【摘要】 本文以麦秆作为生物吸附剂吸附去除溶液中的Pb2+和Cr3+,针对pH值、吸附时间和金属离子浓度等影响吸附的主要因素进行了实验研究,并探讨了麦秆的改性处理。结果表明,溶液pH值是影响吸附的重要因素,麦秆对Pb2+和Cr3+的吸附量随溶液初始pH值的升高而升高。Pb2+和Cr3+在麦秆表面的吸附速度很快,60 min即可达到平衡,吸附过程符合准二级动力学模型(R2>0.9999)。金属离子初始浓度在0.01～2.0 mmol.L-1范围时,利用Langmuir等温方程拟合得到麦秆对Pb2+和Cr3+的最大吸附量分别为0.1508和0.0982mmol.g-1。麦秆经NaOH处理后,对Pb2+和Cr3+的吸附能力增强,最大吸附量分别增加至0.3109和0.1423mmol.g-1;而经酯化处理后对Pb2+和Cr3+的吸附能力减弱。竞争吸附实验显示,当Pb2+和Cr3+共存时,麦秆对Pb2+的吸附比对Cr3+的吸附强。麦秆价格低廉,产量大,在重金属废水处理方面有很好的应用前景。更多还原

【Abstract】 In this article,wheat stem biomass was used as biosorbent to remove Pb2+and Cr3+ from aqueous solution.The effect of solution pH,agitating time and metal concentration on the sorption process were investigated.Also,chemical modification of the biomass was conducted.Results showed that the metal removal was strongly dependent on solution pH and the sorption capacity increased with the increase of solution pH in the pH range of 2~6.The sorption processes were quick and fit well with pseudo-second-order kinetic models(R2>0.9999).The maximal binding capacities of the biomass to Pb2+and Cr3+,calculated from Langmuir isotherm equation,were 0.1508 and 0.0982 mmol·g-1 respectively.After modification by NaOH,the maximal binding capacities of the biomass to Pb2+and Cr3+increased to 0.3109 and 0.1423 mmol·g-1 respectively.Competition study indicated that Pb2+ was adsorbed more strongly on the biomass than that of Cr3+.Therefore wheat stem shows potential application in wastewater treatment because of its high sorption capacity,low cost and large quantities.更多还原