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Orange (Citrus aurantium) peel was investigated for producing microporous nano activated carbons (OPAC). One-step chemical activation process by zinc chloride as an activating agent and a carbonization temperatures ranging from 500 to 900 °C was used to produce OPAC having high surface area of type I. The effects of carbonization temperature, impregnation ratio, and impregnation time on the properties of the OPAC were studied. The prepared activated carbons were characterized by FTIR; Brunauer–Emmett–Teller (BET); TGA; TEM, SEM, and EDAX analyses; the point of zero charge; and Boehm titration method. The maximal surface area of OPAC was activated by using the impregnation (orange peel/ZnCl2) ratio of 2:1, 700 °C carbonization temperature, and a 30-min holding time. The BET surface area, the total pore volume, and the micropore volume were 1228.2 m2/g, 0.5516, and 0.5482 cm3/g, respectively. The total pore volume increased with the increase of the activation temperature. The minimum pore diameter was 0.7 nm and the mean pore diameter was 1.797 nm. The results proved that the ZnCl2 chemical activation is a useful technique to prepare high surface area activated carbon from Citrus aurantium peels with nano pore size structure. [ABSTRACT FROM AUTHOR]

Biochar has found application in many fields due to its promising physicochemical properties, which can be further improved by various physical and chemical modifications. The aim of this study was to produce and characterize biochar from sugarcane bagasse (SCB), a by-product of the sugar processing industry, and zinc chloride-modified SCB, using a novel low-temperature thermochemical conversion reactor. The biochar was characterized using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM–EDS) and Brunauer–Emmett–Teller (BET) analysis. The biochar samples were found to contain various functional groups that are typical of oxygenated hydrocarbons, reflecting the carbohydrate structure of cellulose and hemicelluloses of SCB. It was also observed that the chemical modification greatly improved the properties of the biochar, with the presence of several mineral elements and a higher specific surface area (172.35 m2/g) in the modified/activated biochar than in the pristine SCB biochar (126.80 m2/g surface area), while reducing its pore volume. The enhanced properties of the engineered biochar would undoubtedly have a positive increase in the applicability of the biochar, including its utilization in pollutant removal and soil reclamation. [ABSTRACT FROM AUTHOR]

In this study, hydrolyzed Dipterocarpus alatus leaves (HDL), waste from biodiesel production, were used as precursor to prepare activated carbon. The HDL residue was treated with 30 wt% ZnCl2 (raw material:ZnCl2 solution = 1:2 by weight) for 1 to 24 h followed by carbonization at 500 °C for 1 h in N2 atmosphere. The highest specific surface area of 497 m2 g1 was obtained with 12 h treatment. The physicochemical properties of the optimum carbon were investigated by thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy, proximate analysis, bulk density and pH, and the potential of the activated carbon for methylene blue (MB) adsorption was tested under various contact times and initial dye concentrations. Adsorption equilibrium was reached within 50 min. The adsorption of MB onto the HDL-derived activated carbon followed pseudo-second order kinetics through chemisorption, with intra-particle diffusion as the significant controlling step. The Langmuir isotherm provided a better fit of the adsorption equilibrium than the Freundlich isotherm, with a maximum monolayer adsorption capacity of 338.86 mg g1. The activated carbon prepared from Dipterocarpus alatus leaves residue exhibited good adsorption uptake for MB and therefore presents an attractive and effective adsorbent for cationic dyes.

A molten salt templating combined with chemical activation is implemented to prepare porous carbons. Gelatin, sodium chloride, and caustic soda are employed as the precursor, salt template, and chemical pore-making agent, respectively. Once the dosage of caustic soda is fixed, the specific surface area of carbons is enlarged with the increase in the proportion of sodium chloride. Chemically activated by caustic soda alone, the carbon is dominated by micropores with a specific surface area of 1284 m2 g−1. Under the two thermochemical pore-creation effects, porous carbon with a specific surface area as high as 2030 m2 g−1 is harvested, in which both micropores and mesopores are well-developed. The atomic content percentage of doped nitrogen ranges from 3.29 to 4.63 %. In a basic aqueous electrolyte at 1 A g−1, the specific capacitance of 322 and 217 F g−1 is achieved in three-electrode and two-electrode test systems, respectively. The contribution of pseudo-capacitance is quantified by the Dunn method and Trasatti model. At the particular power of 195 W kg−1, a specific energy of 7.6 Wh kg−1 is delivered. Results demonstrate the feasibility and efficiency of preparing high specific surface area carbon through sodium chloride templating in conjunction with chemical activation. • Molten salt combined with alkali activation is designed to prepare porous carbons. • Pore-making ability is positively related to the dosage of alkali chloride salt. • Hierarchical and developed pores result in excellent electrochemical properties. • Dunn method and Trasatti model are used to analyze the pseudo-capacitance ratio. [ABSTRACT FROM AUTHOR]

• Carbon spheres KOH-activated are good electrodes due to porosity and conductivity. • Oxidative calcination and thermal bath with KOH-activation boost CSs energy storage. • 6 M KOH solution improve the porosity of CSs showing 871 m²/g SSA. • CSs show 263 F/g at 5 mV/s, 9310.30 W/kg power, and 34.31 Wh/kg energy density. • Deconvolution of cyclic voltammetry shows EDLC remains constant even at 100 mV/s. Carbon spheres (CSs) were synthesized from d-glucose using the hydrothermal carbonization method. These CSs were impregnated using various approaches with several KOH molarities and chemically activated at 850 °C in an inert atmosphere. Calcination in air at 300 °C under room condition was used as a previous step to enhance the KOH impregnation. This process increased the impregnation of K + ions onto the oxidized surface of CSs. The use of reflux at 100 °C also improved the impregnation of the activating agent allowing to increase the microporosity of the CS surfaces. CSs impregnated with the highest KOH molarity (8 M KOH) and refluxed showed the best electrochemical capacitance (CS3-rT-8 M; C g = 283 F g-1 at 5 mV s-1) but due to the high KOH impregnation they lose their morphology spherical and have low yield (17.5%). CSs impregnated with 6 M KOH and refluxed preserved their spherical morphology, presented better yield (43.7%), showed the second best electrochemical capacitance (CS3-rT-6 M; C g = 263 F g-1 at 5 mV s-1) and at 10 mV s-1Vage scan rate, its electrochemical capacitance is already similar (CS3-rT-6 M, C g = 220 F g-1; CS3-rT-8 M C g = 227 F g-1). For these reasons, CS3-rT-6 M could be considered as a good candidate for use as supercapacitor electrodes in practical applications. [Display omitted] [ABSTRACT FROM AUTHOR]

