BENTONITE is a clay which has high surface area and makes it a good option for the placement of metal oxide nanoparticles, such as zinc oxide, thereby forming a nanocomposite. In the recent years, various applications of this kind of nanocomposites have been investigated by researchers in water and wastewater treatment. Accordingly, in this research, the BENTONITE was powdered by ball mills and then, ZnO/BENTONITE nanocomposite was prepared by ultrasound irradiation and gel degradation method with starch. The nanocomposite was identified by XRD, FTIR, SEM and EDX techniques, and the efficiency of the sample was studied for removing of nitrate ions from water. The results showed that environmental factors such as pH, contact time, adsorbent amount, and nitrate concentration were effective in removal percentage. Optimal removing percentage of the nitrate solution with 30 mg/l was achieved by 0. 6 g of nanocomposite which could remove 70% of the nitrate from solution.

In order to investigate the effect of pectin and dextran polymers on the adsorptive capacity of TiO2/BENTONITE nanosorbents, two nanocomposites of TiO2/pectin/BENTONITE and TiO2/dextran/BENTONITE were made by sol-gel method. Their investigation by FT-IR spectroscopy confirms the expected microstructure, and XRD results confirm the formation of anatase titania crystalline phase and also crystalline structure of BENTONITE. FESEM images showed the formation of TiO2 nanoparticles. These two nanocomposites were used for removing copper (II) ion from water and the effective factors on removal were investigated that maximum removal for both nanocomposites is in pH=7, adsorption dosage of 0. 04g and temperature of 25° C, but contact times for two composites of TiO2/pectin/BENTONITE and TiO2/dextran/BENTONITE were equal to 20 and 30 minutes and adsorptive capacity for them were 40. 16 and 22. 12 mg Cu2+ per gram of adsorbent, respectively. Investigating the effect of interference ions had no considerable influence on removal efficiency. The results show that adsorption of Cu2+ by TiO2/pectin/BENTONITE and TiO2/dextran/BENTONITE nanocomposites follows Langmuir and Freundlich isotherms.

Organic pollutants of wastewaters have always been one of the most important environmental challenges. Absorption of contaminants from aqueous solution by nano-BENTONITE is an efficient way due to smaller size and increased surface area of the particles. In this study, BENTONITE prepared from BENTONITE mines of Kheirabad was purified by sedimentation method. Magnetic nano composite was synthesized by coprecipitation method. The properties of nanocomposite was studied using FTIR, XRD, VSM, BET and TEM analyses. The adsorption process of TCP, a toxic carcinogen phenolic derivative (initial concentration of 100 mg/L) by pure BENTONITE and magnetic nano composites (1 gr/L) was evaluated at pH= 5, 23-25 0C and different times. The results indicated that the percentage of adsorption of TCP by magnetized BENTONITE nano composite due to increased surface area (108. 73 m2 g-1) and magnetized nano particles in 60 minutes was attained %96. 777, compared to pure BENTONITE which adsorbed %68. 25 of TCP in 3 hours.

Application of hyperactivation process in palletizing iron ore, in order to decrease BENTONITE consumption has been investigated. Different amounts of BENTONITE and sodium hydroxide, as activating agents, were added to iron ore and the quality of formed pellets was determined. The results show that addition of 0.01 pct. NaOH improves the pellet quality significantly while the BENTONITE content remains constant at 0.7 pct. Moreover, pellet quality parameters were maintained within desired limit values while 0.02 pct NaOH and 0.4 pct BENTONITE were used. NaOH changes the chemistry of calcium-BENTONITE to sodium-BENTONITE that dispatches more easily in iron ore matrix. Homogeneous dispersion of BENTONITE in hyperactive mixtures creates uniform physical bonds between iron ore particles within pellet and results in less BENTONITE consumption.

BENTONITE has been used industrially in various construction projects. This material is used, due to its limited hydraulic conductivity, in some cases such as landfill, sealing walls and nuclear waste disposal tanks. Recently, many researchers have investigated the use of BENTONITE slurry systems for injection into granular soils under static and dynamic loading conditions in order to improve soil engineering performance. In this condition, BENTONITE slurry is deposited in a loose soil with low pressure and without disturbance in the structure of the soil under injection. Due to the nature of the thixotropy of the BENTONITE slurry, the injected material is deposited in the form of gel structures in the soil and leads to increasing soil resistance to static and dynamic loads. For suitable soil engineering properties in granular soil, the use of concentrated BENTONITE slurry is appropriate; high concentrations will limit the penetration of BENTONITE due to low soil permeability. In order to overcome this limitation, slurry rheological properties such as viscosity must be corrected in order to increase the depth of sand penetration. Other researchers observed that with the reduction of viscosity in the cement slurry with micro-size particles, the amount of its penetration in the sand column significantly increased....

