Bentonite

Background: 1E10 monoclonal antibody is a murine anti-idiotypic antibody that mimics N-glycolyl-GM3 gangliosides. This antibody has been tested as an anti-idiotypic cancer vaccine, adjuvated in Al(OH) 3 , in several clinical trials for melanoma, breast, and lung cancer. During early clinical development this mAb was obtained in vivo from mice ascites fluid. Currently, the production process of 1E10 is being transferred from the in vivo to a bioreactor-based method.

each case, side chain alterations of solvent-exposed tyrosine, aspartate, and glutamate residues were observed. For the cytochrome c 552 ± talc complex, these changes are followed by a slow refolding of the peptide chain in the binding domain and, subsequently, a further H/D exchange of amide group protons.

Pectin, with its tendency to gel in the presence of metal ions has become a widely used material for capturing the metal ions from wastewaters. Its dye-capturing properties have been much less investigated, and this paper is the first to show how films based on amidated pectin can be used for cationic dye adsorption. In the present study amidated pectin/montmorillonite composite films were synthesized by membrane casting, and they are stable in aqueous solution both below and above pectin pK a . FTIR, thermogravimetry and SEM-EDAX have confirmed the presence of montmorillonite in the cast films and the interactions between the two constituents.

Sorption hysteresis in natural sorbents has important environmental implications for pollutant transport and bioavailability. We examined sorption reversibility of Cd(II) and Pb(II) on zeolite and bentonite. Sorption isotherms were derived by sorption of Cd(II) and Pb(II) from solutions containing a range of the metal concentrations corresponding to 10-100% maximum sorption capacity (SC max ) of the sorbents. The desorption experiments were performed immediately following the completion of sorption experiments. Sorption and desorption isotherms of Cd(II) and Pb(II) were well described by the Freundlich model. The results revealed that the desorption isotherms of Cd(II) and Pb(II) from zeolite significantly deviated from the sorption isotherms indicating irreversible or very slowly reversible sorption. For bentonite sorption/desorption isotherms were similar indicating reversible sorption. The extent of hysteresis was evaluated from sorption and desorption Freundlich parameters (K f and n) through the apparent hysteresis index (HI = n desorb /n sorb ; n is the exponent in the Freundlich equation) and differences in Freundlich K f parameters. Higher sorption irreversibility was obtained for Pb(II) as compared to Cd(II). The amounts of Cd(II) and Pb(II) desorbed from bentonite were more than from zeolite, indicating that zeolite was a more effective sorbent for water and wastewater treatment.

A series of polypropylene carbonate (PPC)/ ZnO nanocomposite films with different ZnO contents were prepared via a solution blending method. The morphological structures, thermal properties, oxygen permeability, water sorption, and antibacterial properties of the films were investigated as a function of ZnO concentration. While all of the composite films with less than 5 wt % ZnO exhibited good dispersion of ZnO in the PPC matrix, FTIR and SEM results revealed that solution blending did not lead to a strong interaction between PPC and unmodified ZnO. As such, poor dispersion was induced in the composite films with a high ZnO content. By incorporating inorganic ZnO filler nanoparticles, the diffusion coefficient, water uptake in equilibrium, and oxygen permeability decreased as the content of ZnO increased. The PPC/ZnO nanocomposite films also displayed a good inhibitory effect on the growth of bacteria in the antimicrobial analysis. The enhancement in the physical properties achieved by incorporating ZnO is advantageous in packaging applications, where antimicrobial and environmental-friendly properties, as well as good water and oxygen barrier characteristics are required. Furthermore, UV light below $ 350 nm can be efficiently absorbed by incorporating ZnO nanoparticles into a PPC matrix. ZnO nanoparticles can also improve the weatherability of a PPC film. In future research, the compatibility and dispersion of the PPC matrix polymer and the inorganic ZnO filler nanoparticles should be increased.

A series of surface-modified clays containing nanophase (np) iron oxide/oxyhydroxides of extremely small particle sizes, with total iron contents as high as found in Mars soil, were prepared by iron deposition on the clay surface from ferrous chloride solution. Comprehensive studies of the iron mineralogy in these "Mars-soil analogs" were conducted using chemical extractions, solubility analyses, pH and redox, x ray and electron diffractometry, electron microscopic imaging, specific surface area and particle size determinations, differential thermal analyses, magnetic properties characterization, spectral reflectance, and Viking biology simulation experiments. The clay matrix and the procedure used for synthesis produced nanophase iron oxides containing a certain proportion of divalent iron, which slowly converts to more stable, fully oxidized iron minerals. The clay acted as an effective matrix, both chemically and sterically, preventing the major part of the synthesized iron oxides from ripening, i.e., growing and developing larger crystals. The precipitated iron oxides appear as isodiametric or slightly elongated particles in the size range 1-10 nm, having large specific surface area. The noncrystalline nature of the iron compounds precipitated on the surface of the clay was verified by their complete extractability in oxalate. Lepidocrocite (3,-FeOOH) was detected by selected area electron diffraction. It is formed from a double iron Fe(II)/Fe(III) hydroxy mineral such as "green rust," or ferrosic hydroxide. Magnetic measurements suggested that lepidocrocite converted to the more stable maghemite (3,-Fe203) by mild heat treatment and then to nanophase hematite (a-Fe203) by extensive heat treatment. After mild heating, the iron-enriched clay became slightly magnetic, to the extent that it adheres to a hand-held magnet, as was observed with Mars soil. The chemical reactivity of the iron-enriched clays strongly resembles, and offers a plausible mechanism for, the somewhat puzzling observations of the Viking biology experiments. Their unique chemical reactivities are attributed to the combined catalytic effects of the iron oxide/oxyhydroxide and silicate phase surfaces. The reflectance spectrum of the clay-iron preparations in the visible range is generally similar to the reflectance curves of bright regions on Mars. This strengthens the evidence for the predominance of nanophase iron oxides/oxyhydroxides in Mars soil. The mode of formation of these nanophase iron oxides on Mars is still unknown. It is puzzling that despite the long period of time since aqueous weathering took place on Mars, they have not developed from their transitory stage to well-crystallized end-members. The possibility is suggested that these phases represent a continuously on-going, extremely slow weathering process. 20,831 20,832 BANIN ET AL.: NANOPHASE IRON MINERALS IN MA•S SOIL detection systems during the 1988-1990 oppositions [Bell et al., 1990; Roush et al., 1993; Singer et al., 1990]. Yet the mineralogical nature of the soil is far from being understood, nor are its time of formation and weathering processes known.

