Strong Acid Research Articles

Detecting element migration from ore systems: A laser ablation ICP-MS method for the in-situ measurement of element contents and 207 Pb/ 206 Pb values on rough fracture coatings

In-situ elemental content and 207 Pb/ 206 Pb values in three rough fracture coatings within drill cores from the McArthur River unconformity-related uranium deposit, Athabasca Basin, Canada were measured using laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS) image mapping. Fracture coating samples were located proximal and distal to the ore deposit. Samples required minimal preparation in this method, with areas (∼500 by 500 μ m) targeted in a cell spaced grid pattern using a 50- μ m spot, spaced 200 μ m on the x- and y-axis with an offset of 100 μ m, to overcome sample surface topography. A five second (s) acquisition time was applied to elemental content measurements and a 2-s acquisition time was applied to 207 Pb/ 206 Pb measurements. These parameters increased the spatial resolution, analytical sensitivity, and minimized the contribution of the host rock underlying the fracture surface to the geochemical signal in comparison to extended acquisition times. In addition, laser ablation temporal profiles allow for the interpretation of the timing of element/isotope migration and fixation on the rough fracture coating. Rasterized maps generated in Iolite TM v.4 demonstrate the chemical distribution of elements and 207 Pb/ 206 Pb values on the rough fracture coatings, allowing for the identification of mineral phases hosting pathfinder elements, pathfinder element associations, and the generation of bulk in-situ or specific mineralogy geochemical values. Bulk in-situ values calculated using an integration of the 2D image data and targeting the ∼500 by 500 μ m surface of the fracture coating compared to previous bulk geochemical methods obtained by sampling the fracture coating with a micro drill (i.e., modified aqua regia (HCl: HNO 3 : H 2 O), weak acid leach (WAL) (2% HNO 3 )), highlights that in-situ analysis greatly improved detection of pathfinder elements on the fracture surface. This study is the first application of in-situ LA-ICP-MS for measuring element contents and 207 Pb/ 206 Pb values on rough fracture coatings and demonstrates its importance as a new geochemical tool to the mining industry for future mineral exploration.

Formation and Reactions of Brønsted and Lewis Acid Adducts with Electron-Rich Heteroaromatic Compounds.

Electron-rich heteroaromatics, such as furan, thiophene and pyrrole, as well as their benzo-condensed derivatives, are of great interest as components of natural products and as starting substances for various products including high-tech materials. Although their reactions with Brønsted and Lewis acids play important roles, in particular as the primary step of various transformations, they are often disregarded and mechanistically not understood. The present publication gives a first overview about this chemistry focusing on the parent compounds. It comprises reactions with strong Brønsted acids forming adducts that can undergo intramolecular proton and/or substituent transfer reactions, ring openings or ring transformations into other heterocycles, depending on their structure. Interactions with weak Brønsted acids usually initiate oligomerizations/polymerizations. A similar behaviour is observed in reactions of these heteroaromatics with Lewis acids. Special effects are achieved when the Lewis acids are activated through primary protonation. Deuterated Brønsted acids allow straight forward deuteration of electron-rich heteroaromatics. Mercury salts as extremely weak Lewis acids cause direct metalation in a straight forward way replacing ring H-atoms yielding organomercury heterocycles. This review will provide comprehensive information about the chemistry of adducts of such heterocycles with Brønsted and Lewis acids enabling chemists to understand the mechanisms and the potential of this field and to apply the findings in future syntheses.

Disproportionation and Transalkylation of Phenol and Dimethylphenol on Zeolite Catalysts

AbstractSubstantial amounts of phenolic compounds are present in medium‐low temperature coal tar (MLCT), of which dimethylphenol (DMP) is not as valuable to be utilized as the more abundant cresol due to its complex composition and difficulty in isolation. In this study, the disproportionation and transalkylation reactions of MLCT‐related model compound, i.e., 2,6‐DMP, in phenol over zeolite catalysts are investigated using a fixed‐bed reactor for sustainable new option to utilize MLCT‐derived phenolic mixtures. Reactivity is promoted at high temperatures and associated with zeolite acidity and pore structure. Since disproportionation and transalkylation reactions have certain spatial requirements, the micropores of MFI‐type zeolite may cause spatial barriers that make it difficult to carry out the reactions. MCM‐22, characterized by MWW‐type zeolite, maximized the conversion of 2,6‐DMP due to its strong Bronsted acidity and large mesopore volume. FAU‐type zeolite HY with a 3D large 12‐ring through‐channel shows relatively small spatial confinement and certain molecular sieving ability, which enables bimolecular reactions while allowing cresols to flow out of the pores efficiently to obtain the highest cresol selectivity. The addition of phenol significantly inhibits the spontaneous disproportionation of 2,6‐DMP to tricresol. Besides, o‐cresol dominate the cresol products, suggesting that the selectivity of o‐cresol is kinetically controlled.

