Cation Exchange Capacity
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2021 ◽  
Author(s):  
Fatemeh Amir Aslanzadeh Mamaghani ◽  
Amin Salem ◽  
Shiva Salem

Abstract The efficient management of solid waste deposited in the landfill of used motor oil recovery units is an important environmental challenge which is originated from the regeneration by bentonite as an effective adsorbent. The current study was attempted to convert the black waste into zeolite based compounds through fusion technique. The collected waste powder were mixed with sodium hydroxide, and boehmite followed by treatment at different temperatures, 600-800 °C. Then, the obtained precursors were hydrothermally converted to zeolite A or hydroxysodalite. The effect of parameters like alkalinity, boehmite, and sodium aluminate ratios, fusion temperature, and aging time on structural characteristics, and cation exchange capacity (CEC) were studied in details. The potential of solid waste in the production of zeolite A is significantly affected by mentioned factors which govern on purity, crystallinity, morphology, and CEC. The cation exchange capacity about 190 mg g-1 can be achieved by alkali, and boehmite ratios of 2.00, and 0.53, respectively. The microstructural analyses showed the morphological evolution from rounded shape to sharp edges by fusion at 800 °C due to appropriate recrystallization. Besides, hydrosodalite powder with extended surface area, 77 m2 g-1, could be produced by limited content of boehmite in the presence of NaAlO2.


Agronomy ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2052
Author(s):  
Karolina Villagra-Mendoza ◽  
Federico Masís-Meléndez ◽  
Jaime Quesada-Kimsey ◽  
Carlos A. García-González ◽  
Rainer Horn

Soil degradation and water stress in Costa Rica challenge the production of highly sensitive crops. This work is aimed at evaluating the physical and chemical changes in sandy loam (SL) and a silt loam (SiL) soil when amended with bamboo biochar while estimating the enhancement of tomato productivity. Biochar, obtained from Guadua Angustifolia bamboo feedstock, was mixed into sieved bulk soil substrate from the topsoil, from Andosol and Umbrisol groups, at application rates of 1, 2.5, and 5% (dry mass). Physicochemical and morphological properties of biochar such as pH, hydrophobicity, scanning electron microscopy images, helium picnometry, specific surface area by the Brunauer–Emmett–Teller (BET) method, CHNS, and ash content were determined. Soil hydrophobicity, acidity, electrical conductivity, cation exchange capacity and water retention, available water content, and air capacity were analyzed for the amended soils. Tomato yield was quantified after a harvest period of two months. The admixture of biochar did not significantly increase soil cation exchange capacity but increased water retention in the range of available water content. Class A (>200 g) tomato yield increased 350% in the SL and 151% in the SiL. Class B (100–200 g) tomato yields increased 27% in the SL but decreased about 30% in the SiL. Tomato yield response seems attributable to variation of water retention capacity, available water content, and air capacity. These results support the use of adapted water management strategies for tomato production based on soil physical changes of biochar.


2021 ◽  
Author(s):  
Wenwen Zhou ◽  
Haoran Jia ◽  
Lang Liu ◽  
Baotong Li ◽  
Yuqi Li ◽  
...  

Abstract. (E)-Pyriminobac-methyl (EPM), a pyrimidine benzoic acid esters herbicide, has a high potential as weedicide; nevertheless, its environmental behaviors are still not well understood. In this study, we systematically investigated for the first time the adsorption–desorption, degradation, and leaching behaviors of EPM in agricultural soils from five exemplar sites in China (characterized by different physicochemical properties) through laboratory simulation experiments. The EPM adsorption–desorption results were well fitted by the Freundlich model (R2 > 0.9999). In the analyzed soils, the Freundlich adsorption (i.e., Kf-ads) and desorption (i.e., Kf-des) coefficients of EPM varied between 0.85–32.22 mg1−1/n L1/n kg−1 and between 0.78–5.02 mg1−1/n L1/n kg−1, respectively. Moreover, the degradation of EPM reflected first-order kinetics: its half-life ranged between 37.46–66.00 d depending on the environmental conditions, and abiotic degradation was predominant in the degradation of this compound. The mobility of EPM in the five soils varied from immobile to highly mobile. The groundwater ubiquity score ranged between 0.9765–2.7160, indicating that EPM posed threat to groundwater quality. Overall, the results of this study demonstrate the easy degradability of EPM, as well as its high adsorption affinity and low mobility in soils with abundant organic matter content and high cation exchange capacity. Under such conditions, there is a relatively low contamination risk for groundwater systems in relation to this compound. At the same time, due to its slow degradation, EPM has a low adsorption affinity and tends to be highly mobile in soils poor in organic matter content and with low cation exchange capacity. Under such conditions, there is a relatively high contamination risk for groundwater systems in relation to this compound. Overall, our findings provide a solid basis for predicting the environmental impacts of EPM.