Príspevok skúma vplyv natrifikačných činidiel a metód natrifikácie na adsorpčné vlastnosti montmorillonitu, hlavnej a najdôležitejšej zložky prírodného bentonitu. Montmorillonit s dominantným zastúpením Ca 2+ katiónov v medzivrstvovom priestore štruktúry montmorillonitu bol najskôr modifikovaný "polosuchým" spôsobom použitím Na 2 CO 3 ako aktivačného činidla. Na druhú modifikáciu montmorillonitu sa ako aktivačné činidlo použil roztok NaOH. Za účelom porovnania sorpčných vlastností chemicky modifikovaných montmorillonitov sa uskutočnili sorpčné experimenty statickou metódou. Sorpcie katiónov Cd 2+ , Pb 2+ a Zn 2+ sa študovali v rozsahu vstupných koncentrácií 10 až 700 mg/L. Montmorillonit natrifikovaný NaOH dosiahol vyššie hodnoty maximálnej adsorpčnej kapacity pre adsorpciu skúmaných katiónov ťažkých kovov, ako montmorillonit aktivovaný Na 2 CO 3 .

The study on the physio-mechanical behavior of aluminum dross has been carried out. The amount of aluminum dross used varied between 50 and 90 wt %, while bentonite added to the dross varied from 10-50 wt % with a fixed amount of water. Using dross particle sizes of 106 µm and 184 µm, 10 samples are produced from each particle size. The bricks are dried in still air for 24hrs at 31 o C, oven drying at 110ºC for 24hrs and sintered at 450ºC for 8hrs. The bricks characteristics in terms of volume shrinkage, apparent porosity, bulk density, cold crush strengths and permeability are then evaluated. The results show that the 106µm particle size dross brick has the highest volume shrinkage of 24%, apparent porosity of 15% and peak bulk density of 1.9g/c.c. However, the dross brick exhibits relatively low cold crush strength of 940KN/m². The 106µm size bricks demonstrate a minimum of 85% permeability compared with 70 wt% of 184 µm bricks which may be due to variation in dross particles agglomeration. Given these results, the 106µm particle size brick can serve as acid refractory because its properties compared well with medium-alumina fireclay.

journal homepage: www.else vier.com/locate /wa tres w a t e r r e s e a r c h 4 7 ( 2 0 1 3 ) 5 9 3 0 e5 9 4 2 0043-1354/$ e see front matter ª 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.watres.2013.07.016 to predict concentrations of La 3þ ions and the potential for negative ecological impacts.

Obtained from the research on oilfield drilling fluids as a way to improve colloidal and rheological properties of bentonite (sodium montmorillonite) mud (slurry), the polymer based synthetic fluid arrived to a point that itself can work as a substitute of mineral slurry on excavations for foundations of engineering structures.
The use of this type of fluid in the geoconstruction industry was born from the need to find a new solution with less environmental impact and at the same time improve the final results (saving time, improving excavation geometry and saving concrete).
Once there are a lot of doubts at the moment of using and accepting the synthetic mud as a real technical option, this report is intended to clear ideas about the characteristics, how to use and in which aspects can the use of polymer slurry be more advantageous than bentonite slurry on soil stabilization.

Dye bearing effluent have become one of the most dangerous environmental complications, and the removal of synthetic dyes (e.g., acid dyes, azoic (or naphthol) dyes, basic dyes, chrome (or mordant) dyes, developed (or diazo) dyes, direct dyes, disperse (or acetate) dyes, reactive (or fiber-reactive) dyes, sulphur dyes, Vat dyes) from water and wastewater is of unique concern because they are unmanageable and sustained in the environment. As of late, bentonites and its composite have been moderately applied to the removal of dye bearing effluent from contaminated water through adsorption processes. This paper reviews recent progress in the application of bentonites and its composites for the removal of synthetic dyes from contaminated water. The purpose of this article is to provide a comprehensive literature review of the performance of adsorption process in removing synthetic dyes from water and wastewater by using bentonites and its composites. This study assesses the removal data compare from recent research relating to various dyes during the adsorption process. The paper discusses removal efficiencies, thermodynamics and reaction kinetics. Bentonites are anticipated to have significant potential for comprehensive application to wastewater treatment in the near future. Various challenges encountered in using bentonites and its composite are highlighted and a number of future prospects for the bentonites based adsorbents are proposed.

