Study of the organic-inorganic phase interactions in polyester-titania hybrids

Radiopaque organic-inorganic hybrids were prepared by the sol-gel procedure. The hybrid the organic phase is a polyester, poly(1,4-butyleneglutarate), while the inorganic domains are in situ synthesized titania. FT-IR and XPS analyses show that organic and inorganic phases strongly interact mainly because of transesterification reactions involving the polyester chain and Ti atoms during hybrid synthesis. Synthetic parameters, namely solvent, environment acidity and inorganic precursor content, are investigated in order to assess their influence on the solid-state behaviour of the hybrid. The ability of the solvent to solvate, but not complex, Ti atoms and the presence of an inorganic acid in the feed increase interaction between the organic and inorganic phases, thus hindering polymer chain mobility. A similar effect, outlined by T_g increase and crystallization inhibition, is induced by increasing inorganic phase content. All obtained hybrids are optically transparent and opaque to X-rays.     

A practical review of the performance of organic and inorganic adsorbents for the treatment of contaminated waters

A wide range of materials known for their adsorption properties have the potential for being used for the removal of trace substances from drinking and wastewaters. These include physically and chemically activated carbons, surface modified carbons, non‐porous resins with ion exchange capacities, inorganic microporous solids like zeolites and clays, and mixed organic–inorganic materials like bone chars. The adsorption capacity exhibited by each material relates primarily to its textural and chemical properties. Other factors, however, such as apparent density, regeneration potential and cost, need to be taken into consideration when selecting one adsorbent over another. A comparative investigation of 18 solids and their capacity to remove organics and metals from natural waters and solutions reconstituted to simulate the conditions in natural waters is presented. The experiments were carried out using batch and small‐scale column adsorption tests. In general, zeolites and ion exchange resins exhibited limited capacities to remove organic matter from solution but were highly effective with metallic species like manganese and aluminium. Activated carbons adsorbed organic matter very efficiently, with results showing a correlation between adsorption capacity and surface area (up to 1791 m² g^?1). Metal removal was highly variable and was enhanced in activated carbons subjected to acid washing. Owing to its mixed organic/inorganic nature, and despite its poorly developed micropore structure, bone char exhibited a strong adsorption capacity for both organic and metal species. The high apparent density of this material (0.763 g cm^?3) meant that its performance was greatly improved when tests were conducted on the basis of volume, matching and surpassing the performance of the best carbons. The possibility of using mixtures of complementary adsorbents for the removal of organic and inorganic species from solution was also successfully evaluated in this work. Copyright © 2006 Society of Chemical Industry     

Effect of pH on the rejection of inorganic salts and organic compound using nanofiltration membrane

Nanofiltration (NF) has recently received increased attention as a possible tertiary treatment process providing high rejection of solutes and high water flux rate. In this research, solute separation experiments using NF membranes were made with inorganic salts including heavy metal and organic compounds in different pH levels. The rejection of inorganics from feed solution was found to be dependent on the electric charge of membrane as well as the ionic radius and valence of ion. The divalent cation appeared to reduce the potential of negatively charged membrane to lower the rejection of ion. The results of organic compounds showed that the rejection could be estimated from the pKa value and molecular weight of organics, and the pH of the feed solution.     

磺化聚醚砜纳滤膜性能研究

本文主要研究了磺化聚醚砜 (SPES)复合纳滤膜的性能。详细讨论了纳滤膜对不同溶质的分离特性 ;探讨了无机盐浓度 ,操作压力 ,溶液 p H值及磺化聚醚砜的离子交换容量(IEC)与膜性能的关系 ;并对纳滤膜的电性能进行了初步研究。研究结果表明 ,磺化聚醚砜复合纳滤膜为一荷负电性纳滤膜 ,对无机盐有较好的选择分离性能。磺化聚醚砜的离子交换容量 ,无机盐浓度以及操作压力对膜性能影响较大 ,且对于两性溶质 ,膜的脱除性能与溶液 p H值有关     

Biosorption: critical review of scientific rationale,environmental importance and significance for pollution treatment