In many industrial scenarios, not only pore characteristics but also shape or macro morphology of activated carbon (AC) matters. Herein, influence of typical activating reagents (ZnCl 2 , H 3 PO 4 or K 2 C 2 O 4) on transformation of spherical hydrochar derived from rice were investigated. Activation of the hydrochar with H 3 PO 4 and ZnCl 2 at 550 °C promoted condensation reactions to yield more AC than that in activation with K 2 C 2 O 4 at 800 °C (70.4 % with ZnCl 2 versus 46.7 % with K 2 C 2 O 4). The specific surface area (S BET) of AC produced with ZnCl 2 or K 2 C 2 O 4 showed similar values (1159.5 versus 1180.3 m2g−1). Nevertheless, the intensive cracking with K 2 C 2 O 4 formed AC of more mesopores and micropores of larger diameter, facilitating adsorption of phenol (removal rate: 97.6 % versus 85.0 % over AC from ZnCl 2). In-situ DRIFTS characterization of the activation indicated that H 3 PO 4 and ZnCl 2 catalyzed fast transformation of -OH and C O at < 300 °C via dehydration and condensation but still retained a large portion of H and O in AC. K 2 C 2 O 4 catalyzed cracking but also retained oxygen-containing species and hindered aromatization. Pyrolysis of the hydrochar at 800 °C released around half of organic matters but did not result in burst of spheres. H 3 PO 4 activated outer surface of hydrochar spheres, forming layered lamella structures via interparticle cross-condensation. ZnCl 2 permeated into inner core of spheres and induced condensation inside, showing little effect on spherical morphology. Severe cracking with K 2 C 2 O 4 led to partial crack of spheric structures and formation of piled particulate matters. Life cycle assessment (LCA) showed that the activation of the hydrochar with ZnCl 2 showed the greatest impact on environment. [Display omitted] • Starch rich biomass can be used as hydrothermal feedstock to form spherical hydrochar through the nucleation reaction. • Infer the mechanism of activators from different perspectives based on the macroscopic structure of activated carbon. • Mainly studied the macroscopic regulation of spherical hydrochar by adding different activators. • The addition of activators can make the reactions more intense such as cracking, aromatization, and gasification. [ABSTRACT FROM AUTHOR]

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. [Display omitted] • Microwave-induced H 3 PO 4 activation was used to produce activated carbon (AC). • Microwave-assisted activation enriched the chemical composition of bio-oil. • Microwave-activation approach improved the surface area and porosity of AC. • The resultant char exhibited high thermal stability and hydrophilicity. [ABSTRACT FROM AUTHOR]

The activated carbons were derived from fennel seeds (Foeniculum vulgare), a by-product of the herbal industry, through chemical activation. This research explored the influence of impregnation ratios of the precursor with potassium and sodium carbonate on the physicochemical and sorption characteristics of the resulting adsorbents. Thorough analyses were conducted on the activated carbons. Furthermore, adsorption studies were undertaken for two dyes: methylene blue and methyl red. The adsorption models' constants, along with thermodynamic parameters and kinetics of the process, were determined for each dye. Additionally, desorption tests of the adsorbed compounds were carried out. The materials obtained had a specific surface area ranging from 260 to 866 m2·g−1. The study found that the adsorption of methylene blue followed the Langmuir model, while the adsorption of methyl red followed the Freundlich model. The sorption capacities of the materials were dependent on the type of activator and the precursor:activator impregnation ratio and ranged from 5 – 216 mg·g−1 for methyl red and 11 – 314 mg·g−1 for methylene blue. The most effective eluent for methylene blue was found to be the hydrochloric acid solution. Meanwhile, for desorbing methyl red, both ethanol and 0.1 M HCl solution were found to be effective. [Display omitted] • Type of activator and impregnation ratio have impact on the adsorbent sorption capacity. • The best activated carbons obtained had a high 866 m2/g specific surface area. • The maximum adsorption capacity for methylene blue was 314 mg/g, while for methyl red it was 216 mg/g. • Thermodynamic studies indicated that the adsorption process was both spontaneous and endothermic. [ABSTRACT FROM AUTHOR]

Several chemical, mechanical, or physical stimuli can be used to promote oocyte activation during ICSI cycles. Calcium ionophore is the most commun method for chemical oocyte activation and activation may be beneficial for cases of globozoospermia, low oocyte count, total fertilization failure, recurrent implantation failure (1,2). In what concern low ovarian reserve cases, a subgroup of infertile couples with relatively poor prognosis, artificial oocyte activation with calcium ionophore may improve fertilization rates, embryo number, embryo quality and pregnancy rates. This study aimed to find out whether Ca2+ ionophore improves fertilization, embryo development and pregnancy out comes in patients with low ovarian reserve. This study is conducted at Istanbul University, Istanbul Faculty of Medicine, Department of Obstetrics and Gynecology, Reproductive Endocrinology and Infertility Unit. All IVF-ICSI cycles performed because of female factor, low ovarian reserve between November 2023 and July 2024 are included.Patients with DOR indication, who were administered calcium ionophore(GROUP I/Experimental Group, n:30) and patients who were not administered calcium ionophore (GROUP II/Control Group, n:30) were included. These patients were compared in terms of fertilization, embryo quality and pregnancy rates.Oocytes at the MII stage obtained from patients were subjected to ICSI approximately 4 hours after oocyte retrieval(OPU). After ICSI, the oocytes were incubated in a calcium ionophore solution for 20 minutes and then transferred to culture media. On the following days, fertilization rates, embryo development, and pregnancy statuses were assessed. The results were statistically evaluated using independent samples t-test and chi-square test. Statistical significance was considered as p<0.05 No differences were observed between the two groups in terms of female age, BMI, duration of infertility, AMH, FSH, LH, estradiol, oocyte count, oocyte maturation, and fertilization rate factors.However, the transfer of medium-quality embryos was found to be significantly higher in the DOR group without calcium ionophore application(p=0.035).The number of embryos frozen in Group I was significantly higher compared to Group II (p=0.020) (Table).No significant difference was found between the two groups in terms of clinical pregnancy and ongoing pregnancy rates. Alternative laboratory treatments applied to patients with low ovarian reserve may yield positive results in terms of increasing the likelihood of success. Our study has shown that the application of calcium ionophore in these cases leads to better-quality embryo development and consequently an increased number of frozen embryos. Although no significant difference was observed in clinical pregnancy and ongoing pregnancy rates, increasing the number of patients in the study could yield more definitive results. [ABSTRACT FROM AUTHOR]

