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bentonite clay

Ellen Besseling, Joris T K Quik, Muzhi Sun, Albert A Koelmans
Riverine transport to the marine environment is an important pathway for microplastic. However, information on fate and transport of nano- and microplastic in freshwater systems is lacking. Here we present scenario studies on the fate and transport of nano-to millimetre sized spherical particles like microbeads (100 nm-10 mm) with a state of the art spatiotemporally resolved hydrological model. The model accounts for advective transport, homo- and heteroaggregation, sedimentation-resuspension, polymer degradation, presence of biofilm and burial...
October 12, 2016: Environmental Pollution
Claudia Joseph, Jens Mibus, Paul Trepte, Christa Müller, Vinzenz Brendler, Dan M Park, Yongqin Jiao, Annie B Kersting, Mavrik Zavarin
As a contribution to the safety assessment of nuclear waste repositories, U(VI) diffusion through the potential buffer material MX-80 bentonite was investigated at three clay dry densities over six years. Synthetic MX-80 model pore water was used as background electrolyte. Speciation calculations showed that Ca2UO2(CO3)3(aq) was the main U(VI) species. The in- and out-diffusion of U(VI) was investigated separately. U(VI) diffused about 3mm, 1.5mm, and 1mm into the clay plug at ρ=1.3, 1.6, and 1.9g/cm(3), respectively...
October 11, 2016: Science of the Total Environment
Seong-Hwan Park, Juil Kim, Dongwook Kim, Yuseok Moon
Deoxynivalenol (DON), the most prevalent mycotoxin worldwide, leads to economic losses for animal food production. Swine is a most sensitive domestic animal to DON due to rapid absorption and low detoxification by gut microbiota. Specifically, DON can severely damage pig intestinal tissue by disrupting the intestinal barrier and inducing inflammatory responses. We evaluated the effects of several mycotoxin detoxifiers including bentonites, yeast cell wall components, and mixture-typed detoxifier composed of mineral, microorganisms, and phytogenic substances on DON-insulted intestinal barrier and pro-inflammatory responses using in vitro porcine enterocyte culture model...
October 10, 2016: Toxicology in Vitro: An International Journal Published in Association with BIBRA
N Rodella, M Pasquali, A Zacco, F Bilo, L Borgese, N Bontempi, G Tomasoni, L E Depero, E Bontempi
A sustainable economy can be achieved only by assessing processes finalized to optimize the use of resources. Waste can be a relevant source of energy thanks to energy-from-waste processes. Concerns regarding the toxic fly ashes can be solved by transforming them into resource as recycled materials. The commitment to recycle is driven by the need to conserve natural resources, reduce imports of raw materials, save landfill space and reduce pollution. A new method to stabilize fly ash from Municipal Solid Waste Incinerator (MSWI) at room temperature has been developed thanks to COSMOS-RICE LIFE+ project (www...
September 2016: Heliyon
M Ferhat, S Kadouche, N Drouiche, K Messaoudi, B Messaoudi, H Lounici
Evaluation of modified Algerian clay as mineral adsorbent was done for its adsorbing capacity on copper (Cu) and Zinc (Zn) cations. The results obtained show a rapid kinetic adsorption for both metals (less than 2 h) following the pseudo-second order model with high elimination rates of 67.2 and 61.8% for Cu and Zn respectively. The adsorption isotherms analyzed with Langmuir model revealed a correlation with the experimental values. While the use of obtained chitosan at room temperature, as flocculent coagulant, accelerates the decantation of the colloidal particles in suspension generated after adsorption process...
December 2016: Chemosphere
Krzysztof Bobrowski, Konrad Skotnicki, Tomasz Szreder
The most important contributions of radiation chemistry to some selected technological issues related to water-cooled reactors, reprocessing of spent nuclear fuel and high-level radioactive wastes, and fuel evolution during final radioactive waste disposal are highlighted. Chemical reactions occurring at the operating temperatures and pressures of reactors and involving primary transients and stable products from water radiolysis are presented and discussed in terms of the kinetic parameters and radiation chemical yields...
October 2016: Top Curr Chem (J)
I O Ntwampe, F B Waanders, J R Bunt
The physicochemical treatment was employed to treat acid mine drainage (AMD) in the removal of turbid materials using clay only (exp A) and a combination of clay, FeCl3 and Mg(OH)2 (exp B) to form a polymer. A 5 g sample of clay (bentonite) was added to 1.2 L of AMD and treated in a jar test at 250 rpm for 2 min and reduced to 100 rpm for 10 min. A 200 mL sub-sample from the 1.2 L mother liquor was poured into five 500 mL glass beakers, and 20 mL dosages of a polymer of 0.1 M Fe(3+) in (FeCl3) and 0.1 M Mg(2+) in (Mg(OH)2) was added to the beakers...
