【作者】 郑国宽；

【导师】 王擎；

【作者基本信息】 东北电力大学 ， 热能工程， 2009， 硕士

【摘要】 工农业废水、城市生活污水及各种采矿废水均含有大量重金属元素,水环境重金属污染不仅造成重大经济损失,还严重危胁着包括人类在内的各种生命体的健康生存。油页岩电站飞灰的主要成分和物理性质决定其具有很强的吸附能力,适合用于处理废水。开展油页岩飞灰吸附重金属元素的研究具有重要意义。本文以吉林桦甸热电厂循环流化床锅炉油页岩飞灰为研究对象,采用静态吸附法研究了其对模拟废水中Pb2+、Zn2+、Cu2+、Cd2+的吸附特性。对吸附动力学和吸附热力学进行了分析,并用Langmuir和Freundlich吸附等温线对吸附方程进行了拟合,在此基础上,探讨其对四种重金属离子的吸附机理。试验研究了投加量、时间、pH值等因素对吸附特性的影响。动力学研究表明,Pb2+符合吸附动力学准二级反应方程模型,Cd2+符合准二级反应方程模型和Elovich方程模型,Cu2+、Zn2+则都能与吸附动力学一级反应方程、二级反应方程和Elovich方程相吻合。油页岩飞灰吸附过程是吸热反应,对Cu2+、Zn2+、Cd2+的吸附符合Langmuir和Freundlich吸附等温线,而Pb2+不符合这两种吸附等温线模型。对酸化油页岩飞灰吸附特性研究表明,酸化油页岩飞灰对四种离子最大吸附量都有所增加,达吸附动态平衡时间比油页岩飞灰短。Pb2+吸附量随pH值的增加呈先上升后下降规律,当pH﹥6时,Cu2+、Zn2+、Cd2+都达吸附动态平衡。四种离子的吸附反应是吸热反应,且都能很好地与吸附动力学一级反应方程、二级反应方程和Elovich方程相吻合。酸化油页岩飞灰对四种离子的吸附是一个非自发进行的过程,且Langmuir型和Freundlich型吸附等温线都能较好地描述酸化油页岩飞灰对四种离子的吸附性能,其中Langmuir型吸附等温线的拟合效果更好。更多还原

【Abstract】 A large quantity of heavy matel ions are contained in industrial and agricultural wastewater, municipal sewage, and mining wastewater, the pollution of heavy matel in water not only cause momentous economical losses, but also can seriously endanger health of lives, which including human beings. The main components and physical properties of oil shale ash in power plants determained them with strong adsorbability, so it is suitable for treating the wastewater. It has important social and economic meaning to test the oil shale fly ash as adsorbent.This study puts forward a new adsorbent-oil shale fly ash (OSFA) adsorbent and evaluates the potential use of it to remove heavy metal ions from aqueous solutions as a low-cost-adsorbent. The properties of the novel adsorbent were presented and the adsorbent were then used in batch experiments to study the adsorption properties of Pb2+, Zn2+, Cu2+ and Cd2+ in simulated wastewater. On the basis of theoretical analysis of the adsorption kinetics, adsorption thermodynamics, Langmuir and Freundlich adsorption isotherm, the adsorption mechanism of the four heavy metal ions by oil shale fly ash was investigated. The affects of influential factors including oil shale fly ash dosage, contact time, pH, temperature and initial metal concentration were evaluated in the experiments. The Pb2+ accords with Pseudo second order kinetics model, Cd2+ accords with both Pseudo second order kinetics model and Elovich kinetics model, Cu2+, Zn2+ accords with the all of the three kinetics models. The process of adsorption was a endothermic nature. Equilibrium isotherms at different temperatures have been determined and analyzed by Langmuir model andFreundlich model,we could conclude that Freundlich model. We could conclude that Cu2+, Zn2+, Cd2+ was accordesd with both Langmuir model andFreundlich model, and the Pb2+ did not accord with both of them.Compared with OSFA, adsorption capacity of the acidification OSFA had increased, and the homeostasis times were shorter than the OSFA adsorption times. The adsorption capacity of Pb2+ was increased first and then descreased with the increased pH, and the Cu2+, Zn2+, Cd2+ could reach to the adsorbed homeostasis when pH greater than 6. The reacted of four heavy matel ions were all the endothermic reaction, and could accord with the Pseudo frist order kinetics model, Pseudo second order kinetics model and Elovich kinetics model welly. The process of adsorbed was a non-spontaneous process for all of four ions. The studies of adsorption isotherms showed that both the Langmuir model and Freundlich model could characterizetion the four heavy matel ions welly, but the Langmuir model fits better than the Freundlich model for them.更多还原