Bentonite Dosage Research Articles

Optimization of arsenic ions adsorption and removal from hospitals wastewater by nano-bentonite using central composite design

Nano-bentonite was prepared from Iraqi bentonite clay by the co-precipitation method and the adsorption technique was used under many factors to determine the adsorption capacity (q) and removal% of arsenic ions (As) from the hospital's wastewater. The optimization process was conducted to choose the optimal parameters for adsorption and removal of arsenic by applying the central composite design (CCD) to form a surface response with three levels and three central points. Three operational factors were optimized of pH (5.5), bentonite dose (100 mg/L), and contact time (5 min), as well as developing the regression quadratic equations to assess the important models for the arsenate adsorbing and removing which dependent on the correlation factor (R2) that was (q = 0.9998) and (removal% = 0.9709), the adsorption isotherm results were fit well with the Langmuir model (R2 = 0.972), and the adsorption kinetics results were perfect with the second model (R2 = 0.951). We conclude that bentonite clay is a good adsorbent that can be used in the processes of removing toxic ions from water.

Active adsorption performance of planetary ball milled Saudi Arabian bentonite clay for the removal of copper ions from aqueous solution

We report the role of local bentonite clay in the removal of Cu2+ ions from aqueous solution. The fine bentonite clay powder was analysed by XRD, FTIR, SEM and DLS analysis techniques. Further, the adsorption experiments were carried out by varying many factors such as weight and size of bentonite clay, residence time, pH of the solution, stirring rate, temperature, and flow rate. The optimum conditions for effective removal of Cu2+ ions was 1 g dose of bentonite and 63 μm size of bentonite, 50 minutes of residence time and 50 °C temperature at pH 3 with a flow rate of 1 L/min. The data fitted well the Freundlich model and a maximum adsorption capacity of 61.72 mg/g has been obtained. The value of Gibbs free energy changes (), enthalpy changes () and entropy changes (S°) were found to be , and , respectively.

Local Cuban bentonite clay as potential low-cost adsorbent for shark liver oil pool purification

Context: The shark liver of the species Ginglimostoma cirratun, Carcharhinus longimanus, and Carcharhinus falciformis, captured in the north-central coast of Cuba are a source of oil, that when extracted it must be purified due to its bad smell, taste and the amount of impurities it has. Aims: To evaluate the purification of the shark liver oil (SLO) pool of species Ginglimostoma cirratun, Carcharhinus longimanus, and Carcharhinus falciformis, by Cuban bentonite clay. Methods: The effects of bentonite dose, contact time and speed rate were studied using the 23 factorial designs. The parameters are evaluated in the experiment design: acidity value, p-anisidine value, peroxide value, Totox value and Bleaching performance. Response Surface Methodology modeling techniques were applied to model the process and their performance and predictive capabilities of the response (purification efficiency) was also examined. Results: The experiments showed that the oil is suitable for consumption after the purification process. The best treatment, which could reduce the impurities in the SLO pool, was a treatment with bentonite dose at 80 g/L, time at 15 min, and speed rate at 250 rpm. Cuban bentonite clay is a promising adsorbent candidate for the removal of impurities of the SLO. Conclusions: The local Cuban bentonite clay can be used as potential low-cost adsorbent for shark liver oil pool purification, as showed the experiments.

Lethal Dose of Calcium Bentonite in Wistar Rats

Background: Calcium bentonite is a type of clay produced by a devitrification of volcanic ash which is often used as a traditional medicine to absorb toxins and waste products of metabolism. The aim of this study was to determine the lethal dose of calcium bentonite in Wistar rats to explore its toxicity level and safe use.Methods: Fifty male and female Wistar rats were randomly divided into five groups for each sex. The control group was given 5 cc aquadest whereas the other four groups received calcium bentonite solution of 50 mg/kgBW, 300 mg/kgBW, 2,000 mg/kgBW, and 5,000 mg/kgBW, respectively, at a single dose. The weight was observed for up to 7 days and analyzed using the unpaired t-test and Mann-Whitney test. The death rate was calculated using the probit analysis. Median lethal dose results were then classified according to Loomis Criteria. Results: No deaths occurred at the highest dose, suggesting that the median lethal dose value of calcium bentonite was >5,000 mg/kgBW. No weight loss occurred due to the administration of calcium bentonite and a significant increase in the body weight was even observed in the male rat group. Interestingly, a significant decrease was found in the female rats group when compared to the control group.Conclusions: Calcium bentonite is classified as a practically non-toxic material with a median lethal dose of over 5,000 mg/kgBW.

