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In this study, a series of HZSM-5-X were prepared by acid modification, then Ce/HZSM-5-X (X = 0, 0.2, 0.4, 1.0, 2.0) were prepared by impregnation method. The catalytic performance of the catalysts on dichloromethane (DCM) oxidation was investigated. Through different characterizations, HZSM-5-X exhibit higher specific surface area, better redox ability, richer acidity and more suitable acidic site distribution after acid treatment. Among them, Ce/HZSM-5-0.4 shows better catalytic activity with the lowest by-product and the best CO2 yield, its T90 is 302 °C and the CO2 yield of T90 more than 80 wt%, which demonstrates that the acid modification of carrier plays the positive effect on the catalyst capacity for DCM oxidation.

Graphene oxide is successfully synthesized using Hummer’s method and Hummer’s method with additional KMnO4. Hummer’s method with additional KMnO4 shows higher oxidation of graphite as compared to Hummer’s method. The reduction of graphene oxide using sodium hydrosulfite shows some of functional group remains on the lattice of graphite as clear from FTIR spectra. Further, acid treatment of graphene is carried using H2SO4 at 90 °C for 90 min, showing removal of functional group of graphene from the surface revealed by XRD and obtaining more pure graphene.

Fiber-type supercapacitor (FSC) is indispensable for soft electronics. Modifying substrate without depositing electroactive material can prevent electroactive material from peeling off and enhance flexibility of FSC. Acid treatment is one of the most effective methods to enhance energy storageability of carbon fiber (CF) via inducing functional groups and creating defects for charge accumulation. In this work, it is firstly to apply sonication and heat treatments on CF electrodes in acid mixture to enhance hydrogen ion diffusion path and acid etching rate. The highest specific capacitance ( C L ) of 319.0 mF/cm is obtained at 20 mV/s for the CF electrode prepared using full sonication for 45 min and heat treatment at 80 °C at last 25 min, while the untreated CF electrode only shows C L value of 8.3 mF/cm. The FSC with optimized CF electrodes shows maximum energy density of 12 μ Wh/cm at 250 μ W/cm. After 10,000 times repeated charge/discharge process, C L retention of 78% and Coulombic efficiency of 88% are achieved. Excellent flexibility is attained with high C L retentions with bending angle of 180° and bended for 1000 times. Other energy supplying methods are expected to promote the acid treatment on CF and create more efficient FSC in near future.

The development of active oxidative desulfurization (ODS) catalysts is of practical importance. Recently, MOF-808(Zr) has been attempted to use as ODS catalyst due to its various advantages. However, generally MOF-808(Zr) prepared by conventional method was less active in the oxidation reactions due to the lack of defect sites in the structure. In this contribution, we report that the catalytic oxidative performance of MOF-808(Zr) can be enhanced by acid treatment due to the formation of defect sites resulting from the partial removal of organic linkers in the structure. During the experiment, the effect of acid concentration, treatment time, the addition amount of oxidant and reaction parameters on the performance of MOF-808(Zr) was studied. The catalytic results show that MOF-808(Zr) treated with 0.4 M HCl for 1h can catalyze the oxidation of dibenzothiophene completely at 60°C in 15 min. The activity (mole number of converted DBT per hour per unit mass) is 70 mmol h−1 g−1, which is much higher than that (45 mmol h−1 g−1) of parent MOF-808(Zr). In addition, the catalyst can be reused several times without obvious loss of catalytic performance.

Background Rising health awareness has driven tremendous public interest among food manufacturers and academicians in identifying and developing novel functional foods. Studies on the health-promoting benefits of soy products and their quality improvement measures have become the hotspot across the globe. However, there is limited information summarizing the existing soy products and their improved quality attributes associated with different technical strategies. Scope and approach New processing strategies (physical, chemical, and biological) applied in the modification of various soy products are summarized and their pre- and post-modified quality attributes are systematically reviewed. The current review also highlights the role of fermentation in enhancing the nutritional, sensory, and health-promoting features of soy products. Key findings and conclusions Traditionally processed soy products exhibit intrinsic quality defects such as beany flavor, high anti-nutrients content, complex structure, and low bioavailability of soy protein and isoflavones. New processing strategies including blending with extra ingredients, non-thermal treatment, dietary fiber modifications, acid treatment, germination and tailored fermentation could render these soy products with improved nutritional and sensory characteristics, especially, fermentation has been reported to provide soy products with enhanced health-promoting features such as anti-diabetic, anticancer, anti-inflammatory, and antioxidant effects as well as improving the cardiovascular and bone health. The information accumulated in this review may provide up-to-date evidence supporting diversified soy products as a class of important functional foods.

La-deficient La1-xCexMnO3 mixed oxides, obtained by selective dissolution in 1 ​M nitric acid, were employed in methane complete oxidation. The majority of the La cations in these perovskites were removed, resulting in increased specific surface areas, better reducibility and greater activity. Incorporation of a small amount of Ce stabilized the structure and a perovskite phase persisted in La-deficient La1-xCexMnO3 mixed oxides after 12 ​h of acid dissolution. La0.95Ce0.05MnO3 after the acid treatment exhibited satisfactory catalytic activity, with T50 and T90 values of 365 and 459 ​°C, respectively, which was even comparable to that previously reported 1% Pd/Al2O3 catalysts. And it showed excellent long-term activity even in the presence of CO2 and H2O.

Consumer waste of cotton cellulose is receiving increasing attention. In this study, in order to recycle waste cotton cellulose fibre into ultrafine powder efficiently, a compact process containing sulfuric acid treatment and stone milling was examined. Scanning electronic microscopy (SEM) and atomic force microscope (AFM) were used to study the morphology of the original cellulose fibre, acid modified fibre and milled cellulose powder. The particle size, crystallinity and strength loss were also explored. The results illustrated that the fibre strength can be largely reduced by acid treatment and high temperature and the crystallinity of the fibre decreased after stone milling. Ultimately, the production efficiency and the output of the micron dry cellulose powder were greatly improved. About 1 kg dry ultrafine powder with particle size around 40 μm was achieved in 1.5 h by stone milling in laboratory. This method shows a great potential for industrial application in the future.

