Acid Functional Groups Research Articles

The Rapid Decrease in the Biological Reactivity of Water Activated by Air Spark Discharge Plasma

ABSTRACTTo investigate the biological reactivity of plasma‐activated water (PAW), we prepared PAW using atmospheric air spark discharge over water at 4°C and 25°C, with Escherichia Coli (E. coli) as the microbial model. The biological reactivity of PAW at 25°C decreased rapidly by 3.32 Logs within 20 s of storage. At 4°C, PAW showed high reactivity within 20–30 s of storage but decreased by 3.50 Logs between 30 and 60 s. Our analysis revealed that PAW reactivity is dependent on short‐lived peroxynitrite (ONOOH), formed through H2O2 and HNO2 under acidic conditions. ONOOH actively reacts with amino acid functional groups, as measured by high‐resolution LC‐MS, likely contributing to the rapid inactivation of E. coli.

Physicochemical and processing properties and in vitro fecal fermentation characteristics of Prunus cerasifera Ehrhart polysaccharide

Prunus cerasifera Ehrhart fruit polysaccharide (PCP) was obtained after determining the optimal extraction conditions for complex enzyme-assisted hot buffer extraction based on single-factor experiments and response surface methodology, followed by characterization of its physicochemical, processing, rheological, and biological properties. PCP was a thermally stable carbohydrate with acidic functional groups and a molecular weight of 1398.69 kDa, exhibiting smooth, dense flake and honeycomb network microstructures. PCP had favorable hygroscopicity, moisturizing properties, water and oil-holding capacity, proemulsification capability, and in vitro antioxidant activity. The apparent viscosity of PCP in an aqueous system was dependent on concentration and temperature and was altered by the variety and amount of metal ions added; its aqueous solutions exhibited strong viscosity and hydrogel-forming tendencies at suitable concentrations, along with excellent hydrogel properties after gelation. Furthermore, PCP favored the growth of beneficial gut microbiota and associated microbes responsible for producing essential short-chain fatty acids. Overall, PCP displayed high potential as a multifunctional additive for applications in the food, pharmaceutical, and cosmetic industries.

In-situ Forming Multipolymeric Glucose-Responsive Hydrogels.

Stimuli-responsive hydrogels (HGs) have shown promise for smart drug delivery applications. Specifically, glucose-responsive HGs having phenylboronic acid (PBA) functional groups are extensively pursued for insulin delivery in hyperglycemia. Current polymeric glucose-responsive HGs are cumbersome to fabricate and show a limited insulin release profile. Herein, we develop a straightforward fabrication of glucose-responsive multipolymer HGs (MPHGs) using a three-component in situ mixing. Molecular cargo, such as insulin, was loaded during the gelation. Heterobifunctional formylphenylboronic acid (FPBA) crosslinkers were used to interconnect polyvinyl alcohol (PVA) and branched polyethyleneimine (PEI) via boronate ester and imine bonds, respectively. Three positional isomers of FPBA (2FPBA, 3FPBA, and 4FPBA) resulted in HGs with distinct viscoelastic behaviors under the same conditions. HGs derived from 4FPBA exhibited more solid-like properties compared to 2FPBA and 3FPBA due to a higher crosslinking density. All the HGs exhibited glucose-responsive dissolution and release of embedded insulin cargo without disrupting the native structure. Insulin release profiles show a higher glucose-responsive release from 4FPBA-derived MPHGs. All the HGs were injectable, self-healing, and noncytotoxic below 10 μg/ml concentrations. The MPHGs developed in this study uncover new directions in creating glucose-responsive matrices for self-regulating drug delivery applications. In the future, detailed in vivo studies will be performed for clinical applications.