Author(s):  
Shefali Giri ◽  
Priyanka Paul Madhu ◽  
Kumar Gaurav Chhabra ◽  
Gopika Mahure ◽  
Shailey Chandak

To assess the cariogenic potential of almond milk, soya milk, coconut milk and bovine milk, was evaluated to check ability to enable Streptococcus mutans association formed, acid manufacturing, as well as their ability to buffer pH transforms. The baseline non stimulated whole salivary sample (2.5-5 ml) will be collected from the students in the morning at least 1 hr after breakfast. The salivary samples (pre-test and post-test) will be collected and tested for the CFUs. Salivary samples are transported in a plastic container to the microbiological laboratory. They were then tested for the number of CFUs for S. mutans using mitis salivarius bacitracin agar. Soya milk promoted much more biofilm development, whereas sugar free almond milk promoted a little. When pH test was performed, sugar free almond milk had the lowest cation exchange capacity, whereas bovine milk had the maximum cation exchange capacity.


2021 ◽  
Vol 11 (3) ◽  
pp. 48-65
Author(s):  
Ahmed Habeeb Alshamy ◽  
Faleh H. M. Almahdawi

Shale and shaly formations constitute about 70% to 80% of the total rock formations drilled worldwide, and the most of footage drilled in gas and oil wells is in shale and shaly rocks. Drilling in shale sections in many cases causes wellbore instability and slow drilling problems. In this study, cation exchange capacity of shale is estimated using a relatively simple petrophysical model. The validation of this model is achieved with experimental values of cation exchange capacity. The estimation of cation exchange capacity by this model and common logs data has exhibited potentiality for distinguishing effective/ineffective drilling in shale formations. Drilling and petrophysical data gathered at controlled condition is required in order to optimize the proposed technique. Have knowledge of properties and location of shales permits for remedial actions in future offset well or while drilling in case of logging while drilling (LWD) is used


Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 962
Author(s):  
Andre Revil ◽  
Marceau Gresse

The mineral alteration patterns in high- to low-temperature geothermal fields affect the induced polarization (electrical conductivity and chargeability) properties of volcanic rocks. Indeed, these properties are sensitive to the cation exchange capacity and the porosity of the rock, which are both dependent on the alteration path, temperature, and depth of burial. Therefore induced polarization tomography appears as a powerful non-intrusive geophysical method to investigate alteration patterns in geothermal fields. Among clay minerals, the production of smectite through prograde reactions occurs progressively in volcanic rocks up to 220 °C. The presence of smectite dominates the induced polarization response of the volcanic rocks because of its very large cation exchange capacity. It follows that induced polarization can be used as a non-intrusive temperature proxy up to 220 °C for both active and inactive geothermal fields, recording the highest temperatures reached in the past. The influence of magnetite and pyrite, two semi-conductors, also has a strong influence regarding the induced polarization properties of volcanic rocks. Various field examples are discussed to show how induced polarization can be used to image volcanic conduits and smectite-rich clay caps in volcanic areas for both stratovolcanoes and shield volcanoes.


BMC Chemistry ◽  
2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Nabil Babahoum ◽  
Malek Ould Hamou