Coal and biomass are two important carbonaceous feedstocks for producing carbon materials. Distinct composition of them might affect pore development of resulting activated carbon (AC) during activation. This was investigated herein via activating anthracite coal and poplar biomass via physical activation (activators: CO 2 and H 2 O) and chemical activation (activators: K 2 C 2 O 4 and ZnCl 2) under the same conditions. The results indicated that the activation of highly aromatic coal produced much higher yield of AC than that from poplar sawdust (ca. 90 % versus ca. 25–37 %). Nonetheless, this was at the cost of limited development of pore structure of AC-coal (121.1 m2g-1 with K 2 C 2 O 4 and 190.8 m2g-1 with H 2 O as an activator). Conversely, abundant aliphatics in poplar created more developed pore structures in AC-poplar (949.0 m2g-1 with K 2 C 2 O 4 and 588.6 m2g-1 with H 2 O), which also enhanced yields of AC-poplar through condensation reactions catalyzed with ZnCl 2 (AC yield: 33.7 % vs 22.8 % from blank experiment). The fused ring structures in coal were hardly activated via cracking with K 2 C 2 O 4. However, H 2 O could oxidize some carbonaceous organics on AC-coal, introducing oxygen-containing species, further cracking of which formed pores. This was an important route for generating pore structures in AC-coal. [Display omitted] • Highly fused aromatic rings in coal inhibit pore development via physical/chemical activation. • Aliphatic structures in poplar are main contributor to pores but diminishes solid yield. • H 2 O is more active than CO 2 for creating pores via cracking/gasification of poplar or coal. • H 2 O oxidizes coal to generate aliphatic O-containing species and then forms pores via cracking. • Ethers, ketones and esters/lactones in coal are cracked over K 2 C 2 O 4 or ZnCl 2 , forming limited pores. [ABSTRACT FROM AUTHOR]

[Display omitted] • Unlock the activated biochar's potential as carbon support for CO 2 RR. • Strategically select K 2 CO 3 based on KOH-activated biochar's performance. • Transition to K 2 CO 3 activation boosts Faradaic efficiency and C 2 H 4 selectivity. • Correlations of performance with diverse properties were identified. • Enhanced microporosity and –OH groups correlate with improved performance. Chemically activated biochar is effective in supercapacitors and water splitting, but low conductivity hinders its application as a carbon support in carbon dioxide reduction reaction (CO 2 RR). Based on the observed CO 2 RR performance from potassium hydroxide (KOH)-activated biochar, increased microporosity was hypothesized to enhance the performance, leading to selection of potassium carbonate (K 2 CO 3) for activation. K 2 CO 3 activation at 600℃ increased microporosity significantly, yielding a total Faradaic efficiency of 72%, compared to 60% with KOH at 800℃. Further refinement of thermal ramping rate enriched micropore content, directly boosting FE C to 82%. Additionally, K 2 CO 3 ′s lower activation temperature could preserve hydroxyl groups to improve ethylene selectivity. These findings demonstrate that optimizing microporosity and surface chemistry is critical for designing activated biochar-based CO 2 RR electrocatalysts. Despite lower electrical conductivity of activated biochar, selecting the appropriate activating agents and conditions can make it a viable alternative to carbon black-based electrocatalysts. [ABSTRACT FROM AUTHOR]

• Chemical & autothermal activation boosts micropores, pore volume, and surface area. • Autothermal oxidation reacts unstable C–C/C–H bonds, forming oxygen-containing intermediates. • Radicals speed up coal oxidation, enhance aromatic polymerization, and improve coal maturity. • Conceptual model of coal pore evolution under dual activation effects presented. Aiming at the limitation problems such as limited scope, high cost and energy consumption of coal bed penetration enhancement technology by traditional physical and chemical methods, a coal seam methane penetration enhancement method based on the combined action of chemical activation and auto thermal oxidation is proposed from the idea of utilizing the in-situ energy of the coal body. In this paper, N 2 and CO 2 adsorption, XPS and FTIR methods are used to study the pore structure evolution law and the change characteristics of the reactive structure of coal matrix under the effect of chemically activated autothermal oxidation. The synergistic microporous pore volume of chemical activation and auto thermal oxidation was 48.91 cm3/g−1 × 10-3, which was 28.96 % and 22.7 % higher than chemical activation and auto thermal oxidation respectively; The microporous specific surface area was 162.7 m2/g, which was 38 % and 26.6 % higher than chemical activation and auto thermal oxidation respectively. Activated coals expand and merge holes to a deeper degree after oxidative warming, and the complexity of the pore structure in the coal decreases; Highly reactive radicals in coal pores substantially promote the oxidation of coal structure, enhance the aromatic polymerization reaction of activated coal, and improve the maturity and aromaticity of activated coal, and the oxygen-containing functional groups in activated coal are negatively correlated with the oxidation temperature. The results of this study reveal the potential of the auto thermal oxidation-driven penetration enhancement method under chemical activation for coal seam gas penetration enhancement and extraction. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel sustainable chemically activated carbons samples were prepared from invasive Goat weed (Ageratum conyzoides). • ZnCl 2 activated carbon are essentially micro porous, whereas H 3 PO 4 activated carbon have both micro and meso porosity. • ZnCl 2 activated carbon have higher surface area and removal efficiency than H 3 PO 4 activated carbon. • ZnCl 2 and H 3 PO 4 activated carbon removes 90–93% and 85–88% of pollutants from hospital wastewater, respectively. Nanoporous activated carbons synthesized from goat-weed (Ageratum Conyzoides) using single-step pyrolytic chemical-activation with ZnCl 2 and H 3 PO 4 at various ratios. Nano-textural properties of samples assessed through N 2 adsorption/desorption, XRD, SEM, and FTIR. ZnCl 2 activation led to a high microporosity and maximum surface-area of 1699 m2·g−1 and total pore-volume of 1.23 cm3·g−1 (Zn/biomass ratio 1:1), while H 3 PO 4 activation yielded 866 m2·g−1 and 1.24 cm3·g−1, respectively (P/biomass ratio 1.5:1). The adsorption capacity of samples follows surface-area variations of samples. During treatment of hospital wastewater, ZnCl 2 -activated carbon removed 90–93 % of pollutants, comparable to commercial carbon, while H 3 PO 4 -activated carbon removed 85–88 %. The adsorption mechanism of carbons during interaction with HWW contaminants was discussed to explain variation in removal efficiency. [ABSTRACT FROM AUTHOR]

AbstractRaisin factories face a problem called waste and unusable waste in their industry. Due to the richness of industrial waste in this industry from carbon, in this work, we synthesized activated carbon by chemical method from raisin waste. For the synthesis of activated carbon, a chemical method with a zinc chloride activating agent was used in one to one mass ratio. After the optimization of various parameters such as type of activation agent, the ratio of activating agent, carbonization temperature and carbonization time, the best conditions for activated carbon were obtained. Then, in order to evaluate the efficiency of the synthesized activated carbon, a methylene blue dye removal test as a model was performed. Optimal conditions for the removal of methylene blue dye using the activated carbon including neutral pH, ambient temperature and the amount of adsorbent 0.01 g in 10 mL of solution with a concentration of 20 mg L-1 were obtained. In these conditions, the removal efficiency is more than 99%. The adsorption capacity is about 20 mg g-1 and the reaction kinetics is quasi-second order and according to thermodynamic studies the endothermic reaction is spontaneous and with increasing entropy. The dye adsorption mechanism on the adsorbent also follows the Langmuir isotherm, which indicates the uniformity of the adsorbent surface and the monolayer adsorption. Finally, in order to compare the performance of synthetic activated carbon, the amount of dye removal under optimal conditions was compared with the commercial activated carbon including Merck, Jacobi and activated carbon obtained from the almond shell. The results showed that synthetic activated carbon can compete with commercial samples.

