生物锰氧化物对4种重金属的吸附特性研究

通过培养锰氧化细菌Sphingopyxis sp.4-15,制备生物锰氧化物,研究了生物锰氧化物的结构性质及其在不同影响因素下对4种重金属Cu、Zn、Cr和As的吸附特性。结果表明该生物锰氧化物中含有MnO₂、Mn₃O₄和MnO等晶体锰氧化物,包裹在菌体细胞表面呈现出规则的花球状。其锰主要以高价态的Mn⁴⁺和Mn³⁺形式存在,平均孔径为35.56 nm,比表面积为41.49 m²/g。锰氧化物对重金属的吸附过程受pH值影响,最适pH值为4~6;离子强度对吸附过程干扰较小;升高温度有利于其对Cu和Zn的吸附,而对As的吸附产生抑制;锰氧化物对Cu(Ⅱ)、Zn(Ⅱ)、As(Ⅲ)的吸附在反应360 min时可达到平衡,对Cr(Ⅲ)的吸附在反应5 min内达到平衡;在4种重金属最大初始浓度下,生物锰氧化物对Cu(Ⅱ)、Zn(Ⅱ)、Cr(Ⅲ)、As(Ⅲ)的吸附量依次为:70.184、15.140、9.141、0.089 mg/g,具有较大的重金属吸附容量。

Study the Adsorption Characteristics of Biomanganese Oxide to four Heavy Metals

Biomanganese oxides were prepared by culturing the manganese oxidizing strain Sphingopyxis sp.4-15,and the structural properties of biomanganese oxides and their adsorption characteristics for four kinds of heavy metals Cu,Zn,Cr and As under different influencing factors were studied.The results show that the biological manganese oxide contains different types of crystalline manganese oxides,such as MnO₂,Mn₃O₄ and MnO,etc.,wrapped on the surface of the bacterial cells in a regular globular shape.The manganese in the manganese oxide mainly exists in the form of high-valence Mn 4+and Mn 3+,with an average pore size of 35.56 nm and a specific surface area of 41.49 m²/g.The adsorption process of manganese oxides for heavy metals is affected by pH,and the optimal pH range is 4-6.The ionic strength has little interference with the adsorption process.Elevated temperature is conducive to its adsorption of Cu and Zn,but inhibits the adsorption of As.The adsorption of manganese oxides to Cu(Ⅱ),Zn(Ⅱ)and As(Ⅲ)can reach equilibrium in 360 mins of reaction,and the adsorption of Cr(Ⅲ)reaches equilibrium within 5 mins of reaction.At the maximum initial concentration of heavy metals,the adsorption amounts of the biomanganese oxide to Cu(Ⅱ),Zn(Ⅱ),Cr(Ⅲ),and As(Ⅲ)is 70.184,15.14,9.141,0.089 mg/g,respectively,which has a large adsorption capacity for heavy metals.