Owing to the rapid construction and rebuilding activities occurring in the country, huge amount of construction and demolition waste is generated. To cater the needs for disposal of this waste, recycling them for use in road construction has great potential and is important for sustainability. In order to address the same, a study has been carried out to explore the use of waste materials such as recycled concrete aggregates (RCA) in pavements. In this paper, few treatment methods of RCA such as acid treatment, thermal treatment and bituminous emulsion have been compared to adjudge the best treatment of RCA. For purpose of comparison, mixes were made using different treatment techniques with RCA. It was observed that the mixes comply with the standards specified in MoRTH, India in terms of Marshall Characteristics and moisture susceptibility. Bituminous emulsion treated RCA was found to be the most appropriate treatment method.

In this work, GdMnO3 material is successfully prepared using sol-gel method and GdMn2O5/GdMnO3 materials are in-situ generated by acid treatment. These materials are investigated and applied as catalysts for oxygenated VOC complete oxidation. The evaluation results show that GdMn2O5/GdMnO3-1.00 exhibits a remarkable increase in catalytic activity (T50% = 198 °C and T90% = 225 °C) of 2-ethoxyethanol oxidation when compared with the initial sample GdMnO3 (T50% = 223 °C and T90% = none). Characterization analyses show that acid treatment can result in the significant improvement of specific surface area from 20.502 m2·g−1 to 67.952 m2·g−1, abundant surface Mn4+ content and active oxygen, excellent reducibility at low temperature in GdMn2O5/GdMnO3-1.00 sample. In-situ DRIFTS results point out that the main functional groups such as νas(OCO), νas(COO), νs(C O) are formed in the process of 2-ethoxyethanol oxidation over GdMn2O5/GdMnO3-1.00 sample and some by-products including ethanol, 2-ethoxyethyl acetate, acetic acid, carbonic acid, 2-ethoxyethyl 2-methoxyethyl ester, ethane and 1,1′-oxybis[2-methoxy-] can be produced at a reaction temperature of 200 °C. Additionally, in-situ DRIFTS studies indicate the presence of gas-phase O2 plays a vital role in facilitating 2-ethoxyethanol deep oxidation to final products.

The gasification slag by acidification can leach abundant heavy metals. In this paper, the fate of heavy metals (Ni, Cd, and As) in the raw slag and the acidified slag that treated by HAc and HCl was systematically investigated combined with Density Functional Theory (DFT) calculations. The results show that the content of Ni and Cd is reduced with an increasing acid concentration and meets the regulatory standards by 7 M HAc and 3 M HCl, respectively. Most of Ni combined with gehlenite is released as gehlenite dissolves during acid treatment, whereas Cd in combination with gehlenite and iron compounds is hard to release at lower HAc concentrations. Unexpectedly, the content of As tends to elevate at a higher concentration of HAc, which is due to the increase in the content of Ca by new Ca-compound formation and the higher binding capacity of Ca to As according to DFT results. Additionally, if the acid-base ratio reaches about 2.0 by acid treatment, there would be a maximum leaching rate. It is recommended that acid concentration should be controlled to avoid a secondary risk of heavy metals.

In recent years, carbon materials are widely investigated because of they are enormously sensitive to H2 at room temperature conditions. In the present work, the inexpensive candle carbon soot (CCS) is used to detect 0.5% concentration of H2 gas at room temperature. A simple flame of candle is used to synthesize the layers of carbon soot at room temperature conditions. It is observed that, the acid treatment of CCS drastically improved their structural and sensing properties as compared to as-synthesized CCS. The effect of acid functionalization on the CCS structure were investigated by X-ray diffraction (XRD) and Raman spectroscopy. To the best of our knowledge, detection of low concentrations of H2 gas is reported here for the first time using economical CCS at room temperature.

This study presents morphological and structural variations of K-Feldspar mineral after acid treatment. Both organic and inorganic acids such as C2H2O4, HCl, HNO3 and H2SO4 were employed for this purpose. Another aim of this study was to find an optimum experimental condition for iron (Fe) removal with a minimum damage on the structure of K-Feldspar in which high whiteness index is obtained. The effect of different parameters such as concentration, pH and temperature on the final structure of this mineral was investigated. To find out the chemical composition of powder, XRF was utilized. FTIR, XRD and SEM were employed to study the structure of mineral. Spectrophotometry was chosen to analyze whiteness index of powder after acid treatment. It was found that O Al O bond at 647 cm−1 for H2SO4 and HNO3 treated sample disappeared. However, HCl and C2H2O4 were ineffective at this band. In addition, the results revealed an increase in K-Feldspar content, a decrease in Fe content, an increase in whiteness index and no significant structural change for C2H2O4 leached sample. Whiteness index of 91% was obtained for C2H2O4 leached sample with the pH of 2.5 to 3 at temperature of 50 °C and during 1 h.

Background Peanut is a nutrient-rich popular food. However, it has been estimated that 1%–2% of the world's population are allergic to peanut, which can cause serious allergic reactions, including allergic shock and anaphylactic death in certain people. Thus, identifying peanut allergens and decreasing allergenicity have been serious and important food safety issues. Scope and approach Sixteen peanut allergens and their structure and IgE linear binding site are summarized in this review. Various techniques and means to reduce peanut allergenicity, including physical (heat, radiation, and high-pressure treatments), chemical (glycosylation, magnetic-bead adsorption, and acid treatment), and biological (microbial fermentation, enzyme catalysis, and genetic engineering) methods, are evaluated and compared. Key findings and conclusions Multiple allergens are present in peanuts. Their sequences, structures and allergenic characters have been examined extensively. Although Ara h 1, Ara h 2, Ara h 3, and Ara h 6 are the major allergens, individuals allergic to peanut often had IgE recognized multiple peanut allergens. Among the various methods capable of reducing peanut allergenicity, heating and high-pressure treatments appear to be practical and effective in general, and irradiation, acid treatment, and other physical and chemical may work under certain circumstances. Of note, fermentation has the advantage of improving tasting and reducing allergenicity at the same time. It is conceivable that combination of multiple methods will result in more effective means to reduce allergenicity of peanut and prevent the development of serious allergy.

