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1.
以眯唑类[PF6]^-型离子液体1-丁基-3-甲基咪唑六氟磷酸盐([Bmim][PF6])、1-己基-3-甲基咪唑六氟磷酸盐([Hmim][PF6])和1-辛基-3-甲基咪唑六氟磷酸盐([Omim][PF6])对苯胺、对氯苯胺等7种胺类化合物的萃取,考察了溶液初始浓度、相比、盐类、pH及离子液体眯唑基团上取代烷基对萃取平衡的影响,并研究了萃取过程的热效应。实验结果表明:溶液初始浓度对分配系数影响较小;相比10:1是离子液体对胺类化合物的溶解饱和临界点,当相比大于10:1时,分配系数降低;NaCl、K2SO4可以增大萃取分配系数,ZnSO4对分配系数几乎没有影响;pH增加,分配系数增大;离子液体对不同取代基的胺类萃取能力有较大的差异,咪唑基团上取代烷基的长度对不同胺类物质的分配系数影响较显著;萃取过程属于焓增大的吸热过程。  相似文献   

2.
通过水溶液聚合法制备了聚丙烯酸水凝胶(polyacrylic acid,PAA),研究了溶液酸碱度和温度对聚丙烯酸水凝胶吸附氯化1-丁基3-甲基咪唑离子液体的影响。结果表明,水凝胶对氯化1-丁基3-甲基咪唑离子液体的吸附量随溶液pH值增大而逐渐增大,pH=2~4时增幅明显,而pH大于4时变化趋于缓慢;随温度的升高而逐渐降低。该等温吸附行为基本符合Langmuir吸附等温式,由二级吸附动力学模型获得的吸附过程活化能(Ea=52.470 kJ/mol)可以看出,PAA对氯化1-丁基3-甲基咪唑的吸附属于化学吸附范畴。  相似文献   

3.
咪唑类[PF6-型离子液体萃取胺类化合物   总被引:3,自引:0,他引:3  
以咪唑类[PF6]-型离子液体1-丁基-3-甲基咪唑六氟磷酸盐([Bmim][PF6])、1-己基-3-甲基咪唑六氟磷酸盐([Hmim][PF6])和1-辛基-3-甲基咪唑六氟磷酸盐([Omim][PF6])对苯胺、对氯苯胺等7种胺类化合物的萃取,考察了溶液初始浓度、相比、盐类、pH及离子液体咪唑基团上取代烷基对萃取平衡的影响,并研究了萃取过程的热效应.实验结果表明:溶液初始浓度对分配系数影响较小;相比10:1是离子液体对胺类化合物的溶解饱和临界点,当相比大于10:1时,分配系数降低;NaCl、K2SO4可以增大萃取分配系数,ZnSO4对分配系数几乎没有影响;pH增加,分配系数增大;离子液体对不同取代基的胺类萃取能力有较大的差异,咪唑基团上取代烷基的长度对不同胺类物质的分配系数影响较显著;萃取过程属于焓增大的吸热过程.  相似文献   

4.
传统CO_2的捕集方法存在设备投资大、环境污染严重、再生能耗高等缺点,利用新型绿色工质离子液体负载于聚偏氟乙烯上制备离子液体支撑膜可以较好地解决该问题。在压力为0.2 MPa、流量为50 m L·min-1、温度在298~318 K范围内变化时,测定了CO_2在1-乙基-3甲基咪唑双三氟磺酰亚胺盐([Emim][Tf_2N])和1-乙基-3-甲基咪唑醋酸盐([Emim][AC])2种离子液体支撑膜中的渗透系数、溶解度和扩散系数,采用Van’t Hoff方程对溶解度数据进行关联、Arrhenius方程对渗透和扩散系数的数据进行关联。实验结果表明,CO_2在2种离子液体支撑膜中的渗透和扩散系数随着温度的升高而增大,溶解度随着温度的升高而降低。[Emim][Tf_2N]离子液体支撑膜对CO_2的捕集性能优于[Emim][AC]支撑膜,CO_2在[Emim][Tf2N]支撑膜中的溶解度最大值为0.447,在[Emim][AC]离子液体支撑膜中的最大溶解度为0.253,由此可确定离子液体支撑膜分离CO_2的最佳工作温度,为其在工业应用中奠定良好的基础。  相似文献   