This study investigated the hydrochar-based porous carbon prepared by combining the technical route of hydrothermal carbonization (HTC) + chemical activation. The hydrochar morphology was adjusted by changing the activation reaction conditions and adding metal salts. Experiments showed that the activation of KHCO3 significantly increased the specific surface area and pore size of the hydrochar. Besides, oxygen-rich groups on the surface of the activated hydrochar interacted with heavy metal ions to achieve efficient adsorption. The activated hydrothermal carbon adsorption capacity for Pb2+ and Cd2+ ions reached 289 and 186 mg/g, respectively. The adsorption mechanism study indicated that the adsorption of Pb2+ and Cd2+ was related to electrostatic attraction, ion exchange, and complexation reactions. The “HTC + chemical activation” technology was environmentally friendly and effectively implemented antibiotic residues. Carbon materials with high adsorption capacity can be prepared so that biomass resources can be utilized with excessive value, as a consequence presenting technical assistance for the comprehensive disposal of organic waste in the pharmaceutical industry and establishing a green and clean production system.

This study explores the chemical activation using K2CO3 and Fe(NO3)3 to alter the porous structure and a novel nitrogen functionalisation biomass derived carbon using cold plasma. The results showed that the obtained walnut shell carbon demonstrated a remarkable CO2 adsorption capacity of 5.69 mmol g−1 at 0°C, 1 bar and 3.94 mmol g−1 at 25°C, 1 bar. Further assessment of adsorption capacities at high pressures (up to 4 bar) demonstrated the adsorption capacity of 8.03 mmol g−1 at 0°C, 4 bar and 6.33 mmol g−1 at 25°C, 4 bar. Cold plasma is a novel method to increase the nitrogen functional group content to 10.37 at%. This study showed that, however, surface nitrogen functional groups do not contribute to CO2 adsorption, and despite the presence of nitrogen groups, physisorption is the dominant factor controlling the CO2 adsorption of walnut shell derived carbon.

During cell-to-cell communications, the interplay between physical and biochemical cues is essential for informational exchange and functional coordination, especially in multicellular organisms. However, it remains a challenge to visualize intercellular signaling dynamics in single live cells. Here, we report a photonic approach, based on laser microscissors and Förster resonance energy transfer (FRET) microscopy, to study intercellular signaling transmission. First, using our high-throughput screening platform, we developed a highly sensitive FRET-based biosensor (SCAGE) for Src kinase, a key regulator of intercellular interactions and signaling cascades. Notably, SCAGE showed a more than 40-fold sensitivity enhancement than the original biosensor in live mammalian cells. Next, upon local severance of physical intercellular connections by femtosecond laser pulses, SCAGE enabled the visualization of a transient Src activation across neighboring cells. Lastly, we found that this observed transient Src activation following the loss of cell-cell contacts depends on the passive structural support of cytoskeleton but not on the active actomyosin contractility. Hence, by precisely introducing local physical perturbations and directly visualizing spatiotemporal transmission of ensuing signaling events, our integrated approach could be broadly applied to mimic and investigate the wounding process at single-cell resolutions. This integrated approach with highly sensitive FRET-based biosensors provides a unique system to advance our in-depth understanding of molecular mechanisms underlying the physical-biochemical basis of intercellular coupling and wounding processes.

Biochar is a potential catalyst for methane decomposition (CMD) owing to its environmental-friendly and application prospects. In this work, the hierarchical porous biochar was prepared by carbonization and H 3 PO 4 activation using Enteromorpha prolifera (EP) as precursor, respectively. The results show that when the ratio of H 3 PO 4 /EP is 1.5, the maximum CH 4 conversion is 46%, along with hydrogen output of 396 mmol/g cat , which is 5.8 times as that of the unactivated biochar. The characterization results by XPS, Raman, SEM and HRTEM indicate that P element is inserted in carbon layer in the form of C–O–P, resulting in lattice distortion of carbon layer and larger defect density, and C–O–P plays a dominant role in initial CH 4 conversion. The mesopores formed by H 3 PO 4 activation alleviate the influence of the deposited carbon on the catalyst and decrease the deactivation rate, thereby exhibiting better performance in CMD. [Display omitted] • EP-based porous carbons with various P contents were prepared for CMD. • 1.5P/CEP950 exhibited high decomposition activity and excellent stability. • H 2 output of 1.5P/CEP950 was 5.8 times as that of CEP950, reaching 396 mmol/g cat. • Doping of P resulted in lattice distortion of carbon layer and more defect density. • C–O–P played a dominant role in CH 4 initial conversion. [ABSTRACT FROM AUTHOR]

In this research, prepared activated carbon by H3PO4 from hazelnut shells was coated with silver ions for the preparation of nanoparticles which were mixed in two ratios (1:0.5 and 1:1) by using of chemical reduction method. The adsorption capacity of activated carbons has been proven by BET and iodine number. Then, the antimicrobial effect of nanoparticles on the Staphylococcus aureus and Escherichia coli was investigated; in addition to that, the characterization of hazelnut shell and silver-coated activated carbons was determined by Brunauer–Emmett–Teller (BET), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD) methods. The optimum condition of activated carbon from hazelnut shells indicated that 66.01% carbon content within 36.22% efficiency, while BET surface area achieved as 1208 m2/g and its contained 0.6104 cm3 g−1 total pore volume. The microbial effect indicated that 105 CFU/mL of E. coli was completely inhibited in 30 min. Silver-coated activated carbon showed excellent bacteriostatic activity against E. coli and S. aureus. The results show that the composite has good prospects for applications in drinking water. E. coli of 104 CFU/mL in drinking water were destroyed within 25 min of contact with the filter made with AgAC. [ABSTRACT FROM AUTHOR]

Activated carbons are widely used especially in the removal of harmful contents of gases and liquids. Activated carbons constitute one of the important import items for our country. It is foreseen that the production of activated carbons from cheap, easily available and abundant raw materials of various organic origins will make significant contributions to the country's economy. In this study, it is aimed to evaluate semi-bituminous coals (Gediz-Kütahya) containing high sulfur as an alternative area of use in the production of activated carbon. In the study where ZnCl2 was used as the activation chemical, the effects of different working parameters (chemical/coal ratio, impregnation time and grain size) on activated carbon production were investigated. Various properties such as BET surface area, pore distribution, SEM surface properties, adsorption capability etc. of the obtained activated carbon were determined. Comparisons of the obtained activated carbon with the imported activated carbons still used commercially were made, and it was determined that there were significant similarities in properties. Optimum production operating parameters, 1/1 ZnCl2/coal mixture ratio, 24 hours impregnation time and +2 mm particle size coal is treated at 650 oC for 60 minutes under N2 atmosphere, with 733 m2/g BET surface area, micro and meso porosity activated carbon with a total pore volume of 0.460 cm3/g was obtained. As a result of the adsorption tests of the obtained activated carbon, it was determined that 99.2% of the Cu2+ ions in the solution could be removed. It has been understood that the obtained activated carbon can be used in many sectors. [ABSTRACT FROM AUTHOR]

