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Activated carbon (AC) adsorption is commonly used for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) removal from flue gas. However, the AC available in the market predominantly possesses a substantial specific surface area and numerous micropores leading to significant variations in their adsorption characteristics. In this study, three types of activated carbon (AC) impregnated with different activating agents, namely K2CO3, KOH, and H3PO4 were evaluated for their effectiveness in removing PCDD/Fs and dl-PCBs compounds. For dl-PCBs, AC impregnated with H3PO4 resulted in a substantial reduction of PCB concentrations with an impressive 98% reduction achieved. Impregnation with KOH proved even more effective attaining a remarkable 99% reduction. In contrast, impregnation with K2CO3 while still effective achieved a slightly lower reduction rate of 95%. For PCDD/F, LACH3PO4 showed selectivity in achieving high reductions across both CDD and CDF congeners however proved effective in reducing the ∑PCCDF from 403.94 ng/Nm3 to 3.463 ng/Nm3 and ∑TEQ from 41.34 ng I-TEQ/Nm3 to 0.35 ng I-TEQ Nm3. LACKOH proved effective in reducing the ∑PCCDF from 540.45 ng/Nm3 to 0.25 ng/Nm3 and ∑TEQ from 57.42 ng I-TEQ/Nm3 to 0.12 ng I-TEQ Nm3 obtaining the overall removal efficiency of 99.5%. While the LACKOH injections were successful in the absorption of PCDD/Fs from the gas phase, it was observed that certain PCDD/F congeners became desorbed and entrapped within the ash necessitating further treatment of the ash residue. The ash underwent a thermal treatment first at 300 °C and 500 °C. The thermal treatment at 500 °C achieved a remarkable degradation of 99.7% removal efficiency rendering the ash and residue safe for disposal in a landfill site.Article Highlights: The study assessed K2CO3, KOH, and H3PO4 for AC activation efficiency. KOH proved most effective (99.5% removal). Post-ash treatment at 500 °C degraded PCDD/Fs by 99.7%, ensuring safe landfill disposal. [ABSTRACT FROM AUTHOR]

Abstract Activated carbon (AC) adsorption is commonly used for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) removal from flue gas. However, the AC available in the market predominantly possesses a substantial specific surface area and numerous micropores leading to significant variations in their adsorption characteristics. In this study, three types of activated carbon (AC) impregnated with different activating agents, namely K2CO3, KOH, and H3PO4 were evaluated for their effectiveness in removing PCDD/Fs and dl-PCBs compounds. For dl-PCBs, AC impregnated with H3PO4 resulted in a substantial reduction of PCB concentrations with an impressive 98% reduction achieved. Impregnation with KOH proved even more effective attaining a remarkable 99% reduction. In contrast, impregnation with K2CO3 while still effective achieved a slightly lower reduction rate of 95%. For PCDD/F, LACH3PO4 showed selectivity in achieving high reductions across both CDD and CDF congeners however proved effective in reducing the ∑PCCDF from 403.94 ng/Nm3 to 3.463 ng/Nm3 and ∑TEQ from 41.34 ng I-TEQ/Nm3 to 0.35 ng I-TEQ Nm3. LACKOH proved effective in reducing the ∑PCCDF from 540.45 ng/Nm3 to 0.25 ng/Nm3 and ∑TEQ from 57.42 ng I-TEQ/Nm3 to 0.12 ng I-TEQ Nm3 obtaining the overall removal efficiency of 99.5%. While the LACKOH injections were successful in the absorption of PCDD/Fs from the gas phase, it was observed that certain PCDD/F congeners became desorbed and entrapped within the ash necessitating further treatment of the ash residue. The ash underwent a thermal treatment first at 300 °C and 500 °C. The thermal treatment at 500 °C achieved a remarkable degradation of 99.7% removal efficiency rendering the ash and residue safe for disposal in a landfill site. Graphical Abstract

This investigation explores “batch adsorption of turquoise blue dye” from aqueous solutions using phosphoric acid-activated “Delonix regia Pod carbon prepared using a tubular furnace” (DRTFC). Various factors were examined and equilibrium data were gathered at different temperatures (205 K, 315 K, and 325 K) and for varying initial dye concentrations. Optimal pH for dye removal was found to be 2. Kinetic modeling was done using “Lagergren's first-order kinetics”, Ho's “second-order kinetics”, and Weber Morris equations, with the “pseudo-second-order kinetic model” showing the best fit based on Sum of Squared Errors (SSE) analysis. Thermodynamic parameters were determined through “Van’t Hoff plots”, suggesting that the adsorption process was endothermic, spontaneous, and with increased randomness. [ABSTRACT FROM AUTHOR]

This work extensively investigated the preparation and dispersion of concentrated aqueous suspensions of H₃PO₄-treated nano-sized Y₂O₃ powder particles. For comparison purposes, the untreated Y₂O₃ powder was also studied. Compared to the untreated Y₂O₃ powder, the treated powder exhibited a narrower particle size distribution and enhanced homogeneity in particle dispersion. In the case of the untreated powder suspension, there was a rapid increase in the pH from 9.34 to 10.4 in a short dispersion time, whereas no variation in the pH was observed for the treated Y₂O₃ suspension during the hydrolysis tests. This was because the phosphate-based protection layer on the surfaces of the particles inhibited the hydrolysis of Y₂O₃ powders, thus enabling the formation of colloidally stable suspensions. TAC was employed as the dispersant in preparing both the treated and untreated Y₂O₃ suspensions. The treated Y₂O₃ suspension exhibited lower viscosity and maintained long-lasting stability for 6 h compared to the untreated one. It was determined that the use of H₃PO₄ at a dosage of 1 wt% allowed one to obtain suspensions with the lowest sedimentation volume and viscosity. A series of treated Y₂O₃ suspensions with solid loadings ranging from 20 vol% to 40 vol% were obtained, which were centrifugal slip cast into cylindrical shapes. The resulting cast green bodies from the 35 vol% treated Y₂O₃ suspensions exhibited a uniform and high packing density of 49.24%.

Comprehensive use of available biomass, especially low-cost forestry waste to produce bioenergy, materials have great meaning for realization of green and sustainable chemical processes. In this work, forestry sawdusty waste (SD) was used to produce biochar (SDBC-P) via a H3PO4 assisted hydrothermal carbonization method. And a novel zirconium-coordinated biochar catalyst Zr-SDBC-P has been prepared by self-assembly method. Characterization results revealed that hydrothermal carbonization in the presence of H3PO4 promoted the formation of oxygen-containing functional groups (–COOH, Ar–OH) which were used as ligand to obtain high contents of Lewis acid − base sites (Zr4+–O2−). Zr-SDBC-P-4 showed satisfactory catalytic activity in synthesis of bioderived γ-valerolactone (GVL) from ethyl levulinate (EL). EL conversion of 98.2% and GVL selectivity of 85.4% were obtained within 5 h at 170 °C. In addition, Zr-SDBC-P-4 displayed outstanding chemical stability. There was no obvious decrease of GVL yield after being used for six cycles. Overall, this work offered a viewpoint to design catalyst from value-added utilization of biomass waste. [ABSTRACT FROM AUTHOR]

Here, the chemical modification of Ziziphus jujuba stones (ZJS) treated with ortho-phosphoric acid (ZJS-H3PO4) is investigated to enhance its adsorption properties for organic dyes. The physicochemical properties of ZJS-H3PO4 reveal increased porosity (87.29%), slightly higher bulk density (0.034 g mL−1), and enhanced acidity (31.42 m eq g g−1) compared to untreated ZJS. XRF analysis confirms the successful incorporation of orthophosphoric acid during treatment due to a significant increase in phosphorus content. The maximum adsorption capacity of methylene blue on ZJS-H3PO4 is found to be 179.83 mg g−1, demonstrating its efficacy as a potential adsorbent for organic dyes. These findings suggest that modifying ZJS with orthophosphoric acid could be a promising strategy to enhance its adsorption performance in various environmental applications. Furthermore, Gaussian process regression (GPR) is employed to model MB adsorption by ZJS-H3PO4. Optimization of the GPR model involves evaluating different kernel functions and meticulously adjusting parameters to maximize its ability to capture complex relationships in the data. The obtained GPR model demonstrates remarkable performance with high correlation coefficients (R) and low root mean square errors (RMSEs) across all study phases. Model validation is performed through residual analysis, confirming its effectiveness and accuracy in predicting MB adsorption. Finally, a user-friendly interface is developed to facilitate the usage of the GPR model in future applications, representing a significant advancement in environmental process modeling and ecosystem management. [ABSTRACT FROM AUTHOR]