Adsorption of Tetracycline Antibiotic from Aqueous solutions using Natural Iraqi Bentonite

Natural Iraqi bentonite was employed in this study as inexpensive adsorbent for the removal of Tetracycline antibiotic from aqueous solutions. The removal of about 90% of the Tetracycline was achieved under the optimum adsorption conditions of 2 h equilibrium time, 0.2 g bentonite dose, 20 mg/L initial Tetracycline concentration, and at a pH between 6 and 7. The thermodynamic investigation was carried out at various temperatures ranging between 20-40 °C. The resulted thermodynamic parameters emphasize a decrease of the randomness, an exothermic, and a spontaneous nature of the adsorption process arising from the negative values of the entropy change, the enthalpy change, and the Gibbs free energy change, respectively. The kinetic studies showed that the pseudo-second order model could fulfill a better fit of the experimental data, and more than one process would influenced the diffusion of tetracycline from the solution into the bentonite. The Isotherm studies reveals that Langmuir model provided a best fit to the isotherm curve, with a maximum adsorption capacity of 23.69 mg g-1. The results suggest that Natural Iraqi bentonite can be used as a cost-effective adsorbent for the removal of Tetracycline from aqueous mediums.

Chemical, Physical, and Sensory Effects of the Use of Bentonite at Different Stages of the Production of Traditional Sparkling Wines.

The addition of bentonite to wine to eliminate unstable haze-forming proteins and as a riddling adjuvant in the remuage is not selective, and other important molecules are lost in this process. The moment of the addition of bentonite is a key factor. Volatile profile (SPME-GC-MS), foam characteristics (Mosalux method), and sensory analyses were performed to study the effect of the distribution of the dosage of bentonite for stabilization of the wine among the addition on the base wine before the tirage (50%, 75%, and 100% bentonite dosage) and during the tirage (addition of the remaining dosage for each case). Results showed that the addition of 50% of the bentonite to the base wine (before the tirage) resulted in sparkling wines with the lowest quantity of volatile compounds, mainly esters and norisoprenoids. No significant differences were found among the sparkling wines after 9 months of aging in relation to foam properties measured by Mosalux, although higher foamability and crown’s persistence were perceived in the sparkling wines with the addition of 75% and 100% of the bentonite dosage in sensory trials. The results of this study suggested that the amount of bentonite added as a fining agent in the tirage had greater effects than during the addition of this agent in the base wine.

Moment of Bentonite Addition, Co-Addition of Tannins, and Bentonite Type Affect the Differential Affinity of Pathogenesis-Related Grape Proteins towards Bentonite during Fermentation.

To test the effect of the moment of bentonite addition, co-addition of tannins, and bentonite type on the differential affinity of pathogenesis-related (PR) proteins towards bentonite during grape must fermentation, three separate experiments were set up. PR proteins in the obtained wines were analyzed by reverse phase and size exclusion high-performance liquid chromatography (HPLC). The most significant reduction of bentonite dose and PR protein concentration was achieved by applying bentonite in the last third of fermentation. Particular thaumatin-like proteins (TLP) and proteins with lower molecular mass in general were more affected than others, while TLPs were more affected than chitinases. Exogenous enological tannins interacted with particular PR proteins, mostly TLPs, and lowered the total bentonite dose required. The combined application of tannins and bentonite in fermentation removed more PR proteins than bentonite alone, but did not achieve a synergistic effect in reducing the bentonite dose. Various bentonite types, including two Na-activated bentonites, an activated Na bentonite with specifically adsorbed silica, and an active Na-Ca bentonite, exhibited differential affinity towards different PR proteins. The results obtained could be used in developing wine fining protocols which combine treatments with complementary affinity for adsorption and removal of PR proteins, and in this way achieve greater efficiency of bentonite fining by reducing its total dose, which is of significant interest to the wine industry.

