scholarly journals Valorization of Moroccan Bentonite Deposits: “Purification and Treatment of Margin by the Adsorption Process”

Molecules ◽  
2021 ◽  
Vol 26 (18) ◽  
pp. 5528
Author(s):  
Hanane Ait Hmeid ◽  
Mustapha Akodad ◽  
Mourad Baghour ◽  
Abdelmajid Moumen ◽  
Ali Skalli ◽  
...  

The main objective of this work was to contribute to the reduction in the contamination of phenolic compounds contained in margin by an adsorption process on two types of raw bentonite. The margin used in the studies was collected from a semi-modern oil mill located in the Nador–Morocco region. The results of the physico-chemical analyses showed that the effluents of the oil mills showed that they are highly polluted, particularly in terms of the total suspended solids (TSS), chemical oxygen demand (COD), and iron content of around 154.82 (mg/L), and copper content of 31.72 (mg/L). The mineralogy of bentonites studied by X-ray diffraction (XRD) reveals the existence of two types of montmorillonite; theoretically, the diffraction peak (001) of the montmorillonite appears at 15 Å, with a basal spacing that corresponds to a calcium pole, and the diffraction peak (001) appears at 12Å, with a basal spacing that corresponds to a sodium pole. The specific surface area of the bentonite used is characterized by a large specific surface area, varying between 127.62 m2·g−1 and 693.04 m2·g−1, which is due to the presence of hydrated interleaved cations. This surface is likely to increase in aqueous solution depending on the solid/liquid ratio that modulates the degree of hydration. With a high cation exchange capacity (CEC) (146.54 meq/100 g), samples of margin mixed with raw bentonites at different percentages vary between 5% and 100%. The potential of Moroccan bentonite for the phenol adsorption of 9.17 (g/L) from aqueous solutions was investigated. Adsorption tests have confirmed the effectiveness of these natural minerals in reducing phenolic compounds ranging from 8.72% to 76.23% contained in the margin and the efficiency of heavy metal retention through microelements on raw bentonites. The very encouraging results obtained in this work could aid in the application of adsorption for the treatment of margin.

2017 ◽  
Vol 68 (3) ◽  
pp. 483-486
Author(s):  
Constantin Sorin Ion ◽  
Mihaela Bombos ◽  
Gabriel Vasilievici ◽  
Dorin Bombos

Desulfurisation of atmospheric distillation gasoline and gas oil was performed by adsorption process on Fe/ bentonite. The adsorbent was characterized by determining the adsorption isotherms, specific surface area, pore volume and average pore diameter. Adsorption experiments of atmospheric distillation gasoline and gas oil were performed in continuous system at 280�320oC, 5 atm and volume hourly space velocities of 1�2 h-1. The efficiency of adsorption on Fe / bentonite was better at desulphurisation of gasoline versus gas oil.


2019 ◽  
Vol 80 (4) ◽  
pp. 737-746
Author(s):  
Rishi Gurjar ◽  
Akshay D. Shende ◽  
Girish R. Pophali

Abstract Studies on laboratory-scale submerged aerobic fixed film reactor (SAFF) packed with synthetic media having specific surface area of 165 m2/m3 with a void volume of 89% were carried out to assess its performance under various organic loading rates (OLR) and hydraulic retention times (HRT). Synthetic wastewater having chemical oxygen demand (COD) and biochemical oxygen demand (BOD) of 400 ± 10% and 210 ± 10% mg/L respectively was fed and the reactor was subjected to OLRs ranging from 0.37 to 1.26 kg COD/m3.d. It was observed that steady sloughing of biofilm occurs within the SAFF reactor all the times and average concentration of sloughed biomass in the effluent was 26 mg/L. The COD and BOD removal efficiencies varied between 85 and 89% and 86 to 94%, respectively. The kinetic studies demonstrated that SAFF reactor followed Stover–Kincannon and Grau models, with high correlation coefficients (R2) of 0.9977 and 0.9916, respectively. Thus, the values of kinetic coefficients such as maximum substrate utilization rate, Umax = 64.1 g/(L.d); saturation value constant, KB = 72.31 g/(L.d) and Grau second-order substrate removal rate constant, Ks = 2.44 day−1 can be useful to develop and design large scale SAFF reactors. Finally, the study reveals that the optimum range for OLR can vary within 0.68–0.94 kg COD/m3.d.