Inorganic-polymer nanocomposites are of significant interest for emerging materials due to their improved properties and unique combination of properties. Poly (methylmethacrylate) (PMMA)/montmorillonite (MMT) nanocomposites were prepared by in situ suspension polymerization with dodecylamine used as MMT-modifier. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to characterize the structures of the nanocomposites. Cytotoxicity test, hemolysis test, acute systemic toxicity test, oral mucous membrane irritation test, guinea-pig maximization test and mouse bone-marrow micronucleus test were used to evaluate the biocompatibility of PMMA/MMT nanocomposites. The results indicated that an exfoliated nanocomposite was achieved, and the resulting nanocomposites exhibited excellent biocompatibility as denture base material and had potential application in dental materials.

This study focuses on the MCM-41 material (Mobil composition of Matter). The MCM-41
nanomaterial presents higher physical properties such as pore sizes, surface areas and
pore volumes. This material is usually synthesized by using laboratory reagents as silicate
sources and aluminium source. These laboratory reagents are still expensive and toxic for
large scale production. The main aim of this work is to resolve this problem and to replace
these expensive laboratory reagents by more cost effective ones. The volclay and Algerian
bentonite low-cost mass clay materials are used as silicate and acuminate sources
separately by adopting an alkaline fusion process to extract both silicon and aluminium
(1 kg of silicium and aluminium from volclay and Algerian bentonite cost around 0.03 and
0.01 s whereas the same amount of silicon from ludox and aluminium from sodium
aluminates cost around 350 s). The synthesis of MCM-41 from bentonite was carried out
by the hydrothermal method using the supernatants of bentonite (in the form of sodium
silicate and sodium aluminate). On the basis of the data obtained from powder X-ray
diffraction (XRD), transmission electron microscopy (TEM) and N2 adsorption and
desorption, the results revealed that the properties of MCM-41 synthesized from Algerian
bentonite and volclay separately depend on both elemental composition and mineral
phase contents of the used bentonite. Pure and highly ordered hexagonal mesoporous
MCM-41 with uniform pore sizes and a high specific surface area have been successfully
synthesized without any phases which exist in natural bentonite. The Algerian bentonite
was chosen because of its low cost compared to volclay, another commercial clay source.

The vast deposits of Nigerian bentonite clay have many significant uses in different aspects of industrial fields of which the oil and gas industry is a potential consumer of this clay mineral. In this review article, the key miner-alogical characteristics and rheological properties of these clay deposits in various locations and their related application for drilling mud formulation were comprehensively reviewed. Various research efforts on these bentonite clay deposits over the past couple of years were summarized with some critical comments and analysis. Attention was given to the clay reserve estimates, mineralogy of the clay deposits, chemical modification of the clays, rheological properties of drilling mud formulated from these clays and its suitability for drilling operations. Moreover, future prospects and key problems to be solved regarding the use of Nigerian bentonite deposits for drilling mud formulation were discussed. This review shed new light on both fundamental and practical studies that are concentrated on the use of Nigerian bentonite for drilling mud formulation.

AB ST R ACT : The purpose of this paper was to prepare purified Na-bentonite with improved properties for use in the pharmaceutical industry. Calcium bentonite from the Shagia region of Karak district, Pakistan, was activated with various proportions of sodium carbonate (2, 3, 5 and 8 wt.%) and purified by sedimentation to remove impurities, especially quartz. X-ray diffraction (XRD), and swelling volume confirmed the conversion of raw bentonite to sodium bentonite by using 5% Na 2 CO 3 . The sodium bentonite (K5) obtained by activation met the chemical and microbiological requirements set by the pharmacopeias regarding the toxic trace elemental content (Pb and As), absence of E. coli, total aerobic microbial contents and physicochemical properties such as swelling volume, pH and sedimentation volume. Therefore K5 bentonite could be designated as potentially suitable for pharmaceutical applications. The CEC, surface area, porosity, pH, gel formation and swelling volume indicated that K5 bentonite could be used in the formulation of oral suspension and in topical application.

Limited research is available that evaluates animal productivity from increasing levels of pasture supplementation to dairy confinement-type diets. Two 8-week field studies (fall of 2004, F2004; and spring of 2005, F2005) and an in vitro continuous culture study were conducted to examine animal performance under different combinations of total mixed ration (TMR) feeding and high-quality pasture grazing. Such feeding systems are increasingly referred to as a partial mixed ration (PMR). Cows were assigned to either an all-TMR diet (100T, no access to pasture) or one of the following three PMR diets: 1) 85% TMR-restricted (85T) 2) 70% TMR-restricted (70T) and 3) 55% TMR-restricted (55T). Actual diets during the fall trial became 59% TMR and 41% pasture, 68% TMR and 32% pasture, and 79% TMR and 21% pasture instead of the formulated 55T, 70T, and 85T, respectively. The corresponding actual diets during the spring trial became 65% TMR and 35% pasture, 79% TMR and 21% pasture, and 89% TMR and 11%, respectively. Cows on the PMR diets had access to pasture (annual ryegrass) and grazed as a single group for 7 h/d between a.m. and p.m. milkings. In F2004, the TMR feeding system maximized total dry matter intake (DMI) and milk production, but 4% fat-corrected milk (FCM), milk fat yield and protein yield did not differ among diets. In S2005, FCM was greatest for treatments 85T and 100T, and lowest for treatment 70T, with 55T yielding an intermediate value. Milk fat and protein yields were greatest for treatments 85T and 100T compared with those diets that included the greatest amount of pasture. Greatest DM intake from pasture was associated with the greatest concentration of conjugated linoleic acids (CLA, a group of fatty acids with potent cancer-fighting properties) in milk. Also, concentrations of saturated fatty acids in milk fat were greatest for cows consuming TMR. Gross feed efficiencies (kg FCM per kg DMI) were similar for all diets in F2004, but in S2005, cows consuming PMR exhibited enhanced gross feed efficiencies compared to cows consuming TMR exclusively.