Chemical, physical, and sensory attributes of Sauvignon blanc wine fermented in different kinds of vessels

The use of vessels that are alternative to conventional cylindrical stainless steel tanks and traditional oak barrels during winemaking has increased in recent years. Examples of these alternative vessels include fashionable, oval-shaped vessels or classic clay jars. A Sauvignon blanc grape juice was fermented (by using a commercial starter made of two different commercial strains from Oenobrands/Anchor Oenology) in four different vessels in triplicate: 150 L cylindrical stainless steel tanks (as a control), 980 L polyethylene oval-shaped tanks, 450 L concrete oval-shaped tanks, and 225 L clay jars. Afterwards, the finished wines were chemically, physically, and sensorially characterized. The wine fermented in the concrete vessels had a slightly higher pH (about 0.05 pH units) and lower titratable acidity (about 0.20 g/L of tartaric acid equivalents) value than those of the control wine. The wine fermented in the clay jars showed the lowest amounts of C10, C12, and C14 volatile compounds (containing about 69% of those compounds when compared with the control wine). The wine fermented in the polyethylene oval-shaped tanks was described as the most bitter, while the wine fermented in the concrete oval-shaped tanks was described as the least fruity when wines were sensory analyzed by a panel of 11 wine experts. The wines fermented in the oval-shaped vessels showed lower volatile acidity (about 25% reduction of volatile acidity when compared with wines fermented in non-oval-shaped vessels), higher residual sugars (wines fermented in the oval-shaped vessels contained about 1.7 g/L of residual sugars, while wines fermented in the non-oval-shaped vessels contained about 1.4 g/L of residual sugars), higher phosphorous content (with an increase of about 12%), and required a lower dose of bentonite to achieve protein stability (about 64 g/hL of bentonite) than those of the other wines (about 75 g/hL of bentonite). Even though some statistical differences were found among wines fermented in the different vessels, it should be noted that the differences were very small. Thus, it seems that the impact of the fermentation vessel type on final wine features is lower than expected.

Zeta potential of inorganic fine particle-Na-bentonite binder mixture systems.

The zeta potential of single and multi-inorganic fine particle mixtures (hematite and gangues, i.e., SiO2 + Al2 O3 ) with Na-bentonite was investigated to understand and properly control the mineral surface properties relevant to pelletization of low-grade fine iron ores. The zeta potential of hematite-bentonite mixture showed more negative charge up to 1wt.% bentonite dosage and became constant. In the multiparticle mixture systems with bentonite, the SiO2 amount in the system controlled the changes in zeta potential due to its high negative charge (-54.9mV at natural pH) and the bentonite attachment on its surface based on the electrostatic interaction while Al2 O3 had no effect due to its negligible surface charge (-1.6mV at natural pH). This article reports the new insight into the characterization of surface chemistry of inorganic/mineral mixture systems to understand their surface charge properties in relation to fine mineral particle processing, and to show a direction toward the elucidation of particle dispersion/aggregation mechanism in complex ore systems aiming for their beneficiations.

Organomodified nanoclays induce less inflammation, acute phase response, and genotoxicity than pristine nanoclays in mice lungs

Surface modification by different quaternary ammonium compounds (QAC) makes nanoclays more compatible with various polymeric matrices, thereby expanding their potential applications. The growing industrial use of nanoclays could potentially pose a health risk for workers. Here, we assessed how surface modification of nanoclays modulates their pulmonary toxicity. An in vitro screening of the unmodified nanoclay Bentonite (montmorillonite) and four organomodified nanoclays (ONC); coated with various QAC, including benzalkonium chloride (BAC), guided the selection of the materials for the in vivo study. Mice were exposed via a single intratracheal instillation to 18, 54, and 162 µg of unmodified Bentonite or dialkyldimethyl-ammonium-coated ONC (NanofilSE3000), or to 6, 18, and 54 µg of a BAC-coated ONC (Nanofil9), and followed for one, 3, or 28 days. All materials induced dose- and time-dependent responses in the exposed mice. However, all doses of Bentonite induced larger, but reversible, inflammation (BAL neutrophils) and acute phase response (Saa3 gene expression in lung) than the two ONC. Similarly, highest levels of DNA strand breaks were found in BAL cells of mice exposed to Bentonite 1 day post-exposure. A significant increase of DNA strand breaks was detected also for NanofilSE3000, 3 days post-exposure. Only mice exposed to Bentonite showed increased Tgf-β gene expression in lung, biomarker of pro-fibrotic processes and hepatic extravasation, 3 days post-exposure. This study indicates that Bentonite treatment with some QAC changes main physical-chemical properties, including shape and surface area, and may decrease their pulmonary toxicity in exposed mice.

