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N‐coordinated Ni sites (NiNx) are effective catalysts for the electrochemical reduction of CO2 to CO. In most researches, modulating the coordination environment of Ni atoms is focused on to improve electrochemical CO2 reduction (ECR) performance. However, the influence of the carbon substrate's structure on the intrinsic activity of NiNx is seldom investigated. The highly curved surface of carbon nanotubes (CNT) may provide a unique curvature effect on NiNx. It is found that the Ni residues in CNT can be atomized to form NiNx sites on the surface of CNT (Ni‐N/CNT@covalent triazine framework [CTF]) through high‐temperature pyrolysis, using a soluble CTF nanosheet as N precursor. The π‐conjugated and ultrathin 2D structure of CTF enables closer interfacial contact between CTF and CNT, which avoids the formation of a thick carbon layer to maximize the curvature effect. Theoretical data reveal that the NiN3 configuration may act as a highly active ECR site, and the curvature effect from CNT can further tune the electronic structure of NiN3, thus improving the ECR kinetics. The Ni‐N/CNT@CTF‐based flow‐cell electrolyzer exhibits a jCO of 201 mA cm−2 at −0.9 V with a high FECO of 98%. [ABSTRACT FROM AUTHOR]

Biowaste fermentation is a promising technology for low‐carbon print bioenergy and biochemical production. Although it is believed that the microbiome determines both the fermentation efficiency and the product profiles of biowastes, the explicit mechanisms of how microbial activity controls fermentation processes remained to be unexplored. The current study investigated the microbiome dynamics and fermentation product profiles of biowaste fermentation under different organic loads (5, 20, and 40 g‐VS/L) and with additives that potentially modulate the fermentation process via methanogenesis inhibition (2‐bromoethanesulfonate) or electron transfer promotion (i.e., reduced iron, magnetite iron, and activated carbon). The overall fermentation products yields were 440, 373 and 208 CH4‐eq/g‐VS for low‐, medium‐ and high‐load fermentation. For low‐ and medium‐load fermentation, volatile fatty acids (VFAs) were first accumulated and were gradually converted to methane. For high‐load fermentation, VFAs were the main fermentation products during the entire fermentation period, accounting for 62% of all products. 16S rRNA‐based analyses showed that both 2‐bromoethanesulfonate addition and increase of organic loads inhibited the activity of methanogens and promoted the activity of distinct VFA‐producing bacterial microbiomes. Moreover, the addition of activated carbon promoted the activity of H2‐producing Bacteroides, homoacetogenic Eubacteriaceae and methanogenic Methanosarcinaceae, whose activity dynamics during the fermentation led to changes in acetate and methane production. The current results unveiled mechanisms of microbiome activity dynamics shaping the biowaste fermentation product profiles and provided the fundamental basis for the development of microbiome‐guided engineering approaches to modulate biowaste fermentation toward high‐value product recovery. [ABSTRACT FROM AUTHOR]

This study used zinc/iron acetate (as a precursor) and a carboxylic variant of activated carbon (as a matrix) to create nanostructured zinc ferrite (ZnFe2O4). Carboxylic derivative (AC–COOH) of activated carbon was obtained by nitric acid oxidation. Then, enhanced activated carbon's surface was impregnated with ZnFe2O4. ZnFe2O4 nanoparticles with a size range of 25–35 nm and a surface area of 165.8 m2g−1 were proven to have been achieved after the ZnFe2O4 nanostructure was characterized by XRD, FESEM, TEM, UV, PL, BET, and XPS. Using the same testing circumstances, the optimized photocatalyst with 10 wt.% ZnFe2O4 inserted AC demonstrated the best degrading efficeicny to methylene blue (99%) and Reactive red (94%). The Langmuir–Hinshelwood hypothesis, which states that the dye concentration is a first-order function of time, was validated by kinetic investigations. The photocatalyst was shown to be stable after 7 cycles of recycling under optimal circumstances in a study of the reusability of a 10-ZnFe2O4/AC photocatalyst. In addition, PL, TRPL, EIS, and transient-photocurrent response all provide strong evidence for the efficient charge separation in ZnFe2O4/AC. [ABSTRACT FROM AUTHOR]