Biosorption may be simply defined as the removal of substances from solution by biological material. Such substances can be organic and inorganic, and in gaseous, soluble or insoluble forms. Biosorption is a physico‐chemical process and includes such mechanisms as absorption, adsorption, ion exchange, surface complexation and precipitation. Biosorption is a property of both living and dead organisms (and their components) and has been heralded as a promising biotechnology for pollutant removal from solution, and/or pollutant recovery, for a number of years, because of its efficiency, simplicity, analogous operation to conventional ion exchange technology, and availability of biomass. Most biosorption studies have carried out on microbial systems, chiefly bacteria, microalgae and fungi, and with toxic metals and radionuclides, including actinides like uranium and thorium. However, practically all biological material has an affinity for metal species and a considerable amount of other research exists with macroalgae (seaweeds) as well as plant and animal biomass, waste organic sludges, and many other wastes or derived bio‐products. While most biosorption research concerns metals and related substances, including radionuclides, the term is now applied to particulates and all manner of organic substances as well. However, despite continuing dramatic increases in published research on biosorption, there has been little or no exploitation in an industrial context. This article critically reviews aspects of biosorption research regarding the benefits, disadvantages, and future potential of biosorption as an industrial process, the rationale, scope and scientific value of biosorption research, and the significance of biosorption in other waste treatment processes and in the environment. Copyright © 2008 Society of Chemical Industry     

Comminution of Organic Material

The comminution of materials of bioorganic origin such as organic solids, biological agglomerates or micro‐organisms is described in this work. The intent of this disintegration process is to release products, to improve the product quality or to enhance biological degradation processes. Special analytical techniques based on biochemical parameters are required in order to characterize the result of the comminution of organic materials. These techniques supplement techniques that are known from the comminution of brittle inorganic materials. The defined stressing of single particles can be used to characterize the comminution properties of solid bioorganic materials. The disintegration of micro‐organisms has been investigated in the fields of biotechnological product release and biodegradability of wastewater sludges. It is possible to optimize the operational parameters of stirred ball mills based on stress intensity and stress number in order to reduce the energy input and to improve product release.     

Kinetic Analysis On The Effects Of Dissolved Inorganic And Organic Substances In Raw Water On The Ozonation Of Geosmin And 2–MIB

The kinetics of geosmin and 2–MIB decomposition by ozonation in the presence of dissolved inorganic and organic substances were studied. As a first approximation, the decomposition rate of geosmin and 2–MIB were analyzed as a first–order reaction with respect to their concentration. The first–order rate constants decreased significantly with increase in the concentration of carbonate ion, free chlorine, alcohols and volatile fatty acids. Small amounts of humic acids or fulvic acids, however, enhanced the rate of decomposition. It was also demonstrated that the decomposition rates in natural waters were influenced mainly by the concentrations of carbonate and humic substances.     

Maximum Effective Hole Mathematical Modei and Exact Solution for Commingled Reservoir

The maximum effective hole-diameter mathematical modei describing the flow of slightly compressible fluid through a commingled reservoir was solved rigorously with consideration of wellbore storage and different skin factors. The exact solutions for wellbore pressure and the production rate obtained from layer j for a well production at a constant rate from a radial drainage area with infinite and constant pressure and no flow outer boundary condition were expressed in terms of ordinary Bessel functions. These solutions were computed numerically by the Crump's numerical inversion method and the behavior of systems was studied as a function of various reservoir parameters. The modei was compared with the real wellbore radii modei. The new modei is numerically stable when the skin factor is positive and negative, but the real wellbore radii modei is numerically stable only when the skin factor is positive.     

A Hydrodynamic Modei for Slug Frequency in Horizontal Gas-Liquid Two-Phase Flow

The prediction of slug frequency has important significance on gas-liquid two-phase flow. A hydrody-namic modei was put forward to evaluate slug frequency for horizontal two-phase flow, based on the dependence of slug frequency on the frequency of unstable interfacial wave. Using air and water, experimental verification of the modei was carried out in a large range of flow parameters. Six electrical probes were installed at different positions of a horizontal plexiglass pipe to detect slug frequency development. The pipe is 30m long and its inner diameter is 24 mm. It is observed experimentally that the interfacial wave frequency at the inlet is about l to 3 times the frequency of stable slug. The slug frequencies predicted by the modei fit well with Tronconi (1990) modei and the experimental data. The combination of the hydrodynamic modei and the experimental data results in a conclusion that the frequency of equilibrium liquid slug is approximately half the miniraum frequency of interfacial wave.     