THE PARTICULARITIES OF THE CLARIFICATION PROCESS WITH BENTONITE OF WHITE WINE VINEGAR

In this study, the physicochemical properties of Italian and German bentonites were evaluated, including the physicochemical characteristics of white wine vinegar. Once established, the optimal clarification regime and its physical parameters were determined. After establishing the optimized sedimentation parameters, the influence of different doses of bentonite on the physicochemical and organoleptic characteristics of the analyzed vinegar was investigated. With this was determined the influence of the different contact periods of vinegar with bentonite, on the physicochemical parameters of clarified wine vinegar. Thus, for the Italian bentonite, the optimal conditions for the clarification process were: dose of bentonite — 2.03 g · 25L -1 , time — 45 min, temperature — 20 ± 1 °C, stirring time — 60 s, centrifugation time — 3 min and spin speed of 300 min-1. Moreover, when using the German bentonite, the optimal parameters were: bentonite dose — 1.96 g · L -1 , contact time — 45 min, temperature — 20 ± 1 °C, stirring time — 300 s, centrifugation time — 3 min and spin speed of 300 min -1 . Finally, the sensory analysis of wine vinegar was performed and it was established, from the data, which of the analyzed bentonites has properties that are more efficient on the clarification process.

Wine Thermosensitive Proteins Adsorb First and Better on Bentonite during Fining: Practical Implications and Proposition of Alternative Heat Tests

Bentonite fining is the most popular treatment used to remove proteins in white and rosé wines. The usual heat test used to adjust the bentonite dose consists of heating the wine during 30 min at 80 °C. At this temperature, all of the proteins are unfolded, and this can lead to an overestimation of the dose. We have shown that proteins adsorb on bentonite in a specific order and, more importantly, that the proteins responsible for haze formation adsorb first. Fluorescence spectroscopy showed that this is due to the structural properties of proteins, which can be classified as hard and soft proteins. Alternative heat tests were performed at a lower temperature (40 °C) and showed a better correlation with accelerated aging. These tests were also less dependent upon the wine pH.

The role of high-grade Bentonite powder in coccidiosis and its effects on feed conversion ratio and blood parameters in broiler chicken.

The aim of this study was to evaluate the effect of high doses of calcium bentonite on the blood parameters, anticoccidial activity and intestinal histology of broiler chickens. Three undred and sixty one-day old broilers were distributed into three treatments (T+VE, T-VE, TB )with three replicates. Amprolium was added to the feed of the positive control group, calcium bentonite powder was added to the TB group, and nothing was added to the feed of the T-VE group. Coccidiosis was induced on day 14, the birds were kept until day 49, measurements of the different variables started from week 3, blood samples were collected via wing vein, and fecal oocysts were counted from the intestinal contents of each individual bird using the McMaster techni- que. A decrease in feed consumption, body weight gain and conversion ratio was noticed in the calcium bentonite group. Broilers in the calcium bentonite group (TB ) and negative control group (T-VE ) showed clinical signs of coccidiosis (blood in feces) and the number of oocysts in feces increased with time. Histopathological examinations of the affected caeca also demonstrated excessive tissue damage, hemorrhage, the presence of clusters of large schizonts and merozoites in the tissue, and coccidian oocysts in the lumen. Feed conversion was highest in the T+VE group.

