两种吸附剂下的多金属吸附与运移特性

发布时间：2018-04-29 11:36

  本文选题：白陶土 + 间歇试验　； 参考：《大连理工大学》2016年硕士论文

【摘要】：寻找高效低廉的吸附剂用于工业废水处理是解决重金属污染的首选课题。本文采用两种试验方法分别研究了重金属在静态与动态条件下的吸附特性。主要开展以下工作：(1)白陶土在静态条件下对多种重金属的吸附特性。包括一元体系下的吸附特性及其影响因素分析；二元体系及三元体系下的竞争吸附特性。 (2)动态条件下,骨炭对重金属的吸附特性与运移特性,包括铅的运移特性及其影响因素：铅铜二元体系的运移特性与竞争特性。经对试验结果的理论分析,得到以下结论：(1)在一元体系下,白陶土对Pb(Ⅱ)、Cu(Ⅱ)、Cd(Ⅱ)具有较高吸附性能。对Pb(Ⅱ)的吸附量显著受土水比、pH、离子强度等因素影响,吸附为吸热反应。其等温吸附可用Langmuir模型描述。白陶上对金属吸附具有选择性,最大吸附量排序为PbCd。动力学试验结果表明,白陶土对Pb(Ⅱ)、Cu(Ⅱ)、Cd(Ⅱ)的吸附为快速反应,3小时即可达到平衡吸附,可用伪二阶动力学模型预测。(2)白陶土,膨润土、高岭土对Pb(Ⅱ)吸附试验结果表明.白陶土吸附能力最高。试验用白陶土具有较大比表面积,且经XRD分析可知白陶土中含有沸石、方解石等特殊矿物成分,导致其对Pb(Ⅱ)具有较高的吸附能力。(3)白陶土对重金属离子的吸附机制主要为：静电吸附,表面络合反应,离子交换,方解石的化学反应(Pb2+)。(4)对于Pb(Ⅱ)-Cd(Ⅱ)与Pb(Ⅱ)-Cu(Ⅱ)二元体系,Cu(Ⅱ)可显著抑制白陶土对Pb(Ⅱ)的吸附,且随Cu(Ⅱ)浓度增加,Pb(Ⅱ)的吸附量显著下降,而Cd(Ⅱ)影响相对较小。对于Cu(Ⅱ)-Cd(Ⅱ)二元体系,当Cu(Ⅱ)浓度为某一值时,Cd(Ⅱ)的吸附受到明显抑制。在三元体系下(Pb(Ⅱ)-Cd(Ⅱ)-Cu(Ⅱ)),白陶土对三种金属的吸附量均显著下降,Pb(Ⅱ)的吸附量随Cu(Ⅱ)与Cd(Ⅱ)浓度增加而下降,而Cu(Ⅱ)与Cd(Ⅱ)的吸附量受Pb(Ⅱ)浓度变化影响较小。(5)以砂-骨炭作为填柱材料,通过土柱试验,探讨了Pb(Ⅱ)初始浓度、柱高、流速等参数对重金属运移过程的影响。试验结果表明,随初始浓度、柱高、入流速度增加.穿透时间相应下降,但初始浓度与柱高影响较大。Dose-Response模型与实测穿透曲线拟合度相对较好。在Pb(Ⅱ)-Cu(Ⅱ)二元体系下,随Cu(Ⅱ)浓度增加Pb(Ⅱ)运移速度加快,主要原因为Cu(Ⅱ)可显著抑制Pb(Ⅱ)在骨炭上的吸附所致。
[Abstract]:Finding efficient and low-cost adsorbents for industrial wastewater treatment is the first choice to solve heavy metal pollution. In this paper, the adsorption characteristics of heavy metals under static and dynamic conditions were studied by two experimental methods. The main work is as follows: 1) the adsorption characteristics of white clay for many heavy metals under static conditions. The characteristics of adsorption and its influencing factors in monolithic system and competitive adsorption in binary system and ternary system are analyzed. (2) under dynamic conditions, the adsorption and migration characteristics of heavy metals by bone charcoal, including the transport characteristics of lead and its influencing factors, the transport characteristics and competition characteristics of lead-copper binary system. Based on the theoretical analysis of the experimental results, the following conclusions are obtained: (1) in the monomorphic system, the white clay has a high adsorption property for Pb (鈪，

本文编号：1819753