A catalytic oxidation treatment to remove coloration and chemical oxygen demand (COD) in an effluent from a food industry was carried out using oxygen and ozone as oxidizing agents and activated carbon as a catalytic. Different experiments of oxidation were conducted using 25, 50 and 100 mL of activated carbon bed to treat 100 mL of sample and constant flow of oxygen 7.2 g/min and ozone 0.034 mg/min, maintaining initial pH of industrial effluent. Almost a complete coloration removal and COD reduction of the sample was achieved for catalytic processes; however, time of treatment and agent oxidant doses were different in each case. According to volume of activated carbon beds, ozone doses for discoloration and COD removal were 8.5, 2 and 1.7 mg/L, whereas the oxygen doses were 2860, 770 and 500 g/L, respectively. Consequently, to eliminate the color in the industrial effluent, the dose of oxygen was higher than that of ozone. In addition, the oxidation agents promoted the regeneration of activated carbon, showing that its activity is declined after 60 cycles of effluent treatment with ozone, whereas with oxygen treatment, the total depletion was observed in 18 cycles. In turn, single adsorption showed activated carbon depletion in 5 cycles of effluent treatment. [ABSTRACT FROM AUTHOR]

This study was planned to explore the AFM1‐reducing potential of various heat and acid‐killed lactic acid bacteria (LAB), activated carbon and bentonite (BENT) in milk contaminated with 0.5 μg/L AFM1 and their impact on milk composition. A negligible impact was observed on milk composition with AC while exhibiting a higher AFM1 removal (78.2%) than bentonite (35.8%). Their combination with LAB cells increased AFM1 decontamination for most of the treatments, with highest AFM1 removal (97.6%) exhibited by a treatment involving 0.1% AC and acid‐killed cells of L. cremoris. The results of this study indicate that LAB cells associated with the adsorbents tested are highly effective in reducing milk AFM1 content. [ABSTRACT FROM AUTHOR]

Summary: This research was designed to examine the effects of activated carbon dosage and pH on various attributes of corn protein hydrolysate, including decolourization efficiency, nitrogen component, amino acid (AA) composition, protein secondary structure, and antioxidant activity. Optimal pigment elimination of occurred within the pH range of 2.0–4.0, utilising the hydrolysate as the control. Remarkably, the removal of trichloroacetic acid (TCA) insoluble peptide was evident at pH 4.0. The decolourization process elicited considerable reduction of the aromatic AA, exhibiting pronounced decreases of acidic AA (Glu and Asp) within the pH range of 2.0–4.0, and basic AA (His, Lys, and Arg) within the range of 6.0–8.0. Meanwhile, infrared spectroscopy analyses indicated that a dosage of 0.5% activated carbon at pH 4.0, effectively preserved the secondary structure and ratios of the control, maintaining its antioxidant activity. These results provide insights into optimisation strategies for decolourization in the food industry. [ABSTRACT FROM AUTHOR]

The output power and combination property of microbial fuel cells (MFCs) are often limited by the sluggish kinetics of the cathodic oxygen reduction reaction (ORR). Therefore, seek noble metal-free materials with good ORR catalytic efficiency and durability is of great significance for practical MFC application. In this paper, ternary transition metal sulfide was successfully loaded on activated carbon by hydrothermal method. In the MnCo2S4@AC nanocomposite, the synergistic effect existing between MnCo2S4 and activated carbon (AC) gives the advantages of large specific surface area, special microstructure, fast electron transmission rate and good electro-catalytic activity of MnCo2S4 for ORR. The electrochemical tests showed that the ORR event of MnCo2S4@AC was the four-electron (4e−) pathway. Therefore, the highest output power density of MFC assembled with MnCo2S4@AC was 239.41 mW m−2, 3.59-fold stronger than AC (66.66 mW m−2). This method can provide the ideas for the synthesis of efficient ORR catalyst. [ABSTRACT FROM AUTHOR]

Concern over safe drinking water has increased. In this study, aluminum oxide was coated with carbon nanotubes by chemical vapor deposition using ethanol or methanol as precursors to remove N-nitrosamines, 2-methylisoborneol (MIB) and geosmin from water. Seven types of N-nitrosamines were investigated. The differences in the surface of the carbon nanotubes were attributed to the carbon precursors ethanol and methanol. Despite the high concentration of analytes, the adsorption capacity of both carbon nanotubes (CNTs) was around 19 mg/mg for MIB and geosmin. Against approximately 0.9 ng/mg for activated carbon. For N-nitrosamines, the adsorption capacity of CNTs reached 50 ng/mg for NDBA, N-nitrosamines with the highest molecular weight, while activated carbon had values below 6.0 ng/mg. The results showed π-π interactions play a dominant role in the adsorption of MIB and geosmin under the investigated conditions. On the other hand, for N-nitrosamines, both dipole-dipole and π-π interactions come into play, with the latter becoming more prominent as the molecular weight of N-nitrosamines increases. The removal efficiencies of CNT-coated aluminum oxide reached 84,0%. The analytes with longer carbon chains were removed more efficiently and CNT-coated aluminum oxide grown from ethanol or methanol had no statistical difference between the removal efficiencies of all evaluated analytes. [ABSTRACT FROM AUTHOR]

