生物炭基复合材料吸附有机污染物的机制研究

发布时间：2018-03-15 22:05

  本文选题：生物炭基复合材料　切入点：吸附　出处：《天津工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：邻苯二甲酸酯(PAEs)和四环素类抗生素(TCs)是两种典型的有机污染物,在土壤中有相当高浓度的残留,迫切需要有效的污染治理和控制技术。生物炭(BC)具有较高的比表面积、发达的孔隙结构和丰富的表面官能团,可以通过改变土壤理化性质增强土壤对有机污染物的吸附和固定能力,减轻有机污染物对土壤的生态毒性。在控制和治理土壤有机污染方面具有广阔的应用前景。本文主要以玉米秸秆为生物炭原料,用化学方法对其改性制备出生物炭-纳米二氧化锰复合体(BMnc)和生物炭-纳米氧化锌复合体(BZnc),然后采用批量平衡法对其吸附邻苯二甲酸二丁酯(DBP)和土霉素(OTC)的性能和机制进行研究。在此基础上,探讨了生物炭基复合材料对棕壤吸附和固定DBP和OTC的影响。主要研究结果如下:(1)BMnc材料中MnO2纳米片团聚成球状结构,XPS分析表明Mn的氧化态为Mn(Ⅳ)。BZnc材料中,梭形的氧化锌纳米棒均匀地分散在BC的表面,XPS分析表明Zn的化合态包含ZnO和Zn(OH)2两种组分。(2)负载MnO2和ZnO均能提高BC对DBP和OTC的吸附能力,且MnO2和ZnO的负载量是影响吸附性能的重要因素。实验结果表明,BC和MnO2质量比为20:1和10:1的BMnc分别对DBP和OTC的吸附效果最好,而BC和ZnO质量比为20:1的BZnc对两种物质表现出更强的吸附能力。(3)BC、BMnc和BZnc吸附DBP及OTC的动力学曲线符合准二级动力学模型,表明吸附过程主要受化学反应控制。Langmuir等温吸附模型和Freundlich等温吸附模型均能很好地对等温吸附数据进行拟合,表明吸附过程包含物理吸附和化学吸附。吸附作用力主要包括范德华力、氢键、π-π EDA作用和化学反应等。(4)BMnc和BZnc均能提高棕壤对DBP和OTC的吸附和固定能力。实验结果表明,棕壤中DBP和OTC的吸附容量随BMnc或BZnc的添加量增加而增大。综合来看,BMnc对棕壤的改良效果好于BZnc,对于修复PAEs和TCs污染的土壤有很好的应用前景。(5)随着pH增加,土壤对DBP和OTC的吸附容量减小。这可能是土壤与DBP和OTC分子间的静电引力增大引起的。
[Abstract]:Phthalate PAEsand tetracycline antibiotics (TCs) are two typical organic pollutants, which have a high concentration of residues in soil, and are in urgent need of effective pollution treatment and control techniques. BCC has a high specific surface area. The developed pore structure and abundant surface functional groups can enhance the adsorption and fixation of organic pollutants by changing the physical and chemical properties of the soil. It has broad application prospect in controlling and controlling soil organic pollution. In this paper, corn straw is mainly used as biochar material. The biocarbonium-nanometer manganese dioxide complex (BMnc) and the biocarbon-nanometer zinc oxide complex (BZncC) were prepared by chemical method. Then the adsorption properties of dibutyl phthalate (DBP) and oxytetracycline (oxytetracycline) were studied by batch equilibrium method. And mechanisms. On this basis, The effect of biocarbonitic composites on adsorption and immobilization of DBP and OTC in brown soil was studied. The main results are as follows: (1) MnO2 nanoplates agglomerate into spherical structure in BMnc. The results show that the oxidized state of mn is mn (鈪，

本文编号：1617012