A new vapor pressure equation for pure substances

A new simple equation for prediction of vapor pressure of pure substances is proposed. The equation which has the Clausius-Clapeyron (C-C) equation form consists of three parameters: critical temperature, critical pressure and normal boiling point. Experimental data for organic and inorganic substances have been used to calculate equation parameters in the boiling point ranges from 169.45 to 457.55 K and critical temperature ranges from 282.75 to 699.15 K. Comparison of proposed equation estimation results with experimental data shows that the new equation has minor average error. The new equation is also 68 percent more accurate than the C-C equation     

腐殖酸聚集体对膜蒸馏过程膜污染的作用机理

膜污染是膜蒸馏过程应用于工业水处理中遇到的主要问题之一。选取水体中具有代表性的有机物（腐殖酸）、微溶无机盐（碳酸钙）作为典型污染物,研究有机腐殖酸聚集体对于膜蒸馏过程膜污染进程的影响规律,探讨天然有机物-无机微溶盐混合水体中腐殖酸聚集体对于无机盐结晶过程的控制机理。结果表明：膜蒸馏通量的衰减大致可分为由滤饼层的形成造成的不可恢复部分以及由浓差极化、膜孔“半润湿”而造成的可部分恢复的通量降低。Ca²⁺通过加速腐殖酸分子的聚集过程,使表面负电性降低的腐殖酸聚集体率先吸附在聚偏氟乙烯中空纤维膜内表面,形成有机基质污染层;碳酸钙在有机腐殖酸聚集体的诱导下在膜内表面异相成核,最终成长为稳定的晶体。腐殖酸聚集体为无机盐晶体在疏水性膜内表面的生长提供了异相成核的基础。可通过控制污染水体中有机物的含量控制微溶碳酸钙在膜内表面成核及生长,实现控制其在膜内表面附着进而诱发疏水膜发生亲水化的过程。     

优良水消毒剂——ClO2的性质表现

二氧化氯是优良的水消毒剂,是氧化型消毒剂。二氧化氯对水中的一些还原态的金属阳离子、低价硫化物、氰化物、有机物等均有氧化作用。ClO2对无机物氧化以祛毒为主,对有机物的氧化降解以含氧基团的小分子化合物为主,即最终以无毒害作用的产物为主。     

Ionenaustauscher als beispiel für reaktionsfähige hochpolymere

The resin-based ion exchange materials used nowadays are insoluble polyelectrolytes. Synthetic processes allow a large variety of modifications of the ion exchange substance itself as well as of the functional groups. It is thus possible to offer tailormade special resins for many different uses. Beside resins which are resistant at elevated temperatures or in oxidizing media, the introduction of the macroporous matrix has proved to be a special success. It leads to more resistant products and makes it possible to use appropriately designed ion exchange resins for general adsorption purposes as well, similar to activated carbon. The range of application of ion exchange resins is rapidly increasing as new resins are being offered and improved process engineering is being developed. The most important fields are water conditioning, detoxification of waste waters, recovery of valuable inorganic and organic substances, as well as use in chemical processes. These versatile products will in future be used in these fields to a greater extent and new applications will certainly be found.     

油田垢样分析检测方法与应用

以现场垢样为例,提供了一种结垢油井垢样的分析检测方法。即称取一定量的垢样进行干燥、焙烧,以确定该垢样为有机垢样或无机垢样;若该垢样为有机垢样,根据行业标准进行蜡含量、胶质、沥青质含量的测定;若该垢样为无机垢样,进行定性分析后用盐酸溶解,然后根据行业标准进行钙离子、镁离子、铁离子、硫酸根离子以及硅离子含量的检测。该方法对垢样进行快速定性、定量分析,操作简单、快速、误差小。     

给水处理中活性炭吸附性能筛选的新指标——焦糖脱色率研究

对给水处理中活性炭吸附水中有机物的性能筛选指标进行研究,由于测定活性炭焦糖脱色率时所用焦糖的分子质量分布与天然水中有机物的分子质量分布相似,故提出用焦糖脱色率评价给水处理用活性炭的吸附性能.经试验证实,以焦糖脱色率评价活性炭吸附性能的试验结果与DL/T 582-2004(以腐殖酸、富里酸、木质素、丹宁进行评价)的结果相同.建议用于给水处理的活性炭焦糖脱色率＞50％.     

Review of pervaporation and vapor permeation process factors affecting the removal of water from industrial solvents

A recent review article (Journal of Chemical Technology & Biotechnology 94 : 343–365 (2019)) identified several commercially-available permselective materials for drying organic solvents with pervaporation (PV) and vapor permeation (V·P) separation processes. The membrane materials included polymeric and inorganic substances exhibiting a range in the performance characteristics: water permeance, water/solvent selectivity, and maximum use temperature. This article provides an overview of the factors affecting the design of PV/V·P processes utilizing these membranes to remove water from common organic solvents. Properties of the specific membrane and of the solvent substantially affect the PV/V·P separation. Equally important is the impact of operating parameters on the overall separation. To study these impacts, simplified process performance equations and detailed spreadsheet calculations were developed for single-pass and recirculating batch PV systems and for single-pass V·P systems. Estimates of membrane area, permeate concentration, solvent recovery, permeate condenser temperatures, and heating requirements were calculated. Process variables included: solvent type, water permeance, water/solvent selectivity, initial and final water concentrations, operating temperature (PV) or feed pressure (V·P), temperature drop due to evaporation (PV) or feed-side pressure drop (V·P), and permeate pressure. The target solvents considered were: acetonitrile, 1-butanol, N,N-dimethyl formamide, ethanol, methanol, methyl isobutyl ketone, methyl tert-butyl ether, tetrahydrofuran, acetone, and 2-propanol. Published 2019. This article is a U.S. Government work and is in the public domain in the USA.     