Activated carbon has a huge demand for its broad applications in batteries, supercapacitors, wastewater treatment, etc. Activated carbon possesses a porous morphology, which facilitates its enhanced thermal stability, and surface area. Researchers employing agro-waste have focused on meeting the high demand of low-cost activated carbon production. This paper reports coconut-shell-derived activated carbon prepared by the thermal and chemical activation processes. The prepared samples are investigated for their structural, morphological, elemental composition, electrochemical properties, and functional groups. The prepared samples evidenced the amorphous nature, and some graphitic disordered, as confirmed by the x-ray diffraction (XRD) and Raman investigations. The morphological analysis demonstrated the formation of a nanoflakes-like structure; however, another sample prepared with chemical activation endorsed the porous carbon nanostructures. Furthermore, we have examined electrochemical properties and explored. [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs) released in air represent a major potential for environmental pollution. Capture methods based on activated biochar have attracted attention because of their low cost and for the high removal capacity of the material due to its physical and chemical properties. In this paper, activated biochars were developed and their adsorption performance for VOC capture was evaluated. In the first step, biochars derived from rapeseed cake (RSC) and walnut shells (WSC) were obtained through a carbonization process and then were activated using basic/acid agents (KOH/H2SO4) to increase their performance as adsorbents. Acetone and toluene were used as the VOC templates. The adsorption capacities of toluene and acetone for non-activated biochars were reduced (26.65 mg/g), while that of activated biochars increased quite significantly, up to 166.72 mg/g, and the biochars activated with H2SO4 presented a higher adsorption capacity of VOCs than the biochars activated with KOH. The higher adsorption capacity of biochars activated with H2SO4 can be attributed to their large surface area, and also to their larger pore volume. This activated biochar adsorbent could be used with good results to equip air purification filters to capture and remove VOCs. [ABSTRACT FROM AUTHOR]

The efficient adsorption application and electric double-layer capacitor material with low-cost biomass-based activated carbon materials have been quite common recently. In this study, chestnut shell-based activated carbons were produced by chemical activation. ZnCl2, H3PO4, and KOH agents were used for chemical activation. The obtained activated carbon, iodine adsorption from aqueous solutions, and its use as an electro capacitor were investigated. The scanning electron microscope, nitrogen adsorption/desorption, and Fourier transform infrared spectroscopy were used for characterization. The values of surface area and iodine adsorption capacity of the chestnut shell-based activated carbon are 1544 m2 g−1 and 1525 mg g−1. As a result, a specific capacitance of 97 Fg−1 with chestnut shell-based activated carbon was obtained in a 1 M KCl electrolyte for the electrochemical double-layer capacitor. This study shows that activated carbon based on the chestnut shell can be used both as an electrochemical energy storage material and as an adsorbent in iodine adsorption. [ABSTRACT FROM AUTHOR]

H3PO4/KOH combined solution is proposed as a new effective activation agent for activated carbon production from rice husk. Several activated carbon samples were produced by using different volumes of the utilized acid and alkali individually, in addition to the combined solution. FTIR results indicated that the mixed agent partially decomposed the chemical compounds on the rice husk char surface, resulting in an increase in the surface area. Moreover, XRD and EDS analyses showed the presence of a considerable amount of amorphous silica. Electrochemical measurements concluded that the volume of the activation agent solution should be optimized for both single and mixed activation agents. Numerically, for 0.3 g treated rice husk char, the maximum specific capacitance was observed at 7, 10 and 14 mL of H3PO4, KOH (3 M) and mixed (1:1 by volume) activation agents, respectively; the determined specific capacitance values were 73.5, 124.2 and 241.3 F/g, respectively. A galvanostatic charging/discharging analysis showed an approximate symmetrical triangular shape with linear voltage versus time profile which indicates very good electrochemical performance as an electrode in the supercapacitors application. The stability of the proposed activated carbon was checked by performing a cyclic voltammetry measurement for 1000 cycles at 2 mV/s and for 30,000 cycles at 10 mV/s. The results indicate an excellent specific capacitance retention, as no losses were observed. [ABSTRACT FROM AUTHOR]

A series of activated carbons were prepared from Zonguldak Karadon bituminous coal by single-step chemical activations with NaOH, KOH, ZnCl2, and H3PO4 and investigated for the adsorption of two types of alcohols: isopropyl and ethyl alcohol. The effects of various preparation conditions, such as coal to activating agent ratio, temperature and time of carbonization on the final porous texture of the carbons were studied. Pore characterization of carbon samples was analyzed by the nitrogen adsorption-desorption isotherm data recorded at 77 K. Adsorption behavior of alcohol vapors on various activated carbons was investigated using a volumetric apparatus at room temperature. The adsorption isotherm data were analyzed with various isotherm models. KOH activated carbon was found to yield the highest surface area and alcohol adsorption capacity. The highest surface area obtained was 1659 m2/g by KOH treatment of coal at 700°C. Adsorption capacity of carbon having the maximum surface area determined was 38.83 and 38.29% wt for isopropyl alcohol and ethyl alcohol, respectively. [ABSTRACT FROM AUTHOR]

A method has been proposed for the synthesis of activated carbon materials (ACMs) based on polyacrylonitrile (PAN) by activation with potassium hydroxide under the action of IR heating. Two approaches to the chemical activation of the polymer precursor were presented: formation of ACM based on PAN preliminarily heat-treated at 200°C and based on PAN carbonized at 700°C by impregnation with an aqueous alkali solution followed by heating to 800°C. Due to the use of IR radiation, the heating can be performed at a rate of 50 K/min, and the exposure time at a given temperature can be reduced to 2 min. The dependence of the specific surface area and porosity of ACM according to BET on the synthesis conditions was studied. The proposed approaches lead to the formation of ACMs with specific surface areas of 1091 and 2121 m2/g, respectively. [ABSTRACT FROM AUTHOR]

This paper presents the use of Agave leaves for the removal of an anionic dye Cibacron Blue P 3R (CB) from aqueous solution. The work reports the preparation of activated material (ALa) by impregnation with H3PO4 and carbon fibers (ALc) by pyrolysis at 800°C, from Agave leaves (AL). The materials were characterized by potentiometric titrations, scanning electron microscope, thermogravimetric analysis, and Fourier transform infrared spectroscopy. Initial pH, contact time, and initial dye concentration were evaluated in batch mode studies. Statistical analysis root-mean-square error (RMSE) was compared in the Langmuir, Freundlich, and kinetic equations. The kinetic investigation was fitted with pseudo-second-order model for both native (AL), calcined (ALc) and activated (ALa) adsorbents with R2 values higher than 0.99. Processes were well described with Langmuir isotherm model at the dye concentration range of 10–250 mg/L for all adsorbents. AL, ALa, and ALc samples exhibited, at pH=2.2, high maximum adsorption capacity of 20.83, 50.76, and 102.04 mg/g respectively. The experimental data are fitted well by the Langmuir in case of native (AL) and activated (ALa) adsorbents, where a high correlation coefficients (R2) and a low root-mean-square errors (RMSE). For the adsorption of CB dye on the calcined material (ALc), the Freundlich mode perfectly describes the adsorption process with a very low-root-mean-squares error (RMSE) = 0.62. [ABSTRACT FROM AUTHOR]

