Showing papers in "Separation and Purification Reviews in 2006"
TL;DR: In this article, the authors present a systematic and comparative presentation of the possibilities of the above adsorbents, arising from the data reported in the literature for the period 1990-2004.
Abstract: Carbonaceous and polymeric materials have been extensively used in adsorption processes for the removal of pesticides from aqueous solutions. The aim of this review is the systematic and comparative presentation of the possibilities of the above adsorbents, arising from the data reported in the literature for the period 1990–2004. A brief description of each article is given in tables. The data is divided into two groups, based on the chemical structure of adsorbent (carbonaceous or polymeric material) and is given in tables. In each table information on the type of adsorbent (powder, granular, fibers, cloths, resins, cartridges etc), pesticide structure, experimental conditions, aim and results of each work, is reported. In addition, data is included concerning single pesticides adsorption, competitive adsorption, parameters of adsorption isotherms (Langmuir, Freundlich, Dubinin–Radushkevich) and kinetic model's parameters (homogeneous surface diffusion model‐HSDM, equivalent background compound...
106 citations
TL;DR: In this paper, a thorough literature survey was conducted on the freezing-melting (FM) process for desalination, and collected literatures were studied and analyzed to identify the current state-of-the-art of the FM process, and its practical limitations.
Abstract: A thorough literature survey was conducted on the freezing‐melting (FM) process for desalination. Collected literatures were studied and analyzed to identify the current state‐of‐the‐art of the FM process, and its practical limitations. The main advantages of the FM process are the requirement of low energy and low temperature operation compared to thermal desalination. Other advantages are less scaling or fouling and fewer corrosion problems, ability to use inexpensive plastics or low‐cost material, and absence of pretreatment. The three broad classes of FM process are: direct contact freezing, indirect contact freezing, and vacuum freezing. Different types of processing options in each class are discussed with their operating principles and merits and downsides of each process.
103 citations
TL;DR: In this article, a review of precursors and their influence on the separation properties of carbon molecular sieve membranes (CMSMs) is presented, and the evolution of membrane structure and separation performance from the state of polymer to carbon is also included.
Abstract: It is widely accepted that the characteristics and separation performance of carbonized membranes can be optimized by controlling the parameters of pyrolysis protocol. In spite of this, plenty of research studies have pointed out that the chemical composition and moiety geometry, chain rigidity and structure, and physicochemical properties of polymeric precursors play major roles in determining the properties of the resultant pyrolytic membranes, especially the micro‐pore structure and separation capability. Therefore, the morphological, structural and microphase control of the polymeric membranes are the essential keys to fabricate highly permeable and selective carbon membranes. This review paper aims to give an overview about the precursor materials aspects, preparations and their influence on the separation properties of carbon molecular sieve membranes (CMSMs). The evolution of membrane structure and separation performance from the state of polymer to carbon is also included. The subjects co...
76 citations
TL;DR: An overview of the use of PANI membrane in gas separation (GS), pervaporation (PV) and electrodialysis (ED) applications can be found in this article.
Abstract: Conjugated polymers are excellent barriers for membrane separations because their porosity can be controlled at the molecular level through chemical doping. Polyaniline (PANI) is particularly attractive because simple acid/base doping/undoping enables a controllable level of doping that can be readily achieved using dopants of different sizes and shapes. PANI, which belongs to an important member of the family of electrically conducting polymers, has been studied extensively as a membrane due to its distinct electrochemical properties and environmental stability. Adding dopants to PANI leads to a decrease in gas permeability, while removal of these dopants would produce extremely high permeability. This review provides an overview of the use of PANI membrane in gas separation (GS), pervaporation (PV) and electrodialysis (ED) applications. Our discussion will be concerned with the utility of PANI as a homopolymer, blend and composite membrane, discussing a considerable amount of background informa...
67 citations
TL;DR: In this article, a review of the possible paths in which water can be contaminated by pesticides is presented, and the performances of some commercial membranes in pesticides separation from water are enlisted.