AlFe2B2 was synthesized by arc-melting to investigate its magnetic properties. The magnetic properties of AlFe2B2 with impurities are different from those of pure AlFe2B2. In this study, an as-cast sample and an annealed sample followed by acid treatment were prepared to understand the magnetic properties of pure AlFe2B2. In the powder X-ray diffraction measurements, a pure AlFe2B2 phase was confirmed after annealing followed by acid treatment. Various magnetic properties were investigated by using superconducting quantum interference device (SQUID) measurements for the as-cast and the post-treated samples. Saturation magnetization and effective magnetic moments of the post-treated sample are close to the theoretical values of pure AlFe2B2. The maximum magnetic entropy change (˗ΔS) of pure AlFe2B2 is 6.95 J/kg∙K at 5 T. Pure AlFe2B2 shows a positive slope in the Arrott plots corresponding to a second-order magnetic transition. Magnetic transition temperatures estimated from dM/dT, the Arrott plots, and the Curie-Weiss law are mutually complementary.

Fusarium rot of muskmelon is a common and frequently-occurring postharvest disease, which leads to quality deterioration and neosolaniol (NEO) contamination. New strategies to control postharvest decay and reduce NEO contamination are of paramount importance. The effects of acetylsalicylic acid (ASA) treatment on the growth of Fusarium sulphureum in vitro, and Fusarium rot development and NEO accumulation in fruits inoculated with F. sulphureum in vivo were investigated. The results showed that ASA inhibited the growth of F. sulphureum, evident morphological and major cellular changes were observed under the microscope. In vivo testing showed that 3.2 mg/mL ASA significantly suppressed Fusarium rot development and NEO accumulation after 6 and 8 d of pathogen inoculation. Meanwhile, Tri gene expressions involved in NEO biosynthesis were down-regulated after treatment. Taken together, ASA treatment not only reduced Fusarium rot development by inhibiting the growth of F. sulphureum, but decreased NEO accumulation by suppressing NEO biosynthesis pathway.

Garnet-type solid-state electrolytes (SSEs) are very promising due to their high ionic conductivities at room temperature and high stability against Li metal. However, the poor garnet/Li interfacial contact caused by Li2CO3 surface contaminant can lead to lithium dendrite growth and the performance decay of solid-state batteries (SSBs), which still hinders their practical application. Herein, a universal and simple method of rapid acid treatment is proposed to perfectly remove the surface Li2CO3 and retrieve a lithiophilic SSE surface. The SSE/Li interfacial resistance dramatically decreases from 940 Ω cm2 to 26 Ω cm2 at 30 °C. The acid treated garnet-SSE pellets exhibit an interfacial resistance comparable to the pellets with various surface coatings. In addition, the intrinsic garnet/Li interface remains stable during cycling, which enables the Li symmetric cells continuously cycle over 700 h under 0.2 mA cm−2 at 30 °C. And the LiFePO4/Li and LiCoO2/Li cells with acid treated garnet-SSE show excellent cycle and rate performances after eliminating the surface contaminant. These results indicate that rapid acid treatment not only guides a new understanding for an intrinsic garnet/Li interface but also is a simple and high-efficiency strategy to well address the interfacial issue for SSBs.

International audience; Gelation of dairy/plant protein mixed dispersions and emulsions was achieved upon heat or acid treatment. The presence of plant proteins is generally leading to a lowering of the gel strength compared to dairy proteins alone. This is mostly due to the formation of independent networks by the different protein sources, which do not often interact strongly. As well, plant proteins were shown to compete with dairy proteins for calcium chelation, which can influence gel properties. Addition of a dispersed oil phase generally allows to better control the gel strength as it induces a specific protein distribution at the interface and enables formation of active oil droplets embedded in the protein network.

Phosphorus (P) dissolution from polyaluminum chlorides (PAC) sludge was investigated for sustainable P recovery. P dissolution followed 1st order kinetics with the rate constants of 3.8 × 10−2, 0.8 × 10−2, 1.3 × 10−2 and 1.9 × 10−2 min−1 at pH 1, 2.5, 10.5 and 12, respectively. Strong acidic and alkaline conditions dissolved about 82 (pH 1) and 88% (pH 12) of the total P by adding 0.214 g HCl and 0.357 g NaOH per gram P dissolved, respectively. Chemical P fractionation showed that more than 96% of the total P of the PAC sludge was Al P and it was reduced to 11.3 (pH 12) and 12.6% (pH 1.0) after the acid and alkali treatment. ATR-FTIR showed that AlPO4 in the PAC sludge was transformed to Mg3(PO4)2∙4H2O and CaHPO4∙2H2O after alkali treatment and H3PO4 and Na/Mg P after acid treatment. Dissolved P can be recovered by precipitation with Ca and Mg.

Two different methods, ultrasound at three temperatures (UT, 25, 50 and 70 °C) and acid treatment for two lengths of time (AT, 1 h or 4 h), were applied for OSA corn starch, and the physicochemical properties of the products as emulsifiers were examined. The degree of substitution decreased with UT temperature increase or AT time increase. For pasting and thermal properties, the amorphous region of the OSA starch was initially degraded by UT or AT, and the crystalline regions were subsequently degraded, inducing a continual decrease in relative crystallinity. The stability of the emulsion containing OSA-50UT, OSA-70UT or OSA-AT1H was well-maintained over three weeks. A higher correlation between variables was observed in UT samples than in AT samples. It was observed that OSA dextrin was more suitable as an emulsifier than was OSA starch. In particular, both control (with yolk) and mayonnaise containing OSA-70UT were evaluated as the most acceptable in sensory test.ss.