AbstractThe adsorption performance of 2-mercaptobenzothiazole from an aqueous solution on activated carbon synthesized through grape marc was explored. In this research, the agricultural waste was chemically treated with phosphoric acid (40% H3PO4, 170 °C, 3 h), then pyrolyzed at 650 °C for 2 h, to obtain the GMAC-650 to be used as an adsorbent. The resulting material was characterized by Fourier-transform infrared spectroscopy, X-ray diffraction, and Brunauer–Emmett–Teller (BET). Maximum uptake (∼99%) is obtained under ideal conditions: an adsorbent dose of 0.8 g L−1 and pH = 8 for an initial concentration of 10 mg L−1 at 45 °C. The adsorption equilibrium data were fitted to the following isotherm models: Langmuir and Freundlich. For optimal equilibrium isotherm selection, a comparison of linear and non-linear methods for the adsorption of MBT. It was based on four error functions: the coefficient of determination R2, the sum of squared errors, the Chi-square (χ2), and the root mean square error. The current work has shown that the non-linear method is a more adequate method for estimating the parameters of the isotherm compared with the linear method. The comparative analysis of the models shows that the Freundlich model is more appropriate for describing equilibrium data. [ABSTRACT FROM AUTHOR]

Abstract In this study, activated carbon was synthesized using the almond shell and palm kernel by physical activation with water vapor and chemical activation with phosphoric acid (H3PO4) methods. Then, the structural and optical properties of the activated carbons were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and UV–Vis spectroscopy. The SEM images showed that in the raw sample of hard almond shell and palm kernel, there is no porosity and pores, but in the activated carbon samples, porosity and structural defects were clearly observed. The XRD patterns showed that porous and amorphous structure was formed in all samples synthesized with physical and chemical activation. The results of FTIR spectra of activated carbons showed that there are carbon functional groups in all samples. The optical absorption coefficient (α) of the activated carbon with physical and chemical activation methods was obtained in order of 105–106. The band gap measurement of porous nanostructures showed that the activated carbon synthesized with chemical and physical activation methods have energy gap (Eg) in region = 2.80 to 3.15 eV and urbach energy (EU) in region = 120 to 210 meV.

In this study, using waste materials such as hard almond bark and palm kernels, the porous activated carbon has been synthesized by chemical activation method with activation agents of sodium hydroxide (NaOH), sodium chloride (NaCl), and phosphoric acid (H3PO4). Then, the structural, morphological, and optical properties of the synthesized activated carbons were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and UV–Vis spectroscopy. The XRD patterns showed that an activated carbon structure was formed in all the samples synthesized with chemical activators. The SEM and TEM images showed that there is no porosity and pitted for raw and primary carbon samples of hard almond bark and palm kernels, but for activated carbon by various activating agents, it was clearly porous structure in the activated samples. Also, in the FTIR spectra of activated carbon, it was confirmed that there are carbon single and double bonds for in all samples. The measurement of the optical absorption coefficient (α) and optical band gap (Eg) of porous carbon nanostructures showed that α is in order of 106–107 cm−1 and energy gap is in range of 1.98–2.83 eV. The activated carbon sample synthesized from almond bark with H3PO4 activator has highest energy gap (Eg = 2.83 eV) and NaCl activator has lowest energy gap (Eg = 1.98 eV). [ABSTRACT FROM AUTHOR]

Activated carbon was prepared from Chinese prickly seeds activated by H3PO4. It was characterized by the methods of FT-IR, N2 adsorption/desorption, XRD, SEM and EDS. The adsorption performance for methylene blue was investigated. Under the conditions that impregnation mass ratio of 85 wt% H3PO4 to Chinese prickly seeds was 0.8, impregnation time was 10 h, carbonization temperature was 550 ℃ and carbonization time was 60 min, activated carbon containing micro- and meso-porous was prepared successfully with the yield and BET specific area were 23.4% and 740 m²/g, respectively. The adsorption for methylene blue investigation showed the adsorption capacity could be achieved to 495 mg·g when the initial concentration of methylene blue is 500 mg·L under the adsorption temperature at 30℃ and pH of 13.0 after adsorbed for 60 min. Thermodynamics studies showed the adsorption process can be favorably described by Langmuir isotherm that ΔH is 33.7 kJ·mol and ΔS is 125.9 J/(mol·℃). The adsorption kinetics was satisfactory fitted to the pseudo-second-order model that the activated energy is 6.33 kJ/mol. The study provides a reference for the high-quality utilization of Chinese brickly seeds and the useful dada for the adsorption treatment of dye wastewater by activated carbon preparation from Chinese brickly seeds. [ABSTRACT FROM AUTHOR]

In this study, activated carbon was synthesized using the almond shell and palm kernel by physical activation with water vapor and chemical activation with phosphoric acid (H3PO4) methods. Then, the structural and optical properties of the activated carbons were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and UV–Vis spectroscopy. The SEM images showed that in the raw sample of hard almond shell and palm kernel, there is no porosity and pores, but in the activated carbon samples, porosity and structural defects were clearly observed. The XRD patterns showed that porous and amorphous structure was formed in all samples synthesized with physical and chemical activation. The results of FTIR spectra of activated carbons showed that there are carbon functional groups in all samples. The optical absorption coefficient (α) of the activated carbon with physical and chemical activation methods was obtained in order of 105–106. The band gap measurement of porous nanostructures showed that the activated carbon synthesized with chemical and physical activation methods have energy gap (Eg) in region = 2.80 to 3.15 eV and urbach energy (EU) in region = 120 to 210 meV. [ABSTRACT FROM AUTHOR]

Herein, tropical fruit biomass wastes including durian seeds (DS) and rambutan peels (RP) were used as sustainable precursors for preparing activated carbon (DSRPAC) using microwave-induced H3PO4 activation. The textural and physicochemical characteristics of DSRPAC were investigated by N2 adsorption-desorption isotherms, X-ray diffraction, Fourier transform infrared, point of zero charge, and scanning electron microscope analyses. These findings reveal that the DSRPAC has a mean pore diameter of 3.79 nm and a specific surface area of 104.2 m2/g. DSRPAC was applied as a green adsorbent to extensively investigate the removal of an organic dye (methylene blue, MB) from aqueous solutions. The response surface methodology Box–Behnken design (RSM-BBD) was used to evaluate the vital adsorption characteristics, which included (A) DSRPAC dosage (0.02–0.12 g/L), (B) pH (4–10), and (C) time (10–70 min). The BBD model specified that the DSRPAC dosage (0.12 g/L), pH (10), and time (40 min) parameters caused the largest removal of MB (82.1%). The adsorption isotherm findings reveal that MB adsorption pursues the Freundlich model, whereas the kinetic data can be well described by the pseudo-first-order and pseudo-second-order models. DSRPAC exhibited good MB adsorption capability (118.5 mg/g). Several mechanisms control MB adsorption by the DSRPAC, including electrostatic forces, π–π stacking, and H-bonding. This work shows that DSRPAC derived from DS and RP could serve as a viable adsorbent for the treatment of industrial effluents containing organic dye. The novelty of this research work comes from the conversion of the mixed biomass wastes from tropical fruit including durian seeds and rambutan peels as precursor for activated carbon (DSRPAC) using microwave assisted H3PO4 activation. The effectiveness of DSRPAC as promising adsorbent was tested for methylene blue (MB) dye adsorption. Furthermore, response surface methodology with Box Behnken design (RSM-BBD) was applied to optimize the adsorption key parameters. A tailored adsorption mechanism of MB on the surface of DSRPAC was proposed. [ABSTRACT FROM AUTHOR]