Large‐scale synthesis of nano‐ZIF‐90 from zinc chloride application orientation heat storage materials

AbstractThe paper presents the results of the first research on the synthesis of nano‐ZIF‐90 from zinc chloride. More specifically, the paper also introduces the results of large‐scale pure nano‐ZIF‐90 synthesis with a high specific surface, uniform cubic crystals, and good thermal strength. ZIF‐90 is synthesized from zinc chloride‐containing medium capillaries, which have both a weak acid center and a strong base center. The post‐synthetic ZIF‐90 was also evaluated for heat storage based on its ability to adsorb water, methanol, and ethanol. XRD, FTIR, SEM, TEM, N2 adsorption and desorption methods, TG mass thermal analysis, and NH3‐TPD/CO2‐TPD were used to study the ZIF‐90 crystallization process with modifications of precursors, solvents, additives, and reaction conditions. From this, a large‐scale synthesis of nano‐ZIF‐90 from high‐efficiency zinc chloride has been derived. DSC measurements are used to evaluate the enthalpy adsorption of water, methanol, and ethanol on ZIF‐90.

Highly Active and Stable P2O5 Catalysts Supported on Mesoporous Silica Promoted with Ce for the O‐Methylation of Catechol

AbstractP2O5 has been widely used as an acid‐base catalyst for the O‐methylation of catechol to guaiacol due to its suitable acid strength; however, its stability, which is a significant concern for industrial applications, has not seen significant breakthroughs. Herein, we developed a facile impregnation strategy to synthesize Ce promote P2O5 supported on mesoporous silica (CeP/SBA). The CeP/SBA‐500 carbonized at 500 °C exhibited the highest catalytic activity with a catechol conversion of 71.5 %. The high activity stems from the addition of Ce, forming CePO4, which exhibits improved surface acidity compared to P2O5. Importantly, chemisorption and in situ infrared studies revealed that CePO4 shows stronger adsorption of catechol, which then rapidly converts to guaiacol. The CeP/SBA‐500 exhibits excellent stability with no activity decrease after 10 h of continuous flow reaction, attributed to the absence of a decrease in CePO4 surface acidity.

Separation of Weak Acids, Neutral Compounds, and Permanent Anions using Sequential Elution Liquid Chromatography with Tandem Columns

This paper discusses the development of an analytical method by an alternative separation approach, sequential elution liquid chromatography (SE-LC), to separate permanently charged ions (anions), weak acids, and neutral compounds using anion exchange and reversed-phase columns in tandem. SE-LC separates classes of compounds by group by employing two or more elution modes. Advantages to using SE-LC over conventional HPLC are a greater peak capacity and a reduced separation disorder. Importantly, the same HPLC as used for a conventional HPLC separation may be used to afford a successful SE-LC separation. Mobile phase selection and gradient optimization are integral for a successful SE-LC class separation of permanent anions, weak acids, and neutral compounds and will be discussed in detail in this paper. The most successful (best resolution and repeatability) SE-LC separation was achieved by applying isocratic elution at low pH to elute the weak acids, followed by an acetonitrile gradient to elute the neutral compounds, and last a sodium methanesulfonate gradient to elute the anionic compounds using a superficially porous C18 column coupled with a strong anion exchange (SAX) column. Repeatability (RSD) in the retention times and peak areas of the analytes was less than 0.25% and 1.5%, respectively.

The effect of weak acids on active corrosion rate in top-of-line corrosion

The corrosion rate of pipelines in the petroleum industry is heavily influenced by the weak acids present in the production stream. In a series of experiments at 65 °C, weak acids enhanced the cathodic reaction currents, significantly increasing the corrosion rate. The experiments were designed to investigate limiting electrochemical factors in solutions with low salt concentrations, focusing on predicting top-of-line corrosion corrosion rate. Carbonic acid, acetic acid, and formic acid, commonly found in produced fluids, were the subjects of this corrosion investigation. Under the investigated conditions, the corrosion rates were found to correlate with the undissociated weak acid concentration.