5.
铁炭微电解法降解1-丁基-3-甲基咪唑四氟硼酸盐的研究   总被引:4,自引:3,他引:1  
1-丁基-3-甲基咪唑四氟硼酸盐([BMIM]BF4)是一种常用的离子液体,被越来越多地应用于精细化学品及药物的合成。由于其对水生生物有毒性的影响且难于生物降解,提出了采用铁炭微电解法来降解[BMIM]BF4,并探讨了影响处理效果的主要因素、工艺条件及其反应动力学。结果表明,影响铁炭微电解降解[BMIM]BF4的因素按从小到大的顺序为:炭铁比、反应时间、pH;铁炭微电解降解[BMIM]BF4的最佳工艺条件是:铁粉用量3 g/L、水样pH2.5、炭铁比2、反应时间为60~90 min;在此条件下,[BMIM]BF的去除率可以达到80%以上,且该降解反应为二级反应。  相似文献   

6.
制备了膨胀珍珠岩(EP)为载体的TiO2催化剂(TiO2/EP),对使用较为广泛的抗生素磺胺嘧啶(SDZ)进行了光催化降解研究,探讨了TiO2的负载量、溶液的初始浓度、初始pH、无机离子(HCO3^-、SO4^2-和Cl^-)和腐殖酸(HA)对SDZ降解效果的影响。结果表明:SDZ的光催化降解符合一级反应动力学方程;当TiO2最佳负载量为20 wt%,SDZ浓度为5 mg/L,pH=6.7,紫外光照射强度为1 000μW/cm^2,反应时间为45 min时,SDZ的降解率达到96%;HCO3^-在低浓度时能促进SDZ的光催化降解,高浓度时促进作用不明显;SO4^2-和Cl^-对SDZ的光催化降解有轻微的抑制作用;HA对SDZ光催化降解有显著的抑制作用,浓度越高,抑制作用越强。UV-TiO2/EP是一种去除水体中微污染SDZ的有效方法。  相似文献   

7.
以二环己基-18-冠醚-6(DCH18C6)为萃取剂,一系列离子液体为溶剂的冠醚-离子液体萃取体系对水相中铀酰离子(UO2+2)进行萃取实验。结果表明:UO2+2在1-丁基-3-甲基咪唑双三氟磺酰亚胺盐([C4min]NTf2)体系的去除效率明显高于六氟磷酸盐类(PF-6)离子液体。在水相中当硝酸浓度在3 mol·L~(-1)左右时萃取效率最高,体系的萃取效率随着萃取剂浓度的增加而变大,共存离子的加入会降低体系的萃取效率,但是当加入的是硝酸根离子时,萃取率会相应增大。根据实验结果分析可以判断此萃取体系主要为阳离子交换过程。  相似文献   

8.
采用微乳法制备铁掺杂TiO2纳米晶(Fe-TiO2)复合体,通过热重-差热(TG-DTA)、X射线衍射(XRD)、扫描电镜(SEM)和紫外漫反射光谱(DRS)等对其结构和形态进行表征;以亚甲基蓝溶液(MB)为标准模拟降解物,对Fe-TiO2,纯TiO2和P25光催化降解性能进行评价。结果表明,Fe-TiO2的光催化活性明显〉P25,原因是Fe掺杂不仅能抑制TiO2晶粒生长,提高TiO2的热稳定性和比表面积,而且能够拓展TiO2的吸收波长范围至可见光区,提高了Ti3+离子浓度,降低了光生载流子的复合几率。  相似文献   

9.
采用离子液体辅助水热法制备锡酸锌,考察了离子液体添加量对锡酸锌晶相、形貌及光催化性能的影响。通过XRD、TEM分别对锡酸锌的晶相和形貌进行研究。通过在紫外光照射下光催化降解亚甲基蓝溶液对锡酸锌的光催化性能进行表征。当[Emim]BF_4添加量为0.5 mmol时,制得的八面体锡酸锌结晶度高且对染料亚甲基蓝有较高光催化降解能力。自由基捕获实验证明羟基自由基是光催化反应的主要活性物种。  相似文献   