2016: Water Science and Technology: a Journal of the International Association on Water Pollution Research
Bhabananda Biswas, Binoy Sarkar, Asit Mandal, Ravi Naidu
Bioremediation of polycyclic aromatic hydrocarbons (PAHs) is extremely challenging when they coexist with heavy metals. This constrain has led to adsorption-based techniques that help immobilize the metals and reduce toxicity. However, the adsorbents can also non-selectively bind the organic compounds, which reduces their bioavailability. In this study we developed a surface-engineered organoclay (Arquad(®) 2HT-75-bentonite-palmitic acid) which enhanced bacterial proliferation and adsorbed cadmium, but elevated phenanthrene bioavailability...
November 1, 2016: Water Research
Laurence N Warr, André Friese, Florian Schwarz, Frieder Schauer, Ralph J Portier, Laura M Basirico, Gregory M Olson
Adding clay to marine oil pollution represents a promising approach to enhance bacterial hydrocarbon degradation in nutrient poor waters. In this study, three types of regionally available clays (Ca-bentonite, Fuller's Earth and kaolin) were tested to stimulate the biodegradation of source and weathered oil collected from the Deepwater Horizon spill. The weathered oil showed little biodegradation prior to experimentation and was extensively degraded by bacteria in the laboratory in a similar way as the alkane-rich source oil...
November 2016: Chemosphere
Venkatrajan Gopalakannan, Soodamani Periyasamy, Natrayasamy Viswanathan
Biocomposites were synthesized by dispersing bentonite (Bent) clay in a biopolymer namely alginate (Alg) and cross-linked with bi (Ca(2+)), tri (Ce(3+)) and tetravalent (Zr(4+)) metal ions viz., Ca@AlgBent, Ce@AlgBent and Zr@AlgBent composites respectively. The synthesized biocomposites were characterized by various instrumental techniques like FTIR, SEM and EDAX. Cr(VI) sorption capacities (SCs) of the biocomposites Ca@AlgBent, Ce@AlgBent and Zr@AlgBent were examined by batch process. Various adsorption influencing factors viz...
October 20, 2016: Carbohydrate Polymers
M R Redding, R Lewis, T Kearton, O Smith
The key to better nutrient efficiency is to simultaneously improve uptake and decrease losses. This study sought to achieve this balance using sorbent additions and manure nutrients (spent poultry litter; SL) compared with results obtained using conventional sources (Conv; urea nitrogen, N; and phosphate-phosphorus; P). Two experiments were conducted. Firstly, a phosphorus pot trial involving two soils (sandy and clay) based on a factorial design (Digitaria eriantha/Pennisetum clandestinum). Subsequently, a factorial N and P field trial was conducted on the clay soil (D...
November 1, 2016: Science of the Total Environment
Derya Ayral-Cinar, Margarita Otero-Diaz, Avery H Demond
There has been concern regarding the possible attack of clays in aquitards, slurry walls and landfill liners by dense nonaqueous phase liquid (DNAPL) wastes, resulting in cracking. Despite the fact that a reduction in basal spacing in sodium smectitic clay materials has been linked to cracking, no plausible mechanism by which this reduction occurs in contact with waste DNAPLs has been formulated. To elucidate a mechanism, screening studies were conducted that showed that the combination of an anionic surfactant (AOT), a nonionic surfactant (TritonX-100) and a chlorinated solvent, tetrachloroethylene (PCE), could replicate the basal spacing reduction and cracking behavior of water-saturated bentonite caused by two waste DNAPLs obtained from the field...
September 2016: Chemosphere
E Alhajji, M S Al-Masri, H Khalily, B E Naoum, H S Khalil, A Nashawati
The sorption of radium 226 ((226)Ra) on different clay materials (bentonite, illite and a mixture of bentonite-illite) was studied. Clay materials are used in the construction of disposal pits for technically enhanced naturally occurring radioactive materials (TENORM) wastes (i.e., contaminated soil and sludge) generated by the oil and gas industry operations. Experimental conditions (pH, clay materials quantity, and activity concentrations of (226)Ra) were changed in order to determine the optimal state for adsorption of (226)Ra...
August 2016: Bulletin of Environmental Contamination and Toxicology
Hongbin Yin, Ming Kong, Meixiang Han, Chengxin Fan
Modified clay-based solid-phase phosphorous (P) sorbents are increasingly used as lake geoengineering materials for lake eutrophication control. However, some still dispute the feasibility of using these materials to control internal P loading from shallow eutrophic lakes. The lack of information about P behavior while undergoing frequent sediment resuspension greatly inhibits the modified minerals' use. In this study, a sediment resuspension generating system was used to simulate the effect of both moderate winds (5...
