Quantitative Extraction of p-Coumaric Acid and Ferulic Acid in Different Gramineous Materials and Structural Changes of Residual Alkali Lignin

Ferulic acid(FA)and p-coumaric acid(pCA)in bagasse,wheat straw,corn straw,and corncob were extracted by alkaline hydrolysis and characterized by gas chromatography(GC)and gas chromatography-mass spectrometry(GC-MS).It was found that the FA and most of the pCA in gramineous biomass could be dissociated and released after being treated with 1 M NaOH at 100℃for 4 h.The yields of pCA/FA in bagasse,wheat straw,corn straw,and corncob determined by GC-FID are 39.8/11.5,13.7/11.0,28.0/11.0,and 35.1/14.5 mg/g,respectively.The raw materials and the treated solid residues were characterized by gel-state 2D Heteronuclear Single Quantum Coherence Nuclear Magnetic Resonance(2D HSQC NMR).It was found that only a small amount of lignin was detected in the residue after alkali treatment,indicating that the alkali treatment conditions can effectively cleave the FA and pCA.Additionally,the lignin in the alkali solution was recovered and characterized by 2D HSQC NMR.The FA was not able to be detected by NMR,whereas a small amount of pCA remained in the alkali lignin.This study reveals the structural change of residual lignins during the quantitative isolation of FA and pCA,which is essential for the selective isolation of pCA/FA and valorization of residual alkali lignin.

Influence of Acid Treatment on Pore Structure and Fractal Characterization of a Tight Sandstone:A Case Study from Wudun Sag,Dunhuang Basin

In this study,X-ray diffraction,N_(2)adsorption(N_(2)A),and mercury intrusion(MI)experiments were used to investigate the influence of acid treatment on pore structure and fractal characterization of tight sandstones.The results showed that acid treatment generated a certain number of ink-bottle pores in fine sandstone,aggravated the ink-bottle effect in the sandy mudstone,and transformed some smaller pores into larger ones.After the acid treatment,both the pore volume in the range of 2–11 nm and 0.271–8μm for the fine sandstone and the entire pore size range for the sandy mudstone significantly increased.The dissolution of sandstone cement causes the fine sandstone particles to fall off and fill the pores;the porosity increased at first but then decreased with acid treatment time.The fractal dimension obtained using the Frenkel-Halsey-Hill model was positively correlated with acid treatment time.However,the total fractal dimensions obtained by MI tests showed different changes with acid treatment time in fine sandstone and sandy mudstone.These results provide good guiding significance for reservoir acidification stimulation.

Scaling and clogging treatment of aging tunnel drainage pipes in karst areas using eco-friendly acid agent

In karst areas,the drainage pipes of aging tunnels are prone to be clogged by precipitated carbonates,resulting in lining cracking and tunnel leaking.As a result,not only the driving safety will be deteriorated,but also the water pressure on the lining might also be elevated significantly.For the structural stability and service lifespan of old tunnels,it is of great importance to remove these precipitated carbonates in time.Traditional treatment methods are often destructive to some extent or not efficient enough.This study aims to experimentally develop an eco-friendly acid-based chemical cleaning method to remove carbonate precipitations efficiently.The proposed chemical cleaning agent is an aqueous solution with strong acidity,consisting of sulfamic acid,water,and additives.The factors affecting the cleaning efficiency include the acid solubility,temperature and flow rate of the cleaning agent,as well as additives.Elevating the solution temperature to 50
C or a flow rate of no less than 0.2 m/s can improve cleaning efficiency.Although the salt effect cannot work,1 wt%of polymaleic acid as a surfactant could further promote the cleaning rate.The cleaning efficiency will increase with the flow rate in a power function.The relatively low flow rate that improves the cleaning rate considerably can avoid highpressure-induced mechanical damage to tunnel drainpipes.The waste could be easily treated to acceptable levels using commercial sewage treatment products and can also be recycled in agriculture.With the chemical cleaning,the water pressure at the arch springing of the lining will reduce with the increased radius of transverse drainpipes in a power function.The proposed acid-based cleaning method,which is highly efficient,non-or low-destructive to aging tunnels,sufficiently safe for humans,and friendly enough to the environment,will offer a promising alternative to remove the precipitated carbonates in tunnel drainpipes efficiently.

