Qiryat Shemona, Israel
Qiryat Shemona, Israel

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Ganigar R.,Hebrew University of Jerusalem | Ganigar R.,Tel-Hai Academic College | Rytwo G.,Tel-Hai Academic College | Rytwo G.,Galilee Technological Center | And 4 more authors.
Applied Clay Science | Year: 2010

Phenolic compounds pose health and environmental hazards. This study focused on two priority pollutants, trinitrophenol (picric acid-PA) and trichlorophenol (TCP), which were detected in rivers, lakes and water reservoirs. Polycation-clay mineral nanocomposites were characterized and designed for the removal of these pollutants from water. The adsorption kinetics of polydiallyl dimethylammonium chloride (PDADMAC) and poly-4-vinylpyridine-co-styrene (PVPcoS) on montmorillonite (MMT) was significantly faster (2-4. h) than on sepiolite (3-4. days), which was explained by the latter's porous structure. Consequently, polycation-MMT composites were chosen to test pollutant adsorption. Both PA (anionic) and TCP (non-ionic) showed higher affinity to the less charged polycation PVPcoS (40% of the monomers charged) than to the highly charged polycation PDADMAC. However, PA removal by the PVPcoS-MMT composite was nearly complete whereas TCP removal reached 40 to 60% of the added amounts. The adsorption isotherms of the pollutants suggested that the binding to PVPcoS-MMT was driven mainly by hydrophobic interactions, but also by electrostatic interactions in the case of PA. Differences were also seen in the binding kinetics of PA and TCP to dried and wet composites. The hydration properties of PA enhanced its binding to wet composites whereas the hydrophobic properties of TCP enhanced its binding to dehydrated composites. The results of this study emphasize the importance of better understanding pollutant-adsorbent interactions to enable more efficient tailoring of polymer-clay mineral composites for water treatment. © 2010 Elsevier B.V.

Rytwo G.,Galilée College | Rytwo G.,Galilee Technological Center | Mendelovits A.,Galilée College | Mendelovits A.,Hebrew University of Jerusalem | And 4 more authors.
Applied Clay Science | Year: 2010

Adsorption of proteins to clay minerals is widely studied, mostly in agricultural issues, due to its importance in soil. The poultry industry experiences an increasing need for new generations of effective vaccines, requiring minimal handling of bird during administration. Among the problems of vaccination with genetically engineered vaccines is low immunogenicity. Therefore, the development of effective adjuvants for vaccination is a central task. In addition, oral administration of vaccines is more convenient and economic for the poultry industry. The modified heat-labile eteroxin (LT) protein was found to be a safe and immunogenic adjuvant, and showed the ability to enhance immune responses against an antigen co-administered with, for example-the viral protein 2 (VP2). As a model of a possible combination for an oral administrated vaccine, adsorption of VP2 and LT on SWy-2 montmorillonite and on an organo-montmorillonite (berberine adsorbed on SWy-2) were tested. Results of this multidisciplinary study, which combines methods used in clay mineral studies with biological assays, prove feasibility to attach two vaccine-related proteins to organoclay mineral particles, yielding close vicinity between the proteins that may lead to an immune response via the monosialoganglioside (GM1) receptor. Such complexes may be used as vaccine carriers to stimulate desired immune responses. © 2010 Elsevier B.V.

Rytwo G.,Galilée College | Rytwo G.,Galilee Technological Center | Rettig A.,Galilée College | Gonen Y.,Galilée College | Gonen Y.,Hebrew University of Jerusalem
Applied Clay Science | Year: 2011