June 13, 2016: Environmental Pollution
Janaína Nones, Jader Nones, Anicleto Poli, Andrea Gonçalves Trentin, Humberto Gracher Riella, Nivaldo Cabral Kuhnen
Bentonite clays exhibit high adsorptive capacity for contaminants, including aflatoxin B1 (AFB1), a mycotoxin responsible for causing severe toxicity in several species including pigs, poultry and man. Organophilic treatments is known to increase the adsorption capacity of bentonites, and the primary aim of this study was to evaluate the ability of Brazilian bentonite and two organic salts - benzalkonium chloride (BAC) and cetyltrimethylammonium bromide (CTAB) to adsorb AFB1. For this end, 2(2) factorial designs were used in order to analyze if BAC or CTAB was able to increase AFB1 adsorption when submitted in different temperature and concentration...
September 1, 2016: Colloids and Surfaces. B, Biointerfaces
I M Ogunade, K G Arriola, Y Jiang, J P Driver, C R Staples, A T Adesogan
This study examined whether adding 3 mycotoxin-sequestering agents to diets contaminated with aflatoxin B1 (AFB1) would reduce milk aflatoxin M1 (AFM1) concentration, and improve the performance and alter immune status of dairy cows. Fifteen lactating dairy cows were used in an experiment with an incomplete crossover design including four 28-d periods. Treatments included a control diet (C), a toxin diet (T; 1,725µg of AFB1/head per day; 75µg/kg), and diets containing the toxin and 20g/head per day of a proprietary mixture of Saccharomyces cerevisiae fermentation product containing a low (SEQ1) or high (SEQ2) dose of a chlorophyll-based additive, or a low dose of the chlorophyll-based additive and sodium bentonite clay (SEQ3)...
August 2016: Journal of Dairy Science
Paola Mura, Francesca Maestrelli, Carola Aguzzi, César Viseras
A combined approach based on drug complexation with cyclodextrins, and complex entrapment in nanoclays has been investigated, to join in a single delivery system the benefits of these carriers and potentiate their ability to improve the dissolution properties of oxaprozin (OXA), a poorly water-soluble anti-inflammatory drug. Based on previous studies, randomly methylated ß-cyclodextrin (RAMEB) was chosen as the most effective cyclodextrin for OXA complexation. Adsorption equilibrium studies performed on three different clays (sepiolite, attapulgite, bentonite) allowed selection of sepiolite (SV) for its greater adsorption power towards OXA...
July 25, 2016: International Journal of Pharmaceutics
Marzieh Taghipour, Mohsen Jalali
In this study, batch experiments were conducted to investigate the effects of nanoparticles (NPs) (MgO, ZnO, TiO2) and clay minerals (bentonite, zeolite) on the release of chromium (Cr) from leather factory waste (LFW) and LFW treated soil using organic acids. Chromium release from all treatments was studied in the presence of citric acid, oxalic acid and CaCl2 solutions. The results showed that, in all treatments, organic acids released more Cr than inorganic salt (CaCl2). The release of Cr by citric acid was higher than that by oxalic acid...
July 2016: Chemosphere
N Contreras Olivares, M C Díaz-Nava, M Solache-Ríos
The sorption processes of red 5 (R5) and yellow 5 (Y5) dyes by iron modified and sodium bentonite in aqueous solutions was evaluated. The modified clay was prepared, conditioned and characterized. The sodium clay did not remove any of either dye. The sorption kinetics and isotherms of R5 and Y5 dyes by iron modified clay were determined. The maximum removal percentages achieved were 97% and 98% for R5 and Y5, respectively, and a contact time of 72 h; the experimental data were best adjusted to Ho model. The isotherms of both dyes were best adjusted to the Langmuir model and the maximum adsorption capacities of the modified clay were 11...
2016: Water Science and Technology: a Journal of the International Association on Water Pollution Research
Jayabrata Maity, Samit Kumar Ray
Composite hydrogels were prepared by in situ incorporation of a natural macromolecule guar gum and nano sized bentonite clay in an acrylic network during copolymerization of acrylic acid, N,N-methylenebisacrylamide (MBA) and hydroxyethyl methacrlylate (HEMA) in water. The structure of the hydrogels was characterized and the hydrogels showing the best results in mechanical and swelling properties were used for the removal of low (5-50mg/L) and high (100-800mg/L) concentration of Cr(VI) ions from water. The composite hydrogel showed a high removal of 97...
August 2016: International Journal of Biological Macromolecules
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