Targeting astrocytic TDAG8 with delayed CO2 postconditioning improves functional outcomes after controlled cortical impact injury in mice

T-cell death-associated gene 8 (TDAG8), a G-protein-coupled receptor sensing physiological or weak acids, regulates inflammatory responses. However, its role in traumatic brain injury (TBI) remains unknown. Our recent study showed that delayed CO2 postconditioning (DCPC) has neuroreparative effects after TBI. We hypothesized that activating astrocytic TDAG8 is a key mechanism for DCPC. WT and TDAG8−/− mice received DCPC daily by transiently inhaling 10% CO2 after controlled cortical impact (CCI). HBAAV2/9-GFAP-m-TDAG8-3xflag-EGFP was used to overexpress TDAG8 in astrocytes. The beam walking test, mNSS, immunofluorescence and Golgi-Cox staining were used to evaluate motor function, glial activation and dendritic plasticity. DCPC significantly improved motor function; increased total dendritic length, neuronal complexity and spine density; inhibited overactivation of astrocytes and microglia; and promoted the expression of astrocytic brain-derived neurotrophic factor in WT but not TDAG8−/− mice. Overexpressing TDAG8 in astrocytes surrounding the lesion in TDAG8−/− mice restored the beneficial effects of DCPC. Although the effects of DCPC on Days 14–28 were much weaker than those of DCPC on Days 3–28 in WT mice, these effects were further enhanced by overexpressing astrocytic TDAG8. Astrocytic TDAG8 is a key target of DCPC for TBI rehabilitation. Its overexpression is a strategy that broadens the therapeutic window and enhances the effects of DCPC.

Phosphorus in belemnites: Extraction, quantification, and variability

Phosphorus is generally considered the ultimate limiting nutrient for marine primary productivity over geological timescales and plays a key role in modulating several biogeochemical cycles. Most established methods for investigating P cycling do not provide direct evidence for water-column P concentrations, but recent work on carbonate associated phosphorus (CAP) has shown there is a potential to record ancient dissolved P concentrations. We present a method to extend the application of carbonate associated P measurements to belemnites, and we quantify variability in P contents within and between belemnite specimens from two stratigraphic levels in Jurassic rocks from the Yorkshire coast, UK, as well as in modern analogues of belemnites.We show that there is little difference in P measurements between different preparative methods in uncontaminated belemnite calcite samples. In samples with higher levels of contaminant phases of P (P other than CAP), or a greater extent of diagenetic alteration, cleaning with non-oxidative methods and dissolution in weak acids (acetic) was found to minimise the impact of contamination on the measured P contents. P concentrations vary within and between specimens, but variations are not a result of taxonomic differences, and overall P measurements are reproducible between replicate samples, within individual belemnites and within stratigraphic levels. There were statistically significant differences in belemnite P concentrations between the stratigraphic levels studied here, indicating the potential for this technique to be used to measure changes in belemnite CAP through time.

Forbidden ion transport through cation exchange membranes

Cation exchange membranes (CEMs) are widely used in many applications. The fixed anionic groups e.g., COO−, –SO3-, etc. in the polymer matrix ideally allows the passage only of oppositely charged cations, driven by a potential or a concentration gradient. Anions, charged negative, the same as the membrane matrix, cannot pass through the membrane due to electrostatic repulsion. Such “Donnan-forbidden” passage can, however, occur to some degree, if the electrical or concentration gradient is high enough to overcome the “Donnan barrier”. Except for salt uptake/transport in concentrated salt solutions, the factors that govern such Forbidden Ion Transport (FIT) have rarely been studied. In most applications of transmembrane ion transport, whether electrically driven as in electrodialysis, or concentration-driven, it is the transport of the counterion to the fixed charged groups, such as that of the proton through a CEM, that is usually of interest. Nevertheless, CEMs are also of interest in analytical chemistry, specifically in suppressed ion chromatography. As used in membrane suppressors, both transport of permitted ions and rejection of forbidden ions are important. If the latter is indeed governed by electrostatic factors, other things being equal, the primary governing factor should be the charge density of the membrane, tantamount to its ion exchange capacity (IEC). In fabricating microscale suppressors, we found useful to synthesize a new ion exchange polymer that can be easily molded to make tubular microconduits. Despite a high IEC of this material, FIT was also found to be surprisingly high. We measured several relevant properties for thirteen commercial and four custom-made membranes to discover that while FIT is indeed linearly related to 1/IEC for a significant number of these membranes, for very high water-content membranes, FIT may be overwhelmingly governed by the water content of the membrane. In addition, FIT through all CEMs differ greatly among strong acids, they may still be transported as the molecular acids and the extent is in the same order as the expected activity of the molecular acid in the CEM. These results are discussed with the perspective that even for strong acids, the transport does take place as un-ionized molecular acids.