Plasma electrolytic fluorination (PEF) was performed on AZ31 Mg alloy in the ethylene glycol (EG) electrolytes containing varying quantities of H 3 PO 4. Effects of the H 3 PO 4 addition on the microstructure, growth behaviour and corrosion resistance of the PEF coatings were analyzed. Results revealed that after the addition of H 3 PO 4 , the plasma discharges became weaker and the crystallinity of the PEF coating was detected to decrease with the H 3 PO 4 content. As the H 3 PO 4 content reached 20 g/L, the PEF coating was completely transformed into an amorphous state. Beside, adding H 3 PO 4 into the EG electrolytes increased the growth rates of the PEF coatings, and changed the growth mechanism of the PEF coatings from inward growth to mixed growth dominated by outward growth. The influence of the H 3 PO 4 addition on the corrosion resistance of PEF coating varied with the H 3 PO 4 content in EG electrolytes. When the H 3 PO 4 content was 10 g/L, the PEF coating had the best corrosion resistance. [ABSTRACT FROM AUTHOR]

Extensive research has demonstrated the advantageous utilization of medium–low temperature fast pyrolysis (FP) for biomass, yielding high–grade liquid–phase chemicals or fuels. However, the field of FP–based high–performance solid biochar research still presents several gaps. Herein, a one–step versus two–step method for biomass H3PO4 activation under FP was comparatively analyzed for the first time, and efficiently activated carbons (ACs) for dye removal were successfully synthesized at a low temperature (723 K). Investigation of methylene blue (MB) adsorption revealed that the one–step sample P–H–0.5, possessing a specific surface area of 1004 m2·g−1, exhibited a remarkable adsorption capacity of 695.54 mg·g−1 with an ultra–high removal rate (99.94%, C0 = 150 mg·L−1). The two–step sample P–2–H–2, a modified byproduct of FP, achieved efficient dye adsorption in the shortest time (2 min, 383.91 mg·g−1). This originated from the well–developed surface macropores and elevated group content derived from phosphorus (P)—modification. Both adsorption data were well–fitted with pseudo–second–order kinetics and the Langmuir model, revealing the presence of chemical effects and the dominance of monolayer adsorption. A more detailed kinetic study suggested intrapore transport primarily governed the adsorption process on P–H–0.5, whereas P–2–H–2 relied on surface diffusion. FTIR and XPS revealed notable differences in the active sites between the two methods. Aside from –OH, –COOH with C–O–P, the P elements of P–H–0.5 were classified as C–P–O3 and C2–O–P2, demonstrating the ability of one–step FP to introduce heteroatoms into carbon defects. The basic interactions of ACs with MB were π–π stacking and hydrogen bonding established by –OH–containing groups. At a suitable pH (>5), most H+ was removed from the surface, and the electrostatic attraction became the strongest linking force. Both ACs exhibited exceptional reusability, with removal rates surpassing 90% of the initial rate after four cycles of regeneration. [ABSTRACT FROM AUTHOR]

This study, in the quest for rugged, robust and greener and cleaner technology, investigated efficiency ofDaniellia-oliveri sawdust for the removal of pyrimethamine from aqueous medium. Two adsorbents were prepared by carbonising and activating the sawdust with ZnCl2 and H3PO4.The adsorbents were characterised using various methods. Batch adsorption experiments were conducted to evaluate the equilibrium isotherm, kinetics and thermodynamics of the process, and to determine the effects of various experimental conditions. The pHpzc were 7.6 (for ZnCl2 activated carbon) and 6.6 (for H3PO4 activated carbon). The adsorption of pyrimethamine onto the adsorbents was pH independent. The best isotherms for describing the processes were Langmuir (R2 = 0.987) and Dubinin-Radushkevich (R2 = 0.996) while the kinetics were pseudo-second order (R = 0.980) and intraparticle (R = 0.985) respectively. The monolayer adsorptive capacities of the adsorbents were 4.27 mg/g and 4.43 mg/g.The processes were spontaneous, thermodynamic feasible and endothermic. The results reveal that the two adsorbents were good prospects for the removal of pyrimethamine from wastewater. [ABSTRACT FROM AUTHOR]

This research aims to ascertain the optimum conditions and interaction effects of selected variables via response surface methodology incorporated with central composite design in a batch treatment system. A quadratic model was obtained through the influence effects of the selected variables. Four variables pH (A), initial concentration (B), contact time (C), and biosorbent dosage (D), were selected to obtain high efficiency in the removal of the steroid hormone 17α-ethinylestradiol using modified kenaf core. The biosorbent characterisation, which was modified via chemical acid activation, was investigated through surface morphology structures using field emission scanning electron microscopy, Brunauer–Emmett–Teller, and fourier transform infrared spectroscopy analyses. The optimum conditions in an aqueous solution, obtained through a verification optimisation process, are 5.9, 28.2 mg/L, 216 min, and 0.40 g for variables A, B, C, and D, respectively. The pH and initial concentration explain the most significant interaction effect (F-value 23.12) at pH 4.6–5.8, with the lowest initial concentration being a good sign for the application of modified kenaf core in the real environment. The optimum removal rate computed in the quadratic model was 100%. In comparison, the real experimental set-up achieved a 99.3% 17α-ethinylestradiol removal rate, which is in great agreement with the predicted rate with a small percentage error (0.7%) between the experimental and predicted values. Linear regression provided a best-fit isotherm with the Langmuir model. The results prove that modified kenaf core has enormous potential for 17α-ethinylestradiol removal due to its excellent surface morphological structure and high removal efficiency. [ABSTRACT FROM AUTHOR]

Activated carbon was prepared from grape marc after activation with H3PO4. It was used to adsorb an azo dye (AO7) from aqueous solutions. The adsorption process was spontaneous (∆G ˂ 0) and endothermic as indicated by the thermodynamic parameters (∆H = 12.28 kJ /mol and ∆S = 0.041 kJ/mol K). The adsorption capacity was found to increase with increasing temperature (from 140.5 mg/g at 25 °C to 174.6 mg/g at 55 °C). The nonlinear regression adsorption equilibrium modeling revealed that the adsorption of AO7 by the activated carbon was best represented by the Freundlich model (R2 > 0.975). The desorption of the dye and the regeneration of the activated carbon are crucial steps to consider in evaluating the efficacy of contaminant elimination from aqueous solutions. Among six solvents used, ethanol had the greatest capacity of dye desorption from the activated carbon (48%). The FTIR investigation revealed that ethanol was partially bound to the activated carbon which adversely decreases the adsorption capacity in each adsorption–desorption cycle. The investigation carried out revealed that the grape marc adsorbent was effective in removing dyes from waste water. [ABSTRACT FROM AUTHOR]

Egypt is considered one of the largest marble-producing countries in the world. The extensive marble production has resulted in a significant amount of waste marble powder (WMP). Safely recycling this waste is one of the state's most important priorities due to its abundance, which may cause an environmental disaster. Following this policy, the authors of this article sought to develop a novel method for recycling WMP into metakaolin (MK) geopolymer pastes activated with H 3 PO 4. This study represents the first investigation into using WMP, given its high CaCO 3 content, as a foaming agent in MK-H 3 PO 4 pastes. To this end, MK was partially replaced with WMP in proportions ranging from 2 wt% to 10 wt% with a pace of 2 wt%. A constant amount of H 3 PO 4 was used as an activator. After proper curing, parameters such as bulk density, compressive strength, transport properties, and thermal conductivity were evaluated. An accelerated aging test was also conducted to evaluate the material's durability. Advanced instruments were utilized to analyze the results. The outcomes affirmed that WMP is a viable, sustainable foaming agent capable of creating a porous microstructure. Incorporating 10 % WMP into the matrix optimized the material, achieving the least bulk density (850 kg/m3), thermal conductivity (0.124 W/mK), and acceptable compressive strength (2.25 MPa) alongside the highest porosity (59.5 %). Moreover, the porous microstructure of WMP-containing specimens improved their durability, as demonstrated by enhanced performance in the accelerated aging test due to facilitated water vapor transport. • It is possible to employ WMP as a foaming agent for MK-H 3 PO 4. • Including WMP decreased thermal conductivity, compressive strength, and density. • Including WMP increased porosity. • Including WMP mitigated the deterioration caused by accelerating aging. [ABSTRACT FROM AUTHOR]