GC–MS analysis, molecular docking, and pharmacokinetic studies on Dalbergia sissoo barks extracts for compounds with anti-diabetic potential

Diabetes is a metabolic condition defined by abnormal blood sugar levels. Targeting starch-hydrolyzing enzymes and Dipeptidyl Peptidase 4 (DPP-4) expressed on the surface of numerous cells is one of the key strategies to lower the risk of Type-2 diabetes mellitus (T2DM). Dalbergia sissoo Roxb. bark (DSB) extracts have been reported to have anti-diabetic properties. This study intended to scientifically validate use of alcoholic and hydro-alcoholic extracts of DSB for T2DM by conducting preliminary phytochemical investigations, characterising potential phytochemicals using Fourier transform infrared (FT-IR) spectroscopy and Gas chromatography-mass spectrometry (GC–MS) analysis followed by comprehensive in-silico analysis. A qualitative phytochemical evaluation indicated the presence of alkaloids, phenolics, glycosides, conjugated acids and flavonoids. Ethanolic extracts showed highest total phenolic content (TPC) (127.072 ± 14.08031 μg GAE/g dry extract) and total flavonoid content (106.911 ± 5.84516 μg QE /g dry extract). Further FT-IR spectroscopy also revealed typical band values associated with phenol, alcohol, alkene, alkane and conjugated acid functional groups. The GC–MS analysis identified 139 compounds, 18 of which had anti-diabetic potential. In-silico ADMET analysis of potential compounds revealed 15 compounds that followed Lipinski’s rule and demonstrated drug-like properties, as well as good oral bioavailability. Molecular docking was utilised to analyse their potential to interact with three targets: α-amylase, α-glucosidase, and DPP-4, which are crucial in managing diabetes-related problems. Molecular Docking analysis and membrane permeability test utilising the PerMM platform revealed that compounds in the extracts, such as Soyasapogenol B and Corydine, had better interactions and permeability across the plasma membrane than standard drugs in use. Molecular dynamics simulations also showed that selected compounds remained stable upon interaction with α-amylase. Overall, using the in-silico approaches it was predicted that DSB extracts contain potential phytochemicals with diverse anti-diabetic properties. It further needs to be investigated for possible development as formulation or drug of choice for treating T2DM.

Discovery and Biosynthesis of Sulfenicin and Its New-to-Nature Acylsulfenic Acid Functional Group.

Life's organic molecules are built with diverse functional groups that enable biology by fine tuning intimate connections through time and space. As such, the discovery of new-to-nature functional groups can expand our understanding of the natural world and motivate new applications in biotechnology and biomedicine. Herein we report the genome-aided discovery of sulfenicin, a novel polyketide-nonribosomal peptide hybrid natural product from a marine Streptomyces bacterium bearing a unique acylsulfenic acid functionality. Through a series of heterologous biosynthesis, functional genetics, and enzymatic reconstitution experiments, we show that this previously described synthetic functional group is biologically assembled by a set of enzymes from both primary and secondary metabolism, including a novel flavin-dependent S -hydroxylase that hydroxylates a thiocarboxylic acid's sulfur atom. While the sulfenicin biosynthetic gene cluster is presently without parallel in public databases, acylsulfenic acid-encoding enzymes are widely distributed in bacterial genomes, implying that this labile functional group may similarly have a broad distribution among specialized metabolites.

Conversion of Carboxylic Acids to Sulfonamide Bioisosteres via Energy Transfer Photocatalysis.

More than 450 drugs containing a carboxylic acid functional group have been marketed worldwide. Herein, we report a concise and environmentally friendly organic photoinduced protocol for the interconversion of carboxylic acids into their bioisosteres. With this strategy, a variety of substrates, including alkyl, (hetero)aryl, and alkenyl acids, as well as various biologically relevant acids are successfully converted into primary sulfonamides.