Advances in CIGS thin film solar cells with emphasis on the alkali element post-deposition treatment

In the past tens of years,the power conversion efficiency of Cu(In,Ga)Se2(CIGS)has continuously improved and been one of the fastest growing photovoltaic technologies that can also help us achieve the goal of carbon emissions reduction.Among several key advances,the alkali element post-deposition treatment(AlK PDT)is regarded as the most important finding in the last 10 years,which has led to the improvement of CIGS solar cell efficiency from 20.4%to 23.35%.A profound understanding of the influence of alkali element on the chemical and electrical properties of the CIGS absorber along with the underlying mechanisms is of great importance.In this review,we summarize the strategies of the alkali element doping in CIGS solar cell,the problems to be noted in the PDT process,the effects on the CdS buffer layer,the effects of different alkali elements on the structure and morphology of the CIGS absorber layer,and retrospect the progress in the CIGS solar cell with emphasis on the alkali element post deposition treatment.

PREPARATION OF HOLLOW LATEX PARTICLES BY ALKALI-ACID TREATMENT

Hollow polymer latex particles were prepared by seeded emulsion polymerization. A seed latex consisting of styrene (St), butyl acrylate(BA) copolymer was first prepared, and seeded terpolymerization of St BA MA(methacrylic acid) were then carried out in the absence of surfactant. Final latex was treated by a two step treatment under alkaline and acidic conditions, thus, the particles with hollow structure were obtained. We discussed the effects of pH value, temperature and time in alkali and acid treatment processes on hollow structure within the polymer latex particles and amount of carboxylic group on particle surface. The results show that the hollow polymer latex particles with the largest hollow size can be obtained under a certain condition (pH12.5, 90°C, 3 h in alkali treatment stage and pH2.5, 85°C, 3 h in acid treatment stage).

COVID-19 mortality paradox(United States vs Africa):Mass vaccination vs early treatment

The coronavirus disease 2019(COVID-19)mortality rate in 55 African countries is almost 4.5 times lower than in the coronavirus disease 2019(COVID-19)despite Africa having over 4.2 times more people.This mortality paradox is also evident when comparing Nigeria,a heavily populated,poorly vaccinated and weakly mandated country to Israel,a small,highly vaccinated and strictly mandated country.Nigeria has almost 4 times lower COVID mortality than Israel.In this Field of Vision perspective,I explain how this paradox has evolved drawing upon my academic,clinical and social experience.Since April 2020,I’ve developed and been using the Egyptian immune-modulatory Kelleni’s protocol to manage COVID-19 patients including pediatric,geriatric,pregnant,immune-compromised and other individuals suffering from multiple comorbidities.It’s unfortunate that severe acute respiratory syndrome coronavirus 2 is still evolving accompanied by more deaths.However in Africa,we’ve been able to live without anxiety or mandates throughout the pandemic because we trust science and adopted early treatment using safe,and effective repurposed drugs that have saved the majority of COVID-19 patients.This article represents an African and Egyptian tale of honor.

Six Amino Acids among Natural Moisturizing Factors Responsible for Skin Hydration: Improvement and Anti-Aging of Skin by Galactomyces Ferment Filtrate-PiteraTM Containing Skin Moisturizer

