Phosphoric Acid Research Articles

Sustainable ammonia and amines from chitin

Efforts are underway to explore alternative methods to the Haber-Bosch process for sustainable ammonia production, while the potential for ammonia extraction from natural nitrogenous biomass is under-exploited. Here, a synergistic catalytic strategy involving acid and modified Ru-based catalysts is communicated for the direct production of amines and ammonia from chitin. Phosphoric acid promotes the cleavage of ether bonds in biomass polymers and also serves to protect amino groups from being removed. Selective hydrogenation, deoxygenation, and amination can be achieved by controllably adjusting the ratio of Ru0/Run+. The utilization of nitrogen atoms in chitin can reach up to 95 % (21 % amines, 74 % ammonium), and the catalytic process is applicable to waste shrimp shells. This study demonstrates the possibility of efficient production of nitrogen-containing compounds from abundant biopolymers.

Supercritical CO2 Extraction and HPLC Quantification of Carnosic Acid from the leaves of Rosemary Officinalis: A Green Approach to Bioactive Compound Purification

This study explores the extraction and purification of carnosic acid, a potent antioxidant found in rosemary (Rosmarinus officinalis), using a green and sustainable method involving supercritical CO₂. The extraction was conducted at 45°C and 350 bar, with three cycles lasting 45 minutes each. The process resulted in the collection of 75 grams of oleoresin from 1 kg of dried rosemary leaves which is an optimal yield. The oleoresin underwent further purification via hexane precipitation, yielding a carnosic acid powder with a purity of 40% as determined by Gradient elution of Mobile phase A: Methanol: Water + Phosphoric acid solution, Mobile phase B: Methanol: Acetonitrile + Phosphoric acid solution by high-performance liquid chromatography (HPLC). Comparisons with a 60% purity standard highlight the potential of supercritical CO₂ extraction in obtaining bioactive compounds, though additional optimization is necessary to achieve higher purity.

Soil ammonia volatilization after fertilization using antibiotic-contaminated swine wastewater

The application of wastewater from pig farming is an alternative to fertilize crops using the effluent produced in the activity. However, in addition to nutrients capable of meeting the needs of crops, this effluent also has residues of antibiotics for livestock use in its composition, which can interfere with the activity of soil microorganisms and reduce the enzymatic activity, leading to nitrogen losses into the atmosphere. Hence, this study evaluated ammonia volatilization behavior after adding swine wastewater with tetracycline-class antibiotics. Pots containing soil received doses of raw and digested wastewater (0.06 and 0.09 L), combined or not with doses of tetracycline (35 µg L-1), chlortetracycline (40.9 µg L-1), and doxycycline (14.9 µg L-1 volatilized NH3 was collected by foam absorbers containing phosphoric acid solution on the soil, which were changed every 48 h, totaling 11 collections at a time. The NH3 volatilization significantly increased when the swine wastewater (raw or digested) was added. The presence of antibiotics reduced NH3 losses, showing that they can inhibit urease activity. Our findings showed that tetracycline-class antibiotics can inhibit urease activity, contributing to the continuity of nitrogen in the soil.

Effects of using different dentin conditioners on dentin regeneration.

This experiment aimed to evaluate the impact of several dentine etching and conditioning agents on growth factors (GFs) liberation from dentine slices. Eighteen dentine slices were obtained from nine premolars divided in to six groups, the slices immersed in one mL test solutions for 5 min; Group 1: white Mineral trioxide aggregate (MTA), Group 2: Phosphate buffered saline (PBS), Group 3: 37% phosphoric acid, Group 4: 17% Ethylenediaminetetraacetic Acid (EDTA), Group 5: 10% Maleic acid (MAc), and Group 6: 0.7% Fumaric acid. The solutions were removed and stored directly at for further detection and quantification of transforming GF beta 1 (TGF-b1), bone morphogenetic protein 2 (BMP2) and vascular endothelial growth factor (VEGF) by enzyme-linked immunosorbent assay (ELISA). One-way ANOVA was used to compare the mean release and standard deviation between groups (α = 0.05). Tukey's post hoc applied for multiple comparisons. After five min conditioning of dentine slices, white MTA released the highest level of TGF-b1, BMP2 and VEGF among all groups, followed by 0.7% Fumaric acid with no significant difference between them, but compared to 37% phosphoric acid and PBS groups significant difference observed, which they released the least amount of GFs amongst all groups. Based on the results of this research the detectable release of TGF-b1, BMP2 and VEGF by 0.7% fumaric acid was comparable with white MTA from dentin slices.