Transition metal catalysts coordinated with electrochemistry for preparation of graphene

It is still crucial to produce mass high-quality graphene through simple and low-cost methods for its wide applications. Herein, a simple and fast method by combining inexpensive transition metal catalysts with electrochemistry to exfoliate natural flake graphite is reported. The electrode is prepared in a sandwich structure, where the titanium mesh will enwrap the nickel net coated with graphite powder. This method can quickly achieve the large-scale preparation of graphene within 15 min. The quality of graphene with large lateral size and few layers has been characterized by XRD, SEM, TEM, Raman, and AFM. The possible electrochemical exfoliation mechanism has been proposed. Oxygen evolution reaction occurs at the anode due to the transition metal catalysts, and hydrogen ions (H+) are generated along with oxygen, H+ and SO42− ions will form a local strong acid. The formation of strong acidic H2SO4 in-situ around electrode will oxidize the edge of the graphite, allowing the intercalation of SO42−, H2O, SO2 and O2 into the graphite sheets, which will inflate the graphite and exfoliate of graphite into graphene. This strategy is reliable, environmentally friendly, and suitable for industrial production.

Synergistic enzymatic mechanism of lepidolite leaching enhanced by a mixture of Bacillus mucilaginosus and Bacillus circulans

Numerous studies have demonstrated that the co-leaching of ores by different silicate bacteria significantly improves the performance of bioleaching systems. Nevertheless, the mechanism of different silicate bacteria synergistically or complementarily enhanced the leaching process of lithium-containing silicate remains unclear. This study discussed the leaching impact of the combined presence of two metabolically distinct silicate bacteria on lepidolite, with the aim of comprehending the synergistic effect resulting from the presence of Bacillus mucilaginosus and Bacillus circulans in the leaching process. The results indicated that the polysaccharides and proteins secreted by bacteria-containing functional groups such as -OH and -COOH, which played an important role in the complex decomposition of ores. Organic acids played the role of acid etching and complexation. Bacillus mucilaginosus and Bacillus circulans exhibited low individual leaching efficiency, primarily due to their weak organic acid secretion. Moreover, the prolific polysaccharide production by Bacillus mucilaginosus led to bacterial aggregation, diminishing contact capability with minerals. Bacillus circulans decomposed the excessive polysaccharides produced by Bacillus mucilaginosus through enzymatic hydrolysis in the co-bioleaching process, providing later nutrient supply for both strains. The symbiosis of the two strains enhanced the synthesis and metabolic capabilities of both strains, resulting in increased organic acid secretion. In addition, protein and humic acid production by Bacillus mucilaginosus intensified, collectively enhancing the leaching efficiency. These findings suggested that the primary metabolic products secreted by different bacterial strains in the leaching process differ. The improvement in bioleaching efficiency during co-leaching was attributed to their effective synergistic metabolism. This work contributes to the construction of an efficient engineering microbial community to improve the efficiency of silicate mineral leaching, and reveals the feasibility of microbial co-culture to improve bioleaching.

Promoting effects of cerium oxide on catalysts performance for selectivity catalytic oxidation of NH3 over RuOx/TiO2