Background: Natural moisturizing factors (NMFs) are filaggrin-derived components in the cornified layer that are critical for maintaining healthy skin moisturization and barrier function. However, studies have reported conflicting findings on the relationship between NMF levels and aging, while few studies have investigated this relationship clinically. To fill this research gap, we determined the levels of major NMF components such as free amino acids, pyrrolidone carboxylic acid, and urocanic acids, and individually verified their relationships with skin hydration, barrier function, age, and skin aging. Purpose: The objective of this study was to clinically investigate the relationship between NMF components levels and skin aging in facial skin. The main NMF components were obtained from facial skin and quantified. We then selected NMF components showing strong relationships to skin hydration, and analyzed the relationships of the levels of these selected NMF components with signs of skin aging, namely, texture, pores, wrinkles, and dullness (L-value). We also examined the efficacy of treatment with a skin care formula (SK-II Facial Treatment Essence, called SK-II FTE hereafter) including Galactomyces ferment filtrate (GFF, PiteraTM) on the selected NMF component levels associated with skin hydration and barrier function, and the signs of skin aging of texture, pores, wrinkles, and dullness (L-value). Method: We conducted two clinical trials in this research. In Study 1, we measured 23 NMF components using tape-stripped cornified layer to quantify them via an HPLC method in 196 Asian females aged 20 to 59 (mean S.D., 38.6 9.4). Facial visual aging parameters [texture, pores, wrinkles, and dullness (L-value)], as well as elasticity (R7), skin hydration, and TEWL, were quantified using facial skin imaging and skin physical property measurement devices. Study 2 was performed to evaluate whether the facial application of SK-II FTE affects the NMF levels and skin aging parameters in 63 Asian female volunteers aged 20 to 55 (38.4 9.03). During the course of Study 2, 0.6 mL of SK-II FTE was applied to the face twice daily in the morning and afternoon. Skin measurements were performed at the start of the day (baseline) and at week 8. Results: In Study 1, we examined the stratum corneum levels of 23 NMF components comparing to the skin hydration status in 196 female subjects. The subjects were divided into two groups using the median of each measured NMF component. Skin hydration values were compared between the two groups defined for each NMF component. The results showed that subjects with higher levels of six amino acids, alanine, arginine, asparagine, glutamine, glycine, and histidine, exhibited significantly higher skin hydration than those with lower amino acid levels. No significant differences in skin hydration values were found for the other 17 NMF components. We then analyzed whether the sum of these six amino acid NMF components (called 6-AA-NMFs, hereafter) is affected by aging. The 6-AA-NMF level peaked in the subjects aged 25-29, and then gradually and significantly decreased with age. Interestingly, the 6-AA-NMF level was significantly correlated with the skin hydration value, but not with TEWL. In addition, the 6-AA-NMF level demonstrated significant correlations with the signs of skin aging of texture, pores, wrinkles, and dullness (L-value). Then, in Study 2, we examined whether the daily application of SK-II FTE affects the 6-AA-NMF level and visual aging parameters in 63 females. SK-II FTE demonstrated significant increases of the levels of 6-AA-NMFs and each of its components associated with hydration and barrier function, and improvements of skin texture, pores, wrinkles, and dullness (L-value) during the 8 weeks of treatment of facial skin. Conclusion: These clinical studies with large numbers of subjects across a wide age range revealed that six amino acids as NMF components were highly correlated with facial skin hydration in the stratum corneum. The levels of these six NMF components were also found to decrease at ages after the 30 s and were significantly correlated with major signs of skin aging. Notably, these six NMF components (6-AA-NMFs) were increased by SK-II FTE treatment associated with improvements of skin hydration and signs of skin aging, namely, texture, pores, wrinkles, and dullness (L-value). These studies were limited by the lack of investigation of why some NMF components were not associated with skin hydration. More clinical trials examining various NMF components and their relationship with aging are anticipated.

Simultaneous removal of ammonium and phosphate by zeolite synthesized from coal fly ash as influenced by acid treatment

Zeolite synthesized from fly ash （ZFA） without modification is not efficient for the purification of NH4＋ and phosphate at low concentrations that occur in real effluents, despite the high potential removal capacity. To develop an effective technique to enhance the removal efficiency of ammonium and phosphate at low concentrations, ZFA was modified with acid treatment and the simultaneous removal of ammonium and phosphate in a wide range of concentration was investigated. It was seen that when compared with untreated ZFA, only the treatment by 0.01 mol/L of H2SO4 significantly improved the removal efficiency of ammonium at low initial concentrations. The behavior was well explained by the pH effect. Treatment by more concentrated H2SO4 led to the deterioration of the ZFA structure and a decrease in the cation exchange capacity. Treatment by 0.01 mol/L H2SO4 improved the removal efficiency of phosphate by ZFA at all initial P concentrations, while the treatment by concentrated H2SO4 （≥0.9 mol/L） resulted in a limited maximum phosphate immobilization capacity （PIC）. It was concluded that through a previous mild acid treatment （e.g. 0.01 mol/L of H2SO4）, ZFA can be used in the simultaneous removal of NH4＋ and P at low concentrations simulating real effluent.