Achievement of biochar photocatalytic performance by synergistic oxidation of sulfuric acid/hydrogen peroxide: Towards revealing the mechanism of synergistic oxidation on photocatalytic performance

The oxygen-containing functional groups of biochar have great potential in tailoring photochemical properties, but the content of oxygen-containing functional groups of pristine biochar is insufficient to support photocatalytic reactions. In this study, a synergistic oxidation of H2SO4 and H2O2 was innovatively proposed to prepare biochar photocatalysts (OGPC400). The results showed that the synergistic oxidation of H2SO4 and H2O2 increased the contents of hydroxyl and carboxyl groups of biochar with the degree of oxidation, and the total concentration of acidic functional groups was about 4 mmol/g higher than that of the oxidation with H2SO4 or H2O2 alone, which was attributed to the synergistic oxidation to promote the conversion of CH and C-OH on the benzene ring. The achievement of electron exchange among hydroxyl and carboxyl groups and internal electron transfer within biochar by the benzene ring as a medium resulted in 100 % degradation of rhodamine b (RhB) and 25 times reaction rate constant higher than that of pristine biochar, as compared to only 45 % or 37 % degradation by oxidation with H2SO4 or H2O2 alone. The exciting results confirmed the positive availability of H2SO4 and H2O2 synergistic oxidation on biochar photocatalysts, which is expected to be applied in environmental remediation.

Active sites regulation and adsorption performance of Al-pillared bentonite for the removal of lead from aqueous phase

Developing an environmentally friendly adsorbent with high adsorption capacity and economic benefits is crucial for the treatment of lead-contaminated wastewater. In this study, active clay (A-bent) and Al pillared acid-activated clay (A-AlPILC) were prepared using natural bentonite as the carrier via acidification and pillar-supported technology. The samples were characterized by X-ray diffraction (XRD), N2 adsorption-desorption experiments, Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray fluorescence spectrometer (XRF). The results showed that the amended clay exhibited an increase in specific surface area (SSA) from 39.37 m2/g to 175.28 m2/g and 245.42 m2/g compared to raw bentonite. The interlayer spacing and total pore volume rose respectively. The adsorption technique achieved an impressive removal rate of 90.6 % for Pb(II). Adsorption data were fitted by adsorption kinetics and adsorption isotherm model. Based on the response surface method (RSM), and analysis of variance (ANOVA) showed that the influence of these variables was significant. The simulation of lead ions showed that the acidic functional groups and ligands promote adsorption more than they inhibit it. Using the density function theory (DFT) calculation, the bentonite cycle model was established to demonstrate the interaction between bentonite and lead, with a binding energy of −0.369 eV. Similarly, the density and energy band structure of the state were computed to explore the mechanism of heavy metal adsorption by clay minerals.

Removal of nitrate nitrogen by aerobic denitrification granular sludge under strongly alkaline conditions: Performance and mechanism

Aerobic granular sludge (AGS) technology faces challenges in treating strongly alkaline wastewater because high pH affects sludge settleability and microbial metabolic activity. In this study, aerobic denitrification granular sludge (ADGS) was cultivated with strongly autoaggregating aerobic denitrifying bacteria as the sludge source at an influent pH of 11.0 under aerobic conditions. The formation characteristics of ADGS and its pollutant removal efficiency under strongly alkaline conditions were explored. Compared with ADGS cultivated under neutral conditions, ADGS cultivated under strongly alkaline conditions resulted in superior particle formation rates, settleability, particle strengths and particle stabilities. Nitrate nitrogen was almost completely removed at a pH of 11.0 under aerobic conditions. Protein, polysaccharides and humic acid in extracellular polymeric substances (EPS) under strongly alkaline conditions were involved in the ADGS formation process. In addition, the presence of metallic elements in the EPS and inorganic nuclei in the sludge facilitated the formation of ADGS. The strongly alkaline environment enriched the alkali-resistant aerobic denitrifying bacteria, such as unclassified_f__Rhodobacteraceae, Tessaracoccus, Halomonas, and Pseudofulvimonas, as well as specialized alkali-resistant genera. Furthermore, the strongly alkaline environment increased the abundance of key enzymes involved in carbon metabolism and upregulated the expression of nitrogen metabolism genes in the ADGS to maintain their metabolic activity. In addition, the microorganisms upregulated genes that encoded reverse transporter protein genes (mnhACEFG, nhaACP, and phaACDEFG) and K+ uptake protein genes (trkAHG) and secreted greater amounts of acidic functional groups and free amino groups to help maintain intracellular and extracellular osmolality and acid–base homeostasis under strongly alkaline stress. This research provides a possible option and innovative strategy for the management of highly alkaline nitrate-containing wastewater.

