蒙脱石矿物材料絮凝剂的制备、絮凝效果及机理研究

为了降低絮凝剂毒性、提高絮体的分离效果,以无机矿物材料蒙脱石(MTS)为原料,通过酸改性,制备蒙脱石絮凝剂(MTSF),对比聚合氯化铝(PAC)絮凝剂来处理模拟废水。实验结果表明,MTS没有絮凝作用,但经过酸改性后的MTSF具有很好的絮凝效果,最大浊度去除率为96.73%,在絮体沉降速度及体积上,MTSF远优于PAC。MTSF絮凝机理是吸附-电中和,絮凝过程是固体颗粒和可溶性盐两者的协同作用,MTSF显示出较好的沉降性能和压缩性能,絮体达到沉降平衡后,其体积不足PAC的三分之一。MTSF与PAC絮凝剂复合使用,可有效地减少絮体体积,提高絮体沉降性能。总之,MTSF具有与PAC相同的絮凝效果,但是絮体的沉淀压缩性能远优于PAC,是一种综合性能优越的絮凝剂。     

Synthesis of highly intercalated urea-clay nanocomposite via domestic montmorillonite as eco-friendly slow-release fertilizer

The present study describes the preparation and characterization of montmorillonite-urea nanocomposites (Mt-Ur) using aqueous suspension technique at various stirring times and different ratio of montmorillonite to urea (Mt/Ur) via an impure and domestic montmorillonite (Mt), without the application of any chemical reagents and high-energy-demand process (environmentally friendly). The intercalation of urea into Mt interlayer was clearly demonstrated by a significant expansion of d₀₀₁ spacing (interlayer space of Mt) from 1.23 to 1.71 nm which has not yet been reported by aqueous suspension technique. Analyses performed by Fourier transform-infrared spectroscopy (FT-IR), Thermogravimetric analysis (TGA) and X-ray diffraction (XRD) also confirmed the effectiveness of this simple process to intercalate the urea into clay lamella. The release pattern demonstrated that the nanocomposite had a slow-release behaviour for urea dissolution. The results also suggested that the Mt type applied in the current study, in a 1:20 Mt/Ur ratio and stirred for 1 h, possessed desirable ecological and economic efficiency in the production of slow-release urea fertilizer due to the application of the impure and domestic clay which is of very low-cost and eco-friendly. Nevertheless, urea was fully intercalated into the interlayer of clay by a simple technique and with a good slow-release behaviour.     

纯蒙脱石吸附Zn~（2＋）的研究

[目的]探索纯蒙脱石处理含锌废水的因素与效果。[方法]从蒙脱石提纯入手,进行纯蒙脱石处理含锌废水的试验研究,探讨纯蒙脱石对含锌废水处理效果的影响因素,确定纯蒙脱石去除水中Zn2＋的工艺条件,并研究纯蒙脱石对Zn2＋的吸附等温曲线。[结果]纯蒙脱石对含锌废水处理效果主要受振荡速度、吸附时间、溶液pH值和投加量等因素影响。温度为30℃时纯蒙脱石对Zn2＋的吸附等温曲线更符合Langmuir方程和BET方程,相关系数均为0.986 9,最大吸附容量39.00 mg/g。在该试验条件下,纯蒙脱石对水中Zn2＋（20ml,Zn2＋浓度均为50 mg/L）达到最佳去除效果时的工艺条件为：振荡速度150 r/min,吸附时间60 min,溶液pH值6.10,此条件下Zn2＋去除率达到85.3%。[结论]该研究为应用蒙脱石开发污水处理新材料提供了科学依据。     

氧化石墨烯和五价砷在改性多孔介质中的共迁移特征

砷是农田土壤重金属污染的主要元素之一,在砷污染农田土壤的修复过程中往往忽视纳米颗粒能够使结合态的砷重新释放,导致有效态砷浓度升高,探究土壤中黏土矿物对氧化石墨烯(Graphene Oxide,GO)和五价砷(As(V))在多孔介质中迁移行为的影响,对进一步完善农田土壤砷修复理论以及提高农作物产量、保护人体健康具有重要意义。该研究利用蒙脱石和高岭石改性石英砂,通过砂柱迁移试验系统地研究了GO、As(V)和GO-As(V)在填加0%、10%、30%和50%的蒙脱石和高岭石改性石英砂柱中的迁移行为。研究结果表明,随着高岭石和蒙脱石改性石英砂填加比例的增加,GO和As(V)的迁移能力均呈降低趋势,且GO和As(V)在不同条件下的迁移曲线均存在显著差异(P0.05);GO在50%高岭石和蒙脱石改性石英砂柱中的回收率相对于石英砂柱分别下降了14%和17%,As(V)分别下降了15%和12%;在共迁移试验中,GO和As(V)在石英砂柱中回收率分别上升至99%和100%。分析表明,As(V)在蒙脱石改性石英砂柱中的迁移能力大于高岭石改性石英砂,而GO与之相反;当GO和与As(V)共迁移时,二者在介质中的迁移能力均大于其单独迁移。本研究表明GO、As(V)释放到土壤后,能够加速As(V)的迁移,造成土壤砷污染的扩大化。     