Reduction in Activity/Gene Expression of Anthocyanin Degradation Enzymes in Lychee Pericarp is Responsible for the Color Protection of the Fruit by Heat and Acid Treatment

Heat and acid treatments were reported to be a promising substitute for SO2 fumigation in color protection of postharvest lychee （Litchi chinensis） fruits, but the mechanism was not clear. In the present study, hot water （70℃） dipping followed by immersion in 2% HC1 （heat-acid） substantially protected the red color of the fruit during storage at 25℃ and inhibited anthocyanin degradation while hot water dipping alone （heat） led to rapidly browning and about 90% loss in anthocyanin content. The pH values in the pericarp of the heat-acid treated fruit dropped to 3.2, while the values maintained around 5.0 in the heat-treated and control fruit. No significantly different pH values were detected among the arils of heat-acid, heat treated and control fruit. Heat-acid treatment dramatically reduced the activities of anthocyanin degradation enzyme （ADE）, peroxidase （POD） and polyphenol oxidase in the pericarp. A marked reduction in LcPOD gene expression was also detected in heat-acid treated fruit, in contrast, induction was found in heat treated fruit. The pericarp of heat-acid treated fruit exhibited significantly lower respiration rate but faster water loss than that of the untreated or heat treated fruit. Taken together, heat treatment triggered quick browning and anthocyanin loss in lychee fruit, while heat-acid treatment protected the fruit color by a great reduction in the activities/gene expression of anthocyanin degradation enzymes and acidification of lychee pericarp.

Creating mesopores in ZSM-48 zeolite by alkali treatment: Enhanced catalyst for hydroisomerization of hexadecane

ZSM-48 zeolites with various Si/Al ratios were hydrothermally synthesized in the H;N（CH;）;NH;（HDA）-containing media. The obtained samples were highly crystallized with minor mixed phases as evidenced by X-ray powder diffraction（XRD）. The alkaline treated ZSM-48 zeolites maintained its structure under different concentrations of Na OH aqueous solution. Micropores remained unchanged while mesopores with wide pore size distribution formed after the alkaline treatment. The surface area increased from 228 to 288 m;/g. The Br?nsted acid sites had little alteration while an obvious increase of Lewis acid sites was observed. The hydroisomerization of hexadecane was performed as the model reaction to test the effects of the alkali treatment. The conversion of hexadecane had almost no change, which was attributed to the preservation of the Br?nsted acid sites. While high selectivity to iso-hexadecane with an improved iso to normal ratio of alkanes was due to the mesopore formation and improved diffusivity.

Preparation of the Supported Heteropolyacids Catalyst by Ultrasound-plasma Treatment

Novel catalysts of phosphotungstic heteropolyacids （PW12） supported on neutral alumina were prepared by assistance of ultrasound and plasma treatment. The prepared catalysts were characterized by FT-IR pyridine adsorption （Py-IR）, temperature programmed desorption of Pyridine （Py-TPD）, BET and X-ray diffraction （XRD）, and their catalytic performances were evaluated by the cationic polymerization of tetrahydrofuran. The results indicate that plasma treatment remarkably increases the surface acidity of the prepared catalyst while ultrasonic treatment induces PW12 to uniformly disperse on the support surface and expose more active sites for the acid catalytic reaction. A higher catalytic activity （69.7%） is obtained on the novel catalyst, which significantly outstripped that on the conventional sample （57.5%）.

Extraction process of chlorogenic acid in flos lonicerae by enzymatic treatment

A new method of extracting chlorogenic acid from flos lonicerae, and treating the materials with enzyme before being extracted by ethanol is developed, and the optimum conditions are also investigated in detail. Three important factors, enzyme dosage, treatment time and treatment temperature are adapted to optimize the extraction process. The experimental results show that the extract yield of flos lonicerae and chlorogenic acid can be obviously increased by the cellulase treatment, 61.5 mg chlorogenic acid is obtained from 1.00 g flos lonicerae at most. The optimal temperature of enzymatic treatment is 40 50 ℃. Compared with the use of single cellulase, the combined treatment of cellulase and pectinase increase the extract yield obviously but fail to improve that of chlorogenic acid.

ACID ELECTROLYTIC TREATMENT PROCESS OF SCRAP BATTERY SLUDGE

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Comparison of Alkaline Treatment of Lead Contaminated Wastewater Using Lime and Sodium Hydroxide

A lead-acid storage battery manufacturing industry in India produces several thousand liters of lead con-taminated acidic wastewater on a daily basis and uses hydrated lime to render the lead-contaminated acidic wastewater alkaline (pH = 8.0). Alkaline treatment of the acidic wastewater with lime though a cost-effective method, generates copious amount of lead-contaminated gypsum sludge. Other alkali agents such as sodium hydroxide, sodium carbonate and dolomite are also used for alkali treatment of the acid wastewaters. The present paper compares the relative efficiency of hydrated lime and 0.05 M to 1 M NaOH solutions with re-spect to 1) amounts of sludge produced, 2) immobilization of the soluble lead in the acidic wastewater (AWW) and 3) increase in TDS (total dissolved solids) levels upon treatment of AWW with NaOH solutions and lime. The study also performs equilibrium speciation upon alkaline treatment of AWW with lime and NaOH (sodium hydroxide) solutions using the Visual MINTEQ program to understand the chemical reac-tions occurring during treatment process.