Concrete grinding from highway maintenance operations produces large amounts of a highly basic liquid residue, posing a significant challenge to proper disposal. To discard this residue with little risk to human health or the environment, it should be solidified and its pH should be neutralized. Herein we present the serendipitous discovery that both goals can be met by treatment with citric acid. Through the use of 13C and 29Si solid-state NMR we determined that such treatment removes the calcium from the concrete structure, thus allowing the solubilization of its one-dimensional silica chains. These silica chains then cross-link in solution forming a highly porous silica material that is able to absorb the water from the residue. This new waste treatment process, which may utilize other acids with low water content, promises to facilitate a significantly improved methodology for the disposal of concrete grinding residue in a safe and environmentally friendly manner.

Crushed stone powder and aluminum ash are industrial wastes, and effective utilization of these wastes has been highly expected. Since the main components of the two wastes are Si, Al and O, those wastes can be used as starting materials for synthesis of zeolites of which some types have been commercialized as catalysts and ion-exchangers. In this study, zeolites A and X well-known as practical materials were successfully synthesized with high purity using the two industrial wastes by a mild process based on two hydrothermal treatments with intermediate acid treatment. In the first hydrothermal treatment at 150 °C, quartz in the crushed stone powder was dissolved and acid-soluble hydroxysodalite (Na8(AlSiO4)6(H2O)2(OH)2) with Si/Al = 1 and sodium aluminosilicate (Na6(AlSiO4)6) were formed. Those compounds were dissolved with HCl aq. solution. The zeolites were successfully synthesized from the second hydrothermal treatment of the yellow dried filtrates at 80 °C in NaOH aq. solution. In the process proposed, removal of Ca from the crushed stone powder was effective to formation of zeolites A and/or X. Selective synthesis of zeolites A and X was achieved by controlling the acid treatment conditions. Furthermore, the effect of the drying condition of the filtrate obtained after the acid treatment was also investigated on the differences in the product phase.

The reasons for the drill pipes failure as a result of interaction with formation water and killing fluids were analyzed. It was determined that the aggressiveness of killing fluids increases as a result of acid treatment of wells, which causes severe pitting corrosion. The main corrosive components of the killing fluids from the exploited wells determined by chemical analysis were chlorides. The determined residual life-time of the G105 drill pipe in the acidic killing fluid was only 16.65 days, indicating that their usage in acidic, highly mineralized killing fluids is unacceptable.

In this study, removal of cadmium (Cd2+) from rice proteins (RPs) by soaking with hydrochloric acid (HCl) or ethylene diamine tetraacetic disodium (EDTA-2Na) solutions was reported. For HCl-soaking, Cd2+ removal reached equilibrium within 30-min treatment, and the size of RPs particles and reaction temperature had negligible effects on the Cd2+ removal rate (RCd). However, extra washing of HCl-treated RPs by distilled water or acid solution can further enhance RCd effectively. The reaction pH had a profound effect on RCd, and the reduction of pH values from 5.5 to 4 can boost RCd from 16.4% to 92.3%. On the other hand, by increasing the concentration of EDTA-2Na from 10 μg/mL to 40 μg/mL at pH 7, RCd increased from 69.1% to 92.0%. However, the reduction of pH resulted in the formation of insoluble conjugates consisting of RPs, EDTA and Cd2+, therefore lowering RCd. Both of the two methods reduced the mineral content in RPs, but had no significant impact on their amino acid compositions. Furthermore, compared to the soaking by EDTA-2Na, acid treatment weakened the emulsifying and foaming capabilities of RPs to a greater extent.

In this work, waste coconut husk was explored as potential raw material for silica production. Coconut husk was burned in controlled environment inside electrical furnace at 500, 600 and 700 °C. These ashes were treated by using two different chemical treatments to extract the highest percentage of silica. XRF analysis of coconut husk ash (CHA) revealed that the content of SiO2 varies between 8 and 11% and increased up to 90% after chemical treatment. Based on the XRD spectrum, silica obtained was in crystalline form after acid treatment but was in amorphous form after the alkali treatment. The CHA morphology on FESEM images observed to be rod-like structure but changed to irregular shapes and started to agglomerate together after the chemical treatments. EDX results show good agreement with XRF data as the same elements detected during both analysis. Alternative source of high purity silica can be obtained from CHA and it has high potential in optoelectronic application. Keywords: Coconut husk ash, Silica, XRD, XRF, FESEM, Agricultural waste

The design and development of highly efficient non-precious metal single-atomic ORR catalysts for proton exchange membrane fuel cells (PEMFCs) are highly desirable but challenging. Herein, we report a novel polydopamine (PDA)-metal complex-assisted pyrolysis strategy for producing zeolitic imidazolate framework-derived catalysts with a hierarchically porous carbon support and highly exposed dense-FeN4 sites (Z8@DA-FIP-950-C). The resultant Z8@DA-FIP-950-C catalyst shows remarkably enhanced performance for oxygen reduction reaction (ORR) with a half-wave potential (E1/2) of 0.828 V in 0.1 M HClO4 solution, which is close to commercial 20 wt% Pt/C catalyst. Impressively, the Z8@DA-FIP-950-C exhibits peak power densities of 982 and 454 mW cm-2 in H2/O2 and H2/air PEMFCs, respectively, which are superior to most of non-precious metal catalysts reported to date. In addition, we construct the quantitative relationship between the active site activity and ORR performance, and prove the dominating role of the FeN4 site density to the observed excellent PEMFC performance. This work demonstrates a facile strategy to prepare the 3D hierarchically porous carbons with a maximized exposure of high-dense FeN4 sites (without acid treatment), providing a useful guidance for the design and development of novel highly-efficient single-atom catalysts for the renewable energy applications.

Background Due to excellent oxygen storage capacity and redox ability, Ce-based catalysts are usually considered as one of the promising candidates of traditional V-based catalysts for NH3-SCR of NO. However, surface acidity of Ce-based catalysts is often insufficient which restrains their SCR performance to some extent. Methods Herein, ZrO2-supported CeO2 catalysts were prepared by precipitation and wet impregnation methods. Aiming to promote catalyst surface acidity, a novel method was proposed to pre-treat ZrO2 support with various acids (HCl, HNO3, H3PO4 and H2SO4) via impregnation process. and the effects of acid treatment on SCR performance of CeO2/ZrO2 catalysts had been investigated. Significant findings It was worthy to note that H2SO4-treated CeO2/ZrO2 catalyst exhibited a superior NO removal efficiency which was higher than 94% in a wide temperature range of 248–500 °C. NH3-TPD results revealed that the surface acidities acidity of CeO2/ZrO2 catalysts had been obviously enhanced after acid treatment with HNO3, H3PO4 and H2SO4, except for HCl. According to in-situ DRIFRS results, one could infer that SCR reactions occurred over CeO2/ZrO2 catalyst without acid treatment might proceed only in E-R mechanism. But for acid-treated CeO2/ZrO2 catalysts, both E-R and L-H mechanisms were might be followed in SCR reaction process.