[Display omitted] • LLE data for the quaternary systems of H 2 O+H 3 PO 4 + DIPE+TBP/MIBK. • Study of the effect of TBP and MIBK on the three-phase zone. • Three-phase zone disappeared after the addition of 0.206 of TBP and 0.583 of MIBK. • The mixed solvent (TBP+DIPE) is the best-performing solvent. • The mixed solvent (0.3TBP+0.7DIPE) has the potential to enhance H 3 PO 4 extraction. The three-liquid-phase formation in the ternary system of water + phosphoric acid + diisopropyl ether (DIPE) makes the phosphoric acid extraction only effective for acid mass fractions above 0.69. To avoid the undesirable formation of the third phase and enhance acid extraction, particularly at low concentrations, two phase modifiers, methyl isobutyl ketone (MIBK) and tributyl phosphate (TBP), were systematically studied. In order to quantify the synergetic effect of the mixed solvents of DIPE+TBP and DIPE+MIBK, the liquid–liquid equilibria for the quaternary systems of H 2 O+H 3 PO 4 + DIPE+TBP and H 2 O+H 3 PO 4 + DIPE+MIBK were fully established for different DIPE/phase modifier (TBP or MIBK) mass ratios (90/10, 70/30, 50/50, and 20/80) at 298.2 K under atmospheric pressure using the cloud point and Othmer graphical method. Othmer-Tobias and Hand correlations were used to fit the tie-line data and assess its consistency. In addition, the behavior of the three-phase zone was also studied as a function of the phase modifiers content. Separation factor (S) and acid distribution (D 2) were used to identify the most effective solvent with the potential to enhance phosphoric acid extraction from aqueous solutions. [ABSTRACT FROM AUTHOR]

• Systematic investigation of solid-liquid equilibria (SLE) of H 3 PO 4 H 4 P 2 O 7. • Analytical representation of liquidus curves using Quasi-ideal model. • Delimitation of the stability range of ortho- and pyrophosphoric acid (I and II). The study of the system formed by ortho- and pyrophosphoric acid was resumed in order to understand the crystallization conditions of these two compounds and to highlight the existence of their possible polymorphism. To this end, the solid-liquid equilibria (SLE) of pyrophosphoric acid was studied in depth. Contradictions in literature data were resolved through systematic experimentation: solubility measurements, differential scanning calorimetry (DSC), and X-ray diffraction (XRD). Calorimetric measurements confirmed the existence of two crystalline forms of pyrophosphoric acid, and their stability domains were determined. Furthermore, thermodynamic modeling of the SLE has led to a consistent and refined representation of the observed phenomena. In particular, the transition temperature from low-temperature (form I) to high-temperature form (form II) of pyrophosphoric acid was determined at 298.4 K and the coordinates of the eutectic point common between H 3 PO 4 and H 4 P 2 O 7 (I) were precisely determined. Modeling also confirms the non-negligible quantity of triphosphoric acid in the liquid state throughout virtually the entire compositional range. Finally, X-ray powder diffraction data were used to determine the cell parameters and space group of pyrophosphoric acid using EXPO 2014 software. [Display omitted] [ABSTRACT FROM AUTHOR]

Extensive research has demonstrated the advantageous utilization of medium–low temperature fast pyrolysis (FP) for biomass, yielding high–grade liquid–phase chemicals or fuels. However, the field of FP–based high–performance solid biochar research still presents several gaps. Herein, a one–step versus two–step method for biomass H3PO4 activation under FP was comparatively analyzed for the first time, and efficiently activated carbons (ACs) for dye removal were successfully synthesized at a low temperature (723 K). Investigation of methylene blue (MB) adsorption revealed that the one–step sample P–H–0.5, possessing a specific surface area of 1004 m2·g−1, exhibited a remarkable adsorption capacity of 695.54 mg·g−1 with an ultra–high removal rate (99.94%, C0 = 150 mg·L−1). The two–step sample P–2–H–2, a modified byproduct of FP, achieved efficient dye adsorption in the shortest time (2 min, 383.91 mg·g−1). This originated from the well–developed surface macropores and elevated group content derived from phosphorus (P)—modification. Both adsorption data were well–fitted with pseudo–second–order kinetics and the Langmuir model, revealing the presence of chemical effects and the dominance of monolayer adsorption. A more detailed kinetic study suggested intrapore transport primarily governed the adsorption process on P–H–0.5, whereas P–2–H–2 relied on surface diffusion. FTIR and XPS revealed notable differences in the active sites between the two methods. Aside from –OH, –COOH with C–O–P, the P elements of P–H–0.5 were classified as C–P–O3 and C2–O–P2, demonstrating the ability of one–step FP to introduce heteroatoms into carbon defects. The basic interactions of ACs with MB were π–π stacking and hydrogen bonding established by –OH–containing groups. At a suitable pH (>5), most H+ was removed from the surface, and the electrostatic attraction became the strongest linking force. Both ACs exhibited exceptional reusability, with removal rates surpassing 90% of the initial rate after four cycles of regeneration.

Palm oil mill boiler ash is one of the substances that can be used as an adsorbent. The adsorbent can absorb certain components of a fluid phase, which before being applied needs to be activated using chemicals so that the effectiveness of the absorption is increasing. The use of adsorbents in CPO is quite effective in maintaining its quality. Several previous studies have studied the application of adsorbents in maintaining the quality of CPO. The purpose of the study was to utilize palm oil mill boiler ash as an adsorbent of several types of activators and to determine the effect of effective activator types in application to the quality of CPO oil. This study used a non-factorial completely randomized design with adsorbent activation treatment using H3PO4 and NaCl with a concentration of 10% and soaked for 24 hours. There are 3 parameters observed in the adsorbent application to CPO, namely free fatty acids, water content, and dirt content. The results showed that the adsorbent activated with H3PO4 was an effective adsorbent with a decrease in its free fatty acids up to 0.43%, water content decreased to 0.07%, but an increase in CPO impurities content of 0.24%. While the adsorbent activated using NaCl showed free fatty acids 0.22%, water content decreased by 0.03% and dirt content also increased by 0.24%.

In this article, activated carbon was produced from Lantana camara and olive trees by H3PO4 chemical activation. The prepared activated carbons were analyzed by characterizations such as scanning electron microscopy, energy-dispersive X-ray spectroscopy, Brunauer–Emmett–Teller, X-ray diffraction, thermogravimetric analysis, and Fourier transform infrared spectroscopy. H3PO4 is used as an activator agent to create an abundant pore structure. According to EDX analysis, the crystalline structure destroys and increases the carbon content of the olive tree and Lantana camara by 77.51 and 76.16%, respectively. SEM images reveal a porous structure formed as a result of H3PO4 activation. The Brunauer–Emmett–Teller (BET) surface area of the olive tree and Lantana camara activated carbon was 611.21 m2/g and 167.47 m2/g, respectively. The TGA analysis of both activated carbons shows their thermal degradation starts at 230 °C but fully degrades at temperatures above 450 °C. To quantify the potential environmental implications related to the production process of the activated carbon (AC) from olive trees, the life cycle assessment (LCA) environmental methodology was employed. For most of the tested indicators, chemical activation using H3PO4 showed the greatest ecological impacts: the ozone layer depletion potential (42.27%), the acidification potential (55.31%), human toxicity (57.00%), freshwater aquatic ecotoxicity (85.01%), terrestrial ecotoxicity (86.17%), and eutrophication (92.20%). The global warming potential (5.210 kg CO2 eq), which was evenly weighted between the phases, was shown to be one of the most significant impacts. The total energy demand of the olive tree's AC producing process was 70.521 MJ per Kg. [ABSTRACT FROM AUTHOR]