Effect of tranexamic acid on the treatment of patients with upper gastrointestinal bleeding: A double-blinded randomized controlled clinical trial

Objective:To determine the efficacy of tranexamic acid(TXA)in the management of acute upper gastrointestinal(GI)bleeding.Methods:A total of 70 patients with acute upper GI bleeding were included in this double-blinded randomized controlled clinical trial from September 2018 to December 2018.Patients were divided into the control group(received fluid therapy and intravenous infusion of pantoprazole,35 cases)and the TXA group(received intravenous TXA besides the treatment of control group,35 cases).Rebleeding,admission duration,and need for blood transfusion were compared between the two groups.Results:Fifteen patients(42.9%)in the TXA group and 10 patients(28.6%)in the control group stayed in hospital for more than 3 days during their admission(P=0.21).Rebleeding occurred in 8 patients(22.9%)and 5 patients(14.3%)of the TXA group and the control group,respectively(P=0.35).More patients in the TXA group(21 cases,60%)received blood transfusion than the control group(8 cases,22.9%)(P=0.02).Conclusions:TXA did not improve the outcome of patients with acute upper GI bleeding.

New Progress regarding the Use of Lactic Acid Bacteria as Live Delivery Vectors, Treatment of Diseases and Induction of Immune Responses in Different Host Species Focusing on <i>Lactobacillus</i>Species

Lactobacillus species are non-spore-forming, gram-positive bacteria and lactic acid producing bacteria (LAPB) that naturally inhabit the human and animal gastrointestinal and mouth organs. The aim of this review was to evaluate the new progress regarding the use of Lactobacillus species as live delivery vectors, prevention, and treatment of pathogenic and metabolic diseases. Lactobacillus strains of probiotics have been extensively studied and have confirmed that they can absolutely improve performance as live delivery vectors, a treatment option of various diseases such as: Hemorrhagic cecal coccidiosis in young poultry, hypertension, avian flu, obesity, diabetes, Derzsy’s disease or parvovirus infection, human immunodeficiency virus infections, irritable bowel syndrome, gastrointestinal disorders, Fungal infections, vaginal eubiosis, fish and shellfish species diseases. We give you an idea about that Lactobacillus species have been proficient in preventing and treating both disorders in animal models and some are used for clinical trials. We present the most current studies on the use of Lactobacillus strains that had an impact on an effective immune response to a specific antigen because a variety of antigens have been expressed. Therefore Lactobacillus strains can be considered as good candidates because of its potential for diseases treatment and vaccine development as heterologous protein secretion to date.

An in Vitro Investigation of Acid Etching Treatment Prior to Post and Core Cementation and Teeth Fracture Resistance

In order to investigate how to enhance the teeth fracture resistance after the post and core treatment, an in vitro study was conducted to measure the fracture resistance of endodontically treated teeth restored with cast post and core with two kinds of surface treatment technology and acid etching preparation on the dentinal surface. Sixty-four recently extracted human single-rooted first premolars were endodontically treated and sectioned approximately 1.5 mm above the cementoenamel junction to remove the coronal portion. Each specimen received a cast post, core build-up and a metal alloy crown restoration. All teeth were randomly divided into the smooth surface post, core repair group, the sand blasting surface post, and core repair group, each group was divided into 10 s, 30 s, 60 s acid corrosion treatment group and control group. In acid test groups, an acid etching solution was applied for 10, 30 and 60 seconds, respectively, to the root canal wall surface. Each specimen was embedded in acrylic resin block and tested in an electronic universal testing machine. Fracture loads results showed that canal acid etching could increase teeth fracture resistance strength both in smooth groups and sandblasting group, and achieved the best effect when acid etching for 30 s. Sand spray treatment on the surface of the cast metal post can improve the flexural strength of the teeth after postcrown restoration. Acid etching on the root canal wall surfaces and sand spray treatment on the surface of the cast metal post can improve the flexural strength of the root after post-crown restoration. Therefore, these two methods could be used to strengthen the tooth fracture resistance, and maintain the long-term therapeutic effect of cast post and core restoration.