The value-added utilization coal gasification fine slag (FS) is extremely vital for minimizing the environmental problems. In this study, coal gasification FS was successfully used to prepared hierarchical porous composites (HTC) for CO2 adsorption. Furthermore, the role of slag particles (SP) in the composites was also studied through orthogonal experiments designed by acid washing conditions. Orthogonal experiments showed that the surface area of the HTCs was varied from 852 to 1295 m2/g except the samples treated by HF. The changes were primarily contributed to the SP content and the existing forms in the HTCs. There had no micropores in the HTCs treated by acid at low temperature and acid concentration because those pores were blocked by the SP. While increasing the treatment temperature and acid concentration, the acid could diffuse into the micropores to remove embedded SP and the micropores were exposed. The HTCs also proved to be attractive for CO2 capture. The highest CO2 adsorption capacity of 2.64 mmol/g at 25 °C was achieved with 1- FSHTC-AT sample. The sample not only exhibited good selectivity of CO2 over N2 of 10.8, but also had fast adsorption kinetics that it reached adsorption equilibrium in less than 2 min. Besides, there were no apparent decrease in the CO2 adsorption capacity after ten cycles. All these results suggest that fine slag has a great potential to produce HTCs for practical CO2 adsorption applications. Furthermore, it also provides a sight into the role of SP in HTC which could realize pore structure control by changing acid treatment conditions.

Injection of acidic formulations into a carbonate reservoir is commonly used in the oil industry to enhance or restore well productivity. The purpose of this method is to create empty channels, the so-called wormholes, which pass deeper into the formation further than the perforated area in the near-wellbore zone of the formation. During the oil production, wormholes become pathways for crude oil to flow into wells. Most of the experimental and numerical studies carried out on this issue are limited in their observations, because they think the issue of wormhole formation only depending on the technological parameters of acidizing (speed and volume of injection). Our study aimed at investigating the effect of the material composition (content of calcite and dolomite) of carbonate rocks on the efficiency of acid treatments. We focus on investigating the effect of the percentage of calcite and dolomite fractions in a carbonate rock on acidizing efficiency, and try to elaborate the influence caused by the percentage of calcite and dolomite associated with the carbonate samples. Note that not all carbonate rocks need to use the same technological parameters for acidizing. However, it is necessary to individually select a few critical technological parameters based on the holding time of the composition in the reservoir as well as on the volume of the composition. In conclusion, the authors have developed recommendations for the application of acid treatment of oil fields in the Perm Krai (Russia), which differ in the material composition of the rock. At one of the oil fields, the authors have conducted pilot tests considering the developed recommendations and received a significant increase in oil recovery (on average, an increase of 1.5–2.0 times) compared to the previous acidizing measures. The results obtained have scientific and practical significance and prospects for further improvement of acid action in carbonate reservoirs.

International audience; Commercial zeolites with CHA, MFI, and LTL framework topology are subjected to acid treatment with chromic acid (H2CrO4) solutions with concentrations ranging between 0.1 and 10 w/%. As chromic acid forms polymeric species as a function of concentration, specific effects were obtained with these three zeolites, differing by their framework topology, pore size, Si/Al ratios and crystal size. The etched zeolites are characterized by X-ray diffraction, SEM, TEM, N 2 physisorption, ICP-AES, 27 Al and 29 Si MAS NMR, 29 Si{ 1 H} cross-polarization spectra, EDX. Their acidic properties are probed with pyridine and d 3-acetonitrile by in situ FTIR. Results indicate that the 8 MR (CHA) and 10 MR (MFI) zeolites are more resistant to acid treatment with chromic acid than the 12 MR (LTL) zeolite. This paves the way for rational control of zeolite dealumination since adjusting chromic acid concentration will generate anions appropriate for treating a particular zeolite.

The effect of a post-synthesis treatment of 7.5 wt% CuO-CeO2 catalyst with acid solutions on its performance towards the preferential oxidation of CO reaction was investigated. The acidic environment was found to affect the redox and catalytic properties of this solid composition. In particular, modification at low pH (

Plasma-assisted catalysis technology has been identified as one of the most efficient feasible routes for DeNOx. In this work, a combined NOx adsorption-CH4 plasma discharge process has been developed for DeNOx. The conversion of the adsorbed NOx on H-MOR and Co-MOR could reach 99.7% and 98.3% in the present process at ambient temperature, respectively. The results verified the feasibility of the present process using MORs as adsorbents and catalysts in theory. Then, the cost-effective natural mordenite (NMOR) was used as the adsorbent and catalyst instead of MOR. After acid treatment and ion-exchange, the modified Co-NMOR exhibited higher NOx adsorption capacity than MOR. The NOx conversion and N2 selectivity on Co-NMOR were 95.0% and 100.0% in the CH4-plasma discharge stage, respectively. Meanwhile, the cyclic operation of Co-NMOR for DeNOx has also been investigated.