[Display omitted] • Porous carbon fibers catalysts were prepared by electrospinning of Alcell lignin. • The addition of H 3 PO 4 allows to obtain carbon fibers with acid character. • The catalysts show high activity and selectivity to dehydration products. • The catalysts show a high stability in the studied reaction condition. Porous carbon fibers catalysts have been prepared by electrospinning of Alcell lignin, a green carbon precursor, which could be obtained as by-product in wood-to-ethanol biorefineries. The addition of H 3 PO 4 , a well-known chemical activation agent, to the electrospinning lignin solutions, at different mass ratios and the use of different carbonization temperatures, between 500 and 1600 °C, were analyzed in order to obtain carbon fibers with a large variety of porosity and chemical surface properties. Isopropanol decomposition was used as a catalytic test. Phosphorus-containing carbon fibers showed acid character and high catalytic activity, achieving propylene selectivity of 100 % under inert atmosphere. However, the use of air atmosphere increases the isopropanol conversion but produces the formation of acetone, via oxidative dehydrogenation, at low temperatures (∼20 %). Ethanol and methanol decomposition were also evaluated in air stream for the most active phosphorus-containing carbon catalyst, showing improved alcohol conversions with minimal gasification of the carbon fibers. These results confirmed that phosphorus-containing carbon fibers prepared by electrospinning of lignin solutions were excellent catalysts for alcohol dehydration reactions. [ABSTRACT FROM AUTHOR]

To analyze the effects of binder content on the performance and durability of high-temperature PEMFC, we investigate detailed distribution of PTFE-binder whose content ranges from 7.7 to 35.1 wt% on Pt/C models in the presence of H 3 PO 4 at room (298.15 K) and operating (433.15 K) temperatures. Pair correlation function (PCF) analysis shows that the distribution of H 3 PO 4 on the Pt particle significantly changes as a function of PTFE-binder content beyond 20.0 wt% at 298.15 K due to the onset of Pt particle coverage by PTFE-binder starts. However, under 433.15 K, the higher kinetic energy enables more H 3 PO 4 to access the Pt surface to maintain greater contact. In case of H 3 PO 4 on the carbon surface, the intensities of PCF significantly decrease with increasing PTFE-binder levels up to 20.0 wt% at both 298.15 and 433.15 K as the carbon surface becomes occupied by the PTFE-binder up to ~20.0 wt%. The surface coverage analysis also shows that the H 3 PO 4 coverage on Pt surface decreases from 72.4 to 30.5% with increasing PTFE-binder content from 7.7 to 35.1 wt% at 298.15 K. However, the H 3 PO 4 coverage on Pt surface is significantly higher at 433.15 K in comparison to that at 298.15 K because H 3 PO 4 could still permeate the PTFE-binder to contact the Pt particle due to the favorable interactions. Three-phase interfacial configurations of Pt/C catalyst layer as increasing binder contents. [Display omitted] • Detailed molecular distributions were investigated using full atomistic molecular dynamics. • Force fields for the van der Waals parameters between H 3 PO 4 and Pt particles were developed. • H 3 PO 4 on Pt particle significantly changes as binder content beyond 20.0 wt% at 298.15 K. • Under 433.15 K, the higher kinetic energy enables more H 3 PO 4 to access the Pt surface. • Carbon surface becomes occupied by the binder up to ~20.0 wt% at both 298.15 and 433.15 K. [ABSTRACT FROM AUTHOR]

In this article, activated carbon was produced from Lantana camara and olive trees by H3PO4 chemical activation. The prepared activated carbons were analyzed by characterizations such as scanning electron microscopy, energy-dispersive X-ray spectroscopy, Brunauer–Emmett–Teller, X-ray diffraction, thermogravimetric analysis, and Fourier transform infrared spectroscopy. H3PO4 is used as an activator agent to create an abundant pore structure. According to EDX analysis, the crystalline structure destroys and increases the carbon content of the olive tree and Lantana camara by 77.51 and 76.16%, respectively. SEM images reveal a porous structure formed as a result of H3PO4 activation. The Brunauer–Emmett–Teller (BET) surface area of the olive tree and Lantana camara activated carbon was 611.21 m2/g and 167.47 m2/g, respectively. The TGA analysis of both activated carbons shows their thermal degradation starts at 230 °C but fully degrades at temperatures above 450 °C. To quantify the potential environmental implications related to the production process of the activated carbon (AC) from olive trees, the life cycle assessment (LCA) environmental methodology was employed. For most of the tested indicators, chemical activation using H3PO4 showed the greatest ecological impacts: the ozone layer depletion potential (42.27%), the acidification potential (55.31%), human toxicity (57.00%), freshwater aquatic ecotoxicity (85.01%), terrestrial ecotoxicity (86.17%), and eutrophication (92.20%). The global warming potential (5.210 kg CO2 eq), which was evenly weighted between the phases, was shown to be one of the most significant impacts. The total energy demand of the olive tree’s AC producing process was 70.521 MJ per Kg.

One-pot condensation of pyrazole-4-aldehydes and hydroxylamine hydrochloride to form the corresponding oxime using formic acid as a medium and further dehydration of oxime using a catalytic amount of orthophosphoric acid to afford novel pyrazole-4-carbonitrile. This protocol serves as an ortho-phosphoric acid-catalyzed one-pot conversion of aldehyde to nitrile. Most remarkable features of this method are metal-free, cost-effective, atom efficiency with excellent yield (98–99%). This process will serve as a robust and scalable tool for the synthesis of valuable and versatile precursor (nitriles). This precursor will pave the way for the synthesis of various medicinally important valuable compounds. [ABSTRACT FROM AUTHOR]

The object of this study was to prepare activated carbons containing nitrogenous functional groups by a chemical method from nitrogen-containing raw materials. Fish (Ctenopharyngodon idellus) scales were impregnated with phosphoric acid (H3PO4) and activated at varied temperatures. The adsorption ability, structural characteristics, surface chemistry, and morphology of the activated carbons were characterized by methylene blue and iodine values, nitrogen adsorption, the Boehm method, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The total alkaline groups content of the activated carbon produced from fish scales was 0.4330 mmol/g, the total acidic groups was 1.68 mmol/g, the Brunauer--Emmett--Teller (BET) surface area was 501 cm²/g, and the total pore volume was 0.284 cm³/g. The average pore diameter was 1.94 nm under an activation temperature of 550 °C, an activation time of 1 h, and an impregnation ratio of 2. As a result of this study, nitrogenous functional groups that contained acid-base amphoteric adsorbent were produced. [ABSTRACT FROM AUTHOR]

A highly shape‐selective and relatively long‐lifetime HZSM‐5‐based catalyst (Zn‐2P/HZSM‐5) was prepared by chemical modification with both ZnSiF6·6H2O and H3PO4 solution. The phosphoric acid modification could effectively modulate the Brønsted acid strength of the HZSM‐5 catalyst, which promotes the oligomerization, alkylation, cyclization, and hydrogen transfer reactions. The introduction of Zn‐Lewis acid sites significantly improved the dehydroaromatization of higher olefins. All of these were very beneficial for the generation of BTX (i.e. benzene, toluene, and xylene) hydrocarbons in aromatization of methanol. The coke amount and the average rate of coke formation decreased over the Zn‐2P/HZSM‐5 catalysts, which may largely be ascribed to its lower strong acid sites and lower outer surface acidity. The catalytic performance of methanol aromatization showed that the Zn‐2P/HZSM‐5 catalyst exhibited the highest BTX selectivity of about 46.76% and the longest catalytic lifetime of about 498 h at T = 400 °C, P = 0.1 MPa, and weight hourly space velocity = 0.7 h−1. [ABSTRACT FROM AUTHOR]