The performance of Alizarin impregnated bentonite for the displacement of some heavy metals ions from the wet phosphoric acid

ABSTRACT The removal of Pb2+, Ni2+, Cd2+, Zn2+, Cu2+, and UO2 2+ ions from wet phosphoric acid were employed to gain the purified acid by the low-cost adsorbent that prepared by activation of natural bentonite followed by impregnation with Alizarin. The adsorbent was characterized by X-ray diffraction, scanning electron microscopy – energy dispersive X-ray spectroscopy, and Fourier transforms infrared spectroscopy techniques. The adsorption experiments were applied for the removal of studied metals ions from phosphoric acid. The best conditions for H3PO4 are 5 M/L H3PO4 concentrations (29% P2O5), 150 mg.L−1 initial concentrations of each metal ions, and 50 mg Alizarin impregnated activated bentonite dose for 60 min contact time at room temperature. Whereas the optimum removal conditions of the studied metals ions from wet phosphoric acid (29% P2O5) were 60 min contact time, 150 mg adsorbent amount, and 50 mL acid volume at room temperature. The adsorption-desorption procedures were repeated by several times, till the desorption efficiencies were reduced from 98.5 to 83.0% for Alizarin impregnated activated bentonite after five successive cycles, it was indicated that the excellent adsorption stability for removal of Pb2+, Ni2+, Cd2+, Zn2+, Cu2+, and UO2 2+ on the studied adsorbent.

Composite of chitosan and Bentonite as coagulant agents in removing turbidity from Ismailia canal as water treatment plant.

The use of chemical coagulants is not suitable due to health and economic considerations. In the last time, the use of natural additives that are biocompatible, are biodegradable, have low toxicity and are from renewable resources attracted the attention of many types of research due to their high ability to retain different pollutants from wastewaters. Ismaili Canal is one of the most important tributaries of the River Nile in Egypt. This study successfully proved the effectiveness of the combination of chitosan and bentonite as a coagulating agent in the (Ismailia canal) for the wastewater treatment process. Chitosan and Bentonite were known as coagulant agents, thus were used in this study. Laboratory tests were conducted to test the water quality based on turbidity values and basic drinking water parameters. Chitosan and Bentonite can be applied on (Ismailia canal) resulting in a turbidity removal 97.7% at 30 minutes. The optimal dosage of bentonite(clay) combined with chitosan(polymer) was 5 and 1mg/L at PH=7.4.

Miscible displacement of copper in soil columns using increasing doses of bentonite

The objective of this research was to evaluate the effect of applying increasing doses of bentonite to the soil on the miscible displacement of copper, quantifying copper retention in the soil and elimination by leachate, in order to prevent potential risks for environmental contamination. The experiment was conducted on a laboratory using leaching columns filled by a sandy texture soil contaminated with 250 mg kg-1 of copper each. The experimental design was a completely randomized with four doses of bentonite, 0; 30; 60 and 90 t ha-1, and three replications totalizing 12 experimental units. The leaching columns were made with PVC tubes constituted by three rings, overlaid and joined with silicone glue. Each column was filled with 4 kg of Cu contaminated soil, mixed with the doses of bentonite specified by the treatments (0; 45; 90 and 135 g). After the filling of the columns, each one received five pore volumes of distillated water, and left to percolation under a steady state flux. After percolation, the Cu concentrations in the soil and in the percolate, the breakthrough curves of the flux density and the percolation velocity were determined. The results were submitted to variance analyses using the F test and regressions. The increasing doses of bentonite until 90 t ha-1 increased the adsorption of copper by the soil, reducing the percolation of this element around 72%. Bentonite application to the soil decreased the flux density and flux velocity of the copper percolation, diminishing the potential risks for the environment contamination.

Enhancement of performance and stability of anaerobic co-digestion of waste activated sludge and kitchen waste by using bentonite.

There are large amounts of waste activated sludge (WAS) and kitchen waste (KW) produced every year in China. It has been confirmed that anaerobic co-digestion is an effective method to solve this problem. The targets of the present study were optimizing the digestive performances and clearing of the mechanism of bentonite addition by adding bentonite into digestive system. Group M (WAS: KW = 1:2, based on VS) presented higher cumulative methane yield (CMY), where the CMY increased from 19.8 to 36.3 mL/g VS with the bentonite dosage from 0 to 2 g/g VS. After bentonite addition, the lag phase of every digester presented an obvious decrease from 15.1 to 1.4 d. Furthermore, and the moderating effects on microbial community by bentonite. The addition of bentonite improved methane production, and it can also reduce the lag phase of methane production in co-digestion. What's more, bentonite addition increased the speed of pH recovery from 4.2–4.8 to normal level (7.0–8.0) and thus enhanced the system stability. The conclusion of this study can be used to guide practical engineering.

