【作者】 陈振；

【导师】 马伟；

【作者基本信息】 大连理工大学 ， 水科学与技术， 2008， 硕士

【摘要】 本文选用大连特产海芥菜为研究对象,对其进行改性,研究其对重金属离子镍和铜的吸附能力,论文主要通过震荡实验研究改性吸附剂对重金属离子镍和铜吸附参数,并通过吸附数学模型模拟其吸附行为。主要用到吸附等温模型有Langmuir,Freundlich,Temkin,另外动力学模型有一级反应动力学,二级反应动力学和扩散方程,并对其机理进行探讨研究。首次将生物吸附剂与膜反应器联用,为其工业应用提供有效数据。在震荡试验中,选用了低浓度下的吸附情况进行考察,通过主要参数的变化（初始浓度5-50 mg/L,吸附剂投加量0.1-0.5g,pH3-7,吸附时间0-120min）,知道吸附量随着浓度的升高而升高,随着吸附剂投加量的增加而降低,镍和铜的吸附最佳pH值分别为4.7和4.0,吸附时间均约为100min。在吸附平衡时,镍和铜的最大吸附量分别为24.71mg/g和38.82mg/g。等温吸附模型中,镍离子的吸附更加接近Langmuir,而铜离子的吸附则更加接近Temkin方程。动力学实验则二者同样满足二级动力学方程。机理探讨中主要探讨海藻酸盐与CaCl₂的反应关系,水溶液中重金属离子的存在状态,以及吸附剂的傅立叶红外光谱解析。在吸附剂的处理过程中,Ca²⁺的引入使得原本链状的海藻酸盐形成了网状结构;重金属溶液中的离子状态与溶液中的pH值有关,在对应最优pH值下,两种离子均以[M²⁺]态存在,而不是[M（OH）⁺]形式,也即吸附过程中没有发生沉淀行为;红外谱图显示,在处理和吸附过程中,主要是吸附剂的-OH和对应的C=O键发生移动较多,也就是说改性和吸附过程主要与—COOH有关,在吸附的过程中不只有离子交换,还有络合吸附。在膜反应器实验中,主要研究了铜离子溶液与反应器的关系,膜在反应器中的作用,和连续反应实验的研究。结果表明,吸附剂的吸附对浓度越大的吸附量越大,初始浓度为45mg/L时,可达到24mg/g左右,对浓度低的则去除率较高,初始浓度为10mg/L时,最高可达80%以上;膜在反应器中阻隔大分子作用明显,初始浓度为10mg/L时,透膜浓度和直取浓度最大可差1mg/L左右;连续实验简单的研究了连续进水的情况,可以为保持连续进水而固定时间更换吸附剂的连续反应器实验提供依据。根据实验结果,可以采用多级串联膜反应器来达到重金属离子回收的目的。更多还原

【Abstract】 Biosorption of nickel and copper ions from aqueous solution onto treated alga biomass Undaria pinnatifida which was artificially cultured in Dalian has been studied and the Langmuir,Freundlich and Temkine equilibrium isotherms,pseudo-first-order,pseudo-second -order and intra-particle diffusion kinetic model were determined respectively.Mechanism and membrane reactor experiment are brought at the second and final part.Within the test range（initial concentration 5-50 mg/L,biosorption doze 0.1-0.5 g,pH 3-7）, biosorption performance for metal ions showed an increase in specific metal uptake capacity with an increasing in initial ions concentration and decreasing in biosorbent doze.The optimized condition of pH value for nickel and copper is 4.7 and 4.0 respectively,while contact time is about 100 min.At equilibrium,the maximum total uptake by Undaria pinnatifida was 24.71 mg/g for nickel and 38.82 mg/g for copper.The results for nickel and copper fit well to the Langmuir and the Temkin isotherm respectively.Pseudo-second-order model described well the sorption kinetic of nickel and copper ions in comparison to pseudo-first-order and intra-particle diffusion kinetic model.Then the mechanism about the adsorbent and the ions has been discussed.It is deemed to the adsorbent was changed from a catenarian to a retiary structure after treated.It is propitious to adsorb the metal ions.Ions of the solution can be considered to be[M²⁺]than[M（OH）⁺]at the optimized pH value.FTIR results indicate that the CaCl₂ treated biosorbent impacted the -OH and C=O stretching.It means that adsorption is closely contact with the -COOH.It also indicate that the ion on the biomass surface may not only due to the ion exchange but also due to the chelation interaction during the adsorption process.The final part aims at developing a simple and practical methods to study the effect of a submerged membrane adsorption hybrid system.Adsorption kinetic study was first carried out with treated biomass for removing copper ions from a synthetic wastewater.A series of short-term experiments were conducted with preadsorption at different operating conditions such as biosorption time and continuous.Biosorption performance for the membrane reactor show a higher capacity to the higher initial concentration.It has a ion removal of 50%at the intial concentration 45mg/L and 80%at the intial concentration 10mg/L.It is suggested that a multipolar reacter can be used for reclaiming the metal ions.更多还原