Tripolyphosphate-functionalized cellulose: A green solution for cadmium contamination

This study introduces a highly efficient tripolyphosphate -tethered cellulose sorbent for cadmium (Cd2⁺) removal from aqueous solutions. Characterization through FTIR and SEM revealed the material's structural properties. The sorbent achieved 99% Cd2⁺ removal even at a minimal dosage of 0.05 g. Optimal sorption occurred within the pH range of 4–6, influenced by the sorbent's weak acidic functional groups. Rapid kinetics, reaching equilibrium within a minute, and a high sorption capacity (up to 18.03 mg/g at 50 °C) were observed. Langmuir isotherm modeling confirmed monolayer sorption, and thermodynamic studies indicated a spontaneous, endothermic process with increased randomness at the solid-liquid interface. Selectivity studies demonstrated strong Cd2⁺ removal performance in the presence of competing ions, with minimal interference from monovalent ions but notable effects from divalent ions. The sorbent exhibited consistent reusability over multiple cycles. XPS analysis conclusively established an ion exchange mechanism between Cd2⁺ and negatively charged P3O105− groups as the primary removal pathway. This research highlights the potential of TPP-tethered cellulose as a promising sorbent for effective Cd2⁺ remediation.

Tangerine peel modified with sodium hydroxide for the removal of methylene blue: A calorimetric approach

Biosorbents have been studied as low-cost and efficient materials for removing dyes from wastewater. However, thermodynamic investigations into the interactions between these materials and dyes remain scarce, particularly concerning the effects of chemical modifications to the biosorbents. This article describes the biosorption of methylene blue (MB) by unmodified tangerine peel (BN) and tangerine peel modified with sodium hydroxide (BM). The materials were characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and by assessing the point of zero charge as well as the number of acidic and basic functional groups. The biosorption studies combined kinetic and equilibrium analyses with isothermal titration calorimetry (ITC) measurements to characterize the sorption process in detail. BM exhibited a sorption capacity (328 mg g−1) approximately three times higher than that of BN. The adsorption process was enthalpically driven and at least 3 kJ mol−1 more exothermic for the untreated material, indicating that treatment with NaOH was unfavorable for the interaction between the dye and biosorption sites but favored the process entropically. The enthalpy of sorption depended on the amount adsorbed, indicating a high heterogeneity of biosorption sites within the materials. The results suggest that the lower availability of biosorption sites in BN led to the sorption of MB dimers, whereas in BM, the sorption of monomers was the preferred mechanism at less hydrophilic sites.

Eco‐friendly approaches for synthesis of indolyl 1H‐pyrroles using rice‐husk‐derived carbonaceous sulfonation as the green catalyst

AbstractBACKGROUNDAmorphous carbon‐bearing sulfonic acid groups (AC–SO3H) are a kind of solid acid that exhibits high acidity and belongs to the new generation of solid acids. The presence of acidic functional groups, including carboxylic acid, phenolic and sulfonic acid groups, allows for several key activities such as strong Brønsted acid properties, high surface area, stability, reusability and recyclability.RESULTSIn this work, we synthesized indolyl 1H‐pyrroles from indoles, phenylglyoxal monohydrate, 1,3‐diketones and ammonium acetate using rice‐husk‐derived carbonaceous sulfonation (AC–SO3H) as a catalyst. We explored the impact of catalyst quantity, reaction time, solvent, mineral acid and temperature in order to determine the optimal reaction conditions. Additionally, indolyl 1H‐pyrrole derivatives were also synthesized based on the optimal conditions that were completely investigated, and the structure of these synthetic compounds was characterized by 1H‐ and 13C‐nuclear magnetic resonance.CONCLUSIONThe yield of indolyl 1H‐pyrroles was up to 84% in 6 h at 100 °C with the activity of 30 mg AC–SO3H. Besides, based on the optimal conditions, 21 indolyl 1H‐pyrrole derivatives were formed with the high‐yield and green method. The catalyst could be reused multiple times without a significant decrease in catalytic performance. According to the findings from the experiments, a potential mechanism that included a radical process has been suggested. This eco‐friendly approach provided a straightforward and efficient method to produce a variety of indole–pyrrole conjugates in a single step. © 2024 Society of Chemical Industry (SCI).