While the solar water disinfection (SODIS) method of treating microbiologically contaminated water at the household level has proven to be effective at reducing incidence of diarrhea, its effectiveness is limited to waters of low turbidity. This study investigates the use of table salt (NaCl) to reduce turbidity in water containing dispersed colloidal clay particles as a means of expanding the user base of SODIS. Jar tests were performed on solutions of a low-activity clay, simulating the general composition of soils of the Vertisol type, which are found in key developing regions. Results show that dispersions exhibited as high as 92% particle removal efficiency. The results of this study suggest that NaCl in combination with as little as 30% bentonite by mass may be used to produce a small-scale jumpstart effect by reducing turbidity to a level suitable for SODIS treatment. Soil type was mapped and overlaid with population estimates in a GIS environment to highlight geographic areas where salt+SODIS may be most viable in the case study of South Sudan. Findings suggest that the NaCl method could expand access to SODIS technology by about 1.56 million people who currently lack access to an improved water source in the case study.

Abstrakt: Článok sa venuje prírodnej jemnozrnnej ílovitej hornine -bentonitu, ktorého ložiská sa nachádzajú na strednom aj východnom Slovensku. Do značnej miery flexibilná štruktúra smektitových minerálov, ktoré predstavujú hlavnú zložku bentonitu ho predurčuje k náročným environmentálnym aplikáciám. Chemickou aktiváciou dochádza k zmenám adsorpčných, mechanických aj štruktúrnych vlastností bentonitu, čo významne rozširuje oblasti jeho využitia.

We investigated the capability of Pepto-Bismol | and its components (Veegum | and bismuth subsalicylate) to sequester bile acids from aqueous solution in vitro and compared it to that of cholestyramine. Through a pH range of 3-9, all substances tested sequestered free and conjugated bile acids in quantities directly related to the concentration of the sequestering agent within the incubation mixture. Veegum was more effective gram for gram than bismuth subsalicylate. Pepto-Bismol, whose sequestering capacity approximated cholestyramine's, absorbed more than either of its components alone. The relationship between Pepto-Bismol's in vitro bile acid binding and its in vivo antidiarrheal properties is unknown.

The interaction between Cd(II) in aqueous solution and two 2:1 expandable clay minerals (i.e., montmorillonite and vermiculite), showing different layer charge, was addressed via batch sorption experiments on powdered clay minerals both untreated and amino acid (cysteine) treated. Reaction products were characterized via X-ray powder diffraction (XRDP), chemical analysis (elemental analysis and atomic absorption spectrophotometry), thermal analysis combined with evolved gasses mass spectrometry (TGA-MSEGA) and synchrotron-based X-ray absorption spectroscopy via extended X-ray absorption fine structure (EXAFS) characterization. Sorption isotherms for Cd(II) in presence of different substrates, shows that Cd(II) uptake depends both on Cd(II) starting concentration and the nature of the substrate. Thermal decomposition of Cd-cysteine treated clay minerals evidences the evolution of H 2 O, H 2 S, NO 2 , SO 2 , and N 2 O 3 . These results are well consistent with XRDP data collected both at room and at increasing temperature and further stress the influence of the substrate, in particular cysteine, on the interlayer. EXAFS studies suggest that Cd(II) coordinates with oxygen atoms, to give monomer complexes or CdO molecules, either on the mineral surface and/or in the interlayer. For Cd-cysteine complexes EXAFS data agree with the existence of Cd-S clusters, thus suggesting a predominant role of the thiol group in the bonding of Cd with the amino acid.

Bu çalışmanın amacı doğal bentonit minerallerinin nikeli adsorplama kabiliyetini karakterize etmektir. Nikel iyonunun potansiyel adsorpsiyonu Langmuir ve Freundlich denklemleri uygulanarak değerlendirilmiştir. Adsorpsiyonun hızlı olduğu ve kısa sürede dengeye ulaştığı gözlenmiştir. Denge adsorplama kapasitesinin başlangıç nikel konsantrasyonuna, bentonit miktarına, sıcaklığa ve temas süresine bağlı olarak değişimi araştırılmıştır. Sonuçlar sulu çözeltilerden metal iyonu giderimi ve geri kazanımında bentonitin uygun bir adsorplayıcı materyal olduğunu göstermiştir.

