性沼渣的吸附动力学数据对二级动力学方程的拟合效果最好,说明改性沼渣的生物吸附更多涉及到化学吸附。因此,黑曲霉改性后的沼渣可能成为一种有前景的生物吸附剂。

The biogas residue modified by Aspergillus niger was used,for the first time,as a biosorbent to treat simulated wastewater containing Pb2+and achieved higher adsorption capacity.After modification by Aspergillus niger,the specific surface area of the biogas residue increased from 1.524 7 m^2·g^-1 to 7.054 2 m^2·g^-1,and the surface of the biogas residue had a large number of aerial mycelium and spores,indicating that the modification process of Aspergillus niger can improve the adsorption potential of biogas residue.Different p H and dosage were selected as factors to explore its effect on biosorption capacity.The experimental results show that the optimum p H is 4~natural p H.The results shows the optimum p H is 4~natural p H,and he maximum adsorption capacity of the raw biogas residue and modified biogas residue was 2.86 mg·g^-1 and 6.32 mg·g^-1,respectively,when adsorbent dosage was 0.1 g,temperature was 30℃,p H was nature.It indicates that the adsorption capacity of modified biogas residue is better than that of biogas residue,which can be attributed to the enzymes secreted by Aspergillus niger and the spores and aerial hyphae that change the surface adsorption characteristics of the biogas residue.The adsorption kinetics data of the modified biogas residue has the best fitting effect on the second-order kinetic equation,indicating that the biosorption of the modified biogas residue involves more chemical adsorption.Therefore,the biogas residue modified by Aspergillus niger may become a promising biosorbent.