Effect of H<sub>3</sub>PO<sub>4</sub> and Phenol Additives on Gel Formation in Silica Fire Retardant Coatings for Building Materials

Increasing the fire resistance of wooden building structures is quite effectively ensured thanks to the development of fire-fighting compositions with aromatic components that contribute to the formation of a carbonized layer on the surface of the material during combustion. It is also known about the mutual positive influence of benzene fragments and phosphate-containing compounds on the fire-resistant characteristics of wood. The paper considers the possibility of complex use of phenol and orthophosphate acid to improve the flame retardant properties of SiO2-based coatings. The effect of modifying additives on the rheological properties of silicic acid sols was determined. Based on the results of IR spectroscopy, the influence of components on the nature of polycondensation in experimental SiO2 sols was evaluated. It is shown that the use of orthophosphate acid as a modifier leads to the initiation of predominantly linear polycondensation in experimental sols. It was established that small additions of phenol practically do not affect the course of polycondensation in experimental sols. Increasing the phenol content to 0.5% showed an effect on gel formation due to the possible addition of phenol to the skeletal silanol groups by the donor-acceptor mechanism, which makes it possible to have a synergistic effect of the complex additive of orthophosphate acid and phenol on the properties of the silica-containing flame retardant composition.

Facilitating effects of plant extracts on soil health and replanted Panax ginseng growth in recession soil.

Plant extracts have been shown to be effective agricultural strategies for improving soil fertility and quality, and promoting plant growth in soil degradation remediation. The application of plant extracts improves the material cycle of soil microecology, such as the decomposition of nitrogen, phosphorus, and potassium, while increasing plant resistance. However, there is currently no experiment to demonstrate whether plant extracts have a promoting effect on the growth of ginseng and the mechanism of action. Pot experiments were carried out to investigate the effects of extracts, namely Rubia cordifolia (RC), Schisandra chinensis (SC), and Euphorbia humifusa (EH) on soil properties, enzyme activities, and plant physiological characteristics were evaluated. Results showed that compared with CK, plant extract-related treatments increased soil Organic carbon (OC), Available nitrogen (AN), Available phosphorus (AP) contents, and Soil urease activity. (S-UE), Soil sucrase activity (Soil sucrase), Soil acid phosphatase activity. (S-ACP). Meanwhile, plant extract-related treatments significantly increased plant physiological properties and TP (Total protein) content, and decreased the content of MDA (malondialdehyde) by 15.70% -36.59% and PRO (proline) by 30.13% -148.44%. Furthermore, plant extract-related treatments also significantly promote plant growth and reduce plant incidence, the fresh weight of ginseng increased by 27.80% -52.08%, ginseng root activity increased by 45.13% -90.07%, and ginseng incidence rate decreased by 20.00% -46.67%. Through correlation analysis between fresh weight of ginseng and root parameters and soil index, fresh weight is significantly positively correlated with root diameter, fiber root number, root activity, total protein (TP), catalytic activity (CAT) and superoxide dismutase activity (SOD), H, soil urea activity (S-UE), soil sucrose activity (S-SC), soil acid phosphate activity (S-ACP), and soil laccase activity (SL); The fresh weight was significantly negatively correlated with incidence rate, disease severity index, and malondialdehyde content (MDA). In summary, plant extract-related treatments improve soil quality and promote ginseng growth, further enhancing soil health and plant disease resistance. These findings provide new insights into ginseng cultivation and soil health management and highlight a new approach that can be applied to a wider range of agricultural practices and environmental sustainability.