There is an urgent need to process specific agricultural effluents that are unsuitable for discharge into standard sewage treatment plants. The nature and complexity of such effluents constituents vary widely, therefore, environmentally safe, cost-effective solutions to these wastewaters must be found. Colloidal particles that tend to clog filtering devices are one of the problems in such effluents. Wineries, for example, are producers of wastewater characterized by high contents of organic material and large variations in the seasonal flow production. Destabilization of the colloidal dispersion, inducing flocculation of large amount of dispersed matter, might result in an effective pretreatment that can lower total dispersed solids (usually incorrectly denoted as "Total Suspended Solids" - TSS), turbidity, and even part of the chemical oxygen demand (COD). By performing such a pretreatment, following treatments (as aeration, filtration, etc.) would be more efficient, reducing environmental hazard. Clay minerals have been widely used for the pretreatment of effluents, and combination of clay minerals and organic compounds efficiently removed colloidal particles in several types of industrial effluents. This study focuses on a pretreatment that combines sepiolite modified with crystal violet, and raw sepiolite. The rational of the approach is that dispersed organic material in the effluents would be bound by the modified sepiolite, yielding large particles which settle. The results demonstrated that this technique can effectively reduce dispersed solids in winery effluents. The use of cycles based on a two-step reactor led to two orders of magnitude reduction of TSS, even after several cycles. Based on the results, colloidal particles in 8000. L of effluent might be removed with 1. kg of organo-sepiolite, and 1. kg of raw sepiolite. © 2010 Elsevier B.V.

Rytwo G.,Galilée College | Rytwo G.,Galilee Technological Center | Varman H.,Galilée College | Varman H.,Hebrew University of Jerusalem | And 6 more authors.
Applied Clay Science | Year: 2011

There is interest in studying interactions between organic modifiers and raw commercial clays aiming the production of low-cost "organoclays". In this study we report the interaction between berberine - a monovalent organic cation - and three commercial bentonites and a Turkish zeolite. The Turkish zeolite exhibited adsorption at values of 5-10% of the cation exchange capacity (CEC) with no neutralization of the particles. Adsorption of the organo-cation on Egyptian bentonite, Volclay KWK and Pure-Flo B80, was above the CEC of the bentonites, yielding neutral and even slightly positively charged particles. Electron microscopy and X-ray diffraction results showed expansion of the basal spacing of the smectite. Such low-cost organo-bentonites might be suitable for environmental applications as removal of pollutants, drug and pesticides delivery, or water treatment. Application in turbidity reduction of industrial effluents is demonstrated. © 2010 Elsevier B.V.

Bluvshtein N.,Hebrew University of Jerusalem | Bluvshtein N.,Galilée College | Mahrer Y.,Hebrew University of Jerusalem | Sandler A.,Geological Survey of Israel | And 2 more authors.
Atmospheric Environment | Year: 2011

Rock quarrying and processing is a source of coarse and fine particulate matter, which is transported by wind to the quarry surroundings and may have an environmental impact. The current study evaluated the possible contribution of dust from such a pollution source, a limestone quarry in north Israel, during the dry summer season. Accumulated dust and total suspended particulate matter were collected following an analysis of the prevailing synoptic conditions to evaluate the background dust, its origin and expected mineralogical and chemical properties. We performed comparative gravimetric, chemical and mineralogical analyses between sites lying upwind and downwind of the limestone quarry and defined the background dust and its origin. During the summer season under the Persian trough synoptic system, mineral dust in the research area was mostly composed of material similar to the local lithosphere, mainly carbonate rocks, and thus to the quarried rock. High concentrations of some trace metals, on the other hand, were related to remote sources, as has been documented previously for the Persian trough synoptic condition. Gravimetric analysis found 300 to 400% more accumulated dust and up to 400% more total suspended particulate matter about 1. km downwind versus upwind of the quarry. Mineralogical and chemical analyses of the dust samples, and of the quarried rock, revealed that the downwind site is enriched, relative to the upwind site, in the major component of the quarried rock-calcite, and that both sites are enriched in the major components of background dust. © 2010 Elsevier Ltd.