Crystal structure of perfluorononanoic acid, C9HF17O2

The crystal structure of perfluorononanoic acid (PFNA) was solved via parallel tempering using synchrotron powder diffraction data obtained from the Brockhouse X-ray Diffraction and Scattering (BXDS) Wiggler Lower Energy (WLE) beamline at the Canadian Light Source. PFNA crystallizes in monoclinic space group P21/c (#14) with lattice parameters a = 26.172(1) Å, b = 5.6345(2) Å, c = 10.9501(4) Å, and β = 98.752(2)°. The crystal structure is composed of dimers, with pairs of PFNA molecules connected by hydrogen bonds via the carboxylic acid functional groups. The Rietveld-refined structure was compared to a density functional theory-optimized structure, and the root-mean-square Cartesian difference was larger than normally observed for correct powder structures. The powder data likely exhibited evidence of disorder which was not successfully modeled.

Efficient cascade reactions involving esterification, hydrogen transfer, and lactonization for biomass conversion using MOF/Metal oxide composites as heterogeneous catalysts

Development of heterogeneous catalysts with both Brønsted and Lewis acid properties has proved to be promising and useful because they offer an efficient way to cascade reactions. In this study, we present the synthesis pathway and efficacy evaluation of new composites which combined by sulfonic acid functional group modified TiO2 and MIL-101, analyzing their structure-performance correlation as heterogeneous catalysts in cascade reactions involving esterification, hydrogen transfer, and lactonization. These composites possess an open porous structure (MOF and porous TiO2), as well as active sites including Lewis acid (unsaturated coordination metal), Lewis base (Ti-OH), and Brønsted acid (-SO3H). The role of these active sites and the synergies between them were investigated through the esterification of levulinic acid and the direct synthesis of γ-valerolactone from levulinic acid and furfural under cascade reactions. The composites exhibit a 100% ethyl levulinate (EL) yield at 120°C for 6 hours, with γ-valerolactone yields reaching up to 94.5% (160 °C, 9 h) and 89.5% (160 °C, 16 h) from levulinic acid and furfural, respectively. This synergistic effect of Lewis acid/base and Brønsted acid ensures efficient esterification. The presence of a sulfonic acid group promotes the lactonization reaction, while the Meerwein-Ponndorf-Verley reduction is facilitated by the dual Cr sites located adjacent to each other in the secondary building unit of MIL-101(Cr). Moreover, the double-porous structure of porous TiO2 and MIL-101(Cr) effectively guarantees the efficient mass transfer of reactants and intermediates, leading to enhanced synergistic effects that promote more efficient reaction conversion.

Mechanism of reinforced interfacial adhesion between steel slag and highly devulcanized waste rubber modified asphalt and its influence on the volume stability in steel slag asphalt mixture

The volume expansion risk of steel slag is a predominant challenge hindering its usage as an alternative aggregate in road pavements. In this study, the interfacial adhesion properties of base asphalt-basalt, base asphalt-steel slag, rubber modified asphalt (RMA) -basalt and RMA-steel slag were compared employing both experiment and molecular dynamics simulation. The volume stability and road performance of the asphalt mixture was also explored. The results showed that the residue rate of the RMA asphalt mixed with steel slag aggregates showed an increase from 87.5 % to 95.7 % compared to base asphalt after 100°C boiling water test. The interfacial adhesion between steel slag and asphalt surpasses that of basalt and asphalt, with the use of rubber modified asphalt further enhancing the adhesion with steel slag aggregates, as investigated through quantitative evaluation of interface adhesive work. The enhanced interaction between steel slag and RMA was primarily due to the integration of acidic functional groups from rubber chain with the alkaline active constituents (f-CaO) of steel slag aggregates, as confirmed by molecular dynamics simulations and accurate density functional theory calculations. Furthermore, the volume stability and road performance of the steel slag stone mastic asphalt were also greatly improved compared with basalt asphalt mixture. The dynamic average stability of RMA steel slag mixture was 9218 cycles/mm and the expansion rate of steel slag asphalt mixture under did not exceed 1.2 % after 216 hours water immersion. Therefore, this study provides an alternative aggregate for road pavement and a sustainable recycling strategy for the steel slag waste.