Demographic changes are leading to an aging society with a growing number of patients with cardiovascular diseases, relying on antiplatelet drugs like acetylsalicylic acid (ASA). Although antiplatelet agents are suspected to be protective not only in the cardiologic but in the neurovascular field, the alteration of the coagulating process could have a major impact on the course and outcome after rupture of intracranial aneurysms.Between June 1999 and December 2014, 1422 patients were treated for aneurysmal SAH in our institution, 144 (10.1%) with continuous ASA at the time of aneurysm rupture. A matched-pair analysis was performed.The rate of patients with continuous ASA treatment while rupture of the aneurysm is rising significantly (P0.01). Those patients were significantly older than patients without ASA (60 vs. 53 years, P0.001). ASA-treated patients more often had aneurysmal rebleeding (4.7% vs. 2.3%, P = 0.3) and treatment-related hemorrhagic complications (13.9% vs. 6.2%, P = 0.06). However, rates were not different in microsurgical or endovascular procedures (16.4% vs. 12.2%, P = 0.6). Favorable outcome (Modified Rankin Scale 0-2) was achieved in 49.3% of the ASA group and 52.1% of the control group (P = 0.7).Patients with continuous ASA treatment were significantly older than patients without ASA, but there was no difference in admission status or bleeding pattern. Outcome was not different in the matched-pair analysis. There was no statistical difference in treatment related-complication rates of microsurgical and endovascular procedures. Therefore, ASA use should not influence treatment decision of the ruptured aneurysm.

In this study, the combined ionizing radiation-acid pretreatment process was firstly applied to enhance hydrogen fermentation of grass waste. Results showed that the combined pretreatment synergistically enhanced hydrogen fermentation of grass waste. The SCOD and soluble polysaccharide contents of grass waste increased by 1.6 and 2.91 times after the combined pretreatment, respectively. SEM observation and crystallinity test showed the combined pretreatment effectively disrupted the grass structure. Owing to the more favorable substrate conditions, the hydrogen yield achieved 68 mL/g-dry grassadded after the combined pretreatment, which was 161.5%, 112.5% and 28.3% higher than those from raw, ionizing radiation pretreated and acid pretreated grass waste, respectively. The VS removal also increased from 13.9% to 25.6% by the combined pretreatment. Microbial community analysis showed that the abundance of dominant hydrogen producing genus Clostridium sensu stricto 1 increased from 37.9% to 69.4% after the combined pretreatment, which contributed to more efficient hydrogen fermentation.

Design of structure and properties of short carbon fibers (CF) reinforced hydroxyapatite (HA) composites is hard to achieve and satisfy performance requirement for weight-bearing bones replacement materials because of agglomeration and uncontrollability of distribution state of short CF. In this study, CF reinforced hydroxyapatite HA (CF/HA) composites with controllable orthogonal arrangement of CF in matrix were first designed and prepared by hot-pressing sintering. Properties of starting monofilament and mixed acid treated monofilament (TCF) were characterized for designing the composites. The results suggest that mixed acid treatment can change surface structure of CF by eliminating some structural defects as well as homogenizing surface structure. Surface roughness of fiber varied from 4.57 nm (CF) to 9.02 nm (TCF). Although tensile strength distribution of the TCF was reduced, average tensile strength of the TCF was reduced more quickly than that of the CF after high temperature treatment. When three-layer CFs was used as reinforcing material, largest bending strength and fracture toughness of 16.57 ± 0.90 MPa and 1.43 ± 0.11 MPa m 1/2 respectively were achieved, which increased by 16.77% and 22.22% compared with pure HA, and increased by 50.64% and 25.44% compared with three-layer TCF reinforced HA composites.

International audience; The rheological and microstructural properties of pure pea, pure milk, and mixed pea/milk gels were investigated and compared. Three gelation techniques were used: a thermal treatment, an acid treatment employing glucono delta-lactone, and an enzyme treatment employing chymosin and transglutaminase. Considerable differences in the gels' rheological and microstructural properties were observed. The thermally induced pure pea and mixed gels had comparable rheological and microstructural properties, suggesting the existence of interactions between pea and whey proteins. The enzyme-induced gels had a higher strain at rupture, a property that was associated with the presence of coarse aggregates. Within this gel type, mixed gels displayed a lower storage modulus than did pure pea or pure milk gels. Among acid-induced gels, pure pea gels were much stiffer than pure milk or mixed gels, probably because their final pH was lower. The addition of fat strengthens the mechanical properties of all pea gels studied, in particular in the mixed gels obtained by acid and enzyme gelation. The microstructural differences were consistent with the rheological differences. These results provide insight into the formation of gels via these gelation techniques and could inform the formulation of new food products that are enriched in plant protein.

In this work, we report a promising processing methodology for enhancing the comprehensive properties of twisted carbon nanotube (CNT) fibers by combining drawing treatment with a copper capsule and subsequent acid treatment. This strengthening methodology enables the accurate control of the diameter of the as drawn CNT fibers, and provides an effective way to minimize surface damage to the CNT fibers during processing. The results show that the density, the CNT bundle alignment and the CNT fiber purity were improved after the combined strengthening treatment. Consequently, the tensile strength, electrical conductivity and thermal conductivity were significantly enhanced. Owing to the excellent properties, the strengthened CNT fibers have potential applications as an electric wire material. Keywords: CNT fibers, Drawing treatment, Acid treatment, Mechanical property, Electrical conductivity, Thermal conductivity

Dimethylglyoxime (DMG) is an analytical reagent used to precipitate Ni from its aqueous solution. The process is very efficient for Ni recovery in terms of selectivity and completeness but hardly adopted industrially. The reason is attributed to the loss of the reagent when calcined. The paper outlines extraction of DMG from Ni-DMG complex by sulphuric acid treatment in two methods i.e. leaching and dissolution-recrystallization. In leaching the Ni-DMG is just treated with sulphuric acid and DMG is recovered. In the second case the Ni-DMG complex is completely dissolved in sulphuric acid and recrystallized through refrigeration.

Molybdenum disulfide (MoS2), a 2D layered structure, because of its unique properties has widely attracted many researchers. In this study, by employing physical and chemical methods, not only layers of MoS2 have been intercalated, but also their surface properties enhanced. Low-dimensional and potential properties of intercalated MoS2 nanosheets are the aim of many researches. Here, we report a novel four step method to intercalate the layers of MoS2 nanosheets successfully using acid treatment, sonication, oxidization and thermal shocking. The other goal in this study is to evaluate the cation exchange ability and anticorrosion performance of the Ce3+ doped MoS2 nanosheets. The intercalated MoS2 is further characterized using analyses such as FE-SEM, BET, ICP-OES and EIS measurements. The results showed that the expanded MoS2 nanosheets had the higher anticorrosion performance and potential for the intercalation and cation-exchange compared to the unmodified MoS2 nanosheets.