Henkin Z.,Newe Ya'ar Research Center | Seligman N.G.,Galilee Technological Center
Plant Biosystems | Year: 2011

Ephemeral grasslands follow fire in Mediterranean batha communities on phosphorus-deficient terra-rossa soils, but successional processes rapidly restore shrub dominance. In an experiment aimed at reducing the rate of successional change and extending the period of grassland dominance, phosphorus was applied to a shrub community dominated by Sarcopoterium spinosum. This was done once in 1988, immediately after a fire. Two years later, the regenerating shrubs were treated with herbicide. Subsequently, the vegetation in the treatments was monitored for 20 consecutive years. The vegetation was undisturbed during the winter/spring growing season but was grazed during the dry summer of each year by beef cattle, which were given ad libitum access to poultry litter to supplement the nitrogen deficiency of the dry herbaceous vegetation. In control plots, the shrubs returned to pre-fire dominance within 5 years. With phosphorus and herbicide, shrub dominance was delayed by the vigorous herbaceous vegetation for more than 20 years. The practical feasibility of this management option depends on the relation between costs and benefits. A preliminary economic analysis based on the longterm experiment and a case study allowed us to define the conditions under which control of successional shrub encroachment can be economically feasible. © 2011 Società Botanica Italiana.

Brosh A.,Newe Ya'ar Research Center | Henkin Z.,Newe Ya'ar Research Center | Henkin Z.,Israel Agricultural Research Organization | Ungar E.D.,Israel Agricultural Research Organization | And 5 more authors.
Journal of Animal Science | Year: 2010

We determined the energy costs associated with the activities of beef cows grazing on Mediterranean foothill rangeland covered with herbaceous vegetation. Our central aim was to compare the energy cost coefficients obtained in this study, using relatively large plots, with those obtained in a previous study conducted on smaller plots. Measurements were performed in 3 seasons: in March on nursing cows grazing a 135-ha plot of high quality herbage (11.4 MJ/kg of ME), and in May and September on nonlactating cows grazing a 78-ha plot of low quality herbage (6.2 MJ/kg of ME). Poultry litter manure was given as a supplement in September. Stocking rates on the respective plots were 2.25 and 1.95 ha/cow; 5, 5, and 7 cows were monitored in the respective months. Heat production was determined by continuous monitoring of the heart rate and measurement of the oxygen consumption per heartbeat. Animal location was tracked with global positioning system (GPS) collars equipped with motion sensors. Activity was determined for 5-min intervals using suitable calibration equations. Horizontal and vertical distances traveled were computed by integrating GPS data and plot maps in a geographic information system. Three models were used to estimate the energy cost coefficients of engaging in a given activity and locomotion. Total daily heat production ranged from 644 (September) to 1,014 kJ·kg of BW-0.75·d-1 (March; P = 0.04). Estimates of the energy cost coefficients for activity states (kJ·kg of BW-0.75·d-1) ranged from 42.7 to 46.2 for standing, from 84.5 to 92.4 for walking idle, and from 89.4 to 103.2 for grazing; those for locomotion (kJ·kg of BW-0.75·d-1·km-1) ranged from 2.8 to 2.9 for horizontal locomotion and from 21.4 to 27.9 for vertical locomotion. Estimated cost coefficients of standing, grazing, and horizontal locomotion derived in the present study from animals on relatively larger plots were similar to those of the previous study based on data from smaller plots, but the energy costs of walking idle and of vertical locomotion were greater in the present study than in the previous one. The differences found are associated with the fact that cows in the present study walked for longer periods of time and traveled longer distances in single uninterrupted bouts of locomotion than those in the previous study. © 2010 American Society of Animal Science.

Henkin Z.,Newe Ya'ar Research Center | Ungar E.D.,Israel Agricultural Research Organization | Dolev A.,Galilee Technological Center
Rangeland Journal | Year: 2012