Numerous studies have established that aflatoxin is a potent developmental toxin in animals. Previous research has demonstrated that a phyllosilicate clay, hydrated sodium calcium aluminosilicate (HSCAS or Novasil™), tightly binds and immobilizes aflatoxins in the gastrointestinal tract of animals and markedly reduces the bioavailability and toxicity of aflatoxin. Our objective in this study was to utilize the pregnant rat as an in vivo model to compare the potential of HSCAS and bentonite to prevent the developmental toxicity of aflatoxin. Aluminosilicates (HSCAS) and bentonite were added to the diet at a level of 0.5% (w/w) and fed to the pregnant rat throughout pregnancy (i.e. days 0-20). Test animals were fed an aflatoxin-contaminated diet (2.5 mg kg ؊1 diet) with or without sorbents during gestation days 6-15. Evaluations of toxicity were performed on day 20. These included maternal (mortality, body weights, feed intake and litter weights), developmental (embryonic resorptions and fetal body weights) and biochemical (ALT, AST and AP) evaluations. Sorbents alone were not toxic and aflatoxin alone resulted in significant maternal and developmental toxicity. Animals treated with phyllosilicate (plus aflatoxin) were comparable to controls following evaluations for resorptions, live fetuses and fetal body weights, as well as biochemical parameters. While bentonite plus aflatoxin resulted in significant reduction in fetal body weight, none of the fetuses from HSCAS or bentonite plus aflatoxin-treated groups had any gross, internal soft tissue or major skeletal malformations.

During the Hadean to early Archean period (4.5-3.5 Ga), the surface of the Earth's crust was predominantly composed of basalt and komatiite lavas. The conditions imposed by the chemical composition of these rocks favoured the crystallization of Fe-Mg clays rather than that of Al-rich ones (montmorillonite). Fe-Mg clays were formed inside chemical microsystems through sea weathering or hydrothermal alteration, and for the most part, through post-magmatic processes. Indeed, at the end of the cooling stage, Fe-Mg clays precipitated directly from the residual liquid which concentrated in the voids remaining in the crystal framework of the mafic-ultramafic lavas. Nontronite-celadonite and chlorite-saponite covered all the solid surfaces (crystals, glass) and are associated with tiny pyroxene and apatite crystals forming the so-called "mesostasis". The mesostasis was scattered in the lava body as micro-settings tens of micrometres wide. Thus, every square metre of basalt or komatiite rocks was punctuated by myriads of clay-rich patches, each of them potentially behaving as a single chemical reactor which could concentrate the organics diluted in the ocean water. Considering the high catalytic potentiality of clays, and particularly those of the Fe-rich ones (electron exchangers), it is probable that large parts of the surface of the young Earth participated in the synthesis of prebiotic molecules during the Hadean to early Archean period through innumerable clay-rich micro-settings in the massive parts and the altered surfaces of komatiite and basaltic lavas. This leads us to suggest that Fe,Mg-clays should be preferred to Al-rich ones (montmorillonite) to conduct experiments for the synthesis and the polymerisation of prebiotic molecules.

Compacted tropical soils have great potential to be used in barriers, once some technical issues are correctly addressed, including low hydraulic conductivity and compatibility to the disposed fluids. This paper involves a laboratorial study of the hydraulic conductivity of mixtures of a tropical soil sample and bentonite and also their compatibility to different chemical solutions. The experimental program consisted of (1) sample characterization, (2) hydraulic conductivity determination using a triaxial cell, and (3) compatibility assessment with different chemical solutions (HNO 3 , NaOH, NaCl, and ethanol) using the modified Atterberg Limits. The characterization results revealed important changes in the index properties of the tropical soil sample as the result of the bentonite addition, especially in the plasticity, cation exchange capacity and free swelling. The hydraulic conductivity, in turn, experimented significant decreasing as the proportions of bentonite and confining pressure increased. The compatibility results showed a significant reduction in the plasticity of the samples when subjected to the chemical solutions, especially for the salt solution. In general terms, the addition of bentonite reduced the compatibility of the samples.

Physical, chemical, and mineralogical characteristics of six bentonites were assessed and related to their elemental release to wine. Extraction essays of bentonites in wine at three pH levels were carried out. The multielemental analysis of bentonites and wines was performed by atomic absorption spectrometry (AAS) and inductively coupled plasma mass spectrometry (ICP-MS). Bentonite addition resulted in significantly higher concentrations of Li,

The scope of the present study was the preparation and characterization of irinotecan nanocomposite beads based on montmorillonite (Mt) and sodium alginate (AL) as drug carriers. After irinotecan (I) incorporation into Mt, the resulting hybrid was compounded with alginate, and I-Mt-AL nanocomposite beads were obtained by ionotropic gelation technique. The structure and surface morphology of the hybrid and composite materials were established by means of X-ray diffraction (XRD), IR spectroscopy (FT-IR), thermal analysis (TG-DTA) and scanning electron microscopy (SEM). Irinotecan incorporation efficiency in Mt and in alginate beads was determined both by UV-vis spectroscopy and thermal analysis and was found to be high. The hybrid and composite materials were tested in vitro in simulated intestinal fluid (pH 7.4, at 37 • C) in order to establish if upon administering the beads at the site of a resected colorectal tumor, the delivery of the drug is sustained and can represent an alternative to the existing systemic chemotherapy. The in vitro drug release test results clearly suggested that Mt, and Mt along with AL were able to control the release of irinotecan by making it sustained, without any burst effect, and by reducing the released amount and the release rate. The nanocomposite beads may be a promising drug delivery system in chemotherapy.