A purine fluorescent derived probe assay for glyphosate and mesotrione via Schiff base cleavage

A fluorescent probe derived from purine with Schiff base moiety was developed for the recognization of glyphosate and mesotrione. The detected glyphosate and mesotrione can lead to the dissociation of the Schiff base probe to enhance the fluorescence via a turn-off PET process. Mechanism study revealed that the synergistic effect of the phosphoric acid and the secondary amine moieties in glyphosate results in the bond cleavage of the Schiff base probe. Quantitative measurements of glyphosate and mesotrione were achieved with the detection limits of 17.2 nM and 484.32 nM, respectively. Meanwhile, the detection of glyphosate pesticide in real samples and cells was also conducted, demonstrating the good practicality and cytocompatibility of the probe.

Assessment of Activated Charcoal and Phosphorus for Promoting Maize Production

The most continuous farming practice is the yearly addition of phosphorus fertilizers to soils in arid and semi-arid regions that all suffer from shortages of phosphorus availability. A vital approach is rationalizing applied fertilizers and trying to benefit from their reservoir in yearly-fertilized old soils using an activated charcoal-fertilizer mixture. Thus, a field experiment was conducted at a private farm in Mushtuhur, Toukh, Qalyubia Governorate, Egypt. This trial was set up to study the effect of phosphorus (P) fertilizer sources (phosphoric acid Ph.A and super phosphate S.Ph), the P application rates (P0=control, P1=50%, P2=75% and P3=100% of P requirements), activated charcoal (A.Ch) rates (A.Ch0=control, A.Ch1=1, A.Ch2=3 and A.Ch3=5 g/hole, corresponding to 41, 124, and 207 kg ha-1, respectively) and the interaction between them on promoting maize growth, production and its nutrient status. Generally, adding phosphorus improved plant height (m), dry grains (t ha-1), and ash yield (t ha-1) without a significant difference between all P rates. Phosphoric acid affects most studied parameters, mainly the biological, ear, and ash yield (t ha-1); it was the best compared with superphosphate. Adding the 1st rate of A.Ch improved the studied growth and yield parameters significantly compared with the control. Slight enhancement was induced by the 2nd A.Ch dose, and there was no significant difference between the 3rd and 4th rates in most studied parameters. The heighest value of grain yield resulted from the third interaction between A. Ch3 x P0, followed by A. Ch2 x P0, and the next is Ph.A x A. Ch2 x P1 without significant difference among them. These results shed light on the fact that there is no need to add P fertilizers yearly, as described by the recommendations of the Ministry of Agriculture. Different materials can move the fixed P in old clayey soil, such as A.Ch.

Carbon nanotube-modified adhesive to caries affected dentin conditioned with Nd: YAP laser, Phosphoric acid, and Photoactivated-erythrosine.

Dentin conditioned with phosphoric acid (PA) Nd: YAP laser, and photoactivated-Ery(Erythrosine) on microleakage, shear bond strength (SBS) degree of conversion (DC), and rheological assessment of adhesive-infused with carbon nanotubes (CNTs). Carious ninety-six human mandibular molars were included. Specimens were disinfected and allocated into three groups based on surface pretreatment (n = 32) Group 1 (PA), Group 2 (Nd: YAP) laser, and Group 3 (Photoactivated-Ery). Conditioned groups were further divided into two 2 subgroups based on the application of unmodified ERA and CNTs-modified ERA. Composite restorations were placed on the CAD surface and thermal aging of the samples was performed. The microleakage assessment was conducted using a dye penetration test. Universal testing machine (UTM) assessed SBS bond failure was evaluated using a stereomicroscope. Scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) analyses of CNT, and Fourier Transform Infrared FTIR of adhesives were performed. One-way ANOVA and Tukey post hoc analyzed the outcomes. Group 1B samples (PA+ CNTs modified adhesive) presented the minimum marginal leakage and highest bond integrity. Group 2A (Nd:YAP laser+Unmodified adhesive) displayed the maximum scores of microleakage and lowest bond strength. Photoactivated Ery-PS can serve as an alternative to phosphoric acid for conditioning CAD. Incorporating CNT in adhesive significantly enhanced bond integrity and marginal seal with no significant difference in DC.