Considering the harmful effects of volatile organic compounds (VOCs) on the atmosphere and public health, the search for proper catalytic materials for the effective catalytic elimination of VOCs remains one of the most pressing issues in the environmental field. In this study, a series of mesoporous Co3O4-n (n = 0.00, 0.0001, 0.01, 0.05, 0.10, 1.00, representing the concentration of HNO3 aqueous solution) catalysts were fabricated by the acid treatment of Co3O4 that was previously prepared via a hydroxycarbonate precipitation method (Co3O4-P). The catalytic performances of the prepared catalysts were evaluated for the model reaction of toluene oxidation. An obvious enhancement of catalytic activity in the reaction was achieved over the acid-treated Co3O4 catalysts using lower HNO3 concentrations, with Co3O4-0.01 exhibiting the optimum catalytic activity (T90 = 225 °C, 15 °C lower than that of Co3O4-P), excellent catalytic durability under dry conditions and a high regeneration capability under humid conditions. Benefitting from the dilute acid treatment, the Co3O4-n (n = 0.01, 0.05, 0.10) catalysts presented higher specific surface areas, more weak acidic sites and higher abundances of surface Co2+ and Oads species, which were regarded as the key factors responsible for their enhanced catalytic activities.

Encapsulation is an effective strategy to prevent probiotics from environmental damages. The survivability of Lactobacillus is generally reduced under frozen or acid environments. In this study, an attempt was made to encapsulate Lactobacillus into the egg yolk aggregates formed upon freezing. Lactobacillus broth was mixed with liquid egg yolk and frozen at selected temperatures and time periods. After thawing, the number of surviving bacteria was determined. The results showed that freezing with the addition of egg yolk improved Lactobacillus survivability. It was confirmed that freezing increased the number of egg yolk aggregates, and those aggregates coated Lactobacillus after freezing. The encapsulated Lactobacillus was treated at pH 2.5 for 10 min, and the results showed that the encapsulation process increased the acid resistance of Lactobacillus. These results indicate that freezing-induced encapsulation with egg yolk could effectively protect Lactobacillus against freezing and acid treatment. This finding could be useful for the design and preservation of probiotics-based food products.

With the rapid development of photocatalysis field, photocatalysts have received increasing attention due to their important role in environmental pollution and energy crisis. As a nonmetallic polymeric material, graphite carbon nitride (g-C3N4) is rich in sources and its preparation is simple, and thus has been widely used as a visible-light-responsive photocatalyst. In this review, we have summarized the recent progress related to the design, modification, and construction of g-C3N4 based photocatalysts with excellent photocatalytic performances. First, we have described the basic structure and properties of g-C3N4. Thereafter, we have pointed out that the defects of pristine g-C3N4 and illustrated the general design principles for all of modified strategies. Subsequently, we have discussed various strategies to optimize the photocatalytic properties of g-C3N4 in detail, including constructing Z-scheme heterojunctions based on g-C3N4, morphological controlling, metal deposition, ion doping, dye sensitization, quantum dots modification, and acid treatment. Particularly, we have comprehensively explicated the critical factors governing the performance of the photocatalyst and the enhanced photocatalytic mechanisms of each modification strategy with examples. Finally, we have indicated the challenges of photocatalysis technology using g-C3N4 and proposed the opportunities for further development.

Mesoporous spherical γ-Al 2 O 3 particles were prepared by spray pyrolysis of commercial boehmite without the use of templating materials. Before spray pyrolysis, a boehmite slurry was prepared through thermal acid treatment of commercial boehmite with various concentrations of HNO 3 . The spray pyrolysis process produced spherical γ-Al 2 O 3 particles with a size of 1 μm regardless of the pretreatment conditions. However, the dominant pore size of the produced γ-Al 2 O 3 particles shifted from 35 nm to 3.5 nm when the molar ratio of [HNO 3 ]/[AlOOH] increased from 0.06 to 0.24 during thermal acid treatment.

In this study, a numerical model of activation and ohmic polarization is modified, taking into account the correlation function between surface properties and inner resistance. To investigate the correlation function, the surface properties of coal are changed by acid treatment, and the correlations between the inner resistance measured by half-cell tests and the surface characteristics are analyzed. A comparison between the model and experimental results demonstrates that the absolute average deviations for each fuel are less than 10%. The numerical results show that the sensitivities of the coal surface properties affecting polarization losses change depending on the operating temperature. The surface oxygen concentrations affect the activation polarization and the sensitivity decreased with increasing temperature. The surface ash of coal is an additional index to be considered along with ohmic polarization and it has the greatest effect on the surface properties at 973 K.

Brucellosis is endemic worldwide due to the nomadic heritage of drinking fresh milk from goats, sheeps and camels. This study aims at developing an antibody based sensor for the detection of Brucella, wherein the binding of Brucella to the sensor will be detected by measuring the changes in electrical signals via cyclic voltammetric properties. The morphology of the used MWCNTs was observed under SEM, FESEM, and TEM. The MWCNTs (ropes like structure) used for the development of sensor were 2–4 μm in length and ∼10–15 nm in diameter as observed under SEM, FESEM, and TEM. MWCNTs were functionalized via acid treatment/oxidation process and the functional behavior of molecules was confirmed with FTIR spectroscopy. Antibodies were conjugated onto the functionalized MWCNTs using classical EDC coupling reactions. When observed under SEM, binding of Brucella abortus to these anti-Brucella antibody functionalized MWCNTs was clearly observed. Finally, these antibody functionalized MWCNTs were deposited on aluminum sheets for the voltammetric detection of Brucella. Results indicate that the antibody functionalized MWCNTs prepared in this study can be used successfully for the detection of Brucella.