The low biodegradability of many dyes and textile chemicals indicates that biological treatment is not always successful in the treatment of cotton textile wastewater, in terms of color removal. In this study, a specific organic flocculant (Marwichem DEC), powdered activated carbon (PAC), bentonite, activated clay and commercial synthetic inorganic clay (Macrosorb) were directly added into the activated sludge laboratory pilot plant model. Before dosage, the optimum sludge retention time and hydraulic retention time were determined as 30 days and 1.6 days, respectively. The Monod kinetic constants were determined as Y ¼ 0:76 kg MLSS/kg COD, K d ¼ 0:026 1/day, K s ¼ 113:3 mg/L, k ¼ 0:42 1/day and m max ¼ 0:32 kg MLSS/kg COD day. Under these conditions the average COD removal was 94% and color removal was 36%. The addition of these materials did not change COD removal significantly. The most effective materials were found to be DEC and PAC for color removal. While the color removal efficiency for 120 mg/L DEC addition was 78%, it was 65% for 100 mg/L, 77% for 200 mg/L and 86% for 400 mg/L PAC addition.

Cadmium (Cd 2+ ) is a heavy metal that is dispersed throughout the modern environment mainly as a result of pollution from a variety of sources. The aims of the current study were to investigate the efficacy of purified Tunisian montmorillonite clay (TMC) to adsorb Cd, to test the stability of the resulting complex under different conditions in vitro, and to utilize the rat bioassay as an in vivo model to evaluate the protective role of TMC against Cd-induced toxicity and immunodysfunction. In the in vitro study, three concentrations of TMC (0.5, 1.0 and 1.5 g/l aqueous solution) and three concentrations of CdCl 2 (25, 50 and 100 ppm) were tested. The results of the in vitro study showed that TMC had a high capacity of adsorbing Cd at different concentrations tested. The adsorption ranged from 95.7-100% of the available CdCl 2 in aqueous solutions. The complex TMC-Cd was stable at different pHs at 37°C. The in vivo results indicated that treatment with CdCl 2 (2.5 mg/kg BW) for 2 weeks resulted in a significant decrease in triglycerides, total protein, creatinine, creatine kinase, immunoglobulin profile (Ig A and Ig G) and T-cell sub-types (CD3 + , CD4 + , CD8 + and CD56 + ). Whereas, it significantly increase serum level of AST, ALT, LDH and induced degenerative changes in pro-inflammatory cytokines (TNF-α and IL-1). Rats treated with TMC alone (400, 600 and 800 mg/kg BW) were comparable to the control regarding all the tested parameters. The combined treatment of CdCl 2 and TMC at the lowest dose (400 mg/kg BW) showed a significant improvement of all tested parameters. It could be concluded that TMC was effective to protect against Cd hazards at a dose as low as 400 mg/kg BW. These results supported our hypothesis that TMC tightly-bind and immobilized Cd resulted in reduction of metal bioavailability in the gastrointestinal tract.

BACKGROUND: Extranodal natural killer/T-cell lymphoma, nasal type (ENKTL) is a distinct subtype of non-Hodgkin lymphoma in which the upper aerodigestive tract is the most commonly involved site. To date, optimal treatment strategies and prognosis for patients with ENKTL have not been fully defined. METHODS: This prospective study was conducted to evaluate the efficacy and safety profiles of first-line combined gemcitabine, oxaliplatin, and L-asparaginase (GELOX) followed by involved-field radiation therapy for patients with stage IE/IIE ENKTL. The primary endpoints were the complete response rate, the objective response rate, and toxicities. Secondary endpoints were overall survival and progression-free survival. RESULTS: Twenty-seven patients with newly diagnosed ENKTL were enrolled and completed the entire course of treatment. At the end of treatment, the overall response rate was 96.3%, including 20 patients (74.1%) who attained a complete response and 6 patients (22.2%) who attained a partial response. No patients developed disease progression during therapy. Grade 1 and 2 toxicities were frequent during GELOX, but grade 3 and 4 toxicities were few, and no treatment-related deaths occurred. At a median follow-up of 27.37 months, 7 patients (25.9%) experienced disease progression, and 4 of those patients died of disease. The rates of 2-year overall and progression-free survival were both 86%, and patients who attained a complete response at the end of treatment had significantly longer progression-free survival (P ¼ .012) and overall survival (P ¼ .021) than patients who did not attain a complete response. CONCLUSIONS: The current results indicated that GELOX followed by involved-field radiation therapy can be an effective and feasible treatment strategy for patients with stage IE/IIE ENKTL of the upper aerodigestive tract. These results will require further investigation in larger prospective trials. Cancer

Polymer nanocomposites, based on poly(e-caprolactone) (PCL) and organically modified montmorillonite, were prepared by the solution intercalation technique. The thermal stability of the prepared materials was analyzed by thermogravimetric analysis. Investigation of their mechanical properties revealed that incorporation of the high aspect ratio montmorillonite sheets into the matrix significantly enhanced the polymer stiffness without sacrificing its ductility. Fibrous membranes of neat and nanocomposite PCL were fabricated by electrospinning. The effect of the applied voltage, the solution concentration and the clay content of the nanocomposite materials on the final fibrous structure was investigated. The results showed that the introduction of the inorganic filler and the increase in the applied voltage from 7.5 to 15 kV facilitated the formation of fine fibers with fewer bead defects. The presence of nanoclay resulted in narrower fiber size distributions, although the mean fiber diameter was not significantly altered. The increase in the solution concentration led to the formation of more uniform fiber structures and to a slight increase in the mean fiber diameter. Furthermore, the electrospinning process affected significantly the structure of the nanocomposite material by increasing the interlayer spacing of the inorganic mineral.

