Application Of Bentonite Research Articles

SERAPAN N, P, DAN K PADA JAGUNG MADURA-3 DI TANAH LEMPUNG LIAT BERPASIR DIAMELIORASI BIOCHAR DAN BENTONIT-TERAKTIVASI ASAM

Sandy clay loam soil in Bangkalan is a soil with a low content of nutrients, organic matter, bases, and cation exchange capacity (CEC), which inhibits the growth of maize plants. In addition, the nature of the soil causes the fertilizer to become more soluble, and the absorption of nutrients, especially potassium, is low. One of the efforts to increase potassium uptake in sandy loam soils is applying biochar and acid-activated bentonite. This study aimed to examine the effect of adding biochar and acid-activated bentonite to the nutrient uptake of maize plants in the sandy soil of Bangkalan. Biochar was prepared from maize cobs by the Kon-Tiki method; bentonite was activated by physical (200 oC) and chemical (1N H2SO4) methods. The greenhouse experiment was carried out using a completely randomized design with biochar (B) and acid-activated bentonite (T) as treatments, each with three levels, namely 0, 5, 10 t ha-1 and three replications. Soil analysis performed included pH, organic carbon, CEC and exchangeable bases, while plant tissue analysis included leaf height and area. The results showed that the combination of biochar and acid-activated bentonite significantly increased soil pH, soil exchangeable K, soil exchangeable Na, and leaf area of maize plants. A single application of biochar significantly increased soil organic C and maize plant height. The application of acid-activated bentonite significantly increased the CEC of sandy loam soils.

The Effect of Bentonite Application on Dry Matter Yield and Mineral Nutritional Elements of Durum and Bread Wheats in Salt Conditions

Abiyotik stres etmenlerinden olan tuzluluk, bitki gelişmesinde gerilemeye ve önemli oranda ürün kaybına neden olmaktadır. Deneme, sera koşullarında tesadüf parselleri deneme desenine göre saksı denemesi şeklinde yürütülmüştür. Denemede, tuzlu koşullarda (4000 mg NaCl kg-1 toprak) ve artan bentonit (%0, %5 ve %10) dozları uygulanmıştır. Denemede bir ekmeklik (Vittorio) ve bir makarnalık (Cesare) buğday çeşitleri yetiştirilmiştir. Elde edilen sonuçlara göre, tuzlu koşullarda artan dozlarda bentonit uygulamaları sonucunda ekmeklik ve makarnalık buğdayların kuru madde verimlerinin arttığı belirlenmiştir. Ekmeklik buğdayların makarnalık buğdaylara göre daha fazla kuru madde ürettiği saptanmıştır. En fazla kuru madde verimi ekmeklik buğdayda %10 bentonit uygulamasından 150 mg bitki-1 olarak belirlenmiştir. Tuzlu koşullarda ve artan (%0, %5 ve %10 toprak) dozlarda bentonit uygulamaları sonucunda, ekmeklik ve makarnalık buğday çeşitleri kontrol saksılarıyla kıyaslandığında; yeşil aksam fosfor, potasyum, demir, bakır ve çinko konsantrasyonunda artış meydana gelirken kalsiyum, magnezyum, sodyum, mangan ve bor konsantrasyonları ise azalmalar meydana gelmiştir. Özellikle kumlu topraklarda orta derecede tuzluluk sorunu olan alanlara bentonit uygulamasının buğdayda mineral beslenme problemlerinin bazılarının giderilmesine katkısı olacağından %5 düzeyinde bentonit uygulanmasını önerebiliriz.

Parameter Study of Purification of Low- to Medium-Grade Bentonite from Keerjian

In this paper, low- to medium-grade bentonite derived in Keerjian of Toksun county were characterized. A method combined by chemical dispersion and high-speed centrifugation was used for the purification of the bentonite. Absorption of methylene blue and X-ray diffraction analysis were used to evaluate the effect of purification methods. The result showed that the optimal slurry solid-liquid ratio, dispersant amount, sedimentation time, centrifugal speed, and time of centrifugation was 1:8, 1.2% of the bentonite mass, 24h, 2000 r/min, and 5 min, respectively. The investigation provided experimental evidence for the better development and application of bentonite in this mining area.

