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针对土壤淋洗液中重金属传统萃取及液膜提取方法效率低的问题,提出组合液膜来提高提取率.本研究采用双二-乙基已基磷酸(D2EDTPA)和磷酸三丁酯(TBP)互为协同提取剂的组合液膜提取技术对土壤淋洗液中砷(As)进行提取,考察了系统温度、组合池膜溶液提取剂与膜溶剂体积比(M1/M2)、组合相有机相与水相体积比(O/A)、组合相提取剂比例(VD2EDTPA/VTBP)对As3+和As5+提取率的影响.研究结果表明,组合提取剂与As形成络合物在液膜系统中传输,最佳提取条件为:系统温度在28—30℃左右、M1/M2为4∶1、O/A为2∶1、VD2EDTPA/VTBP为4∶3.As3+和As5+起始浓度为5.45×10~(-4)mol·L~(-1)和1.12×10~(-4)mol·L~(-1)时,90 min最佳提取条件下提取率可达93.1%和82.7%. 相似文献
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乳状液膜法萃取氨基酸的研究 总被引:7,自引:0,他引:7
本文以TOMAC为载体,ECA4360J为表面活性剂,内外相Cl^-浓度梯度为推动力,研究了L-苯丙氨酸在乳状液膜体系中的传输,并对影响液膜萃取的各种因素进行了系统的阐述,确定了此体系的最佳膜相组成的实验条件,实现了L-苯丙氨酸的提取和浓缩。 相似文献
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非均相光敏化氧化治理含酚废水的研究 总被引:3,自引:0,他引:3
利用改进的亚甲蓝-海藻酸钙,作为非均相光敏化剂来光解苯酚水溶液。用分光光度法测定了一定条件下苯酚水溶液光解表观速率常数,并用[Cr(OCN_2H_4)_6)Cl_3化学光量计测定了其量子产率。本文还用膜的存在来解释导致非均相光敏化氧化速率及量子产率都不低于均相光敏化氧化的原因。应用本法处理含酚废水,取得了初步结果。 相似文献
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甲醇对多氯联苯在低密度聚乙烯膜上解吸动力学的影响 总被引:1,自引:0,他引:1
通过分别用纯水和甲醇-水溶液作为预吸附液使单个多氯联苯(PCB-52、PCB-185和PCB-209)分配到低密度聚乙烯膜后,再在纯水中解吸(解吸时间2—110 d),运用交换速率常数和解吸百分比来确定甲醇对目标物解吸动力学的影响.实验结果显示,目标物在两种预吸附方法的交换速率常数没有显著性差异(PCB-52:P=0.96;PCB-185:P=0.19;PCB-209:P=0.46),但负值的交换速率常数暗示:本实验中可能不适合用其来评价甲醇对目标物解吸的影响.而PCB-52在采用纯水与甲醇-水溶液作为预吸附液时所得解吸百分比之间没有显著性差异(P=0.37),但PCB-185和PCB-209的解吸百分比均存在显著性差异(P0.01),故甲醇可能影响PCB-185和PCB-209的解吸动力学.因此,在应用以低密度聚乙烯膜为吸附相的被动采样器,并以行为参考物校正法作为定量依据测定水体中疏水性有机物时,需谨慎使用以甲醇作为助溶剂的预吸附液将强疏水性的行为参考物分配至吸附相. 相似文献
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水样中有机磷污染物的分析首先需要进行样品前处理 ,将目标组分从水样中提取并富集起来 ,之后采用LC或GC方法进行分析 .1 水样中农药的固相提取固相提取技术是水样前处理的有效工具 .采用WatersOasisHLB固相提取产品 ,可以高效提取水样中的有机磷农药 ,获得理想的回收率结果 ( 相似文献
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表面分子膜降低氨挥发的Logistic模型研究 总被引:2,自引:0,他引:2
通过盆钵和田间试验,研究了表面分子膜对水体氨挥发的影响。结果表明,表面分子膜可有效抑制氨的挥发,但抑制效果跟分子膜用量有关。Logistic模型可以很好模拟预测盆钵试验中的氨挥发过程,通过修正氨挥发速率常数c,可较好地模拟田间氨挥发过程。 相似文献
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乳状液膜法处理含柠蒙酸工业废水的研究 总被引:2,自引:0,他引:2
本文研究了以LMA-1为表面活性剂,正三辛胺为流动载体,Na2CO3溶液为内相试剂,煤油为膜溶剂所组成的液膜体系处理柠檬酸废水。 相似文献
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NaOH溶液对有机相苯酚反萃取的研究 总被引:8,自引:0,他引:8
本文系统进行了NaOH溶液对负载苯酚的TBP+煤油溶剂的反萃取平衡实验。考虑苯酚的支萃取平衡和解离平衡,建立了反萃取的计算模式,并证明了模型的可行性。本文还讨论了NaOH溶液浓度,油水相比,萃取平衡分配系数,溶剂中的负载苯酚浓度和NaOH溶液中初始酚含量对反萃取率的影响。 相似文献
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Liang PEI ;Liming WANG ;Zhanying MA 《Frontiers of Environmental Science & Engineering》2014,8(4):503-509
A mathematical model for the transport of Ce (IV) from hydrochloric acid solutions through dispersion flat combined liquid membrane (DFCLM) with contain 2- ethyl hexyl phosphonic acid-mono-2-ethyl hexyl ester (P507) as the carrier, dissolved in kerosene as the membrane solution have been studied. This process of facilitated transport, based on membrane technology, is a variation on the conventional technique of solvent extraction and may be described mathematically using Fick's second law. The equations for transport velocity are derived considering the diffusion of P507 and its metallic complexes through the liquid membrane. In this work, the system is considered to be in a