Abstract Introduction Bentonitic clays from the Hammam Boughrara deposit in the Maghnia area (northwestern Algeria) were studied by mineralogical, chemical and physicochemical characterization to evaluate their potential suitability as raw and purified materials in pharmaceutical and cosmetic applications. Methodology Natural bentonite was purified by Na+ ion exchange treatment combined with sedimentation techniques. Before use in the pharmaceutical industry, bentonite samples must be safe and conform to recommendations and directives of pharmacopeia. A set of technological tests were investigated with the samples, such as cation exchange capacity (CEC), specific surface area (SSA), swelling capacity (SC),sedimentation volume (SV) and viscosity, and mineralogical, chemical and microbial properties were also identified by X-ray fluorescence (XRF), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Results Mineralogical data proved that the raw bentonite is mainly composed of smectite and illite with small quantities of gangue minerals such quartz, feldspars (orthoclase and albite) and calcite. The purified bentonite matches the mineralogical properties of Wyoming bentonite as an international standard clay (deposits of high economic value). Quartz and feldspars were successfully eliminated in the absence of illite and calcite after beneficiation. Investigation of chemical analyses indicated that the contents of trace elements (particularly Pb and As) were below the more restrictive limits proposed by major pharmacopeias for raw and purified bentonite clay. For microbiological tests, the absence of Escherichia coli, Salmonella species, Staphylococcus aureus and Pseudomonas aeruginosa was confirmed. Moreover, we note that a high cation exchange capacity, large surface area, and good swelling capacity and sedimentation volume were also obtained for purified bentonite. Conclusion In view of the fundamentals of major pharmacopoeias for the use of bentonite in pharmacies and considering the results obtained, we identified a pharmaceutically acceptable designation for purified Algerian bentonite, which can be used as a pharmaceutical excipient and in cosmetic products such as creams, powders and emulsions.


Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4915
Author(s):  
Norway Pangan ◽  
Susan Gallardo ◽  
Pag-asa Gaspillo ◽  
Winarto Kurniawan ◽  
Hirofumi Hinode ◽  
...  

This study deals with the impact of calcination, alkalinity, and curing time parameters on the hydrothermal synthesis of zeolite A. The zeolite A sample, produced from corncob-stalk-and-leaves (corn stover) ash was characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermo-gravimetric analysis (TGA), and scanning electron microscopy (SEM). The results showed that calcination, alkalinity, and curing time have significant effects on the crystallization and the morphology of zeolite A. In addition, these parameters also impacted the cation exchange capacity. Furthermore, the synthesized zeolite A was obtained using a calcination temperature of 5000 °C within two hours of airflow, which is much lower than the temperatures previously reported in the literature for an agricultural waste and other waste materials. A fusion ratio of corn stover ash:NaOH of 1.0:1.5 and a curing time of nine hours were achieved. This is a major result as this curing time is much lower than those featured in other studies, which can reach up to twenty-four hours. In this paper, cubic crystal with rounded edge of zeolite A, having a cation exchange capacity of 2.439 meq Na+/g of synthesized anhydrous zeolite A, was obtained, which can be a good candidate for ion-exchange separation.


2021 ◽  
Vol 1044 ◽  
pp. 113-120
Author(s):  
Rina Devnita ◽  
Apong Sandrawati ◽  
Mahfud Arifin ◽  
Pujawati Suryatmana ◽  
Muhammad Amir Solihin ◽  
...  

Nanoparticles of Merapi volcanic ash and phosphate-solubilizing fungi were expected to function as ameliorants in improving some Inceptisols characteristics. Nanoparticles of volcanic ash were used in accelerating and streamlining the chemical reaction in the soil. Phosphate-solubilizing fungi were expected to assist the process of several soil reactions. The aim of the research was to improve some chemical characteristics like available P, cation exchange capacity, Fe, and Zn content of Inceptisols in Cilembu Village, Sumedang District, West Java Province, Indonesia. The research used a complete randomized experimental design in factorial with two factors. The first factor was the nanoparticle of Merapi volcanic ash consisted of four doses on soil weight percentage (0%, 2%, 4%, and 6%). The second factor was phosphate-solubilizing fungi consisted of two doses (without and 10 g.kg-1). The volcanic ash was collected from Mt. Merapi, Central Java, after the eruption of November 2010 and kept in the Laboratory of Soil Physics and Conservation in Faculty of Agriculture, Universitas Padjadjaran. The nanoparticle of volcanic ash was processed at Nanotechnology and Graphene Research Centre, Universitas Padjadjaran. The phosphate-solubilizing fungi were isolated from Inceptisols in Soil Microbiology Laboratory, Universitas Padjadjaran. These treatments were combined and mixed with soils and incubated for three months. Every one month during those three months of the incubation period, some soils were taken to be analyzed of available P, cation exchange capacity (CEC), available Fe, and available Zn. The result showed that there was no interaction between the nanoparticle of Merapi volcanic ash and phosphate-solubilizing fungi to parameters investigated except the CEC after two months of incubation. There was an effect of nanoparticle volcanic ash and phosphate-solubilizing fungi individually to available Fe dan Zn. There was a trend of increasing available P, and CEC and decreasing available Fe and Zn by the longer period of incubation.


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