Study on Wet Purification of Keerjian Bentonite

The application potential of bentonite is closely related to the content of montmorillonite from it, and the purification of bentonite is conducive to expanding its industrial application. In this paper, purification method of Keerjian bentonite with low to medium grade were studied systematically. A comparative study of natural settlement, chemical dispersion and high-speed centrifugation was carried out. In addition, one-factor experiment and orthogonal experiment on a compound purification method, chemical dispersion following by high-speed centrifugation, were conducted. According to the experimental result, the optimal parameters of the compound purification, namely slurry ratio 1:8, dispersant amount 1.2% and soaking time 24h, were obtained. This study solved the problem of low utilization level and low purification efficiency, which shade light in the application of Keerjian bentonite with high efficiency and high economic benefits.

Effect of super-absorbent polymer on swelling pressure of compacted bentonite infiltrated by alkaline solutions

The application of bentonite in geological disposal of radioactive waste is still under evaluation, especially concerning the decreased swelling pressure of pure bentonite exposed to alkaline groundwater. In this paper, in order to improve the chemical resistance of bentonite to alkaline solutions, super-absorbent polymer (SAP), a hydrophilic polymer with much higher swelling ability than that of bentonite, was dry-blended with Gaomiaozi (GMZ) bentonite and compacted into blocks of different dry densities. Swelling pressure of the bentonite-SAP composites infiltrated with deionized water, NaOH and KOH alkaline solutions were tested, accompanied with scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP) and X-ray diffractometer (XRD) tests conducted on the selected specimens. Results showed that, for the specimens hydrated by deionized water, the swelling pressure increased with increasing SAP content, dry density and concentration of NaOH solutions. With increasing concentration of KOH solutions, however, the swelling pressure decreased obviously and tended to undergo a slow long-term degradation. Results of SEM, MIP and XRD indicate that the SAP hydrogels swell extensively to clog the inter-aggregate pores and coat the aggregates (for high density specimens) or montmorillonite stacks (for low density specimens), while do not insert into the interlayer spaces. The swelling pressure was therefore mainly contributed by the crystalline swelling of montmorillonite and the osmotic swelling of SAP. The SAP chains could be associated with the montmorillonite crystallites, protecting them from chemical attack and thus improving the chemical resistance of bentonite to alkaline solutions.

Synthesis, Characterization and Application of Karak Bentonite Clay-Graft-Poly (Acrylamide/Co- Acrylic Acid) Superabsorbent Composite and its Adsorption Study for Selected Heavy Metals

A novel superabsorbent composite (SAC) based on bentonite, acrylamide and acrylic acid was synthesized. The effects of bentonite quantity, initiator content on the grafting degree and on the water absorbency for the samples were studied. Synthesis mechanism, morphology and thermal properties of the SAC were characterized. FTIR results confirmed the presence of acrylamide/ acrylic acid onto bentonite backbone while TGA showed that introduction of 70 % bentonite to polymer increases thermal stability. The SAC was also tested in the removal of heavy metal in aqueous solution where kinetics analyses were performed using Langmuir adsorption isotherm. The optimum adsorption capability of heavy metal ions onto bentonite-based SAC from solution was 92, 48 and 91 % for Pb++, Ni++, and Cu++ respectively. The unique characteristics of these SAC such as its slow-release and water-retention capability, nontoxicity in soil, environmentally friendly and high capacity for the removal of heavy metals might be very valuable in agriculture and environmental studies

The Effect of Ca-Bentonite Aplication on Cadmium Uptake and Shoot Dry Matter of Bread Wheat