2019 ◽  
Vol 9 (23) ◽  
pp. 5249 ◽  
Author(s):  
Derlin Hsu ◽  
Changyi Lu ◽  
Tairan Pang ◽  
Yuanpeng Wang ◽  
Guanhua Wang

Chemically activated biochars prepared from sorghum distillers grain using two base activators (NaOH and KOH) were investigated for their adsorption properties with respect to ammonium nitrogen from aqueous solution. Detailed characterizations, including scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetry (TG), and specific surface area analyses, were carried out to offer a broad evaluation of the prepared biochars. The results showed that the NaOH- and KOH-activated biochars exhibited significantly enhanced adsorption capacity, by 2.93 and 4.74 times, respectively, in comparison with the pristine biochar. Although the NaOH-activated biochar possessed larger specific surface area (132.8 and 117.7 m2/g for the NaOH- and KOH-activated biochars, respectively), the KOH-activated biochar had higher adsorption capacity owing to its much higher content of functional groups. The adsorption kinetics and isotherms of the KOH-activated biochar at different temperatures were further studied. The biochar had a maximum adsorption capacity of 14.34 mg/g at 45 °C, which was satisfactory compared with other biochars prepared using different feedstocks. The adsorption process followed pseudo-second-order kinetics, and chemical adsorption was the rate-controlling step. The equilibrium data were consistent with the Freundlich isotherm, and the thermodynamic parameters suggested that the adsorption process was endothermic and spontaneous. Consequently, this work demonstrates that chemically activated biochar from sorghum distillers grain is effective for ammonium nitrogen removal.


Clay Minerals ◽  
2019 ◽  
Vol 54 (4) ◽  
pp. 369-377 ◽  
Author(s):  
Maja Milošević ◽  
Predrag Dabić ◽  
Sabina Kovač ◽  
Lazar Kaluđerović ◽  
Mihovil Logar

AbstractThis study focuses on the mineralogical characterization of four raw clay samples from Dobrodo deposit, Serbia. Several analytical methods were applied to determine the chemical and mineralogical composition, morphology and physical properties (colour, plasticity, specific surface area, particle size and cation-exchange capacity) of the clay samples. Kaolinite, smectite and illite are the predominant phases in all of the samples studied that contain between 60.2 and 87.1 wt.% of clay. Quartz, feldspars, paragonite and Ti- and Fe-bearing phases were also identified. The relatively high SiO2/Al2O3 mass ratio indicates abundant quartz. The cation-exchange capacity of the samples varied between low and moderately charged clay minerals (12–52 mmol 100 g–1) with specific surface area values ranging from 94 to 410 m2 g–1. The plasticity index values (11–23%) suggest low to moderate plasticity. Preliminary results show that most of the raw clay from Dobrodo deposit might be suitable for use in ceramic applications.


2016 ◽  
Vol 30 (3) ◽  
pp. 369-374 ◽  
Author(s):  
Kamil Skic ◽  
Patrycja Boguta ◽  
Zofia Sokołowska

Abstract Parameters of specific surface area as well as surface charge were used to determine and compare sorption properties of soils with different physicochemical characteristics. The gravimetric method was used to obtain water vapour isotherms and then specific surface areas, whereas surface charge was estimated from potentiometric titration curves. The specific surface area varied from 12.55 to 132.69 m2 g−1 for Haplic Cambisol and Mollic Gleysol soil, respectively, and generally decreased with pH (R=0.835; α = 0.05) and when bulk density (R=−0.736; α = 0.05) as well as ash content (R=−0.751; α = 0.05) increased. In the case of surface charge, the values ranged from 63.00 to 844.67 μmol g−1 Haplic Fluvisol and Mollic Gleysol, respecively. Organic matter gave significant contributions to the specific surface area and cation exchange capacity due to the large surface area and numerous surface functional groups, containing adsorption sites for water vapour molecules and for ions. The values of cation exchange capacity and specific surface area correlated linearly at the level of R=0.985; α = 0.05.


2021 ◽  
Author(s):  
Yong Ai ◽  
Na Yin ◽  
Yanquan Ouyang ◽  
Yuanxin Xu ◽  
Pengfei Yang

Abstract In order to make full use of waste as raw materials to prepare low-cost zeolite, develop green chemical industry and achieve the purpose of treating waste with waste. High-purity zeolite X was prepared by the alkaline fusion hydrothermal method (AFH) using waste basalt powder as raw material, and was used as an adsorbent to investigate the adsorption performance for uranium-containing wastewater. The structure, morphology, specific surface area, chemical composition, chemical bonds, characteristic functional groups and chemical states of surface elements of the samples were characterized by XRD, SEM, BET, EDS, FT-IR and XPS. zeolite X with high crystallinity and rich hydroxyl/carboxyl groups was successfully synthesized by the AFH method, and its specific surface area was as high as 623.4 m2·g-1. When the adsorption time (t) is 720 min, the adsorption temperature (T) is 30 ℃, the initial uranium (VI) concentration is (C0) 35 mg/L, pH is 6.0, and the adsorbent dosage (m) is 5/35 mg/mL, the equilibriu adsorption capacity of zeolite X for uranyl ions is 228.4 mg·g-1. Thermodynamic results show that the adsorption process of uranyl ions by zeolite X is spontaneous and exothermic. Freundlich isotherms and quasi-second-order models are suitable to describe the adsorption process of uranyl ions by zeolite X. XPS analysis results show that -OH and -COOH play an important role in the adsorption process. At the same time, there is ion exchange between UO22+ and zeolite during the adsorption process.