The petroleum industry plays a vital role in the economies of developing countries. Refinery wastewater pollution has increased in recent years due to the increase in the industrial and urban use of petroleum products. The present work demonstrates how textile waste can be modified into a material that can effectively remove sulfur pollutants from refinery wastewater. An economic activated carbon (AC) material was developed by using cotton spinning waste from a textile company. The chemical activation was carried out using nitric acid (HNO3), hydrogen peroxide (H2O2), and potassium hydroxide (KOH). The characterization of the obtained activated carbons was performed using the SEM, BET, and FTIR techniques. The effect of the experimental adsorption condition was investigated using both bed and batch isotherms. The results show that effluent flow has the highest effect on sulfur compound adsorption. The greatest adsorption capacity of the sulfur compounds was found to be around 168.4 mg·g−1. The equilibrium data were investigated using the Freundlich, Langmuir, Dubinin–Radushkevich, Tóth, and Sips isotherm models. The Langmuir model exhibited the best fit (R² = 0.98) for the sulfur compounds' adsorption, which implies that their adsorption onto the synthesized AC was homogeneous. The kinetic data were tested with pseudo-first-order, pseudo-second-order, and intraparticular diffusion equations. The pseudo-second-order equation described the kinetic data well (R² = 0.99), indicating that this adsorption may be restricted by the chemisorption process. These properties under optimal conditions make the obtained ACs suitable for use in refinery wastewater treatment. [ABSTRACT FROM AUTHOR]

The Stipa tenacissima S. is an endemic species of the Western Mediterranean countries, which grows on the semi-arid grounds of North Africa and South Spain. This biomass offers an abundant, renewable, and low-cost precursor for the production of activated carbon (AC). In that context, ACs were prepared by chemical activation of Stipa tenacissima leaves (STL) using phosphoric acid (H3PO4). The effects of activation temperature and impregnation ratio on the textural and chemical surface properties of the prepared activated carbons were investigated. Activation temperatures of 450 and 500 °C turned out to be the most suitable to produce activated carbons with well-developed porous textures. The best results in terms of developed surface area (1503 m2/g) and micropore volume (0.59 cm3/g) were observed for an STLs to phosphoric acid ratio of 1:2 and a carbonization temperature of 450 °C. The adsorption capacity of the optimal activated carbon was found to be 110 mg/g for the atenolol drug. The adsorption equilibrium was well explained by the pseudo-second-order model and Langmuir isotherm. This study showed that the chemical activation method using H3PO4 as an activating agent was suitable for developing STL-based activated carbon prepared for the removal of atenolol drug in an aqueous solution and compared with commercial activated carbon supplied by Darco. [ABSTRACT FROM AUTHOR]

The conversion of rice crop residues into activated carbon (AC) and nanosilica was performed via an integrated procedure including successive carbonization, K2CO3 activation, and extraction steps. For the first time, rice husk and rice straw were utilized comparatively as the raw materials for parallel AC and silica production, and the main characteristics of the corresponding products were compared. However, AC produced from rice straw at 1000 °C and impregnation ratio of 1.5 showed a larger surface area and total pore volume (2229 m2/g and 1.6 cm3/g) than AC produced from rice husk (1941 m2/g and 1.5 cm3/g); no definite and general conclusion can be made about the superiority of rice straw as the raw material. This is attributed to the close characteristics of the products, the large variety of rice crop residues, and the strong influence of the operating conditions on the properties of products. The rice husk– and rice straw–based activated carbons had no significant difference in their functional groups and chemical characteristics. The amorphous silica nanosize particles (< 50 nm) were obtained from both raw materials; however, the presence of little crystalline phase impurities (potassium chloride) and silica (tridymite and coesite) was also observed. The most important superiority of rice husk to rice straw was its larger silica production yield from the initial biochar (40% compared to 25%). [ABSTRACT FROM AUTHOR]

Because of its high adsorption capacity, activated carbon is frequently employed as an effective adsorbent. Activated carbon is a main element for treatment of wastewater, groundwater and water purification. The activating agents greatly affects the porosity and surface area of the produced activated carbon. In this study, the use of agricultural leftovers for the production of activated carbon is discussed in detail. The pyrolysis stage is investigated in relation to a number of process variables. The effects of physical and chemical activation circumstances on the properties of activated carbon are discussed. Under controlled process conditions, many active carbons with Brunauer–Emmett–Teller surface areas ranging from 250 to 2,410 m2/g and pore volumes ranging from 0.022 to 91.4 cm3/g were produced. A review of reaction kinetic modelling applied to pyrolysis of agricultural wastes is also carried out. In this study, effort has been given to show the preparation of activated carbon from various agricultural residues. Also the comparisons of different activated carbon prepared from various agricultural residues have been shown. In the present review, the preparation of activated carbon by treating with different chemicals has also been incorporated. [ABSTRACT FROM AUTHOR]

In this study, hazelnut shells, orange peel, and melon seeds were selected as raw materials in the preparation of activated carbon. Various activators at different concentrations under two activation temperatures of 300 °C and 500 °C were utilized. All produced adsorbents and a commercial activated carbon as a reference were used for the adsorption of acetic acid from its aqueous solutions in the various initial concentrations. The effect of the amounts of adsorbents was also studied. Removal efficiencies (Re%) and adsorption capacities (Qe) were experimentally determined. Langmuir, Freundlich, and Temkin isotherms were modelled, and their parameters were calculated. The surface area, pore volumes, and average pore width of the activated carbons were characterized by N2 adsorption at 77.35 K using the BET, t-plot, and BJH methods, respectively. The highest BET surface area of the activated carbon from hazelnut shells was obtained as 717.738 m2/g at 500 °C activation temperature and 60% H3PO4 concentration. SEM images and FTIR analyses were investigated. It was found that activated carbons of hazelnut shells and orange peel showed higher efficiencies than commercial activated carbon. [ABSTRACT FROM AUTHOR]

The objective of this study is the characterization of activated carbon prepared from hawthorn core natural residue which is a vegetation waste. By using zinc chloride (ZnCl2) as a chemical agent 40 for 25 hours at (25 °C) as a raw material in this work. The best conditions were determined to be a carbonization temperature of 400 °C for 1 hour and a maximum yield is 82 %. Different operational factors such as carbonization time and temperature were used to prepare activated carbon from hawthorn core stones, pH, ash content, density, humidity content, conductivity, iodine number, and methylene blue dye absorption were all investigated in the generated activated carbon. The obtained characterization of the activated carbon was performed by using scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive X-ray (EDX). Finally, the activated carbon synthesized in this study acquired good properties that enable it to play an important function in a variety of environmental applications, including eco-protection, water treatment, and wastewater treatment and it was compared to a commercial reference sample from the B. D. H Company in industrial applications. [ABSTRACT FROM AUTHOR]