Enhancing the uranium (VI) adsorption performance of phosphoric acid functionalized porous silica by controlled introduction of phosphoric acid group

The post-grafting of porous silica with organic group is a common method for the synthesis of organo-functionalized silica adsorbent. However, this method usually produces adsorbents with limited adsorption performances due to the pore blocking caused by the irregular introduction of organic group. In this work, we report the controllable synthesis of phosphoric acid functionalized porous silica adsorbent based on the co-condensation method for uranium (VI) adsorptive removal with enhanced adsorption performance. Characterizations of the obtained silica verify its porous structure and confirm the homogeneous distribution of phosphoric acid groups inside the silica. This silica is able to efficiently remove 98 % of uranium from a 100 mg/L uranium (VI) solution within 10 min at a dosage of 0.6 g/L and the maximum uranium (VI) adsorption amount reaches 509 mg/g. Both adsorption capacity and adsorption rate of this silica are superior than that of the silica synthesized based on conventional post-grafting method. Moreover, this silica can be reused for five times with uranium (VI) removal efficiency above 95 % and it is well applied in adsorption column for dynamically adsorptive removal of uranium (VI) from real nuclear wastewater. Mechanism-related investigations reveal that uranium (VI) adsorption on this silica proceeds by effective ion exchange of uranium (VI) ion with either phosphoric acid or silanol group and the formation of uranyl phosphonate or uranyl silicate complex. This work provides a feasible strategy to synthesize functionalized porous silica without significant pore blocking, and demonstrates the enhancement effect of regulating surface adsorption groups on the adsorption performances of porous silica. Besides, this work offers a promising adsorbent for efficient treatment of uranium-containing nuclear wastewater and reveals the mechanism of uranium adsorption on those silica adsorbent containing phosphoric acid, thiol or thioether group.

Whiteness and greenness assessments of a sensitive HPLC method with fluorimetric detection for dapagliflozin quantitation in human plasma: Application to a healthy human volunteer.

The evident ecological impact of human actions, like air pollution, global warming, and ozone depletion, underscores the need for environmentally friendly approaches across various domains, including analytical chemistry. This study aimed to establish a validated, eco-friendly, and sustainable approach utilizing a fluorescence detector coupled with high-performance liquid chromatography for quantifying the antihyperglycemic agent dapagliflozin (DAPA), in human plasma. This method employed a C18 Microsorb MV (4.5 × 250 mm, 5 μm [particle size]) column at 40°C, with 40:60% v/v isocratic elution of acetonitrile and (0.1%) orthophosphoric acid as the mobile phase at 1 mL/min flow rate. DAPA and the internal standard demonstrated their greatest response by performing excitation at 225 nm (λex) and recording chromatograms at an emission wavelength (λem) equal to 305 nm. The presented approach demonstrated high linearity between 50 and 2000 ng/mL and full adherence to the guidelines of the US Food and Drug Administration regarding the validation of bioanalytical methods. The described technique was effectively used for quantification of DAPA in human plasma samples from a healthy male participant who received a tablet of 10 mg DAPA. Analytical Eco-Scale, Analytical GREEnness metric, and the recently created ChlorTox Scale were utilized for greenness assessment. Additionally, the "Red, Green, and Blue 12" model was used in whiteness evaluation.

Development, validation and application of a high-performance liquid chromatography method for the detection of ibuprofen in elephant plasma

A simple and accurate method for the determination of ibuprofen concentrations in elephant plasma was developed and validated using reverse phase high-performance liquid chromatography (HPLC). Utilizing a liquid-liquid extraction with ethyl acetate, methanol, and phosphoric acid, samples were separated on an XBridge C18 column. The mobile phase consisted of 0.005 M ammonium phosphate and acetonitrile (40:60, v/v). Both ibuprofen and the internal standard flurbiprofen were quantitated using an ultraviolet (UV) detector set at 214 nm. The lower limit of quantification (LLOQ) was 0.05 μg/mL in 100 μL of plasma. The average recovery was over 95% while the intra-assay variability ranged from 0.8 to 9.9% and the inter-assay variability ranged from 2.7 to 9.8%. The method was used successfully in a therapeutic drug monitoring program for elephants and could be used in future pharmacokinetic studies.