The feasibility of preparing activated carbon by chemical activation from textile waste flax was studied. According to thermogravimetric analysis, H3PO4 and ZnCl2 changed the pyrolysis behavior of flax. Reactions between H3PO4 or ZnCl2 degradation intermediaries and flax resulted in flax carbonization and activation. The effects of activation temperature, time and impregnation ratio on yield, micropore, mesopore and elemental composition were discussed in detail. Results showed that the optimum activation temperature was 700 °C for H3PO4 and 800 °C for ZnCl2 while optimum activation time and impregnation ratio for both were 60 min and 1.0. H3PO4 activation was higher in yield while ZnCl2 activation obtained carbons that were higher both in surface area and mesopore volume. H3PO4 and ZnCl2 were able to carbonize the original flax components and produced activated flax that is highly carbonaceous, rich in surface functional groups and powdered in particle size. [ABSTRACT FROM AUTHOR]

Tomato cultivation in the Mediterranean region is susceptible to infestation by the parasitic weed branched broomrape (Orobanche ramose L.), and can lead to severe yield losses. Efficiency of individual soil solarization, soil disinfection technique that uses passive solar heating, or in integration with Gesaprim or H3PO4 to control O. ramosa and thus increase the growth and yield of tomatoes (Lojain 935 and GS-12 hybrids) under the conditions of fields experiments was studied over two growing summer seasons of 2018 and 2019. The survey of the distribution of O. ramosa in the provinces of Fayoum Governorate, which was implemented in 2016, showed that Ibshawai, Yusuf AlSeddiq and Itsa provinces had the highest percentages of incidence and attack severity, while Tamyia and Fayoum provinces showed the lowest percentages. The highest infestations were detected in winter season, while fall season showed the lowest infestations. In the field experiments, soil solarization was the best single treatment compared to organic manures, H3PO4, NPK fertilizer, and Gesaprim in controlling O. ramosa and increasing the growth and yield parameters of tomato hybrids. Additionally, soil solarization integrated with Gesaprim or H3PO4 was the best integrative application for Lojain 935 hybrid followed by the same integrative application for GS-12 hybrid. This best integrative application conferred the percent minimal incidence and attack severity of O. ramosa and the highest growth parameters (fresh and dry weights of shoots) and yield components (fruits No. plant-1, and fruits yield plant-1) of both tomato hybrids with superiority of Lojain 935. Therefore, the results of this study recommend the use of this best integrative application [soil solarization integrated with Gesaprim or H3PO4] as an appropriate technique for tomato production where the risk of branched broomrape infestation is high. [ABSTRACT FROM AUTHOR]

A simple method has been developed for the estimation of uranium in reactor grade sodium without the removal of sodium using time gated luminescence with pulsed lamp. Samples are prepared after oxidizing the sodium in air followed by dissolution in H2SO4. Luminescence of uranium is measured in 2 M H3PO4 + 1 M H2SO4 medium. Using this method, the concentration of uranium in synthetic sodium sample was determined to be 0.2 µg/g. The limit of detection of uranium in bulk sodium was found to be 0.016 µg/g. [ABSTRACT FROM AUTHOR]

Soybean shell (SS), as the byproduct of soybeans, is converted into porous carbon (PC) with a high specific surface area (SSA) via hydrothermal carbonization with H3PO4 followed by KOH activation. No obvious effect on the crystal structure of PC can be found by addition of H3PO4 during the hydrothermal process. However, the SSA of PC increases remarkably compared with hydrothermal carbonization without H3PO4, as H3PO4 assists in hydrothermal carbonization dehydration reactions and creates some pores beneficial for KOH activation. The SSA of the obtained PC reaches 2523 m2 g−1, and the hierarchical pore structure is mainly in 0.6–50 nm. The sample prepared by hydrothermal carbonization with 10 wt% H3PO4 and activation by KOH with the ratio of KOH/10‐hydrochar 3 under 700 °C exhibits a specific capacitance of 301 F g−1 in 6 m KOH electrolyte at the current density of 0.1 A g−1. It also has an excellent cycling stability with the specific capacitance remaining at 93.8% after 15 000 cycles. Furthermore, the energy density is 8.1 Wh kg−1 in the two‐electrode system. These results display that PC based on SS is a promising electrode material for the electric double‐layer capacitor. [ABSTRACT FROM AUTHOR]

In this research, engineered biochar and hydrochar derived from paddy husk were compared for the adsorption tetracycline (TC) in water effluents. Biochar was produced at three different pyrolysis temperatures (e.g., 250 °C, 300 °C and 350 °C) while hydrochar was produced using three different HTC temperatures (e.g., 180 °C, 200 °C and 220 °C). The adsorptive experiments were performed for both biochar and hydrochar using well-defined experimental conditions: pH (3); initial TC concentration (10 mg/L); adsorbent dosage (1 g/L); and temperature (27 °C) to study their adsorptive performances (q e in mg/g). After selecting the best q e values for both biochar and hydrochar, both materials were modified using 20% H 3 PO 4. A comprehensive scientific evaluation of both engineered biochar (EBC 350) and hydrochar (EHC 220) was performed using adsorption isotherm, adsorption kinetics, rate-limiting, and thermodynamics tests along with their characterization using FTIR and point of zero charge (pzc). The effects of temperature, dosage, and initial TC concentration on the adsorption process were studied for both EBC 350 and EHC 220. Acid activation improved the adsorptive performance of EHC 220 almost four times (from 1.9 to 7.5 mg/g), whereas adsorptive performance of EBC 350 improved 2.4 times from 3.8 to 9.1 mg/g. The best pH for TC adsorption onto EHC 220 was 5, whereas it was 3 for EBC 350. EBC 350 exhibited a good fit with the Freundlich model, whereas EHC 220 followed the Langmuir model. At 100 mg/L TC concentration, EHC 220 exhibited higher q e value (46.9 mg/g) compared to EBC 350 (41.7 mg/g). The Pseudo-first order kinetic model was the best fit for EHC 220 adsorption, whereas Pseudo-second order model was most suitable for EBC 350. The adsorption mechanisms involved in TC adsorption by EHC 220 included hydrogen bonding, hydrophobic effect, and π − π interaction, whereas cation exchange, mass diffusion, and π − π interaction were involved for EBC 350. The results of this study will facilitate the development of cost-effective filters with the incorporation of engineered biochar/engineered hydrochar for the active removal of emerging contaminants, like tetracycline, from wastewater so as to increase its reusable potential. [Display omitted] • Engineered biochar and hydrochar were examined for the removal of tetracycline from synthetic wastewater. • H 3 PO 4 activation enhanced the adsorption capacity of engineered hydrochar and biochar. • Pseudo-second order model and Pseudo-first order model were well-suited to explain adsorption kinetics of the engineered biochar and hydrochar, respectively. • π − π interaction, mass diffusion and cation exchange were fundamental adsorption processes for engineered biochar. • H-bond, hydrophobic interaction and π − π interaction were fundamental adsorption processes for engineered hydrochar. [ABSTRACT FROM AUTHOR]

[Display omitted] • H 3 PO 4 co-hydrothermal carbonization improved surface area and functional groups. • HC-5P showed highest adsorption and photocatalytic activity for NOR. • The adsorption and photocatalytic degradation mechanisms were proposed. • H 3 PO 4 co-hydrothermal carbonization is a promising way to prepare hydrochar photocatalyst. Hydrochars have been widely applied in removing pollutants from aqueous solutions. In this study, hydrochars synthesized by H 3 PO 4 -assisted hydrothermal carbonization (HC-xPs) were used to remove norfloxacin (NOR) from water through synergistic adsorption and photodegradation. HC-xPs showed the morphology of carbon microspheres with an average diameter of 0.3 μm. The specific surface area of the hydrochar carbonized with 5 mol/L H 3 PO 4 (HC-5P) was 11.2 times higher than that of the pristine hydrochar (HC). Furthermore, phosphorus-containing functional groups were introduced to HC-5P, beneficial to its adsorption of NOR. The highest NOR adsorption was achieved on HC-5P with the maximum Langmuir capacity of 69.1 mg g−1, owing to multiple mechanisms including electrostatic effects, π-π interactions, hydrophobic interactions, and hydrogen bonding. Compared with HC, HC-5P also demonstrated increased visible light absorption capacity. The first-order rate constant of HC-5P on combined adsorption and photodegradation of NOR was 12.0 times of HC. The photodegradation intermediates were identified by HPLC-MS to understand NOR degradation pathways. This work can be extended to the preparation of low-cost and highly efficient hydrochars for adsorption and photodegradation of pollutants in water. [ABSTRACT FROM AUTHOR]