Cadmium(Cd) is a non-essential heavy metal that is highly toxic even at very low concentrations. Although Cd is a non-essential trace metal, when reached to high levels in agricultural soils, it can be easily absorbed by plants. Cadmium accumulation in wheat (Triticum aestivum L.) and its subsequent transfer to food chain is an important problem worldwide. Bentonite is a material essentially composed by montmorillonite and related clay minerals of the smectite group. The purpose of this study was to investigate the effects of bentonite (0, 3, 6 and 12%) application on Cd uptake of bread wheat growing in high Cd (0, 5 and 10 mg/kg soil) application. Plants were grown under greenhouse conditions acid soil. The experiment was conducted randomized block design with three replicates. The results revealed that shoot dry weight of bread was significantly increased with increasing doses of bentonite applications. While the dry weight of shoot without bentonite application was 480 mg/plant, it increased approximately 2 fold with 12% bentonite application. Cadmium concentration with the bentonite of control application decreased 4 times from 20.74 ppm to 5.07 ppm with application of 12% bentonite. The results show that Cd toxicity in the shoot was alleviated by bentonite treatment.

Հողի մշակման տարբեր եղանակների և հողաբարելավիչների ազդեցությունը աշնանացան ցորենի ձմեռադիմացկունության և բերքի կառուցվածքային տարրերի վրա

The article presents the results of the studies on the winter resistance, growth, development, and changes in the structural elements of the crop under the influence of different methods of soil cultivation, equivalent amounts of mineral fertilizers, and biohumus and bentonite application dates against their background. The research conducted in the conditions of waterless agriculture in the Fantan community of the Kotayk region revealed that the cultivation of winter wheat in black soils, out of the three tested methods of soil cultivation (no-till, only loosening: 10-12 cm, deep plowing: 22-25 cm), only loosening with soil discing is the most effective, and the best fertilizing technology is the autumn application of bentonite 3 t/ha on the background of mineral fertilizers N60P60K60 or biohumus equivalent to 3.5 t/ha, in which cases the winter resistance of plants increases, an improved environment for the normal growth and development of autumn crops is created and as a result 51.3 - 54.9 c/ha of grain and 98-102 c/ha of straw yield․

Bentonite as a Functional Material Enhancing Phytostabilization of Post-Industrial Contaminated Soils with Heavy Metals.

Growing awareness of the risks posed by pollution of the soil environment is leading to the development of new remediation strategies. The technique of aided phytostabilization, which involves the evaluation of new heavy-metal (HM)-immobilizing amendments, together with appropriately selected plant species, is a challenge for environmental protection and remediation of the soil environment, and seems to be promising. In this study, the suitability of bentonite for the technique of aided phytostabilization of soils contaminated with high HM concentrations was determined, using a mixture of two grass species. The HM contents in the tested plants and in the soil were determined by flame atomic absorption spectrometry. The application of bentonite had a positive effect on the biomass of the tested plants, and resulted in an increase in soil pH. The concentrations of copper, nickel, cadmium, lead and chromium were higher in the roots than in the above-ground parts of the plants, especially when bentonite was applied to the soil. The addition of the analyzed soil additive contributed significantly to a decrease in the levels of zinc, copper, cadmium and nickel in the soil at the end of the experiment. In view of the above, it can be concluded that the use of bentonite in the aided phytostabilization of soils polluted with HMs, is appropriate.

Effect of phosphatidylcholine in bentonite-quetiapine complex on enhancing drug release and oral bioavailability

Bentonite (BT) is a biocompatible clay mineral that has advantageous properties as a pharmaceutical excipient. However, the application of BT in controlled-release oral formulations has been challenging due to incomplete drug release from BT-drug complexes. The objective of this study was to investigate the effect of modifying BT with zwitterionic phosphatidylcholine (PC) to enhance the dissolution of drugs, thereby increasing their oral bioavailability. Quetiapine (QTP) was chosen as a model drug, and the composition of the complex (BT-PC-QTP) was optimized to have the maximum QTP content and increase the total amount of QTP released. The in vitro release study showed that the incorporation of an appropriate amount of PC into BT improved the low release rate of the BT-QTP complex at pH 7.4, while the pH-dependent release property of BT was maintained. In an in vivo pharmacokinetic study in rats, the oral administration of the BT-PC-QTP complex showed significantly higher Cmax and AUC values than the BT-QTP complex. Moreover, BT-PC-QTP showed a 2.4-fold enhancement of oral bioavailability compared to the QTP powder group. The scanning electron microscopy (SEM), powder X-ray diffraction (pXRD), and differential scanning calorimetry (DSC) studies confirmed that the intercalation of PC and QTP into BT resulted in the adsorption of QTP in an amorphous state. The characterization of the nanoparticles generated from the BT-PC-QTP complex supported that PC enhanced the dissolution of QTP by forming nanosized PC particles. Taken together, the modification of BT with PC can be applied in pharmaceutical industry as a platform strategy to control the release of the BT-drug complex and enhance the oral bioavailability of poorly water-soluble drugs.