Surface treatment of steel before application of silane coating plays important role to provide better corrosion protection. This work aims to evaluate the effect of steel surface treatment with acid solutions on the protective properties of subsequent organosilane coating. For this purpose, sulfuric, phosphoric and hydrochloric acid solutions were prepared at pH 3. The change in surface chemistry and morphology of mild steel surface after acid treatment was assessed by FE-SEM, XPS and water contact angle measurements. After surface treatment with acid solutions, a silane coating was applied on the steel samples. EIS measurements on the silane coated samples showed that the one treated by sulfuric acid solution provided better protection compared to the rest of samples.

High surface-area manganese oxides catalysts are widely employed in catalytic oxidation of volatile organic compounds (VOCs) because of their high efficiency and good stability. However, template agents are usually introduced to the synthesis process to create the high surface area (>150 m2/g). It is quite expensive and complicated, restricting the widespread applications. Herein, a template-free method was reported here to prepare high surface-area MnO2 catalysts by selectively removing La elements from LaMnO3 perovskites using acid treatment. The obtained MnO2 catalysts possessed excellent catalytic activity in toluene oxidation. Besides, the reserved La elements after acid treatment could be recycled to repeat the preparation process. After three cyclic processes, the catalytic performances were improved gradually, which may provide the possibility for the practical application in VOCs elimination.

Halloysite nanotubes (Hal) with unique nanosized tubular structures are promising nanoclay for potential applications as reinforcement fillers, anticorrosion coatings, as well as drug carriers, and adsorbents. Thus far, previous studies on acid treatment of Hal have focused only on Hal from a single source under various conditions of acid strength, temperature, and treatment duration. This study is the first to characterize and compare the effects of acid treatment on three types of Hal (Dragonite (DG), HalloPure (HP), and Camel Lake (CLA)) originated from different geological deposits, and the results considered in terms of their suitability for various applications. Analyses revealed porous tubular structure with an increased lumen diameter of up to 78% and improved surface area from 54 m2 g−1 to 160 m2 g−1 on acid-treated CLA (acid-CLA). By comparison, lumen diameters were reported to increase by only 46% and 52% for acid-DG and acid-HP, respectively. Despite that, crystallinity of acid-DG showed the most reduction, from 64.5% to 59.4%, with a high recorded surface area of 229 m2 g−1, whereas crystallinity of acid-HP showed the least reduction from 62.5% to 61.1% with a surface area of 121 m2 g−1. Therefore, the obtained results support the hypothesis that various Hal can be affected differently by acid treatment, and not all types of Hal are suitable for acid treatment, especially for those intended for use as reinforcement materials.

Preformed particle gel (PPG) is an effective technique for conformance improvement in petroleum reservoirs. It can selectively penetrate high-permeability channels to form effective plugging and divert the chasing injection fluid to low-permeability unswept oil zones. However, conventional PPG would be dehydrated under acidic conditions and could not be easily degraded, which will cause a certain amount of damage to the target formation. Therefore, this study proposed to introduce acid-resistant functional groups and a self-degradable cross-linking structure into the conventional PPG's compositions to develop a degradable PPG (DPPG). The influence mechanism of the chemical composition, swelling performance, and temporary plugging performance of DPPG was studied. Results show that the DPPG can swell up to 70 times its original size by absorbing water, and swollen DPPG can finally self-degrade to a water-like fluid in acid solution. After injecting of DPPG swelled by 20 times its original volume, the injection pressure could reach 1250 psi. Even during the chase acid treatment period, the average pressure was around 130 psi, which shows excellent plugging performance. Subsequent injection of acid would react with carbonate rocks around the plugging zones, increasing the swept volume. In addition, after acid treatments, the DPPG could be self-degraded into a dilute solution like water, so it has very little damage to the reservoir matrix. Therefore, the DPPG has good temporary plugging and acidizing steering performance in acidizing operations. The research in this article can provide the experimental basis and reference for expanding the further application of DPPG in petroleum reservoir stimulation.

Herein, we demonstrate, for the first time, that covalent organic frameworks (COFs) can be efficient adsorbents for the screening of pharmaceuticals in real water samples, obtaining highly representative data on their occurrence and avoiding the cost of carrying high volume samples and tedious and costly clean-up and preconcentration steps. Of the 23 pharmaceuticals found present in the water samples from the Tagus river estuary using state-of-the-art solid-phase extraction (SPE), 22 were also detected (adsorbed and recovered for analysis) using a COF as the adsorbent material with adsorption efficiency of over 80% for nearly all compounds. In specific cases, acidification of the water samples was identified to lead to a dramatic loss of adsorption efficiency, underlining the effect of sample pre-treatment on the results. The COF efficiently adsorbed (>80%) 19 pharmaceuticals without acid treatment of the sample, highlighting the potential of this class of materials for representative in situ passive adsorption of pharmaceuticals, making this material suitable for being used in water monitoring programs as a simple and cost-efficient sample preparation procedure. In the case of α-hydroxyalprazolam and diclofenac, the COF outperformed the SPE procedure in the recovery efficiency. Although further efforts should be made in tailoring the desorption of the pharmaceuticals from the COF by using different solvents or solvent mixtures, we propose COFs as convenient adsorbent for broad-scope screening and as an efficient adsorbent material to target specific classes of pharmaceuticals. To the best of our knowledge, this is the first study on the use of COFs for contaminant screening in real, naturally contaminated water samples.

This study reports the production of pure titanium carbonitride powder via carbonitrothermic reduction of low grade titanium ore. High temperature reduction of the as-milled samples in a nitrogen-containing atmosphere at 1400 °C for 20 min was maintained for the synthesis of the Fe – TiCN composite. An acid solution of 10% concentration, which contains HCl acid, was used to purify the Fe – TiCN composite, for the purpose of obtaining a high purity TiCN powder. The obtained TiCN powder was characterized using field emission scanning electron microscopy (FESEM), X-ray diffraction spectrometer (XRD), particle size analyser (PSA), LECO non – metal analyser, Raman spectroscopy, and high resolution transmission electron microscope (HRTEM) was used to study the powder lattice orientation and particle distribution. The overall results of these analyses confirm the formation of high grade TiCN powder, as the synthesized powder was free of iron and other impurities, and its mean particle size was found to be 4.687 μm.