The objective of this study was to determine the role of terrain in the foraging behaviour of beef cows grazing hilly Mediterranean grasslands. The study was conducted in eastern Galilee, Israel, during 2002 and 2003 on two similar 28-ha paddocks encompassing distinct terrain types in terms of slope and rock cover. The paddocks were continuously grazed by cows from mid winter (JanuaryFebruary) to autumn (September) at two different stocking rates (1.1 and 0.56 cows per ha). From early June to the end of September the cows were offered poultry litter ad libitum as a supplementary feed. The location and activity of cows were monitored with GPS collars during four periods in each year: early spring (FebruaryMarch), late spring (April), early summer (June) and late summer (August). Herbage mass was measured at the beginning of each of these periods. During early and late spring, when the herbage mass and nutritive value of herbage were high, the cows spent 4050% of the day grazing, with peaks in the morning and afternoon. In the dry, late summer period (August), grazing of the herbage was 2022% of the day, occurring only in the early morning and late afternoon with sporadic bouts of grazing until midnight. In all periods the cows tended to prefer the flattest terrain sites. As the herbage mass declined to 10001500kg ha-1, the exploitation of the pasture during grazing became increasingly similar among the different terrains. Even on relatively small paddocks, where grazing pressure was close to the full potential of the site, free-ranging cows tended to prefer less sloping and rocky sites. It is concluded that the grazing strategy of beef cows is determined by the interaction between terrain, the distribution of the herbage mass and the nutritive value of the herbage. As herbage mass declines during the growing season, the distribution of grazing becomes uniform and all terrain types are exploited. © Australian Rangeland Society 2012.

Rytwo G.,Galilée College | Rytwo G.,Galilee Technological Center | Lavi R.,Galilee Technological Center | Rytwo Y.,Galilee Technological Center | And 3 more authors.
Science of the Total Environment | Year: 2013

Highly polluted effluents from olive mills and wineries, among others, are unsuitable for discharge into standard sewage-treatment plants due to the large amounts of organic and suspended matter. Efficiency of all management practices for such effluents depends on an effective pretreatment that lowers the amount of suspended solids. Such pretreatments are usually based on three separate stages, taking a total of 2 to 6. h: coagulation-neutralizing the colloids, flocculation-aggregating the colloids into larger particles, and separation via filtration or decanting. Previous studies have presented the concept of coagoflocculation based on the use of clay-polymer nanocomposites. This process adds a higher density clay particle to the flocs, accelerating the process to between 15 and 60. min. This study examined suitable nanocomposites based on different clays and polymers. The charge of the compounds increased proportionally to the polymer-to-clay ratio. X-ray diffraction (XRD) measurements indicated that in sepiolite-based nanocomposites there is no change in the structure of the mineral, whereas in smectite-based nanocomposites, the polymer intercalates between the clay layers and increases the spacing depending on the polymer-to-clay ratio. Efficiency of the coagoflocculation process was studied with a dispersion analyzer. Sequential addition of olive mill or winery effluents with a boosting dose of nanocomposites may yield a very efficient and rapid clarification pretreatment. © 2012 Elsevier B.V.

Konig T.N.,Galilée College | Konig T.N.,Galilee Technological Center | Shulami S.,Galilée College | Rytwo G.,Galilée College | Rytwo G.,Galilee Technological Center
Applied Clay Science | Year: 2012

Use of conventional pretreatment for pickle industry brine wastewater (BWW) is not efficient due to its low pH, high salt content and high concentrations of suspended and organic matter. The goal of this work was to inspect different clay minerals and berberine-based organoclays as possible flocculants to reduce BWW turbidity, total and volatile suspended solids (TSS and VSS, respectively) and chemical oxygen demand (COD). Preliminary flocculation tests showed Volclay KWK (VO) and Pangel C150 (C150) to be the best candidates for a two-step sedimentation test, with the highest TSS, VSS, COD and turbidity reductions. Adsorption isotherms showed that VO and C150 adsorb different amounts of berberine, and therefore a common reference line for organoclay preparation was based on their point of zero charge. Two-step sedimentation tests showed that combining VO-berberine and VO (organoclay and raw clay, respectively) better reduces the inspected parameters than two steps with VO, whereas the opposite held true for C150-berberine and C150. Out of all treatments, two steps using C150 showed the best TSS, COD and turbidity reduction. C150 appears to be an excellent candidate for a future multistage flocculation and sedimentation processes for BWW treatment. © 2012 Elsevier B.V.

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