A novel conjugated microporous polymer nano hollow sphere containing N, P and Si flame retardant elements with both thermal insulation and flame retardant properties

It is particularly important to develop new materials with both thermal insulation and flame retardant properties for addressing the severe issues caused by fire accidents. Herein, a kind of conjugated microporous polymer nanospheres with hollow structure (HCMPNS) was synthesized by Sonogashira-Hagihara cross-coupling reaction using SiO2 nanospheres as hard template and 1,3,5-triacetylenebenzene, as alkynyl monomer. Then, HCMPNS was chemically graft-modified with azidotrimethylsilane (TMSA) by "click" chemistry (HCMPNS-FRSi), and the HCMPNS-FRSi obtained from the reaction was introduced into flammable epoxy resin (EP) to obtain EP based composites, i.e. EP-Ⅰ and EP-Ⅱ. The thermal conductivities were found to be 0.0341Wm-1 K-1 and 0.0268Wm-1 K-1 for EP-Ⅰ and EP-Ⅱ, respectively, showing excellent thermal insulation performance. The total heat release (THR), the total smoke production (TSP) and the peak CO2 produced (CO2P) of EP-Ⅰ were reduced by 18.0%, 8.0%, 14.3% compared with pure EP as measured by cone calorimetry (CC), respectively, indicating a certain extent flame retardant effect. In order to further improve its flame retardant properties, phosphoric acid containing the flame retardant phosphorus element was added to HCMPNS-FRSi (HCMPNS-FRSi-P), followed by the introduction of the resulting HCMPNS-FRSi-P into EP matrix to form EP based composites with Si and P dual incorporation (EP-III and EP-IV), with the thermal conductivities of 0.0470Wm-1 K-1 and 0.0855Wm-1 K-1, respectively. Through the cone calorimetry (CC) of EP-III, EP-IV, total heat release (THR) were reduced by 17.0%, 23.8%, total smoke production (TSP) were reduced by 6.2%, 7.2%, respectively. The peak heat release rate (HRR) and the peak CO2 produced (CO2P) of EP-Ⅳ were reduced by 16% and 25%, respectively, compared with pure EP. It has good thermal insulation and flame retardant effect. Therefore, HCMPNS-FRSi-P, as a new type of flame retardant material, has great potential in the fields of electronics, construction, transportation and so on.

Iron removal and valuable metal recovery from spent lithium-ion batteries (LIBs) using solvent extraction after bioleaching

Our study investigated the feasibility of solvent extraction for the separation of impurities, specifically aluminum (Al), copper (Cu), and iron (Fe) from simulated leachate with similar composition to real pregnant leach solution (PLS) obtained after the bioleaching of spent lithium-ion batteries (LIBs). The Fe2+ in the Fe-rich PLS was oxidized to Fe3+ by addition of H2O2. Subsequently, Fe3+, Al3+, Cu2+, and Mn2+ were extracted at pH 4.0 using 20 % di-(2-ethylhexyl) phosphoric acid (D2EHPA) as the extractant. At this pH, 99.99 % of Al3+ and Fe3+, 93 % of Cu2+, and 83 % of Mn2+ were successfully extracted. Co-extracted Co2+ was recovered through a two-stages scrubbing process, where it was replaced with Mn2+ using a MnSO4 solution at an O/A ratio of 1:1. Finally, Al3+, Cu2+, and Mn2+ were stripped with 5 M H2SO4, and 99 % Fe3+ was separated by stripping with 100 % aqua regia. Our study presents an approach for effectively separating valuable metals and impurities, particularly Fe, by optimizing the extraction, scrubbing, and stripping stages of solvent extraction for PLS treatment. Moreover, this study emphasizes the need for further research on the pre-separation of Fe and the development of novel extractants and solvents to enhance the treatment of Fe-rich PLS after bioleaching.