柱撑酸化蒙脱土催化合成丙烯酸正丁酯的研究

将蒙脱土经不同方法进行改性处理,并以此为催化剂,催化丙烯酸与正丁醇反应生成丙烯酸正丁酯。考察了以微波处理的柱撑酸化蒙脱土为催化剂催化合成丙烯酸正丁酯的反应条件。结果表明,以微波处理的柱撑酸化蒙脱土催化效果最好,适宜的反应条件为：丙烯酸为0.1 mol,醇酸的摩尔比为1.2：1,阻聚剂为对苯二酚,其用量为0.3 g,约为丙烯酸质量的4%,催化剂的用量1.7g,约为丙烯酸质量的20%,反应的时间为7 h,在回流状态下,其酯化率为84.1%。催化剂可以重复使用。     

蒙脱土-稻壳炭复合材料对Pb(Ⅱ)吸附特性研究

采用静态吸附实验,研究蒙脱土-稻壳炭复合材料对Pb~(2+)的吸附动力学和热力学特性,并考察吸附剂用量、共存离子及pH等因素对该复合材料吸附Pb~(2+)的影响。结果表明,复合材料对Pb~(2+)的吸附特性符合准二级动力学模型,等温吸附过程能较好地以Freundlich模型进行拟合,且是以物理吸附为主的自发的吸热反应。复合材料对Pb~(2+)的吸附量随吸附时间的延长先快速增加,后缓慢增加最终达到吸附平衡,且随着复合材料投加量的增加,Pb~(2+)的去除率增大。复合材料对水溶液中Pb~(2+)的吸附性能在pH为5时较好,吸附量达52.79 mg·g~(-1);不同浓度Ca~(2+)、Mg~(2+)均会对Pb~(2+)的吸附反应产生抑制作用,且Mg~(2+)的抑制作用更强。     

Evaluation on Tolerance of Montmorillonite as a Mycotoxin Adsorbent

In order to study the tolerance dose of Kunming mice to montmorillonite as a mycotoxin adsorbent in diets,the experiment selected 60 healthy male Kunming mice with initial average body weight of (17±0.12)g,randomly divided them into 5 treatments with two replicates per group and 6 mice per replicate.Five experimental diets were added to 0 (control group),0.5%,1%,2% and 5% montmorillonite,respectively.After 30 days,the growth performance,nutrients apparent digestibility,serum biochemical indices and internal organization were tested to determine the tolerance dose of montmorillonite for Kunming mice.The results showed that the ADFI was significantly increased in 0.5% group (P< 0.05),while there were no significant differences in ADFI and ADG between 1% group and control group (P> 0.05),then the ADFI was significantly decreased with the increasing of montmorillonite supplemental level (P< 0.05).The ADG in 2% group had no significant difference when compared with the control group (P> 0.05),while significantly lower than that in 0.5% and 1% groups (P< 0.05).The apparent digestibility of DM,CP and EE showed no significant effect at any level of montmorillonite (P> 0.05).Serum ALT,AST activities and MDA content were gradually increased with the montmorillonite supplemental level increasing,and that in 1%,2% and 5% groups were significantly higher than that in control group (P< 0.05),but there were no significant differences between 0.5% group and control group (P> 0.05).Tissue sections showed that mice livers were damaged in varying degrees when the montmorillonite supplemental level was 5%.In conclusion,based on a comprehensive consideration of all indexes,it could be seen that the tolerance dose of the tested montmorillonite for Kunming mice was between 0.5% and 2% when mycotoxin contents in diets were in security range.     

酚醛树脂/蒙脱土混合溶液固化特性研究

用单因素法分析蒙脱土和酚醛树脂混合溶液的固化情况,结果表明蒙脱土分散浓度增加,混合溶液固化时间增长;酚醛树脂浓度和固化温度加大,固化时间缩短,其中温度是影响固化效果较为明显的因素;不加固化剂时固化效果更好.     

纳米蒙脱石抑菌性能研究

本文采用快速分散、研磨、高速离心的方法对高纯蒙脱石进行分级,研究普通蒙脱石和纳米蒙脱石抑制黄曲霉菌的效果。结果表明:蒙脱石在水中分散后,逐步由悬浮液转变为凝胶体,当中位径为3.9μm时,抑菌效果较差;中位径为0.92μm时,抑菌效果明显提高;中位径为0.26μm时,抑菌效果最好。     

纳米载铜蒙脱石对生长肥育猪生产性能

摘要：试验旨在研究日粮中添加纳米载铜蒙脱石对生长育肥猪生产性能及血液生化指标的影响。选取72头健康“杜×大×长”三元杂交断奶仔猪，随机分为3组，每组3个重复，每个重复8头(公母各半)。分别饲喂基础日粮（对照组）、基础日粮+20 mg/kg泰乐菌素+100 mg/kg磺胺二甲基嘧啶(SM2)（试验Ⅰ组）和基础日粮+1500 mg/kg纳米载铜蒙脱石（MMT-Cu）（试验Ⅱ组）。比较研究MMT-Cu和泰乐菌素＋磺胺二甲基嘧啶对生长肥育猪生产性能及血液生化指标的影响。结果表明，与对照组和试验Ⅰ组相比，试验Ⅱ组料重比、血清ALB、SUN、Ch、TP含量极显著下降(P<0.01)；血钙含量、GTP活性极显著提高（P<0.01）；TP和GLU含量显著下降 (P<0.05)。因此，纳米载铜蒙脱石提高了生长肥育猪的料重比，并对血清中ALB 、Ca、GPT、SUN、TG、Ch、TP、GLU均产生不同程度的影响。