Cerium oxide (CeO2) was added to modified Ru/TiO2 catalyst by a two-step impregnation method for selective catalytic oxidation of ammonia (NH3-SCO). The low-temperature NH3 oxidation activity and N2 selectivity of the 1Ru/xCe-TiO2 catalyst were investigated with the result that both SCO activity and N2 selectivity were influenced by the amount of Ce. Specifically, the presence of 5 wt% CeO2 demonstrated a great promoting effect on both parameters, reaching an NH3 conversion and N2 selectivity of 97 % and 93 % at 180 ℃, respectively. Various characterization methods indicated that the presence of CeO2 regulates the dispersion of the 1Ru/xCe-TiO2 catalysts, changes the amount, strength and ratio of strong and weak acid sites on the catalyst surface, and promotes the formation of Ru-O-Ce bonds through the interaction between Ce and Ru species, which facilitates electron transfer and oxygen vacancy formation, thereby enhancing the oxidation ability of the catalysts. Furthermore, the results of in situ diffuse reflectance infrared Fourier transform spectroscopy indicated that the NH3-SCO reaction over the 1Ru/xCe-TiO2 catalysts follows the “internal” selective catalytic reduction (i-SCR) mechanism, involving the oxidation of NH3 into nitric oxide (NO) species and the reaction of -NH2 with in situ-formed NO to form N2.

Brønsted acidity of bis(trifluoromethanesulfonyl)amide and trifluoromethanesulfonic acid in ionic liquids of ternary ammonium

Bis(trifluoromethanesulfonyl)amide (Tf2N−) and triflate (TfO−) are commonly used anions of protic ionic liquids (PILs). They are the conjugate anions of strong acids, Tf2NH and TfOH, whose Brønsted acidities crucially influence the performance of the PILs. In this study, the Brønsted acidity of Tf2NH and TfOH was compared directly through potentiometric titrations carried out in the ionic liquids of ternary ammonium salts. As a result, Tf2NH exhibits stronger Brønsted acidity than TfOH by approximately 2 pH units. Furthermore, calorimetric titrations revealed that this difference originates from differences in their entropy states. This suggests that the solvation state, rather than the properties in their isolated state, has a more significant impact on the acidities of Tf2NH and TfOH. Besides, ionization thermodynamics turned out to be governed by both the constituent cations and anions of the PILs. Therefore, once the acid-base natures of the constituent ions are characterized, the overall acid-base behavior of the PIL may become predictable.

Smart nanozymes coupled with dynamic magnet field and laser exposures for cancer therapy

Developing nanozymes for cancer therapy has attracted great attention from researchers. However, enzymes-loaded magnetic particles triggered by both a low-frequency vibrating magnetic field (VMF) and laser for inhibiting tumor growth have never been reported. Herein, we developed a magnetic nanozyme with 3D flower-like nanostructures for cancer therapy. Specifically, the flower-like nanozymes exposed to a VMF could efficiently damage the mitochondrial membrane and cell structure, and inhibit tumor growth through magneto-mechanical force. In parallel, magnetic nanozymes in a weak acid environment containing glucose could generate abundant hydrogen peroxide through glucose oxidase-catalyzed oxidation of glucose, and further significantly promote the Fenton reaction. Interestingly, both glucose oxidase- and Fenton-based catalytic reactions were significantly promoted by the VMF exposure. Flower-like magnetic nanospheres upon a near-infrared laser irradiation could also damage cancer cells and tumor tissues through photothermal effect. The cell-killing efficiency of magnetic nanozymes triggered by the VMF or laser significantly increased in comparison with that of nanozymes without exposures. Mouse tumors grown after injection with magnetic nanozymes was inhibited in a significant way or the tumors disappeared after exposure to a VMF and laser due to the synergistic effect of four major stimuli, viz., magneto-mechanical force, photothermal conversion, improved Fenton reaction, and intratumoral glucose consumption-based starvation effect. This is a great platform that may be suitable for treating many solid tumors.

Achieving high cell performance based on block copolymer PBI membrane with strong acid absorbing Py-PBI segments

Achieving high cell performance based on block copolymer PBI membrane with strong acid absorbing Py-PBI segments

A novel Pumice@PVA membrane with high separation efficiency for oil-water emulsion application

Oil pollution poses a major threat to both human health and economic development, and therefore the development and improvement of oil-water separation technology is urgent. Traditional methods have problems such as complicated preparation, high cost and the vulnerability of lipophilic materials to oil contamination. Therefore, finding an inorganic material that meets the requirements of underwater superoleophobic performance and reduces surface modification has become a new demand. In this study, natural pumice was found for the first time to have excellent underwater superoleophobic performance and chemical stability, and the underwater superoleophobic filter membrane was prepared by vacuum adsorption using hydrogen bond cross-linking between natural pumice and PVA. The experimental data show that the prepared PVA/natural pumice ultrafiltration membrane has superhydrophilic and superoleophobic properties, and exhibits excellent stability (OWA>150°) under the harsh environment of strong acid and strong alkali. In addition, the composite membrane has good emulsion separation efficiency (>97%) and a separation flux of 39.91 Lm-2h-1. It is demonstrated that the composite membrane has oleophobic and wettable properties, and is capable of separating both oil-water mixtures without phase mixing and oil-in-water emulsions without oil contamination. This study provides a new idea for the preparation of superoleophobic materials for oil-water separation, which has the potential for large-scale application.