The current meeting marks authors decade-long collaboration with the Geological Society of America (GSA) in proposing and conducting topical sessions highlighting the importance of undergraduate research involving basic geology and ‘now-a-days’ hot environmental topics since 2004. Topical sessions conducted from 2004-Present, were primarily aimed at opening the door to K12-16 students to sharing their basic geology-and-environmental research as part of experiential learning, comprehension and acquiring critical thinking skills. Through these sessions, well-over 275 students have had the opportunity to present their research at the GSA meetings in the past. Many of the presenters, mostly K9-12 students, either graduated or are now graduating from college have expressed their deep appreciation for having this opportunity made available to them. The current topical session is aligned with GSA’s central thrust of providing training and preparing the next generation's much needed STEM and geoscience workforce in order to meet future challenges of natural resource exploration, management and sustainable environmental planning. It is well-known that undergraduate research experience is vital to geology students and an early involvement in geological research really allows students to measure their strengths and their academic preparation compared to their peers at other institutions at an international convention of such magnitude. From the standpoint of recruitment and retention of geoscience students, such an early experience is also known to work as a catalyst and bring success to many academic institutions. The majority of graduates chose to major in the geosciences at some point during their undergraduate education and this also highlights the importance of undergraduate geoscience courses, particularly stimulating entry level courses, outdoor field and faculty-supported research experience to the recruitment of majors and future graduates. Students who did research and presented at the GSA annual meetings since 2004 reported that such academic experience was deemed to be very useful by their employer since their current job responsibilities require critical thinking skills and in-depth field analyses of geologic data on a regular basis.

Rheological model parameters were determined for bentonite muds treated with two local cassava starches (TMS 98/0581 and M98/0068) and an imported starch. The parameters were that of Power Law, Casson and Herschel-Bulkley models which predict the shear stress-shear strain rate relationships. Physicochemical properties were determined for the starches. Herschel-Bulkley model provided the best correlation with experimental data, while Casson model was next. Correlation between Casson and Herschel models yield stresses was good. The yield stress was found to increase with increase in temperature and behaved differently with the starches. It was found to be highest at 1.0 percent of M98/0068 starch concentration in the bentonite mud system. However, the yield stress did not differ significantly for the mud system with TMS 98/0581 starch concentrations. For the imported starch, the yield stress was highest at 2.0 percent concentration at 80 o F and 120 o F, while it was highest at 0.5 percent at 150 o F and 190 o F. The yield stresses ranged between 3 and 30 Pa for the bentonite starch mud systems investigated. The model parameters predicted the shear stress-shear rate relationships for bentonite-local polymer drilling mud system and supported the utilization of the local cassava starches as drilling fluid additives.

Low cost bentonite clay was chemically modified using magnesium chloride in order to enhance its fluoride removal capacity. The magnesium incorporated bentonite (MB) was characterized by using XRD and SEM techniques. Batch adsorption experiments were conducted to study and optimize various operational parameters such as adsorbent dose, contact time, pH, effect of co-ions and initial fluoride concentration. It was observed that the MB works effectively over wide range of pH and showed a maximum fluoride removal capacity of 2.26 mg g −1 at an initial fluoride concentration of 5 mg L −1 , which is much better than the unmodified bentonite. The experimental data fitted well into Langmuir adsorption isotherm and follows pseudo-first-order kinetics. Thermodynamic study suggests that fluoride adsorption on MB is reasonably spontaneous and an endothermic process. MB showed significantly high fluoride removal in synthetic water as compared to field water. Desorption study of MB suggest that almost all the loaded fluoride was desorbed (∼97%) using 1 M NaOH solution however maximum fluoride removal decreases from 95.47 to 73 (%) after regeneration. From the experimental results, it may be inferred that chemical modification enhances the fluoride removal efficiency of bentonite and it works as an effective adsorbent for defluoridation of water.

Co-adsorption of norfloxacin (Nor) and Cu(II) on montmorillonite at pH 4.5, 7.0 and 9.0 was studied by integrated batch adsorption experiments and extended X-ray absorption fine structure (EXAFS) spectroscopy. Under such pH conditions the dominant species of Nor are cation (Nor + ), zwitterion (Nor ± ), and anion (Nor − ), respectively. Results indicated that Nor sorption decreased with an increase of solution pH. The presence of Cu(II) slightly suppressed the Nor + sorption at pH 4.5, while increased Nor ± and Nor − sorption on montmorillonite at pH 7.0 and 9.0, respectively. In contrast, Nor increased Cu(II) adsorption at pH 4.5, but had little effect on the adsorption of Cu(II) on montmorillonite at pH 7.0 and 9.0. Spectroscopic results showed that, at pH 4.5, Nor + was sorbed on montmorillonite by the formation of outer-sphere montmorillonite-Nor-Cu(II) ternary surface complex. At pH 7.0, montmorillonite-Nor-Cu(II) and montmorillonite-Cu(II)-Nor ternary surface complexes co-exist. At pH 9.0, montmorillonite-Cu(II)-Nor ternary surface complex was likely formed, which was different to Cu(II)(Nor) 2 precipitate of the solution.