10.
采用溴化1-丁基-3-甲基咪唑([Bmim]Br)离子液体辅助水热合成法制备了光催化剂Bi VO4。以高压氙灯作为可见光源,亚甲基蓝为目标污染物,考察反应温度、p H、反应时间和离子用量等制备条件对Bi VO4的可见光催化活性的影响,确定了最佳制备条件。并采用XRD、SEM和UV-Vis漫反射等分析手段对催化剂的晶相、形貌和光学特性进行了表征。结果表明,在离子液体加入量为2 m L、p H=4、反应温度为180℃、反应时间为4 h的条件下,制得的Bi VO4催化剂的可见光光催化活性最高。制得的Bi VO4为单斜相,呈分散的、大小均匀的片状,在200~500 nm范围有一个较宽的强吸收平台,具有良好的可见光催化活性,在可见光照射下对浓度为5 mg/L的亚甲基蓝的光催化脱色率达97%以上。  相似文献   

11.
介绍了电解法生产次氯酸钠的原理 ,并在原有生产工艺的基础上进行了重新设计和对设备的重新选择、改造 ,得出了各个工艺参数的最佳值 ,生产出高品质的次氯酸钠  相似文献   

12.
Abstract

A computer model was used to take random samples from primary sample populations obtained from field trials to simulate the uncertainty of sampling for residue analysis of plant commodities and soil. The results indicate about 40%, 30% and 20% relative uncertainty when random samples of size 5, 10 and 25 are taken respectively, from a single lot. Therefore the sample size should be the same for establishing and enforcing legal limits.  相似文献   

13.
Evaluation of the presence of drugs of abuse in tap waters   总被引:1,自引:0,他引:1  
A total of seventy samples of drinking water were tested for non-controlled and illicit drugs. Of these, 43 were from Spanish cities, 15 from seven other European countries, three from Japan and nine from seven different Latin American countries. The most frequently detected compounds were caffeine, nicotine, cotinine, cocaine and its metabolite benzoylecgonine, methadone and its metabolite EDDP. The mean concentrations of non-controlled drugs were: for caffeine 50 and 19 ng L−1, in Spanish and worldwide drinking water respectively and for nicotine 13 and 19 ng L−1. Illicit drugs were sparsely present and usually at ultratrace level (<1 ng L−1). For example, cocaine has mean values of 0.4 (Spain) and 0.3 ng L−1 (worldwide), whereas for benzoylecgonine, these mean values were 0.4 and 1.8 ng L−1, respectively. Higher concentrations of benzoylecgonine were found in Latin American samples (up to 15 ng L−1). No opiates were identified in any sample but the presence of methadone and EDDP was frequently detected. Total mean values for EDDP were 0.4 ng L−1 (Spain) and 0.3 ng L−1 (worldwide). Very few samples tested positive for amphetamines, in line with the reactivity of chlorine with these compounds. No cannabinoids, LSD, ketamine, fentanyl and PCP were detected.  相似文献   

14.
Biodegradation mechanisms were elucidated for three dibenzoate plasticizers: diethylene glycol dibenzoate (D(EG)DB), dipropylene glycol dibenzoate (D(PG)DB), both of which are commercially available, and 1,6-hexanediol dibenzoate, a potential green plasticizer. Degradation studies were done using Rhodococcus rhodochrous in the presence of pure alkanes as a co-substrate. As expected, the first degradation step for all of these systems was the hydrolysis of one ester bond with the release of benzoic acid and a monoester. Subsequent biodegradation of the monobenzoates of diethylene glycol (D(EG)MB) and dipropylene glycol (D(PG)MB) was very slow, leading to significant accumulation of these monoesters. In contrast, 1,6-hexanediol monobenzoate was quickly degraded and characterization of the metabolites indicated that the biodegradation proceeded by way of the oxidation of the alcohol group to generate 6-(benzoyloxy) hexanoic acid followed by β-oxidation steps. This pathway was blocked for D(EG)MB and D(PG)MB by the presence of an ether function.The use of a pure hydrocarbon as a co-substrate resulted in the formation of another class of metabolites; namely the esters of the alcohols formed by the oxidation of the alkanes and the benzoic acid released by hydrolysis of the original diesters. These metabolites were biodegraded without the accumulation of any intermediates.  相似文献   

15.
影响混凝效果的因素众多,混凝沉淀烧杯试验是进行水的混合、絮凝、沉淀工艺研究、设计和生产指导的最有效方法之一,阐述了智能型混凝试验搅拌器的设计原理和技术性能.  相似文献   