Change of Mineral Elements and Amino Acids in <i>Malus hupehensis var. pingyiensis</i>Leaves under Cd Treatment

The objective of this paper is to research the effects of CdCl2 treatment on mineral elements and amino acids in leaves of Malus hupehensis var. pingyiensis. The seedlings of Malus hupehensis var. pingyiensis with 6 leaf were cultured in 1/2 Hoagland nutrient solutions of different CdCl2 treatments (0, 0.5, 5 and 10 mg·L-1), respectively. The mineral elements and amino acids of the leaves in Malus hupehensis var. pingyiensis were measured in the day 30. Compared with the control (0 mg·L-1 CdCl2), the treatments significantly decreased the contents of Mg, Fe and Zn in the tested leaves and obviously increased the contents of Cd in the experimental leaves. As to Ca and Mn, low concentration Cd treatment (0.5 mg·L-1 CdCl2) promoted their absorption, however, high concentration Cd treatments (5 and 10 mg·L-1 CdCl2) inhibited their absorption. The metabolism pathway and content of amino acids in the Malus hupehensis var. pingyiensis leaves under Cd treatment were modified, the content of amino acids in the glycolate pathway became larger than that in control, the content of amino acids in the pyruvic acid synthesis pathway and tyrosine and phenylalanine became smaller than that in control, the content of other amino acids also had made a certain degree change. The results provided the important basis for safety production and quality evaluation of leaves in Malus hupehensis var. pingyiensis.

Analysis on the Variation Expression of Difficult-Dissolved-Proteins of Diapause Eggs After Activating by Acid Treatment

Using HCl to activate the diapause eggs is a traditional technique of artificial hatching applied in silkworm egg production. Its mechanism has not yet been clarified. This experiment explored the effect of HCl on the termination of diapause of silkworm eggs cold-stored for 45 days from the point of proteomes. Two-dimensional electrophoresis techniques and ESI- MS-MS were used to compare and analyze the variation expression of difficult-dissolved-proteins of diapause eggs coldstored for 45 days before and after acid treatment. Through analysis on the two-dimensional electrophoretogram, there were 296 dots before acid treatment and 302 after the treatment, respectively. Amongst them 265 dots were matchable. The matchability reached 88.6%. There were 31 specific protein dots before acid treatment and 37 after acid treatment, respectively. ESI-MS-MS analysis was conducted for two specific protein-rich dots which disappeared after acid treatment. The results indicated that the sequence of No. 1 protein dot had 55 amino acids＇ peptide matched with those of chorion protein （Bombyx mori）. While the sequence of No. 2 protein dot had only 15 amino acids＇ peptide matched with those of heat shock protein hsp 19.9 （Bombyx mori）, and it was presumed to be an unknown protein. The difficult-dissolvedproteins of diapause eggs have variation expression after acid treatment. Some proteins before and after acid treatment are changed in MW.

Study of Physical, Chemical and Morphological Alterations of Smectite Clay upon Activation and Functionalization via the Acid Treatment

The present study was carried out on the effect of acid leaching on the modification and structure alteration of montmorillonite. A nanostructured, activated material was prepared by selective leaching of pure smectite clay with different concentrations of sulfuric acid (1 - 10 N/L) at 85°C for 120 min using a solid/liquid ratio of 1:20 and a reflux system. The Fourier transform infrared (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-Ray diffraction (XRD) techniques were used for the characterization and study of the acid-treated montmorillonite clay. Chemical structure of specimens was distinguished by FTIR. The results showed that the formation of Si-OH bonds and leaching of Al3+ ions increased progressively with severity of the acid treatment. As the FTIR studies indicated, acid treatment led to the removal of the octahedral Al3+ cations and an increase in the Si-OH bonds. The morphological alteration of the untreated and treated montmorillonite was investigated by using TEM and SEM. X-ray fluorescence (XRF) analysis revealed a considerable decrease in the relative content of Al by increasing the acid strength. Moreover, the XRD results showed that the treatment using highly concentrated acid resulted in the formation of an amorphous silica phase.