In this study, the producibility of activated carbon from wood waste by using the chemical activation method was investigated and the produced activated carbon was compared with commercial activated carbon. Activated carbon was produced from black poplar wood waste using zinc chloride and phosphoric acid. The density values of the produced activated carbons were determined by the picometer method. Field Emission Scanning Electron Microscopy (FESEM) was used to analyze the microstructure and perform the elemental mapping. To determine the chemical content of activated carbon, it was also characterized by Fourier-transform infrared spectroscopy (FTIR) and energy dispersion spectroscopy (EDS). Based on the density and FESEM results, it was determined that the produced activated carbon had a lower density and porous structure. In addition, EDS analysis showed that the activated carbon produced from black poplar wood waste was purer than commercial activated carbon. [ABSTRACT FROM AUTHOR]

The results of a study of the impact of activation temperature and the mass ratio of the activator to the carbonised precursor on the porous structure of nitrogen-doped activated carbons obtained from lotus leaves by carbonisation and chemical activation with sodium amide (NaNH2) are presented. The analyses were carried out via the new numerical clustering-based adsorption analysis, the Brunauer–Emmett–Teller, the Dubinin–Raduskevich, and the density functional theory methods applied to carbon dioxide adsorption isotherms. Carbon dioxide adsorption isotherms' analysis provided much more detailed and reliable information about the pore structure analysed. The analyses showed that the surface area of the analysed activated carbons is strongly heterogeneous, but the analysed activated carbons are characterised by a bimodal pore structure, i.e., peaks are clearly visible, first in the range of pore size from about 0.6 to 2.0 nm and second in the range from about 2.0 to 4.0 nm. This pore structure provides optimal adsorption performance of carbon dioxide molecules in the pore structure both for adsorption at atmospheric pressure, which requires the presence of narrow pores for the highest packing density, as well as for adsorption at higher pressures, which requires the presence of large micropores and small mesopores. However, there are no micropores smaller than 0.5 nm in the analysed activated carbons, which precludes their use for carbon dioxide adsorption for processes conducted at pressures less than 0.01 MPa. [ABSTRACT FROM AUTHOR]

Activated carbons named AC105 and AC11 were prepared from Brazil nut shells using the weight ratios of Brazil nut shells: KOH of 1:0.5 and 1:1, respectively. The prepared materials were characterized using different techniques and applied to remove phenol from the aqueous solution through adsorption. The characterization data showed that both materials presented similar properties, with AC11 exhibiting a slightly higher specific surface area (332.2 m2 g–1) than AC105 (314.3 m2 g–1). The kinetic study showed that AC11 reached the process equilibrium faster than AC105, and the Elovich model was best suited to the kinetic data for both adsorbents. The equilibrium data followed the Sips model; the maximum adsorption capacities were 55.16 and 68.52 mg g–1 for AC105 and AC11, respectively. The application of the materials in the treatment of a simulated industrial effluent showed removal efficiencies of 28.05% and 48.20% for AC105 and AC11, respectively. Therefore, through the adsorption results, AC11 proved to be more efficient towards phenol removal and is a promising alternative for treating wastewater containing this contaminant. [Display omitted] • Brazil nut shells as precursor to produce activated carbons (AC) with KOH. • KOH ratio increased the specific surface area from 314.3 m2 g–1 to 332.2 m2 g–1. • Adsorption capacity for phenol reached 68.52 mg g-1. • AC is a promising alternative for treating wastewater containing phenol. [ABSTRACT FROM AUTHOR]

The preparation and functionalization of activated carbons from different biomass of Mexico and their application in the adsorption of heavy metal ions is reported in this paper. Jacaranda seeds, guava seeds, grape pomace and sugarcane bagasse were utilized as lignocellulosic precursors to obtain activated carbons via the chemical activation of biomass and its pyrolysis. The best conditions to prepare the activated carbons were identified with ZnCl 2 , NaOH, HNO 3 and H 3 PO 4 as activating agents. A systematic analysis of the biomass chemical activation and thermochemical transformation via pyrolysis was performed to maximize the Hg2+, Zn2+ and Pb2+ adsorption properties of activated carbons. These adsorbents showed maximum adsorption capacities from 0.014 to 0.84 mmol/g at 25–40 °C where the best adsorbent was obtained from the Jacaranda fruit activated with 0.5 M ZnCl 2 for 2 h and pyrolyzed at 800 h for 4 h. This adsorbent was effective for the Hg2+ removal in single, binary and ternary systems thus suggesting its potential application for industrial wastewater treatment where several heavy metal ions could be present. The removal of these heavy metal ions with all tested activated carbons was endothermic where the oxygenated functional groups were involved in the adsorption mechanism. Isotherm data modeling with statistical physics indicated that Hg2+ and Pb2+ adsorption was mono-ionic, while the Zn2+ adsorption was multi-ionic. Antagonistic adsorption of these heavy metal ions occurred in multi-metallic solutions where Hg2+ affected significantly Zn2+ and Pb2+ removal. Regeneration of the best activated carbon was feasible with HNO 3. These results contribute to valorize alternative agricultural and biomass wastes to satisfy the demand of activated carbons for water cleaning in Mexico applying a circular economy approach to reduce the production costs and to minimize the solid waste generation. [Display omitted] • Activated carbons were synthetized from different biomass wastes from Mexico. • Heavy metal adsorption properties were maximized via biomass chemical activation. • Multi-metallic adsorption and regeneration of the best activated carbon were studied. • Biomass valorization contributes to satisfy the activated carbon demand for water cleaning. [ABSTRACT FROM AUTHOR]

Due to their low surface energy, poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP) films must be treated by chemical or physical activation methods before using. Among these activation strategies, using sodium naphthalene solution is a popular one. However, the effect of this strategy's chemical activation conditions on the surface properties of the FEP film is rarely discussed. In this study, FEP films were chemically activated by the sodium naphthalene solution with adjusting concentration, solvent, and activation time. With increasing concentration and activation time, many granular substances appeared on the surface of the FEP film. When tetrahydrofuran was used as a solvent, the color of the film gradually turned brown; when 1,3-dimethyl-2-imidazolidinone was chosen as the solvent, the color change was not very significant. The contact angle was significantly reduced from 112° before activation to 26° after activation, and the surface energy was greatly enhanced from 34 mN m−1 before activation to 66 mN m−1 after activation. In addition, compared with the FEP samples treated by Ar plasma, the sodium naphthalene system showed a stronger activation ability. Activated FEP films that suffered from the Ar plasma treatment could still maintain a higher energy surface than that of the pristine FEP. [ABSTRACT FROM AUTHOR]