Synthesis of Solketal Catalyzed by Acid-Modified Pyrolytic Carbon Black from Waste Tires.

Solketal, a widely used glycerol-derived solvent, can be efficiently synthesized through heterogeneous catalysis, thus avoiding the significant product losses typically encountered with aqueous work-up in homogeneous catalysis. This study explores the catalytic synthesis of solketal using solid acid catalysts derived from recovered carbon blacks (rCBs), which are obtained through the pyrolysis of end-of-life tires. This was further converted into solid acid catalysts through the introduction of acidic functional groups using concentrated H2SO4 or 4-benzenediazonium sulfonate (BDS) as sulfonating agents. Additionally, post-pyrolytic rCB treated with glucose and subsequently sulfonated with sulfuric acid was also prepared. Comprehensive characterization of the initial and modified rCBs was performed using techniques such as elemental analysis, powder X-ray diffraction, thermogravimetric analysis, a back titration method, and both scanning and transmission electron microscopy, along with X-ray photoelectron spectroscopy. The catalytic performance of these samples was evaluated through the batch mode glycerol acetalization to produce solketal. The modified rCBs exhibited substantial catalytic activity, achieving high glycerol conversions (approximately 90%) and high solketal selectivity (around 95%) within 30 min at 40 °C. This notable activity was attributed to the presence of -SO3H groups on the surface of the functionalized rCBs. Reusability tests indicated that only rCBs modified with glucose demonstrated acceptable catalytic stability in subsequent acetalization cycles. The findings underscore the potential of utilizing end-of-life tires to produce effective acid catalysts for glycerol valorization processes.

Synthesis of carrageenan/DFNS composite and its application in the esterification of levulinic acid with alcohols

The surface acidity of dendritic fibrous nano-silica (DFNS) was modified by a k-carrageenan biopolymer having sulfonic acid functional groups. The composite was used as a solid acid catalyst in the Fischer esterification reaction to convert levulinic acid (LA) to alkyl levulinates. The samples were characterized by analytical and instrumental techniques such as FT-IR spectroscopy, X-ray diffraction (XRD), N2 adsorption–desorption analysis, FESEM, and TEM. By using different alcohols including a short chain (ethanol), a medium chain (n-butanol), and a long chain (n-hexanol), the impact of various parameters on the esterification reaction was investigated. Under the optimum reaction conditions including 6 h as the reaction time, 10 mg catalyst amount, 12:1 ethanol: LA ratio, and 150 °C as the reaction temperature a 61 % ethyl levulinate was obtained. The selected catalyst was recycled and regenerated for use in successive runs without worthy loss in its activity.

Anion exchange recovery of rhenium from industrial liquors followed by direct synthesis of a rhenium halide salt