Evaluation of Bentonite Application for the Abandonment of Deep Geo-energy Wells

Hydrated bentonite is considered an alternative subsurface sealing/plugging material for deep geo-energy wells. However, the knowledge related to this application and the corresponding properties of bentonite is still lacking. This includes the mechanical properties at the interface of bentonite plugs with the adjacent materials (surrounding rock or casing steel) and the mechanical stability of plugs under downhole in-situ conditions. In this work, we performed experiments investigating the interface shear properties and shear strength of a bentonite plug under various settings for deep geo-energy applications, such as hydrocarbon and geothermal wells. The interface’s shear properties against various adjacent materials and fluid conditions were characterized. The influence of chemical exposure, the salinity of the curing fluid, fluid pH, pressure, and temperature on bentonite’s mechanical stability was evaluated in a small- and large-scale setting. The latter was performed using realistic casing sizes and placement methods, relevant for the field application. The experimental results show that the averaged shear strength of the bentonite plug interface is 13.3 kPa and 9.1 kPa when cured in freshwater and seawater, respectively. The increase in strength with increasing curing pressure, temperature, and fluid pH was characterized for the first time. The interfacial properties of cohesion and friction angle vary with different surrounding materials. They are also influenced by the saturating condition and salinity of the saturating fluid. Based on the experimental results, a bentonite plug with a minimum length of 15–43 m placed in casings of 7–5/8″ to 13–3/8″ would be sufficient to meet the necessary criteria of the Dutch regulators as an isolating material for well abandonment.

Calcareous Materials Effectively Reduce the Accumulation of Cd in Potatoes in Acidic Cadmium-Contaminated Farmland Soils in Mining Areas.

The in situ chemical immobilization method reduces the activity of heavy metals in soil by adding chemical amendments. It is widely used in farmland soil with moderate and mild heavy metal pollution due to its high efficiency and economy. However, the effects of different materials depend heavily on environmental factors such as soil texture, properties, and pollution levels. Under the influence of lead–zinc ore smelting and soil acidification, Cd is enriched and highly activated in the soils of northwestern Guizhou, China. Potato is an important economic crop in this region, and its absorption of Cd depends on the availability of Cd in the soil and the distribution of Cd within the plant. In this study, pot experiments were used to compare the effects of lime (LM), apatite (AP), calcite (CA), sepiolite (SP), bentonite (BN), and biochar (BC) on Cd accumulation in potatoes. The results showed that the application of LM (0.4%), AP (1.4%), and CA (0.4%) had a positive effect on soil pH and cations, and that they effectively reduced the availability of Cd in the soil. In contrast, the application of SP, BN, and BC had no significant effect on the soil properties and Cd availability. LM, AP, and CA treatment strongly reduced Cd accumulation in the potato tubers by controlling the total ‘flux’ of Cd into the potato plants. In contrast, the application of SP and BN promoted the migration of Cd from the root to the shoot, while the effect of BC varied by potato genotype. Overall, calcareous materials (LM, CA, and AP) were more applicable in the remediation of Cd-contaminated soils in the study area.