2012 ◽  
Vol 17 (1) ◽  
pp. 83-88 ◽  
Author(s):  
Andrzej Olchawa ◽  
Aleksandra Gorączko

Abstract The liquid limit - wL, the external surface area - Se, the concentration of exchangeable cations - Zi and the cation exchange capacity - CEC of seventeen clayey soils were determined. Finding the correlation between the liquid limit, external specific surface area and exchangeable cation concentration was the aim of this study. Experimental study performed using soils of the external surface area within the range of 4.1 to 118.5 m2·g-1. The relative content of sodium cation (i.e. Na+/CEC) varying between 0.03 and 1.0. Obtained results point to statistically significant relationship between these three properties. The greatest predictive power of linear regression was found for soils of external specific surface area larger than 60 m2·g-1. For the soils of comparable external surface area, the liquid limit increase with increasing the ratio of the content of sodium cation to the cation exchange capacity - Na+/CEC. For the soils of comparable composition of exchangeable cations the liquid limit increase with increasing the external surface area. These relationships indicates that interparticle forces have a prominent role in determining liquid limit of clayey soils.


2010 ◽  
Vol 2 (3) ◽  
pp. 173-176
Author(s):  
Hery Haerudin ◽  
Nino Rinaldi ◽  
Adel Fisli

The modification of bentonite by pillarization using aluminum polycation type Keggin [Al13O4(OH)24(H2O)12]7+ has been carried out, by exchange of cation from interlayer with aluminum polycation. The amount of aluminum polycation, which was used for the pillaring of bentonite was varied, i.e. 5 mmol/gram, 10 mmol/gram, and 20 mmol/gram of bentonite. After drying, the pillared bentonite was calcined at 400 oC for 6 hour with temperature rate of 5 oC/min. The cationic exchange capacity (CEC) of starting bentonite was 98.3 meq/100 gram. The concentration ratio of Al/Si increased from 0.27 to 0.34 for pillared bentonite and of Ca/Si was decreased from 0.06 to 0.006 for pillared bentonite. The basal space for pillared bentonit increased significantly from 7.30 Å to about 18 Å . The measured specific surface area (by BET) of pillared bentonite was also increased significantly from 46 m2/g to about 162 m2/g. It was concluded that bentonite has been pillared by aluminum polication successfully.   Keywords: aluminum polycation, bentonite


2020 ◽  
Vol 42 (5) ◽  
pp. 728-728
Author(s):  
Aleksandra Micic Aleksandra Micic ◽  
Dragan Djordjevic Dragan Djordjevic ◽  
Ivona Jankovic Castvan Ivona Jankovic Castvan ◽  
Nenad Cirkovic Nenad Cirkovic ◽  
Bratislav Todorovic Bratislav Todorovic

The paper investigates the possibility of removing acid dye from the aqueous solution by an adsorption process on new adsorbent prepared from waste cotton textile from the ready-made garment industry. It is a waste generated during the cutting of the layers of cotton knitwear, which is practically the product from the textile cutting process. The obtained adsorbent is a bulk material with heterogeneous porous particles, of ragged shapes. In particle interiors, there are pronounced cracks, cavities and channels that form the basis of microporous material. The qualitative and quantitative characterization of the obtained adsorbent shows that this is a relatively porous material where the carbon is dominant in the chemical composition. The results of textural properties of new adsorbent from cotton knitwear waste show different parameters which with their numerous values characterize the specific surface area, pore volume or pore diameter. It can be said that the obtained new adsorbent has micropores and small mesopores, which produce a high specific surface area. During adsorption, the longer contact time causes a greater amount of dye on the adsorbent, i.e. with the duration of the adsorption process the dye concentration in the solution decreases. A number of isotherms of two- (Langmuir, Freundlich and Jovanovic), three- (Toth, Sips and Radke-Prausnitz), and four-parameter models (Fritz-Schlunder and Marczewski-Jaroniec) were used to describe the adsorption process. The four-parameter isotherms are best covered by experimental points and most accurately describe the events of adsorption of acid dye on the surface and in the interior of the new adsorbent particles obtained from ready–made garment cotton waste. The results of this research suggest the possibility of practical application in the decolorization of the colored waste waters of the textile industry providing a contribution to protecting the environment from both an economic and a practical point of view.


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