In the present study, the sorption of perrhenate ions from sulfuric acid liquors was studied using three types of polymer ion exchange resins. An anion exchange resin type 1 (a copolymer of 2-methyl-5-vinylpyridine with divinylbenzene (VP-DVB)) as well as two polyfunctional resins containing anion and cation exchange functional groups, namely, type 2 (a carboxylated VP-DVB with pyridine-2-carboxylic acid (picolinic acid) functional group) and type 3 (an aminophosphorylated VP-DVB with pyridine-2-[(methylamino)methyl]phosphonic acid functional group), were studied. The resins before and after rhenium sorption were characterized by FT-IR spectroscopy and XPS spectroscopy. The incorporation of additional acidic functional groups into the polymer matrix of the VP-DVB resins led to a slight decrease in the rhenium anion exchange capacity. At the same time, polyfunctional resins make it possible to strip rhenium with hydrochloric acid. A completely new process for the preconcentration of rhenium as a halide compound, which will contribute to the low-cost production of metallic rhenium, can be implemented using these new polyfunctional resins. Column sorption experiments using real uranium leach liquors demonstrated an exchange capacity of 33.2 mg of Re per gram of resin and a concentration factor in the eluate of ∼2500. The possibility of anion exchange recovery of rhenium from uranium leach liquors by Type 3 resin followed by direct precipitation of potassium hexachlororhenate from hydrochloric acid desorption liquor was demonstrated. The present study provided a new resin for rhenium recovery with excellent adsorption and elution characteristics, which is a promising candidate for practical applications.

Effects of Sugarcane Bagasse Biochar on Ammonium and Nitrate Adsorption and Leaching in a Japanese Tropical Soil Cropped with Japanese Mustard Spinach (Brassica rapa)

This study investigated the dynamics of ammonium-nitrogen (NH4+-N) and nitrate-nitrogen (NO3–-N) adsorption and leaching in a Japanese tropical soil amended with sugarcane bagasse biochars (SBBs) in the presence of plant. Adsorption and column leaching studies were conducted in a laboratory in Japan, and the column study was performed for 21 days. Biochar was produced from sugarcane bagasse at the maximum pyrolysis temperatures of 400°C (SBB400) and 800°C (SBB800) for use in the experiments. Adsorption isotherms for NH4+-N and NO3–-N were developed for soil only, SBB400-amended soil, and SBB800-amended soil. Column leaching study included 6 treatments: fertilizer only, fertilizer and plant, fertilizer and SBB400, fertilizer and SBB400 and plant, fertilizer and SBB800, fertilizer and SBB800 and plant. This study showed that soil and SBBs-amended soils fitted well into the Langmuir adsorption model for NH4+-N and NO3–-N (r2= 0.983–0.994 and 0.956–0.970, respectively). Application of SBBs to soil significantly decreased cumulative NH4+-N leached from the soil (P < 0.05) because of increased adsorption capacity due to high acid functional groups and increased soil water holding capacity (WHC) due to high specific surface areas and pore volumes, regardless of the presence of plant. However, the SBBs application did not affect the adsorption capacity for NO3–-N because of negatively charged surfaces. However, cumulative NO3–-N leached was significantly reduced (P< 0.05) due to increased soil WHC, regardless of the presence of plant. Therefore, more soil water contents retained and less NO3–-N leached from the soil may have contributed to greater plant growth with the SBBs application. This study showed that the SBBs application to soil could enhance adsorption capacity for NH4+-N but not for NO3–-N, nevertheless increase soil WHC and reduce leaching of both NH4+-N and NO3–-N, thus contributed to increased plant growth.

Efficient removal and reusage of acid soluble oil in waste H2SO4 of isobutane alkylation by low-temperature carbonization process

Waste H2SO4 from industrial isobutane alkylation, a hazardous thick liquid with a high concentration of acid soluble oil (ASO) impurities, poses challenges in the regeneration process. Herein, an innovative low-temperature carbonization process was proposed to convert waste H2SO4 into the regenerated concentrated H2SO4 and sulfonated activated carbon materials (SACMs) under mild reaction conditions. The optimal reaction temperature is identified at 423.15 K with the highest TOC removal of 90.57%. The high-purity regenerated H2SO4 with a concentration of 95% as a catalyst for isobutane alkylation exhibits excellent catalytic performance with 94.54 research octane number (RON) of the alkylate. SACMs, characterized as a novel porous carbon material with plentiful hydroxyl, carboxylic acid, and sulfonic acid functional groups, demonstrate an efficient catalytic activity in the dimerization of lactic acid to produce lactide with a yield of 46.95%. Hopefully, the novel recovery process provides a promising application to optimize the regeneration process of waste H2SO4 from industrial isobutane alkylation.