Effect of Some Soil Conditioners on Water-Use Efficacy, Growth, and Yield of Date Palm Siwi Grown in Sandy Soil under Different Irrigation Regimes to Mitigate Climate Change

A field experiment was carried out at Al-Bahariya Oasis, Giza, Egypt, during three successive seasons to find out the effect of application of bentonite (BN) as a natural clay deposit at either 6 or 12 kg/palm tree and humic substances (HS) as organic amendment at either 0.75 or 1.0 L/palm tree incorporated with Bacillus polymyxa (BP) as a biofertilizers at 14 and 28 mL/L rates on growth, yield, and fruit weight of 10-year-old Siwi date palm cv. (Phoenix dectylifera L.). Siwi trees were cultivated in sandy texture soil at a distance of 8 × 8 m and were irrigated with 100%, 85%, and 70% of ET crop. Effects of the previous treatments on growth, date palm crop, soil properties, water relations, water-use efficiency (WUE), and economic return were also studied. The obtained results showed that the mean values of leaf length, leaflet length and width, fruit set%, bunch weight, yield/palm, yield/fed, fruit weight, flesh weight, and fruit pulp weight were increased in response to the different individual and combined treatments used in this study with various significance levels compared to the control treatment means in the studied three seasons. However, the superiority was for combining between amending the sandy soil with either low concentrations of BN (6 kg/tree) + HS (0.75 Liter/tree) + BP (14 mL/L) or high concentrations of BN (12 kg/tree) + HS (1.0 L/tree) + BP (28 mL/L) and irrigation with 85% of ETc water level, as such combinations attained the highest values in most of the mentioned values over both the sole and combined treatments in the studied three seasons. Furthermore, the results indicated that the highest monthly ETc values occurred during June and July months, while the lowest values occurred during December and January months. Additionally, water productivity (WP) increased considerably by reduction of water quantity (70% ETc) associated with soil conditioner treatment (BN.12 kg +HS 1 L + BP. 28 mL/L), and values were 2.17, 2.25, and 2.27 kg fruit/m3 of water irrigation during the growing seasons, respectively. The highest net return was attributed to irrigation with 85% of ETc water level along with the application of soil conditioners at high rates. Accordingly, it is advisable to apply the soil conditioners of bentonite (at 6 or 12 kg/tree) and humic substances (at either 0.75 or 1.0 L/tree) with B. polymyxa (at either 14 or 28 mL/L) plus irrigation with either 85% or 70% of ETc water level to obtain the best growth, highest yield, (WP), and gross return from var. Siwi date palm grown under an oasis agro-system.

Preparation and evaluation of the doxazosin-bentonite composite as a pH-dependent controlled-release oral formulation

Bentonite (BT) is a natural clay mainly composed of montmorillonite which has exchangeable cations in the interlayer space. BT has various advantages as a pharmaceutical excipient for the formulation of drug delivery systems (DDSs), including biocompatibility and unique physicochemical properties (i.e., adsorption and pH-dependent cation exchange). However, previous studies on the application of BT for DDSs were usually limited to the characterization of the in vitro adsorption and release properties. Herein, we prepared and characterized a doxazosin-bentonite (DXBT) composite formulation for controlled oral delivery and then evaluated the pharmacokinetics of doxazosin (DX) in rats. The composition of the DXBT composite was optimized based on the adsorption efficiency and the content of DX in the DXBT composite. The change in morphology was observed by scanning electron microscopy (SEM). Intercalation of amorphous DX between the BT interlayer space was confirmed by powder X-ray diffraction (pXRD). The zeta potential of DXBT composite was higher than BT over the pH range between 1 and 8, and was positive in acidic condition and was changed to negative at pH above 4. The DXBT composite showed pH-dependent in vitro release profiles of DX, and the cumulative release amount at 24 h was higher at pH 7.8 than at pH 1.2 and 7.4 (63.9, 29.3 and 47.8%, respectively). In an in vivo pharmacokinetic study after oral administration in rats, the DXBT composite resulted in a significantly lower peak plasma concentration (Cmax) and longer terminal half-life (t1/2) and mean residence time (MRT) of DX compared to DX solution. Thus, the DXBT composite could be an oral drug delivery platform with pH-dependent controlled-release profiles based on the unique ion-exchange property of BT.