[Display omitted] • BPSBC was the first time synthesized to efficiently remove environmental concentration SMX. • Pyrolysis and ball milling parameters were optimized to prepare modified SBC. • PSBC showed higher adsorption capacity than those of ASBC and NASBC. • Physical and chemical forces simultaneously contributed to SMX adsorption by BPSBC. • BPSBC exhibited satisfactory stability in a wide pH range and was easily regenerated. Efficiently eliminating environmental concentration sulfamethoxazole (SMX) from water has become a great challenge because its undesirable removal efficiencies/rates by the present sewage treatment technologies. In this study, various pyrolysis temperatures (400–700 °C), ball milling parameters (speed (300–700 rpm) and time (30–120 min)) and acids (CH 3 COOH, H 3 PO 4 and HNO 3) hydrothermal activation were studied to optimize the preparation of modified sludge biochar (SBC) with the greater adsorption capacity. As expected, ball milling and H 3 PO 4 hydrothermally co-functionalized SBC (BPSBC) showed the optimum adsorption performance for SMX, and its maximum adsorption capacity (4.61 × 104 μg/g) calculated from Langmuir model was 6.30 times that of SBC. The adsorption behaviors and mechanism were investigated by kinetics, isotherms model fitting, thermodynamics, characterization, and density functionalization theory (DFT) calculation etc. Pore filling, π-π conjugation, H-bonding and P-O complexation were proved to be the main contributors to SMX adsorption by BPSBC. BPSBC showed the favorable sustainable adsorption performance for SMX by NaOH regeneration and stability over a broad pH value with the low leaching risk of phosphorus. This work developed a promising adsorbent of BPSBC for environmental concentration SMX removal, in addition to that the resource utilization of sludge was simultaneously achieved. [ABSTRACT FROM AUTHOR]

Abstract ACTIVE CARBON PRODUCTION OF BITUMINOUS COAL WITH SINGLE ACTIVITY H3PO4, H3PO4 COMBINE WITH NH4HCO3, AND THERMAL. Bituminous coal has a good potential to be utilized as activated carbon because it has high carbon, which is between 54-86%. The purpose of research was to obtain moisture content data, ash content, volatile matter, fixed carbon, absorption of iodine (iodine), area surface and the volume of pore activated carbon. Another aim was to study the effect of reagent types and concentrations of H3PO4 reagent and NH4HCO3 reagent to the characteristics of the activated carbon. The study was conducted in six stages: 1) carbonization; 2) chemical activation; 3) neutralizing; 4) filtering; 5) activation in physics; and 6) cooling. The renewal of this study is the use of reagents combination H3PO4-NH4HCO3. The results showed that the active carbon which is activated by a combination of H3PO4 reagent 2 M - NH4HCO3 reagent 2 M and reagent H3PO4 reagent 2.5 M - reagent NH4HCO3 reagent 2.5 M have the best iodine. Activated carbon is activated using H3PO4 reagent 2 M - NH4HCO3 reagent 2 M containing 7.5% water content; ash content of 9,0%; volatile matter content of 43.3%, 40.2% fixed carbon, iodine 1238.544 mg/g. While activated carbon which is activated using H3PO4reagent 2.5 M - NH4HCO3 reagent 2.5 M contain 7.4% water content; ash content is about 10%; volatile matter content is 39.1%, fixed carbon is 43.5%, iodine 1238.544 mg/g, surface area 86.213 m2/g, and pore volume 0.0733 cc/g. Keywords: perf activation; coal; bituminous; H3PO4; NH4HCO3; active carbon Abstrak Batubara bituminus mempunyai potensi bagus untuk dimanfaatkan menjadi karbon aktif karena mempunyai kandungan karbon yang cukup tinggi, yaitu antara 54-86%. Tujuan penelitian adalah memperoleh data kadar air, kadar abu, kadar zat terbang, fixed carbon, daya serap terhadap iodium (bilangan iodin), luas permukaan, dan volume pori karbon aktif. Tujuan lainnya adalah mempelajari pengaruh jenis dan konsentrasi reagen H3PO4 dan NH4HCO3 terhadap karakteristik karbon aktif. Penelitian dilakukan dalam enam tahap : 1) karbonisasi; 2) aktivasi secara kimia; 3) penetralan;; 4) penyaringan; 5) aktivasi secara fisika; 6) pendinginan. Pembaharuan dalam penelitian ini adalah penggunaan kombinasi reagen H3PO4-NH4HCO3. Hasil penelitian menunjukkan bahwa karbon aktif yang diaktivasi dengan kombinasi reagen H3PO4 2 M - NH4HCO3 2 M dan H3PO4 2,5 M - NH4HCO3 2,5 M mempunyai bilangan iodin terbaik. Karbon aktif yang diaktivasi menggunakan reagen H3PO4 2 M - NH4HCO3 2 M mengandung kadar air 7,5%, kadar abu 9,0%, kadar zat terbang 43,3%, fixed carbon 40,2%, bilangan iodin 1238,544 mg/g. Sedangkan karbon aktif yang diaktivasi menggunakan reagen H3PO4 2,5 M - NH4HCO3 2,5 M mengandung kadar air 7,4%, kadar abu 10%, kadar zat terbang 39,1%, fixed carbon 43,5%, bilangan iodin 1238,544 mg/g, luas permukaan 86,213 m2/g, dan volume pori 0,0733 cc/g. Kata kunci: aktivasi; batubara; bituminus; H3PO4; NH4HCO3; karbon aktif

Electrospinning is a suitable top-down technique for the preparation of polymeric fibers using high voltage electrical fields and solutions of the selected polymer of adequate viscosity and conductivity. The versatility of electrospinning allows accurate control of the morphology and composition of the fibers by a wide combination of operating conditions and small modifications of the spinneret and collector. Alcell lignin, which is extracted from lignocellulosic biomass using organic solvents through Organosolv process, is readily solved in ethanol, producing a solution that matches the requirements of the electrospinning process. This review summarizes the vast collection of carbon materials that can be obtained by processing lignin using electrohydrodynamic forces. The coaxial and triaxial electrospinning setups allow for obtaining fibers with two or more components hierchically arranged, the use of these configurations along with a carefully setting of the operating conditions (distance between needle and collector, voltage, flow rate,…) and the solution properties (conductivity, viscosity,…) facilitates the conformation of lignin into spheres, beaded fibers, straight fibers and fused meshes. All these morphologies can be implemented with solid or hollow bodies (i.e., enabling the production of tubes and hollow spheres) by using a sacrificial templating agent. Phosphoric acid can also be added in small amounts to the lignin solution, shortening the thermostabilization time of the fibers. The porosity of the phosphorus containing carbon fibers can be modified in the last stage of the preparation of carbon fibers by controlled gasification process, owing to the extended oxidation resistance of the P-doped fibers. Fibrillar carbon catalysts can be also obtained by one-pot preparation method, only solving small quantities of metallic salts in the lignin solution. All these carbon materials were successfully tested in different applications such as heterogeneous catalysis, energy storage and environmental protection, confirming that electrospinning is a powerful tool for maximizing the value of lignin as carbon precursor.