Alleviation of RO membrane fouling in wastewater reclamation plants using an enhanced acid-base chemical cleaning method

Membrane fouling has always been a critical constraint in the operation of the reverse osmosis (RO) process, and chemical cleaning is essential for mitigating membrane fouling and ensuring smooth operation of the membrane system. This paper presents an optimized chemical cleaning method for the efficient cleaning of RO membranes in full-scale applications. Compared to the regular cleaning method (cleaning with 0.1 % NaOH + 1 % ethylenediaminetetraacetic acid + 0.025 % sodium dodecyl benzene sulfonate followed by 0.2 % HCl), the optimized cleaning method improves the cleaning efficiency by adding sodium chloride to the alkaline cleaning solution and citric acid to the acid cleaning solution. Notably, the membrane flux recovery rate with the optimized cleaning method is 45.74 %, and it improves the cleaning efficiency by 1.65 times compared to the regular cleaning method. Additionally, the optimized cleaning method removes 30.46 % of total foulants (organic and inorganic), which is 2.11 times higher than the regular cleaning method. The removal of inorganic ions such as Fe, Ca, and Mg is significantly improved with the optimized cleaning method. For organic matter removal, the optimized cleaning method effectively removes more polysaccharides, proteins, and microbial metabolites by disrupting the complex structures of organic matter. Furthermore, it also changes the microbial community structure on the RO membrane surface by eliminating microorganisms that cannot withstand strong acids, bases, and high salt environments. However, Mycobacterium can adapt to these harsh conditions, showing a relative abundance of up to 84.13 % after cleaning. Overall, our results provide a new chemical cleaning method for RO membranes in full-scale applications. This method effectively removes membrane foulants and enhances the understanding of the removal characteristics of foulants on RO membrane surfaces by chemical cleaning.

Antimicrobial profile and Turn-On sensing of cyanide and water traces using a dual chromophoric Dansyl-Acridine conjugate as multifunctional system

9-aminocridine derivatives bearing a dimethylmethanimidamide, L1, and the dyad conjugate dansyl-acridine, L2, were synthesized and their ability to be used as multifunctional materials using different polymer matrixes was investigated. L1 was found to modulate its emission in the presence of traces of water with a turn-on effect and to this end was used for the detection of water traces in organic solvents with a LOD and LOQ of 0.0028 and 0.0121 (V%) in acetonitrile, respectively. Due to the observed acidochromism for this compound and the different behaviour in acetonitrile and chloroform due to different stabilization of the excited state a turn-off and turn-on effect was observed for respective solvents. PMMA polymer doped films aided on the elucidation for this compound to be used as a sensor of strong acids. Furthermore, compound L2 was found fruitful for the detection of cyanide through an acid base anion sensing. Incorporation of these compounds in PVA:PVP polymer films and Irogran® microparticles were carried out to assess their antimicrobial profile.

Hydrogen bond regulation to promote the direct production of diosgenin from Dioscorea zingiberensis rhizomes

Herein, a renewable system consisted of tartaric acid and isopropanol was developed to produce diosgenin efficiently from Dioscorea zingiberensis rhizomes. The yield of diosgenin reached 4.15% comparable to the highest value reported in previous researches. The combination of experiment and DFT calculation revealed that the acid-alcohol system could regulate the hydrogen bond interaction of each component in the rhizomes to disassemble the connection network and promote the release of saponin. Meanwhile, the intramolecular hydrogen bond of tartaric acid and the steric hindrance effect of isopropanol could prevent the esterification reaction and maintain the strong acidity of the system for the high yield of diosgenin. The scale-up experiment with a 100-fold feeding capacity was also conducted successfully. Furthermore, the technological process integrated with purification of diosgenin, recovery of organic acid and solvent and upgrading of residual solid to porous carbon materials has been established systematically to verify the prospective of industrialization.