合成斜发沸石影响因素的研究

在不同摩尔配比的条件下水热合成出较高纯度斜发沸石,系统研究了斜发沸石合成的各种影响因素.结果表明,在140、160和180℃条件下均能合成出斜发沸石,且提高温度可以缩短沸石的晶化时间;合成配料的硅铝摩尔比应控制在10-12之间;碱度的降低会导致成核时间延长,过高的碱度则导致晶种溶解.     

铵型斜发沸石脱除Pb~(2+)离子的热力学研究

通过实验测定铵型天然斜发沸石对铅离子全交换容量为80.07mmol/100g沸石.用Langmuir吸附等温方程和Freundlich吸附等温方程拟合了吸附等温数据,绘制NH4--pb2+离_子交换等温线以及Kielland图.依据热力学平衡原理,计算出该过程的焓、吉布斯自由能和熵变化.研究表明天然斜发沸石NH4--pb2+离子交换过程可自发进行,且为吸热反应,高温有利于铅离子的交换.     

Effect of pH and temperature on the ion‐exchange isotherm of Cd(II) and Pb(II) on clinoptilolite

The ion‐exchange equilibrium of Pb(II) and Cd(II) on clinoptilolite from different deposits was studied in this work. The Langmuir isotherm fitted the ion‐exchange equilibrium data of both ions better than the Freundlich isotherm. The capacity of the natural zeolite to exchange Cd(II) and Pb(II) increased, augmenting the solution pH. This behaviour was attributed to the interactions between the ions in solution and the surface charge of the zeolite. Moreover, the capacity of the natural zeolite to exchange Cd(II) and Pb(II) was increased when the temperature was raised from 15 to 35 °C. This tendency was explained by assuming that the ion exchange was an endothermic reaction. The selectivity of the zeolite for the metal cations decreased in the following order: Pb(II) > Cd(II). This order was not modified while reducing the solution pH, but the zeolite selectivity was increased. At pH 2 the selectivity of the zeolite for Pb(II) was nearly three times larger than at pH 4. Copyright © 2006 Society of Chemical Industry     

Purified Clinoptilolite-Tuff as an Efficient Sorbent for Gluten Derived from Food

Various gluten-related diseases (celiac disease, wheat allergy, gluten sensitivity) are known and their incidence is growing. Gluten is a specific type of plant storage protein that can impair the health of gluten-prone persons following consumption, depending on the origin. The most severe effects are induced by wheat, barley, and rye. The only treatment is based on the absolute avoidance of those foods, as even traces might have severe effects on human well-being. With the goal of binding gluten impurities after ingestion, an in vitro setting was created. A special processed kind of zeolite, purified clinoptilolite-tuff (PCT), was implemented as an adsorber of gluten derived from different origins. Zeolites are known for their excellent sorption capacities and their applications in humans and animals have been studied for a long time. Tests were also performed in artificial gastric and intestinal fluids, and the adsorption capacity was determined via a certified validated method (ELISA). Depending on the kind of gluten source, 80–130 µg/mg of gluten were bound onto PCT. Hence, purified clinoptilolite-tuff, which was successfully tested for wheat, barley, and rye, proved to be suitable for the adsorption of gluten originating from different kinds of crops. This result might form the basis for an expedient human study in the future.     

载锌沸石对肉鸡生产性能、抗氧化功能及其相关基因表达的影响

研究载锌沸石(Zn CP,锌含量为15.5 mg/g)对肉鸡生产性能、肝脏锌沉积、抗氧化功能及其相关基因表达的影响,探讨Zn CP作为抗生素替代品的可行性。300只1日龄AA(Arbor Acres)肉鸡随机分成5组,每组6个重复,每个重复10只鸡,试验期为42 d。试验日粮:1)对照组,基础日粮(含Zn SO4,锌含量为60mg/kg);2)基础日粮+抗生素(40 mg/kg金霉素);3)基础日粮+0.1%Zn CP;4)基础日粮+0.2%Zn CP;5)基础日粮+0.4%Zn CP。结果表明,与对照组相比,不同剂量Zn CP显著提高肉鸡前期体增重(P0.05),0.1%和0.2%的Zn CP显著提高21 d肝脏T-SOD和Cu Zn-SOD的活性(P0.05),0.2%的Zn CP显著降低21 d肝脏MDA含量(P0.05),抗生素组和Zn CP组均能显著提高21 d肝脏T-AOC(P0.05);与抗生素组相比,0.1%和0.2%的Zn CP显著降低21 d肝脏MDA含量(P0.05),显著提高21 d肝脏T-SOD的活性(P0.05),0.1%的Zn CP显著提高42 d肉鸡肝脏Nrf2 mRNA的相对表达量(P0.05)。与对照组和抗生素组相比,0.2%的Zn CP显著降低42 d肉鸡肝脏MDA含量(P0.05)。结果提示,肉鸡日粮中添加Zn CP能提高生产性能,效果等同或优于抗生素;Zn CP可能通过提高Keap1/Nrf2/ARE/抗氧化酶信号通路关键基因Nrf2的表达量来提高肉鸡的抗氧化能力;本试验条件下,日粮中Zn CP以0.1%和0.2%的添加量较好。     

吸铵饱和沸石的生物再生性能

考察低浓度条件下制得的吸铵饱和沸石生物再生性能,探讨了不同污泥浓度和钠离子浓度条件下沸石的生物再生情况。结果表明,在一定的范围内,提高活性污泥浓度和适当添加钠离子有利于提高吸氨饱和沸石的再生速率。当MLVSS增加至2750mg／L时,再生时间缩短至2．3h。继续增加污泥浓度和提高钠离子含量,吸氨饱和沸石的再生效果反而下降。通过对比试验结果的关联性分析,认为在污泥浓度较高的条件下,沸石中铵离子的解吸速率是沸石生物再生的限制步骤。