Many countries intend to use compacted bentonite as a barrier in their deep geological repositories for nuclear waste. In order to describe and predict hydraulic conductivity or radionuclide transport through the bentonite barrier, fundamental understanding of the microstructure of compacted bentonite is needed. This study examined the interlayer swelling and overall microstructure of Wyoming Bentonite MX-80 and the corresponding homo-ionic Na + and Ca 2 + forms, using XRD with samples saturated under confined swelling conditions and free swelling conditions. For the samples saturated under confined conditions, the interparticle, or so-called free or external porosity was estimated by comparing the experimental interlayer distances obtained from one-dimensional XRD profile fitting against the maximum interlayer distances possible for the corresponding water content. The results showed that interlayer porosity dominated total porosity, irrespective of water content, and that the interparticle porosity was lower than previously reported in the literature. At compactions relevant for the saturated bentonite barrier (1.4-1.8 g/cm 3 ), the interparticle porosity was estimated to ≤3%.

Four organic-modified clays based on a SWy-2 montmorillonite were prepared by embedding ammonium organic derivatives with different chelating functionalities (-NH 2 , -COOH, -SH or -CS 2 ) in the interlayer space of montmorillonite. Organic molecules such as (a) hexamethylenediamine, (b) 2-(dimethylamino)ethenethiol, (c) 5-aminovaleric acid and (d) hexamethylenediamine-dithiocarbamate were used for the clay modification in order to study the effect of the chelating functionality on heavy metal ions binding from aqueous solutions. The organoclays were characterized by powder X-ray diffraction (XRD), infrared (FTIR) and NMR spectroscopies. The experimental data showed that the organic molecules are intercalated into the interlamelar space with the long dimension parallel to the clay sheets. Their sorbing properties were evaluated for the removal of heavy metals, Pb, Cd and Zn, from aqueous solutions as a function of the pH. When compared with the unmodified SWy-2 montmorillonite, the modified clays show significant improvement in terms of sorbing selectivity as well as of metal loading capacity. The fit to adsorption data by a Surface Complexation Model shows that the intercalated molecules act as specific binding sites in the clay. These contribute additional sorption capacity which is additive to the variable charge edge-sites of the clay in competition with the permanent charge sites. (Y. Deligiannakis). heavy metals. Moreover, due to their abundance in soil systems, their high specific surface area and exchange capacity, clay minerals such as montmorillonite play a significant role in determining the availability and transport of metals species in soil and sediments .

Novel photo-Fenton catalysts were prepared by immobilizing iron species on commercial bentonite plates via two methods: (1) ion exchange reaction (Fe 3+ vs. Na + ) by aqueous suspension powder-clay/ FeCl 3 followed by plate preparation, and (2) forced hydrolysis of Fe(NO 3 ) 3 onto a prefabricated clay plate. The last method led to a more photo-active Fe-oxide/bentonite plate. This material allowed, at a nonadjusted initial pH of 5.5 and in the presence of H 2 O 2 , the total degradation of resorcinol and 55% mineralization in 80 and 100 min of irradiation, respectively. The reached degradation percentages were correlated to the presence of dissolved iron, demonstrating that in these processes, the homogeneous photo-Fenton reactions were mainly responsible for the resorcinol elimination.

A formalism for double structure hydromechanical coupled modelling of aggregated unsaturated soils has been developed. Independent coupled hydromechanical models are considered for each structural level, including independent measures of macromechanical and micromechanical effective stresses. The models are linked using a coupling function to obtain the global response. The individual components have been selected to represent the behaviour of compacted expansive clays. The macrostructural mechanical model is based on the existing hypoplastic model for unsaturated soils. Hydromechanical coupling at each structural level is efficiently achieved by linking the effective stress formulation with the water retention model. An essential component of the model is representation of microstructural swelling. It is demonstrated that its calibration on wetting induced expansion measured in oedometric (mechanical) tests leads to a correct global hydraulic response, providing a supporting argument for the adopted coupling approach. An interesting consequence of the model formulation is that it does not suffer from volumetric rachetting, which is often regarded as one of the main drawbacks of hypoplasticity. The proposed model has a small number of material parameters. Its predictive capabilities have been confirmed by simulation of comprehensive experimental data set on compacted Boom clay.

In this study, anaerobic digestion was carried out along with bentonite addition to avoid ammonia accumulation, which significantly inhibits methane production. To make better use of bentonite, calci-nations were applied for modification. Chicken manure was anaerobically digested for 75 days at 35 ± 1 C in lab-scale sequencing batch reactors. Better performance in methane production and process stability was observed in reactors treated with bentonite, compared to those without bentonite. Among all treatments, the maximum increase of 41% in cumulative methane was found with the treatment where bentonite thermally modified at 300 C was applied. The treatment also revealed stable variation of pH, total ammonia nitrogen (TAN), and free NH 3 contents. In addition, adsorption capacity of bentonite to TAN was enhanced significantly with thermal modification as well, the TAN concentration reduction was improved by 5%e12% compared to natural bentonite.