Biochar from Malt Residue: Toward a Circular Economy for Sustainable Fluoroquinolone Removal in Aqueous Systems

Malt bagasse holds potential as a high-value material, contributing to a circular economy. Biochars were synthesized via pyrolysis (PC-500) and hydrothermal carbonization (HC-150), with one-pot activation using phosphoric acid. Additionally, PC-500 activated with H3PO4 was synthesized for comparison. Various analytical methods were used to characterize the materials. The PC-500 and PCA-500 samples exhibited higher degrees of carbonization, whereas the HC-150 sample retained its functional groups more effectively. Biochars showed higher porosity than biomass, with microspheres present in HC-150. Evaluations were conducted on the removal of fluoroquinolones from water using biochars. Maximum removal efficiency was obtained at pH 8, favoring neutral fluoroquinolone species with a Brønsted acid-base nature. The experimental outcomes were further rationalized by the computational calculation of the physicochemical properties of the adsorbates, in analogy with the structural activity relationship approach in medicinal chemistry. The pseudo-second-order kinetic model proved to be the most suitable for fitting the experimental data, while the Langmuir model effectively described the adsorption isotherms. Ciprofloxacin, enrofloxacin, and norfloxacin showed maximum adsorption capacities (qmax) of 95, 164, and 99mgg-1, respectively, when HC-150 was used. On the other hand, with PC-500, qmax of 57, 12, and 20mgg-1 were obtained for ciprofloxacin, enrofloxacin, and norfloxacin, respectively. Although PCA-500 enhanced adsorption capacity compared to PC-500, the qmax remained lower than the results obtained with HC-500, measuring at 51, 102, and 95mgg-1. These findings emphasize malt bagasse biochar as a viable adsorbent.

Effect of different activating agents on carbon derived from Tinospora cordifolia for EDLC application

Abstract The effect of two activating agents namely phosphoric acid (H3PO4) and iron (III) chloride (FeCl3) is investigated, in activation of carbon obtained from Tinospora cordifolia. The structural and morphological properties of the synthesized activated carbons were investigated using X-ray diffraction, scanning electron microscopy, Raman spectroscopy, and Brunauer–Emmett–Teller analysis. A notable yield of ∼60 % of the activated carbons was obtained using a simple and cost-effective approach of chemical activation followed by the thermal activation method. The electrochemical properties of the activated carbons were studied for electric double-layer capacitor application. The electrochemical impedance spectroscopy, galvanostatic charge–discharge and cyclic voltammetry studies revealed superior charge transfer properties of the carbon activated with H3PO4. The capacitor comprising carbon activated with H3PO4 electrodes shows higher specific capacity of 58 F g−1 at 1 A g−1 than that of carbon activated with FeCl3 (37.5 F g−1). The optimized capacitor delivers superior power density and energy density of 2 kW kg−1 and 28.33 W h kg−1, respectively.

The Corrosion Characteristics of Graphite Coatings on Nickel Foam and Their Applications in High-Temperature Proton Exchange Membrane Fuel Cells

This study investigates the effectiveness of graphite coatings on nickel foam for use in high-temperature proton exchange membrane fuel cells (HT-PEMFCs). Nickel foam, known for its high porosity and good conductivity, serves as an advantageous alternative to traditional flow channels but faces corrosion challenges in HT-PEMFCs, especially from phosphoric acid leakage. Graphite coatings are used as the protection layer and compared with nitride coatings. Chemical vapor deposition process parameters are first optimized for graphite growth. Corrosion polarization curves are then measured using a high-temperature phosphoric acid three-electrode system simulating HT-PEMFC conditions, followed by an analysis of the surface morphology of the samples. Subsequently, the performance and durability of the nickel foams with different coatings are evaluated after being assembled in single fuel cells. The results highlight the superior corrosion resistance of graphite coating under HT-PEMFC conditions, demonstrating its performance over other coatings. Graphite-coated foams showed a significant reduction in corrosion current, approximately 58% lower than uncoated foams and 21% lower than the TiN coated foams. In practical applications, an HT-PEMFC single cell with graphite-coated nickel foam demonstrated a current density of 763 mA/cm2 at 0.6 V under conditions of 180 oC and 2 atm H2/air. The current density is 40% higher than that of the uncoated nickel foam. The results show notable long-term durability under constant current holding tests at 160 oC. The voltage decay rate in the graphite-coated cell was 48% lower compared to the cell with uncoated nickel forms.