Adsorption of aflatoxin B1 mycotoxins by raw and lyophilized bentonitic clay

• Raw and lyophilized polycationic bentonite for AFB 1 adsorption; • AFB 1 removal capacity above 90% for all studied samples; • Optimal conditions obtained for lower temperature and longer freezing time; • Liophilization does not change the cation exchange and adsorption capacities; Aflatoxin B1 (AFB 1 ) is considered the most toxic mycotoxin with the greatest potential for contamination of animal feed. Among the most promising and practical approaches to reducing aflatoxicosis is the addition of non-nutritive adsorbent materials to contaminated food intended for animal feed, such as natural or modified bentonitic clays. The lyophilization process, when compared to other means of dehydration, maintains the product's integrity and characteristics such as contraction, loss of volatiles, thermal decomposition, enzymatic actions, and protein denaturation. The objective of this work was to evaluate the AFB 1 adsorption capacity by raw bentonite and samples submitted to different lyophilization parameters. Statistical design was applied to identify the best freezing parameter for the lyophilized sample in the adsorption of AFB 1 . Possible structural alterations were evaluated by X-ray fluorescence (FRX), X-ray diffractometry (XRD), BET analysis, moisture content, swelling and cation exchange capacity (CEC). AFB 1 adsorption was carried out applying 0.5% of the sample as anti-mycotoxin additive to gastric juice and intestinal juice by the ELISA enzyme-linked immunosorbent assay and by high-performance liquid chromatography (HPLC). The optimal treatment condition was obtained for 150 g of bentonite and 72 h of freezing for the tested temperature range (−75 °C to −90 °C). After freezing, it was observed a reduction of 46% in moisture content, 47% in surface area and 7.12% in total porosity when compared to the standard material. The removal capacity obtained in vitro assays for AFB 1 was above 90% for all samples at pH 3.0 and pH 6.0, being considered promising values for future applications of bentonite as anti-mycotoxin additive.

Sodium modification of low quality natural bentonite as enhanced lead ion adsorbent

Developing efficient and low-cost adsorbent for removing heavy metal ions from aqueous solution is of great significance for environmental protection. Herein, low quality natural bentonite was purified and sodium-modified to adsorb Pb2+ from the aqueous phase. The effects of initial pH value of the solution, type and amount of the adsorbent, contact time and initial Pb2+ concentration on the adsorption performance of sodium bentonite were systematically studied. The adsorption efficiency of sodium bentonite was significantly better than that of purified bentonite and natural bentonite toward Pb2+. Under the optimum adsorption conditions of pH = 5, adsorbent dosage of 0.2 g, initial Pb2+ concentration of 400 mg/L, and adsorption time of 120 min, sodium bentonite can remove more than 99.94% of Pb2+. Adsorption behavior fitted well with Freundlich isotherm and pseudo-second-order kinetics adsorption equations. Adsorption process was endothermic and feasible. The adsorption pathways of Pb2+ on sodium bentonite are mainly including ion exchange, surface hydroxyl functional group capture, electrostatic attraction and chemical precipitation by CO32- in the pore channel to form PbCO3. This research is anticipated to give technical support for prompting the wider application of bentonite as an adsorbent material.

Responses of Different Submerged Macrophytes to the Application of Lanthanum-Modified Bentonite (LMB): A Mesocosm Study

Lanthanum-modified bentonite (LMB) has remarkable efficacy on eutrophication control, but the reduced bioavailable phosphorus and formed anaerobic horizon from LMB may be harmful to submerged macrophytes. We conducted this study to explore the influence of LMB on Hydrilla verticillata and Vallisneria natans in mixed-species plantings. The concentrations of TP, TDP, SRP, and TDN in the LMB treatments were lower than the Control, but the Chl a concentration in the HLMB treatment (850 g m−2) was higher than the Control by 63%. There were no differences of V. natans growth among the treatments. For H. verticillata, its biomass, RGR, height, branch number, root number, and length in the LLMB treatment (425 g m−2) were lower than the Control by 48%, 22%, 13%, 34%, 33%, and 8%, respectively. In addition, the biomass of H. verticillata was 62%, the RGR was 32%, the height was 19%, the branch number was 52%, the root length was 40%, and the root number was 54% lower in the HLMB treatment than those in the Control. In summary, LMB had negative effects on submerged macrophytes with underdeveloped roots. Submerged macrophytes with more developed roots are preferred when using combined biological–chemical methods for water restoration.

