【作者】 许孟；

【导师】 赵茂俊； 张云松；

【作者基本信息】 四川农业大学 ， 生物物理学， 2011， 硕士

【摘要】 随着电镀、印染、机电等工业的迅速发展,大量重金属废水和染料废水排放到环境中,引起了严重的水资源污染,危害到环境生物和人类的健康。所以开展环境废水处理技术的研究迫在眉睫,这对于人类和环境生物的健康以及电镀、印染、机电等工业的快速、友好发展具有举足轻重的作用。目前,单一技术的处理方法普遍存在处理效率低、费用高、二次污染等问题。针对以上问题,以廉价的生物材料为基础,利用高效的化学修饰手段,结合特殊磁性的纳米材料为研究对象来处理重金属废水和染料废水已成为水处理研究的热点。本研究以面包酵母菌为研究材料,在戊二醛的交联下将纳米Fe304负载到面包酵母表面,制备出磁性酵母菌(FB),然后在无水环境下利用EDTAD对EF进行了成功修饰,制备出EDTAD-磁性酵母菌(EFB)。然后利用FB和EFB材料对重金属废水(Pb2+、Cd2+和Ca2+)和染料(亚甲基蓝)废水进行了处理。探讨了溶液pH值、金属离子/染料起始浓度、处理时间、处理温度等对两种吸附剂吸附能力的影响。通过对含Pb2+、Cd2+和Ca2+废水的处理,结果显示EFB对三种金属离子的吸附量明显高于FB,且EFB对三种金属离子的吸附量随着pH值的增加而逐渐增加,吸附过程符合假二级吸附模型和Langmuira等温吸附方程,且在30℃,pH6时对Pb2+(pH5.5)、Cd2+和Ca2+三种金属离子分别有最大吸附量为99.26,48.70和33.46mg/g,共存离子实验显示EFB对金属离子的结合能力如下：Na+,K+<Mg2+<Ca2+<<Cd2+<Pb2+<Ni2+<Cu2+。再利用EFB和FB处理了亚甲基蓝废水,结果显示,EFB对亚甲基蓝的吸附量大约是FB两倍,分别为223.66和110.00 mg/g,且EFB受pH值的影响在pH值小于4的范围内,在pH值大于4以后pH值的变化对EFB吸附能力几乎无影响,FB和EFB对亚甲基蓝的吸附过程均符合假二级吸附模型和Langmuira等温吸附方程,两种吸附剂对亚甲基蓝的吸附受温度的变化影响不明显。回收实验显示两种吸附剂在处理重金属废水和染料废水,利用0.1mol/L HCl洗脱时,吸附剂重复利用三次以后,处理效率仍保持80%以上。利用扫描电子显微镜(SEM)、X射线衍射(XRD)、Zeta电位、红外光谱(IR)、表面滴定、磁响应分析等对FB和EFB及吸附后的材料进行了表征。结果显示制备的材料表面粗糙,纳米Fe3O4负载到酵母菌表面,且磁响应灵敏；EDTAD修饰后EFB表面氨基或羧基数量增加,且增加的基团在吸附重金属离子和染料分子时有重要作用。更多还原

【Abstract】 With the striking development of some industries in our country such as steel production, electroplateing, dyeing and printing industry etc., there exists a severe water resource crisis due to a large amount of water contaminated by heavy metals and dye. metals. The heavy metals and dye contained in waste water not only causes the harm of health for environmental biological but also influences the survival of human. Therefore, the research on disposing heavy metal ions and dye molecules in waster water has quite practical application significance for resolving the water resource crisis and promoting the intensive development of industry, such as leather tanning, mining, smelting, electroplating, etc. The conventional processes were sometimes restricted by the technique, economy and secondary pollution. Recently, the utilization of biomass and agricultural waste materials for the research object, chemically modifield, special properties nanometer materials to removal heavy metal ions and dye molecules has been research hotspot.In the experiment the magnetic Fe3O4 baker’s yeast biomass (FB) was prepared by combining baker’syeast biomass and nano-Fe3O4 using glutaraldehyde as a cross-link agent, and was chemically treated with ethylene-diaminetetraacetic dianhydride(EDTAD). The magnetic Fe3O4 baker’s yeast biomass (FB) and EDTAD-magnetic Fe3O4 baker’s yeast biomass(EFB) were utilized as biosorbents to adsorb heavy metal ions(Ca2+, Cd2+, Pb2+) and dye molecules in the aqueous solution. All the effect condition on adsorption, such as pH value, contact time, initial concentration of heavy metal ions(Ca2+, Cd2+, Pb2+) and dye molecules, coexisting ions, temperature and ehtion experiment were discussed.The adsorption properties of EFB for Pb2+, Cd2+, and Ca2+ions were evaluated. The results showed that the uptakes of EFB for the three metal ions were higher than that of FB, and the adsorption capability of Pb2+, Cd2+, andCa2+ions increased with an increase in pH. The adsorption process was followed by the pseudo-second-order kinetic model and Langmuir isotherm equation. The maximum adsorption capacities of 99.26mg/g for Pb2+ at pH5.5,48.70mg/g for Cd2+ at pH6.0, and 33.46mg/g for Ca2+at pH6.0 were observed at 30℃. The coexisting ions experiments were indicate that the EFB combined with metal ions followed the order:Na+, K+< Mg2+< Ca2+<<Cd2+< Pb2+<Ni2+< Cu2+. The adsorption properties of EFB and FB for methylene blue were also evaluated. The results showed that the adsorption capacities of EFB were two times for FB. The maximum adsorption capacities were 223.66 mg/g for EFB, and 110.00 mg/g for FB. The adsorption capacities of EFB and FB for methylene blue increased with an increase in pH<4, but the the adsorption capacities of EFB for methylene blue keeping stability with an increase in 4<pH<9. The adsorption process of EFB and FB were followed by the pseudo-second-order kinetic model and Langmuir isotherm equation. The uptakes weren’t influenced by a rise reaction temperature from 5 to 40℃. The regeneration experiments showed that the EFB and FB could be successfully reused. The uptakes of EFB and FB for the three metal ions and dye molecules after three consecutive adsorption/desorption cycles keep above 80%.The FB and EFB were investigated by IR, SEM, XRD, Zeta potential, potentiometric titration and magnetic response analysis. The results revealed that the FB and EFB possessed not only a favorable superparamagnetism, but also those surface were tough. The number of carboxyl and amino groups which were magnificent relevant to the three metal ions and dye molecules on surface of EFB was increased by chemically treated with EDTAD.更多还原