Soft computing based formulations for slump, compressive strength, and elastic modulus of bentonite plastic concrete

Utilizing bentonite in composites such as concrete mixture is one of the practical approaches for adsorption of heavy metals. The mixture of bentonite and normal concrete is known as bentonite plastic concrete (BPC). This type of concrete is commonly utilized as the material of cutoff walls under earth dams with the aim of minimizing or preventing water seepage. Plastic concrete should possess high workability and consistency since it is poured into trenches by tremie pipe; this fact highlights the importance of predicting the slump of BPC. Different strength parameters of BPC such as compressive strength and elastic modulus can be predicted by utilizing prediction models. This information is exceedingly useful for modifying mixing design of BPC which results in reducing the cost and time of constructing a project. Consequently, it is vital to propose models that can predict the parameters of BPC with high precision. In this research, 158, 169, and 119 data records respectively for slump, compressive strength of cubic samples (f'c,cube), and elastic modulus (Ec) of BPC were collected from literature in order to propose prediction models. Three soft computing methods of artificial neural network (ANN), Multivariate adaptive regression splines (MARS), and M5 model tree (M5Tree) were utilized and compared in this paper. Then, parametric studies were conducted to study the effect of different variables such as silty clay addition, bentonite dosage, water content, and curing time on the outputs (i.e., slump, f'c,cube, and Ec). Results indicate that ANN models are more accurate than the other models for prediction of all three parameters. The water variable produces the greatest effect on the slump of BPC while the sand variable has the least influence. In addition, both for f'c,cube and Ec models, variables of cement and curing time have the maximum and minimum impact on the outputs, respectively.

Bentonite fining during fermentation reduces the dosage required and exhibits significant side-effects on phenols, free and bound aromas, and sensory quality of white wine

To test the effects of bentonite addition at various stages of fermentation, five Malvazija istarska white grape must vinification treatments were performed with 100 g/hL of bentonite added in clear juice, at the beginning, in the middle, and at the end of fermentation, while control was fermented without bentonite. Phenols and free and bound volatile aromas were determined by HPLC-DAD and SPE-GC-MS. Wines were evaluated sensorially. Fining during fermentation reduced the total bentonite dose required, and was most effective near the end of fermentation with the reduction of 16% and 21%, depending on the protein stability test. All treated wines preserved more hydroxycinnamoyltartaric acids with respect to control. The side-effect of these treatments on varietal aromas was moderate, but enhanced the preservation of key fermentation volatiles in relation to control, and exhibited positive sensory effects. It was concluded that bentonite added during fermentation may positively affect wine quantity and quality.

Influence of Bentonite and MB4 on the Chemical Characteristics of an Oxisol

The growing concern with the quality of life and the environment, due to the degradation of natural resources and their contamination, mainly with agrochemicals, led to the emergence of a sustainable or alternative agriculture. The objective of this study was to evaluate the effect of the addition of increasing doses of bentonite and MB4 on the availability of nutrients to the soil. The experiment consisted of a 4 × 4 factorial, bentonite doses (0, 30, 60 and 90 t⋅ha−1) and MB4 doses (0, 3, 6 and 9 t⋅ha−1) with three replications. The soil mixtures with the treatments were conditioned in the plastic pots, incubated for 90 days in a greenhouse, and chemically analyzed. Data were submitted to analysis of variance and comparison of means by the Tukey test. Increasing doses of bentonite and MB4 promoted an increase in the calcium (Ca), magnesium (Mg) in the soil sample either alone or the mixture of two factors, except for the mixture of the Ca Mg doses. Increasing doses of bentonite increased the cation exchange capacity of the soil, favoring the availability of nutrients in the soil. The increasing doses of MB4 favored the increase of the pH values and, consequently, decreased the soil potential acidity values for the applied bentonite doses. On the other hand, these treatments decreased the cation exchange capacity of the soil.