Spray Drying: Retention of Volatile Compounds Revisited

Retention or loss of trace volatile compounds during spray drying can be vital for product quality. Examples of cases where loss or retentions of volatile substances are important include retention of balanced flavor and aroma in food products, removal of odiferous substances, and control of the release of volatile organic compounds to the atmosphere. Factors and mechanisms determining losses of these substances are reviewed. Losses can occur during atomization, from undisturbed drops and as a result of morphological development. On the basis of this insight, several avenues for controlling the retention of volatile substances are identified and analyzed. These include control of atomizer pressure or rotation speed, choice of spray angle, configuration of air input, lteration of the air temperature profile, feed concentration, the presence of an oil phase and/or suspended solids, foaming of the feed, feed composition, and steam blanketing of the atomizer.

The quality of a spray-dried product can be strongly affected by the presence or absence of volatile compounds that were present in the feed to the spray dryer. For example, spray-dried coffee and tea have suffered from a air and thereby avoid bubble formation, expansion and bursting for deaerated feeds (20). This approach produces a product with high bulk density. If that result is cceptable, then it should also be a way of precluding volatiles loss due to morphological development.     

New macromolecular silane coupling agents synthesized by living anionic polymerization; grafting of these polymers onto inorganic particles and metals

New macromolecular silane coupling agents, which are end-triethoxysilylated poly(styrene) and poly(tert-butylmethacrylate), were investigated as possible inorganic particle and metal surface treatment agents. These polymers containing poly(styrene) and poly(tert-butylmethacrylate) as the main chain, were prepared by living anionic polymerization. Grafting of the polymers onto inorganic particles and metals was performed via the hydrolysis of the triethoxysilyl group using either acidic or basic catalyst. n-Butylphosphate was used as the catalyst for grafting onto inorganic substances having an acidic surface such as silica. However, in the case of grafting onto inorganic substances having a basic surface, tetrabutylammoniumhydroxide was employed as the catalyst. Contrary to expectations, grafting onto titania was successful even in the absence of a catalyst. Particles grafted with these polymers showed excellent dispersibility in organic medium, in which the polymers are soluble. This phenomenon is in contrast to that for particles treated with polymers possessing triethoxysilyl groups at random positions of the chain or those treated with trimethylsilyl groups. Surface tension measurements of metal substrates coated with the grafted polymers, were found to be identical to the values obtained for the bulk polymers.     

Ion transport phenomena in polymeric electrolytes

The aim of the present work is to generalize an ion transport phenomena observed in composite polymeric electrolytes using the previously developed models as well as design a new approach which would be helpful in describing changes in conductivity and lithium ion transference numbers occurring upon addition of fillers to polymeric electrolytes. The concept is based on the observation of changes in ionic associations in the polymeric electrolytes studied in a wide salt concentration range. The idea is illustrated by the results coming from a variety of electrochemical and structural data obtained for composite electrolytes containing specially designed inorganic and organic fillers.     

Sensitivity analysis of a light gas oil deep hydrodesulfurization process via catalytic distillation

In this work, a sensitivity analysis of a light gas oil deep hydrodesulfurization catalytic distillation column is presented. The aim is to evaluate the effects of various parameters and operating conditions on the organic sulfur compound elimination by using a realistic light gas oil fraction. The hydrocarbons are modeled using pseudocompounds, while the organic sulfur compounds are modeled using model compounds, i.e., dibenzothiophene (DBT) and 4,6-dimethyl dibenzothiophene (4,6-DMDBT). These are among the most refractive sulfur compounds present in the oil fractions. A sensitivity analysis is discussed for the reflux ratio, bottom flow rate, condenser temperature, hydrogen and gas oil feed stages, catalyst loading, the reactive, stripping, and rectifying stages, feed disturbances, and multiple feeds. The results give insight into the qualitative effect of some of the operating variables and disturbances on organic sulfur elimination. In addition, they show that special attention must be given to the bottom flow rate and LGO feed rate control.