Effect of elemental and bentonite sulphur applications on some mechanical properties of different polyethylene covering materials

ABSTRACT This study investigated the effects of two different chemical products applied to the soil to on some mechanical properties of greenhouse cover materials produced by CO-EX techology with HALS UV and NIQ UV additives over a period of 12 months. The effects of chemical treatments on the covering materials were investigated in fourteen low tunnels under natural weathering conditions during their useful life. Also, the effects of sulphur products on the pH and electrical conductivity (EC) of the soil were investigated. Initial impact resistance of HALS UV and NIQ UV added PE films were determined as 685.0 and 811.7 g, respectively. Impact resistances of HALS UV and NIQ UV added PE films in bentonite sulphur applications decreased by 48.1% and 33.8%, whereas in elemental sulphur applications decreased by 62.0% and 51.6% after 12 months, respectively. Soil pH was reduced by all sulphur treatments in compared to the initial value.

Application of Ethiopian bentonite for water treatment containing zinc

The raw bentonite has low specific surface area and cation exchange potential. Thus, it needs change of its surface properties to increase its adsorption potential. To achieve this aim, the study was conducted by (1) Thermal modification and (2) characterisation, adsorption, isothermal and kinetics study of Ethiopia's bentonite for removal of Zinc. Characterisation of both the raw and thermally treated bentonite clay for specific surface area and cation exchange capacity, surface functional groups, crystallinity and differential thermal analysis were studied using Methylene blue test, Fourier transform infrared radiation, X-ray diffraction and differential scanning calorimetry respectively. The surface area was increased from 147.1 m2/g to 310.2 m2/g as change in temperature increases from 300 °C to 500 °C. The x-ray diffraction analysis confirms that the mineral is consists of montmorillonite and other impurities such as quartz, feldspar, muscovite, cristobalite and hematite. Thermal stability of bentonite was confirmed that its stable up to 500 °C. The effect of time, initial Zinc ion concentration and adsorbent dosage were experimentally studied using response surface methodology. Thus, the amount of adsorption of Zinc ion increases with increasing contact time and adsorbent dosage and decreasing with increasing Zinc ion concentration. The optimum design parameters were obtained 74.62 mg/l, 90min and 1.35 g and the percentage removal was 99.77% at this condition. The Langmuir isotherm and pseudo-second order kinetics provided best fits of the aggregation. Therefore, thermally treated bentonite provides the large surface area and adsorption potential and can be successfully applied for the removal of Zinc from wastewater.

Nanomagnetit-bentonit vizes közegű diszperz rendszereinek zeta-potenciáljának vizsgálata

The stability of different type nanomaterials play an important role among recent scientific and industrial challenges, including the examination of the effect of polymers, surfactants and their mixture on surface and electric surface properties and aggregation extent of dispersed particles, which are of utmost importance. Bentonite and its composite with different nanomaterials are frequently used for instance in environmental protection for wastewater treatment, since due to their great specific surface area they have excellent sorption properties. There are several publications in the literature for the application of bentonite in drilling muds. By using them the fluid loss can be decreased during the drilling process, the filtration of the fluid can be increased, it also improves the rheological properties and the formation damage can also be mitigated. During research the investigation and the analysis of the zeta-potential of nanoparticles and their composites at different pH and salt content can be an interesting topic. During our experiments the electric surface properties of nanomagnetite synthetized in laboratory (NM), cation exchanged bentonite from Mád (Be) and the composite particles of these particles were investigated. Hybrid particles of different compositions (9:1, 7:3, 1:1, 3:7, 1:9) were analyzed at different potassium chloride concentrations (0.1 – 0.0001 M). The surface adsorption on the surface, i.e. the change in the surface charge can be traced well by analyzing the obtained zeta-potential values. The behavior of such systems was observed in the full pH interval, thus, valuable data were obtained regarding the colloidal stability. As for the stability, different requirements may emerge in practice, there are application fields where the colloidally stable system is advantageous, on the other hand, in some cases, ceasing the stabile system is the goal. Our investigations are of high importance in terms of stability and its characterization [1].