铁锰改性铜绿微囊藻对锑的吸附性能

Fabrication of iron-manganese oxide composite modified Microcystis aeroginosa adsorbent for advanced antimony removal

利用生物质吸附去除水中重金属离子具有制备简单、成本低廉、环境影响小等优点,通过高锰酸钾-硫酸亚铁处理过程对铜绿微囊藻改性,制备了能够高效吸附水中锑(Sb)的铁锰改性藻粉复合材料。扫描电镜和X射线光电子能谱分析表明,改性藻粉中存在大量铁锰氧化物颗粒,铁锰的主要存在形式为Fe2O3和MnO2。改性后的复合藻粉对Sb(Ⅲ)的吸附量从3.06 mg·g-1增加到35.30 mg·g-1,对Sb(Ⅴ)的吸附量从3.07 mg·g-1增加到4.37 mg·g-1,并且改性后的复合藻粉到达吸附平衡的时间更短。Langmuir模型可以很好地描述Sb在复合藻粉上的吸附行为,Elovich模型对藻粉吸附Sb(Ⅲ)和Sb(Ⅴ)的吸附过程拟合较好(R2=0.957,0.943),而复合藻粉更适用准二级动力学模型(R2=0.953,0.961)。Sb(Ⅲ)主要通过氧化和吸附作用被去除,而Sb(Ⅴ)在复合藻粉表面形成表面络合物后被吸附。共存阴离子(SO42-、CO32-、PO43-)的存在对复合藻粉吸附Sb(Ⅲ)几乎没有影响,但是共存阴离子浓度越高,对Sb(Ⅴ)的吸附抑制越明显。

Bioadsorption as a kind of heavy metal biological treatment technology has many advantages,such as low cost,low environmental pollution,and easy process of treatment.Microcystis aeroginosa was modified during its treatment with potassium permanganate and ferrous sulfate,and the iron-manganese modified algae powder composite materials were prepared for antimony removal from water.Scanning electron micrsocopy(SEM)and X-ray photoelectron spectroscopy(XPS)analysis suggests that the modified algae powder contained a large portion of iron(Fe2O3)and manganese(MnO2)oxides particles.In a comparison between normal algae powder and the composite modified algae powder material,the adsorption capacities towards Sb(Ⅲ)and Sb(Ⅴ)increased from3.06 mg·g-1to 35.30 mg·g-1and from 3.07 mg·g-1to 4.37 mg·g-1,respectively,and the adsorption equilibrium time decreased.The antimony adsorption behavior on the modified composite algae could be well described with Langmuir model.The adsorption kinetics of Sb(Ⅲ)and Sb(Ⅴ)onto unmodified algae powder could be well fitted with the Elovich model(R2=0.957,0.943),while the adsorption kinetics onto modified algae powder could be well fitted with the Pseudo-second order kinetic model(R2=0.953,0961).Sb(Ⅲ)removal was primarily ascribed to oxidation and adsorption,and Sb(Ⅴ)adsorption was assigned as the formation of surface complexes with the modified algae powder.The presence of coexisting anions(SO42-,CO32-,PO43-)had slight effect on the adsorption of Sb(Ⅲ)by algae powder,while the higher concentrations of anions were,the more remarkable the inhibition of Sb(Ⅴ)adsorption was.