The presence of emerging contaminants in water can harm both the environment and human health. Traditional water and wastewater treatment cannot eliminate them, so different alternatives for their removal are being studied. The use of activated carbon as an adsorbent is emphasized due to its high adsorption capacity and lower cost, and to the possibility of obtaining it from biomass wastes. Thus, this study evaluated the use of Syagrus coronata waste to produce activated biochars and their adsorption capacity of isoniazid from an aqueous medium. For this, the biochar obtained through slow pyrolysis was chemically activated using two different agents, H2SO4 or KOH. The adsorbent's acidic and textural properties were studied and correlated with adsorption behavior tested in batch and fixed-bed column systems, using commercial activated carbon as a comparison. The KOH activation process produced a predominantly microporous material (BAC), with a high surface area (1006 m2·g−1) and a high content of oxygenated functional groups (1.98 mmol·g−1). BAC outperformed all other materials tested and ones found in other works using isoniazid as a contaminant model, having a high adsorption capacity (712.42 mg·g−1). Thus, this work successfully obtained an efficient adsorbent produced from an agro-industrial waste, with superior performance. [ABSTRACT FROM AUTHOR]

The preparation of biochar from Tannery (chrome) sludge has gained recent attention among many scientists globally. Hydrothermal pre-treatment method was adopted to load TiO2 nanoparticles on the surface of sludge biochar to develop a safe, low-cost, and novel nanocomposite. Chemical activation of sludge with KOH solution for 48 h was done before pyrolyzing the sludge to produce biochar. This novel c-SB/TiO2 nanocomposite exhibits a higher surface area of 636.23 m2/g when compared with the sludge biochar/TiO2 nanocomposite without chemical activation. The present research work mainly focuses on the synthesis and investigation of structural properties of c-SB/TiO2 nanocomposite prepared by hydrothermal pre-treatment. The morphological and structural properties of sludge biochar/TiO2 nanocomposite were identified by Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD). The porosity of the nanocomposite was investigated using a BET surface area analyser. The Thermal decomposition and surface functional group was identified using TGA, FT-IR, PL and Raman spectrophotometer, respectively. c-SB/TiO2 nanocomposite was used to degrade Cr (VI) by varying its initial concentration, catalyst dosage and initial pH. Results indicate that c-SB/TiO2 nanocomposite shows an enhanced photocatalytic activity under UV light irradiation. Further, it was found that under optimal conditions of 10 mg/L of pollutant concentration, pH of 2 and catalyst dosage of 0.3 g/L, degradation efficiency of 98.65% Cr (VI) has been achieved for a reaction time of 180 min. Additionally, COD measurement shows a 69.4% reduction for a reaction time of 180 min, which is found to be more recalcitrant under photocatalytic activity. [ABSTRACT FROM AUTHOR]

Nitrogen-doped porous hydrochar (NPHC) was successfully synthesized by hydrothermal carbonization and activation with KHCO 3 , which was employed for scavenging hexavalent chromium (Cr(VI)) and bisphenol A (BPA) in contaminated water. N doping increased the unique active sites such as amino and molecular N in NPHC for adsorbing contaminants, and enhanced the activation effect. Compared to original (HC) and N-doped hydrochar (NHC), the S BET of material improved from 3.99 m 2 /g and 4.71 m 2 /g to 1176.77 m 2 /g. Meanwhile, NPHC exhibited more superior adsorption capacity for Cr(VI) (323.25 mg/g) and BPA (545.34 mg/g) than that of porous hydrochar (213.17 and 343.67 mg/g). Moreover, NPHC possessed pH-dependence and presented more excellent tolerance for interfering ions and regeneration performance. Notably, the Cr(VI) capture by NPHC was dominated via pore filling, electrostatic interaction, reduction, and complexation, while π-π stacking, H-bond interaction, and hydrophobic action were relevant to the binding mechanism of BPA. Overall, the proposed functionalization strategy for biochar was conducive to enhance the remediation of water bodies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Abstract Porous carbon materials derived from palm date seeds, guava seeds and winged beans are proposed as environmentally friendly and efficient adsorbents for CO2 and H2S adsorption. The feedstock is converted into hydrochar via hydrothermal carbonization (HTC), at 200°C, for several hours, and the textural properties are tuned using the chemical activation approach with KOH. The activated carbons (ACs) prepared in here are characterized by high surface areas, more than 2000 m2 g‐1, and large pore volumes (1.23 cm3 g‐1). It is observed that a lower concentration of KOH results in a larger number of micropores, leading to improved gas uptake properties. The carbons obtained in here present sponge‐like structure with particle sizes in the range of 5–100 µm. Their morphology is characterized by irregular particle shape with large conchoidal cavities and smooth surfaces. The samples display significant gas adsorption capacity, with 5.47 mmol g‐1 CO2 uptake at 0°C, 1 bar and 4.36 mmol g‐1 at room temperature and atmospheric pressure. H2S adsorption is achieved with more than 50% adsorption efficiency in 1 hour exposure time. Through this study we aim to add up to the eco‐friendly and cost‐effective materials, derived from biomass, suitable and efficient in CO2 and H2S adsorption.

Global climate change is currently a major problem and is thought to be due to high levels of CO2 and other greenhouse gases. Several technologies have been built to lower CO2 emissions. Adsorption, a promising technology for CO2 capture, is among these technologies. In addition to adsorbent development, it is essential to determine the influence of operating variables on developed materials. Therefore, in this study, an activated carbon (AC), kaolinite (KAO) and kaolinite-activated carbon (KAC) composite adsorbent characterized was evaluated for CO2 adsorption. The aim of this study was to investigate the effect of operating variables on the CO2 adsorption capacity of each adsorbent (activated carbon, kaolinite, and kaolinite – activated carbon composite) and select the most suitable to serve as the solid anchor in the production of a hydrophobic adsorbent material for CO2 capture. Then, Scanning Electron Microscopy, N2 physisorption and Fourier Transform Infrared were tested for the morphology, surface area and functional groups of the adsorbents, respectively. The CO2 adsorption capacity of the adsorbents was measured using a custom-built 1.0 cm internal diameter adsorption column at of 30 to 70 mL/min bed height, of 3 to 5 cm operating temperature, and of 30 to 70 °C and CO2 feed flow rates. The maximum amounts of AC, KAC and KAO CO2 adsorbed to were found to be 28.97 mg CO2/g, 18.54 mg CO2/g and 12.98 mg CO2/g, respectively.

Carbon adsorbents for use in the removal of gaseous toluene from the air were prepared from buckwheat (Fagopyrum esculentum Moench) hull. A chemically-activated adsorbent was prepared via the impregnation of raw hull powder with potassium carbonate, followed by thermal decomposition. The chemically-activated adsorbent exhibited improved adsorption capacity for toluene compared to the adsorbent prepared without chemical activation. Toluene concentration in the air decreased from 220 ppm to 160 ppm during 24 h of adsorption using unactivated adsorbent. Only a trace amount of toluene remained after the adsorption under the same conditions using K2CO3-activated adsorbent. This improvement was explained based on experimental results, specifically, iodine adsorption tests, methylene blue adsorption tests, and microscopic observations. Chemical activation dramatically increased the specific surface area of the adsorbent and created mesopores capable of adsorbing toluene. This study revealed that a mesoporous adsorbent for use in volatile toluene removal can be prepared from waste biomass (buckwheat hull) by chemical activation using potassium carbonate.