One-step microwave pyrolysis-H3PO4 activation of woody biomass: Insight into the product characteristics and life cycle assessment

Microwave-assisted pyrolysis coupled with chemical activation was developed to prepare the woody biomass-derived activated carbon (AC) with desirable structural characteristics. In this study, sawdust powder was impregnated with phosphoric acid before being microwave-pyrolyzed to achieve AC. The utilization of microwave greatly enhanced the transformation of volatiles into gaseous components, and the yield of char increased when phosphoric acid accelerated the secondary polymerization of volatile matters. Microwave-induced activation may alter the interaction between activator and sawdust-derived organic species, enriching the categories of oily components. The char originating from microwave-activation treatment has a high graphitization degree, exhibiting superior thermal stability and hydrophilic property. Moreover, one-step microwave-activation approach increased specific surface area (978.2 m2g−1 versus 13.0 m2g−1 in conventional pyrolysis) and improved the formation of porous structure. The life cycle assessment analysis revealed that microwave-activation technique had a low environmental impact due to enhanced heating efficiency and reduced energy consumption.

Elaboration of Fibrous Structured Activated Carbon from Olive Pomace via Chemical Activation and Low-Temperature Pyrolysis

The objective of this study is to examine the preparation of activated carbon with a fibrous structure obtained from olive pomace through a chemical activation process using phosphoric acid (H3PO4) as the activating agent under air at a lower temperature. According to the findings, the most effective conditions to achieve high-performance activated carbon were 22 vol.% of H3PO4, a two-hour chemical activation impregnation residence time at 50°C, and a 500°C pyrolysis temperature for one hour. Structural analysis revealed that activated carbons possess highly developed textural and structural properties, resulting in an iodine value of 923 mg/g and a specific surface of 1400 m2/g. In addition to its microporosity, the produced carbon exhibits a highly developed fibrous structure, providing excellent adsorption properties. To confirm these results, SEM, FT-IR, XRF, XRD, Raman, and TGA techniques were employed. The fibrous carbon produced will expand the use of renewable carbon materials for removing various types of contaminants, including organic and inorganic pollutants in water, and numerous other industrial applications.

The role of Ni- and Cd-resistant rhizobacteria in promoting the growth of rice seedlings and alleviating the combined phytotoxicity of Ni and Cd

The problem of potentially toxic metal pollution is increasingly acute with the development of human society. In this study, we investigated the remediation of nickel (Ni) and cadmium (Cd) co-contamination through inoculating rice with three new-isolated Ni- and Cd-resistant plant growth-promoting rhizobacteria (PGPR) Y3, Y4, and Y5. These three strains possessed growth-promoting properties, including 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity, the ability of indoleacetic acid (IAA) production, phosphate solubilization, siderophores production, and exopolysaccharide (EPS) development. According to 16S rDNA sequence homology, strains Y3, Y4, and Y5 were identified as Pseudomonas sp., Chryseobacterium sp., and Enterobacter sp., respectively. Based on the results of rice germination experiments conducted under combined toxicity, we set the contamination concentrations for Ni2+ at 20μgmL-1 and Cd2+ at 40μgmL-1. Then we conducted potting experiments at these concentration levels to study the effects of strains Y3, Y4, and Y5 on rice growth under synergistic Ni and Cd stress. The results indicated that the inoculated strains Y3, Y4, and Y5 were effective in promoting the growth of rice seedlings under the combined stress of Ni and Cd, and conferring tolerance to Ni and Cd by increasing the antioxidant enzyme activities of the seedlings. Among them, strain Y3 exhibited stronger ACC deaminase activity, IAA production capacity, and EPS production capacity, showing the most pronounced growth-promoting effect on rice. It was demonstrated that after inoculation with strain Y3, the germination rate of rice seeds increased by 43%, the fresh weight of stems improved by 35%, and the chlorophyll content enhanced by 70% and other growth-promoting phenomena. Additionally, under Ni and Cd stress, strain Y5 performed better than strain Y4 in terms of IAA production capacity and its influence on rice root growth, suggesting that IAA production might play a specifically essential role in root growth under Ni and Cd stress.