Abstract: Pesticides are the man‐made creation to protect the crops and household items. Too often running water can become insidiously polluted by pesticides. In this review, the possible paths in which water can be contaminated by pesticides are exposed. There are several techniques for water remediation. Membrane separation technique has its potentiality and is an advantageous technique amongst all. The performances of some commercial membranes in pesticides separation from water are enlisted. Factors such as the nature of membranes, nature of pesticides, presence of organic and inorganic matters, temperature and/or pH influence the pesticide separation are discussed.
35 citations
TL;DR: In this article, a detailed knowledge of the CO2 solubility in the seawater at the conditions prevailing in the system is required for the modeling of CO2 release in the multi-stage flash distillers.
Abstract: The two main methods of removing salt from ocean water currently in use for large scale applications are: distillation using thermal desalination and membrane reverse osmosis separation. A detailed knowledge of the CO2 solubility in the seawater at the conditions prevailing in the system is required for the modeling of CO2 release in the multi‐stage flash distillers. The measurement of the solubility of CO2 in pure water has been extensively studied in the literature, whereas there is a lack of saline solutions studies. Several studies have investigated the solubility of CO2 in seawater under different temperatures and pressures without covering the conditions that prevailed in the desalination plants for example low pressures and high temperatures. The gas solubility can be theoretically estimated by considering the ionic strength and the salting‐out parameter in the low‐pressure regime, i.e., near atmospheric pressure. The measurements of gas solubility can be made as a function of the seawater...
34 citations
TL;DR: The task of metabolomics is not attainable with the current state of analytical science, and various approaches are used to accommodate this limitation and the associated complexity of the metabolome.
Abstract: Metabolomics is defined as the comprehensive analysis of all the metabolites of a biological system, although there is considerable confusion in terminology. The task of metabolomics is not attainable with the current state of analytical science, and various approaches are used to accommodate this limitation and the associated complexity of the metabolome. Major advances and a totally new approach to analysis will be essential. Meanwhile, a number of techniques, namely, metabolite profiling, metabolite fingerprinting and target analysis are combined to make this task possible. There is an implicit assumption in these approaches that the data are complementary and that the metabolome can be assessed as a summation of individual data. The integrity of metabolomics data depends on state‐of‐the‐art sample handling and measurement techniques. These ideas are developed in this review.
20 citations
TL;DR: A concise survey of articles dealing with the separation of cis-trans (Z) −(E) isomers is presented in this article, where the geometric isomerism generated by ethylene bonds (carbon-carbon double bond) is the only one treated.
Abstract: This review presents a concise survey of articles dealing with the separation of cis‐trans (Z)‐(E) isomers. The geometric isomerism generated by ethylene bonds (carbon‐carbon double bond) is the only one treated. An introduction focuses on the existing chemical nomenclature and the encountered problems in modern analytical and pharmaceutical chemistry. Next, the study is divided into three parts: synthetic compounds, natural compounds, and fatty acids and vitamins. Within this framework, articles have been selected to describe past and current trends in analytical chemistry and outline relevant research interests. Afterwards, the different mechanistic approaches that could explain the separation of such geometrical isomers is reviewed. These approaches may be used to design and to describe more interesting methodologies.
9 citations
TL;DR: A review of the most frequent analytical techniques described to determine furosemide is presented, special attention has been paid to spectrophotometric and chromatographic techniques, but also to relevant methods using capillary electrophoresis or flow‐injection analysis, as well as the detection modes coupled to these techniques.
Abstract: Due to the clinical importance of furosemide, a large number of analytical procedures to detect the presence of this drug in pharmaceutical and physiological samples has been developed. In this manuscript, a review of the most frequent analytical techniques described to determine furosemide is presented. Special attention has been paid to spectrophotometric and chromatographic techniques, but also to relevant methods using capillary electrophoresis or flow‐injection analysis, as well as the detection modes coupled to these techniques. The review also focuses on the different degradation pathways of the drug and cautions to prevent it, otherwise rarely or confusedly mentioned in the analytical reports. Some guidelines about purification of the raw product after synthesis are also addressed.
8 citations