In this experiment, with stainless steel gas cyclone–liquid jet absorption separator as carrier, NH3 as experimental gas, and water and H3PO4 solution as absorbents, corresponding NH3 absorption rate change is obtained through the adjustment of experimental parameters, such as NH3 inlet concentration, inlet velocity of mixed gas, injection flow rate of absorbent, temperature of absorbent, and H3PO4 absorbent concentration. The NH3 absorption rate decreases with the increase in NH3 inlet concentration and inlet gas velocity. The NH3 absorption rate will increase first and then tends to remain unchanged after reaching a certain degree with the increase in liquid injection flow rate and absorbent concentration. The NH3 absorption rate will increase first and then decrease with the increase in the absorbent temperature. The maximum NH3 removal efficiencies of water and H3PO4 were 96% and 99%, respectively. [ABSTRACT FROM AUTHOR]

Activated carbon (AC) with high specific surface area was prepared by using bifunctional H3PO4 agent, which led to dehydrating and activation effects through hydrothermal pretreatment and subsequent pyrolysis process. N2 adsorption and desorption isotherms of AC showed a high BET surface area of 2434 m2 g−1 and a total volume of pores (VT) of 2.0447 m3 g−1 for AC. The morphology and the chemical components of hydrochar and AC were characterized by scanning electron microscopy and Fourier transform infrared spectroscopy, which indicated that H3PO4 was benefitting for the formation of porous structure of AC. Subsequently, the effect of H3PO4 in hydrothermal pretreatment and activation process was investigated by comparative experiments. The removal and adsorption of methylene blue (MB) dye with different concentrations onto the AC were studied. The monolayer equilibrium adsorption capacity was 644 mg g−1, showing that AC has good adsorption qualities for methylene blue (MB). The adsorption balance data of MB on AC was best fitted to the Redlich-Peterson model. The adsorption kinetic data fit better to the pseudo-first-order model at low MB concentration, and the pseudo-second-order and Elovich models fit better when the MB concentration was rising. [ABSTRACT FROM AUTHOR]

Ethanol is an important bulk chemical with diverse applications. Biomass‐derived ethanol is traditionally produced by fermentation. Direct cellulose conversion to ethanol by chemocatalysis is particularly promising but remains a great challenge. Herein, a one‐pot hydrogenolysis of cellulose into ethanol was developed by using graphene‐layers‐encapsulated nickel (Ni@C) catalysts with the aid of H3PO4 in water. The cellulose was hydrolyzed into glucose, which was activated by forming cyclic di‐ester bonds between the OH groups of H3PO4 and glucose, promoting ethanol formation under the synergistic hydrogenation of Ni@C. A 69.1 % yield of ethanol (carbon mole basis) was obtained, which is comparable to the theoretical value achieved by glucose fermentation. An ethanol concentration of up to 8.9 wt % was obtained at an increased cellulose concentration. This work demonstrates a chemocatalytic approach for the high‐yield production of ethanol from renewable cellulosic biomass at high concentration. [ABSTRACT FROM AUTHOR]

Abstract Ultrasonic impregnation has proven to be an effective method to improve surface area and pore volume during preparation of activated carbons. However, the mechanism by which the promotion effect of ultrasonic impregnation is still ambiguous. Fundamental wave pressure (FWP) and broadband integrated pressure (BIP) were used to estimate the non-cavitation (vibration) energy and cavitation energy, respectively. The effects of FWP and BIP on the pore volume, surface area, surface functional groups, and microcosmic morphology were investigated in non-cavitation and cavitation regimes. Ultrasonic vibration promoted the surface enlargement and pore development of activated carbons, and it mainly affected the development of mesopore volume (V mes) in both the pore volume and the mesopore-size-distribution range. The V mes was enhanced by 60%–100% in the non-cavitation regime. Ultrasonic cavitation also facilitated porosity development of activated carbons, and it mainly affected the development of specific surface area (S BET) and micropore volume (V mic). The excessive cavitation led to a decrease of the porosity of activated carbons, so the BIP should be optimized during impregnation. The highest S BET , V mic , and V mes for activated carbons were obtained by in the presence of both FWP and BIP, which were enhanced by 29.05%, 30.23%, and 113.33%, respectively, compared with the corresponding value for the activated carbon prepared without using ultrasonic impregnation. This work provided new insight into the role of the acoustic energy present during impregnation in tuning properties of activated carbons. [ABSTRACT FROM AUTHOR]

Textile waste jute was activated by H3PO4 and ZnCl2 for reuse as activated carbon. Thermal degradation behavior of jute, impregnated jute and activating agents via thermogravimetric analysis were conducted first. Yield and iodine adsorption number were employed to determine the optimal activation conditions. As a result, activation by H3PO4 was best conducted at 700 °C for 90 min with an impregnation ration of 1.0 while conditions for ZnCl2 were 500 °C, 60 min and impregnation ratio of 1.0. That is, the best activation conditions varied with activating agents. So were the properties of resultant jute-based activated carbons. H3PO4 activation produced an activated carbon that was mostly mesoporous while that by ZnCl2 was more even in micropore and mesopore volumes as proven by pore volume distribution analysis. In addition, both carbons were abundant in surface functional groups which could be beneficial for adsorption of pollutants. Overall, jute could be effectively recycled to produce activated carbon that boasted excellent surface chemistry and textual properties. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A novel double-layer structure was fabricated in 12 wt% H 3 PO 4 mixed electrolyte. • Nanotube diameter in mixed electrolyte is ∼2.84 times larger than that in classical electrolyte. • The large diameter of the double-layer nanotube is ∼392 nm. • The double-layer structure was synthesized during the anodization process. Abstract To increase the specific surface area of nanotubes, we form large diameter nanotubes with double-layer structure by anodizing Ti foils in high concentration H 3 PO 4 and fluoride-containing mixed electrolyte without annealing rather than in pure NH 4 F electrolyte. This double-layer structure consists of the anions-contaminated layer and the barrier layer. Owing to the addition of PO 4 3− ions into electrolyte, the thickness of the anions-contaminated layer and the diameter of the nanotubes increased. Compared to single-layer structure, this double-layer structure exhibits ∼5.81 times increase in specific surface area of nanotubes because of the multi-hole interface between the two layers for supercapacitors. [ABSTRACT FROM AUTHOR]

Metal halide perovskites are attractive light-emitting materials due to their excellent optoelectronic properties. However, the traditional preparation methods are mostly complicated. Recently, we introduced a near room temperature synthesis strategy, named H 3 PO 4 -assisted precipitation method, which has advantages of thermal- and pressure-free, eco-friendly, as well as short reaction time. Here, we taken Cs 2 InBr 5 ·H 2 O as an example to study the impacts of H 3 PO 4 on synthesis and luminescence of metal halide perovskites. Upon adding H 3 PO 4 , Cs 2 InBr 5 ·H 2 O gives a bright red emission peaked at 630 nm. Various analytic techniques, including X-ray diffraction, FTIR spectra, X-ray photoelectron spectroscopy, Scanning electron microscope, Absorption spectra, and Photoluminescence spectra were employed to investigate the structure and luminescent properties of the prepared Cs 2 InBr 5 ·H 2 O perovskites. The results indicate that H 3 PO 4 significantly affects the crystallinity, morphology and STEs emission of Cs 2 InBr 5 ·H 2 O. Additionally, various ions doping (such as Sb3+: Cs 2 InBr 5 ·H 2 O) and other metal halide microcrystals (such as CsPbBr 3 and CsPb 2 Br 5) can also be obtained with the assistance of H 3 PO 4 , indicating H 3 PO 4 is a significant additive for synthesizing and enhancing the luminescence of metal halide perovskites. • Phase-pure Cs 2 InBr 5 ·H 2 O with bright red emission was prepared by a simple H 3 PO 4 -assisted precipitation method. • Effects of H 3 PO 4 on the Cs 2 InBr 5 ·H 2 O enhancing the luminescence; improving the morphology; and rising the crystallinity. • Providing a simple and universal method for preparing high-quality perovskites. [ABSTRACT FROM AUTHOR]