Extracted BENTONITE from different mines has various physical and chemical properties and as a result it would be possible to apply them in various requestes. The main mineral of BENTONITE is montmorillonite and the amount of montmorillonite, associated minerals and the type of BENTONITE affect on its properties. In this study, the samples were obtained from active mines and their X-ray diffraction pattern was studied, then the chemical analysis and swelling index investigated. Based on the results the samples 1 and 2 obtained from kheir Abad BENTONITE mine had relatively high montmorillonite content, while sample 2 was sodium BENTONITE and sample1 was calcium BENTONITE. The sample 3 taken from Horjand BENTONITE mine had relatively high montmorillonite content and qualitative more impurities rather than the other samples and was calcium BENTONITE. Sample 4 from Tang Ghoohan had relatively high montmorillonite and was calcium BENTONITE. Cation exchange capacity (CEC) of BENTONITE samples was determined using copper ethylendiamine complex and methylene blue methods. Copper ethylenediamine complex method in all of the samples was more accurate than methylene blue method. The result showed that methylene blue method was not reliable in determination of CEC of calcium BENTONITE.

The feasibility of natural BENTONITE and rarasaponin-BENTONITE for Evans blue removal from aqueous solution was studied. Rarasaponin is a natural surfactant obtained from Sapindus rarak DC was used as modifying agent for natural BENTONITE modification. Adsorption experiments were conducted in a batch system at various temperatures. Several temperature-dependent isotherm models (Langmuir, Freundlich, Sips and Toth) were used to represent equilibrium data. It was found that Toth model represents the adsorption equilibrium data better than other models. Kinetic data were best represented by the pseudo-first order model. The controlling mechanism of the adsorption of Evans blue onto natural BENTONITE and rarasaponin-BENTONITE was physical adsorption.

Introduction & Objectives: Aniline is an organic compound widely used in various industries. The release of this compound has had various environmental impacts. Thus, the assessment of efficient and practical methods for the removal of aniline from wastewater of these industries is remarkable. Taguchi model is a model for the analysis of experiments, that predicts both the effects of each factors and the optimum level of them using a certain number of experiment. The purpose of this study was the optimization of aniline adsorption on the raw and modified BENTONITE with a cationic surfactant using Taguchi model.Materials & Methods: In this experimental study, the raw BENTONITE and modified BENTONITE was prepared in a few steps. Then, 4 main factors (i.e. pollutant concentration, contact time, pH, and adsorbent dosage) on 4 levels were selected by Matrix L16 trials and the experiments were conducted in this matrix. The factors were also ranked based on the R-value. Then, the data were analyzed with Minitab 17 software. Finally, the adsorption of aniline on raw and modified BENTONITE was determined in optimal conditions.Results: The optimization of adsorption process using Taguchi model showed that the factors of importance for optimizing respectively were: contact time of 360 minutes, pH =10 pH, aniline initial concentration of 300 mg/L and adsorbent dosages of 40 g/L. The maximum ad-sorption of aniline onto raw BENTONITE and modified BENTONITE with cationic surfactant in optimal conditions were determined 81.86 and 8.75, respectively. The results revealed that Freundlich isotherm and pseudo-second-order kinetic model provided a better to the ex-perimental data.Conclusion: The results showed that the BENTONITE modified with cationic surfactant is efficient in the removal of aniline. At the same time, since BENTONITE is cheap and easily accessible, it is considered a desirable adsorbant.

Removal of silica impurities on Reshm BENTONITE sample of Semnan province in Iran was investigated. Two processes of hydrocyclone and sedimentation treatment with sodium hexametaphosphate were used aiming for nanoclay production. Mineralogical studies indicated that the treated sample was a low grade Na-BENTONITE. The dominant impurities were cristobalite and quartz with low amounts of feldspar, gypsum, dolomite, calcite and zeolite. The Purification of the sample was processed by two methods of hydrocyclone and sedimentation treatment with sodium hexametaphosphate as depressant. The purified product was intercalated with octadecylamine. The evaluation of products was performed by XRD analysis. The purification results showed that hydrocyclone process failed to produce a purified montmorillonite product suitable for nanoclay application. Using sedimentation treatment with sodium hexametaphosphate as a depressant, a product with impurities of less than 5 percent, suitable for nanocaly application, can be produced. Intercalation of purified montmorillonite by octadecylamine showed that the application of sodium hexametaphosphate increase the basal spacing up to 36o A.

Background: From old times, the human kind has used clays, externally or internally, for maintaining body health or treating some diseases. Meanwhile there are few scientific articles reviewing the beneficial effects of clays on body function. BENTONITE clay is one of the available clays in nature, used as traditional habits, and remedies in many cul-tures. Methods: These articles explored among 2500 scientific articles published in PubMed to sort the scientific works have been done on the effects of this clay on body function (it was about 100 articles). Results: BENTONITE has a broad range of action on different parts of body. Conclusion: As traditional remedies seem to have a deep root in maintaining body health, it merits doing more re-search works on BENTONITE clay and its impacts on body function.