16.
不同泥源对厌氧氨氧化反应器启动的影响   总被引:2,自引:1,他引:1  
李祥  黄勇  袁怡  张丽  朱莉 《环境工程学报》2012,6(7):2143-2148
采用2套上流式生物膜反应器,分别接种少量厌氧氨氧化污泥和大量硝化污泥,考察其对厌氧氨氧化反应器启动的影响。污泥接种入反应器后,测得接种厌氧氨氧化污泥的反应器(R1)内MLSS为0.22 g/L,另一个反应器(R2)MLSS为2.7 g/L。与直接接种厌氧氨氧化污泥相比,R1经过72 d的运行才显现出厌氧氨氧化特性。经过114 d的培养,前者氮去除速率由0.23 kg/(m3.d)提升到5.29 kg/(m3.d),总氮去除率大于89%;R2的氮去除速率由0.01 kg/(m3.d)提升到1.1 kg/(m3.d),总氮去除率大于84.6%。说明普通污泥启动需要一个较长的筛选过程,直接接种少量的厌氧氨氧化污泥比接种普通的污泥能够更快启动厌氧氨氧化反应器。  相似文献   

17.
生物质快速热裂解主要参数对生物油产率的影响   总被引:5,自引:0,他引:5  
以松木木屑为原料,在自制的小型流化床上,开展了生物质热裂解温度、生物质粒径和进料速率对生物油产率的影响实验研究.结果表明,在热裂解温度分别为450、475、500、525和550℃条件下,当热裂解温度为500℃时,生物油产率最高,平均产率达到53.33%(质量百分比).反应温度越高,炭产量越低,不可冷凝气体产量越高,气体发热值越高;粒径<1 mm的生物质其粒径对生物油产率影响不大;生物质进料速率增加时,生物油产率增加.本研究为生物能的利用提供了新的途径.  相似文献   

18.
The most common technique used for numerical simulations of tracer mixing is that of the numerical solution of the advection–diffusion equation with the unresolved fluxes parameterized using the similarity theory. Despite correct predictions of the overall directions of transport, models based on a numerical solution of the advection–diffusion equation lack sufficient accuracy to correctly reproduce the coupling of mixing with small scale processes which are sensitive to the microstructure of the tracer distribution. The objective of this paper is to revisit the basic formalism employed in numerical models used to investigate atmospheric tracers. The main mathematical method proposed here is the theory of kinematics of mixing which could be applied effectively for simulations of atmospheric transport processes. At the beginning of the paper, we introduce simple mathematical transformations in order to demonstrate how complex topological structures are created by mixing processes. These idealistic flow systems are essential to explain transport properties of much more complex three-dimensional geophysical flows. An example of the application of the kinematics of mixing to the analysis of tracer transport on a planetary scale is presented in the following sections. The complex filamentary structures simulated in the numerical experiment are evaluated using some commonly applied statistical measures in order to compare the results with the data published in the literature. The results of the experiment are also analysed with the help of simple conceptual models of fluid filaments. The microstructure of the tracer distribution introduced in the paper is essential to increase our understanding of atmospheric transport and to develop more realistic parameterizations of small-scale mixing. The presented results could also be used to improve calculations of the coupling between microphysical processes and tracer mixing.  相似文献   

19.
造纸废水混凝处理中SFT助凝替代性研究   总被引:1,自引:0,他引:1  
中小造纸厂废水处理常用PAC作混凝剂 ,PAM作助凝剂。由于PAM成本很高 ,影响了处理设备的投运率。用超细滑石粉 (SFT)替代PAM助凝 ,与混凝剂PAC配合 ,其混凝处理效果基本相当 ,但是处理成本降低 0 .10元 /m3 。由于SFT属环境无害材料 ,不会给排泥带来二次污染  相似文献   

20.
寻找廉价而高效的替代原料是实现生物柴油产业化的关键所在.微藻以含油量高、生长周期短、环境适应能力强、生物产量高等优点,有望成为一种极具潜力的生物柴油生产原料.然而,目前尚存在微藻培养低效成本高和微藻回收效率低两大难题.综述了微藻培养与回收过程中的关键技术,并对存在的两大难题及其改进技术进行了详细的探讨.最后,总结并展望了微藻培养、回收技术未来的发展趋势.  相似文献   

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