transient state, and chemical reaction between Ce(IV) and the carrier to take place only at the solvent-aqueous interfaces. Model concentration profiles are obtained for the Ce(IV), from which extraction velocities are predicted. The experimental and simulated Ce(IV) extractions showed similar tendencies for a high Ce (IV) concentration and acidity case.The model results indicate that high initial Ce(IV) concentrations and acidity both have detrimental effects on Ce(IV) extraction and stripping. The diffusion coefficient of Ce(IV) in the membrane and the thickness of diffusion layer between feed phase and membrane phase are obtained and the values are 6.31 × 10-8m2·s-1 and 31.2 μm, respectively. The results are in good agreement with experimental results. 相似文献
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The availability of high-quality water plays a pivotal role for the protection of the ecosystem and the quality of human life. An important step in assessing ground and surface water quality is sampling. The time-integrated accumulation of environmental contaminants by passive sampling is an attractive alternative to conventional snap-shot sampling. Thein situ accumulation during passive sampling allows the detection of even lowconcentrated contaminants and reduces cost and time for continuous monitoring. Passive sampling provides information on the whole sampling period and avoids the transport and storage of large sample volumes. Matrix effects are reduced due to the selective enrichment. Various passive samplers have been developed for sampling in aqueous media. Early developments used water filled dialysis tubes for the sampling of trace elements. Later on, solvent filled devices and triolein-filled semipermeable membrane devices (SPMDs) were deployed. More recent developments use a solid rather than a liquid sorbent as the receiving phase. Examples of this are the solid phase microextraction (SPME) and the membrane enclosed sorptive coating (MESCO). In addition to comprising miniature devices, SPMEs as well as MESCO are thermodesorbable and, as such, no longer require solvent extraction. Conventionally the sampled contaminants are removed from the passive sampling devices by solvent extraction or thermodesorption in order to be analyzed chemically. For an in-depth analysis of sampled analytes, however, it would be advantageous to modify passive sampling such that sampled contaminants can also be analyzed biologically. Thus, it is our goal to construct a passive sampling device that serves both as a sampling device as well as an exposure chamber for toxicity testing. The principle underlying this technology is the bioavailability of sorbed contaminants, thereby eliminating the need for solvent extraction. 相似文献
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利用海藻酸钙为载体包埋固定化硫酸盐还原菌(SRB)混合菌群,研究了固定化微生物吸附重金属镍离子的动力学特性.结果表明:固定化混合SRB菌群对Ni2 具有良好的吸附性能,最大吸附容量qm高达931.9mg(Ni2 )/g(SRB)颗粒,是一种颇具应用前景的生物吸附剂.固定化SRB吸附Ni2 的动力学过程可以用准二次动力学方程描述,整个吸附过程可以明显地分为两个阶段,即物理化学吸附阶段和生物沉淀阶段.扩散动力学研究表明,固定化颗粒的内扩散并非是唯一控制吸附速率的机制,整个吸附过程涉及到多种吸附机制.图4表3参14 相似文献