[Display omitted] Adsorbents with dual-component active phases have attracted much attention owing to their potential application in synergistic H 2 S removal. The influence of spatial arrangements of two components within a support matrix on their desulfurization performance was investigated through regulating the mutual arrangements of CuO and MgO on an activated carbon surface. Their spatial locations were found to remarkably affect interfacial interactions, local pH, the conductivity of adsorbents, and electronic structure of copper oxide. A close contact of CuO with the carbon surface led to strong interactions of both components, inhibiting the reduction of CuO and decreasing its reactivity with H 2 S. On the other hand, a proximity of MgO to the carbon surface increased local pH, promoting the oxidation of H 2 S into elemental S, instead of sulfates. Cu+ in the copper oxide phase increased the desulfurization performance due to its ability to activate oxygen and to accelerate a lattice diffusion. Enhanced surface conductivity due to the interfacial interactions improved the desulfurization efficiency and favored the formation of elemental S through promoting an electron transfer in redox reactions. [ABSTRACT FROM AUTHOR]

Application of titanium dioxide nanomaterial having different crystal forms has been extensively studied in various fields. However, as a drilling fluid additive it is still an unexplored area. Changing the composition of TiO2 morphology, leads to substantial improvements in the environmental and energy sector. These enhancements are based on the chemical and physical interaction of the crystal structure. In the current work, the carbon supported anatase TiO2 particles are used as a drilling fluid additive to improve the efficiency of water-based mud systems. For the first time, the effect of the crystal system is considered on the drilling fluid performance. Three carbon supported particles in the form of MWCNT/TiO2, GO/TiO2 and activated carbon/TiO2 are used in drilling fluid. Each particle was added in the mud system with concentration ranging from (0.35 g, 0.875 g, 1.75 g, 2.625 g, 3.5 g,) respectively. The rheology, filtration, stability, and shale inhibition characteristics of the samples was performed. Improvement in electrochemical characteristics of the mud system was recorded after the incorporation of carbonaceous TiO2 particles. Moreover, the gelation and filtration characteristics of the muds were also enhanced after the synergy of carbonaceous material with TiO2. This interaction leads to better cutting suspension and provides smooth and compacted mud cake. In addition, all the mud samples interacted with Ranikot formation to observe its stability behavior. Substantial improvement in hydrophobic nature of the shale sample was recorded after interacting with the carbon supported TiO2 nanoparticles. These carbon supported particles are extremely potential in plugging the nano-pores of Ranikot shale and are responsible for maintaining the shale integrity. [ABSTRACT FROM AUTHOR]

The silk sericin (SS) recovered from silk degumming wastewater can be used to develop carbonaceous materials for organic dye removal from wastewater. To improve the adsorption capacity of the carbonaceous adsorbents derived from SS, KOH was used as an activation agent. The maximum adsorption capacity of SS-based activated carbon on methylene blue (MB) was determined by batch adsorption experiments as 964.63 mg/g. Mathematical models of adsorption were studied to reveal the adsorption mechanism. According to adsorption kinetics analysis, a pseudo-second-order model describes the adsorption performance of SS-based activated carbon on MB more appropriately, and the adsorption process follows the Langmuir model. The activated carbon prepared from SS in this work demonstrated improved MB adsorption capacity compared with other SS-based carbonaceous materials and therefore presented prosperous application possibilities for removing organic dyes from wastewater. Creation and application of silk sericin-derived activated carbon. The silk sericin was first enriched from the silk degumming wastewater, then was converted into activated carbon by heating and activation. The generated activated carbon was later used for the adsorption of methylene blue from aqueous solutions through electrostatic and π-π interactions [ABSTRACT FROM AUTHOR]

Lead is one of the primary pollutants found in water and poses significant toxicity risks to humans; thus, it is necessary to investigate techniques for removing it economically and efficiently. In order to enhance the removal capacity of Pb2+, coconut shell-based activated carbon (AC) was modified with introducing oxygen-containing functional groups (OFGs) via nitric acid (HNO3) or hydrogen peroxide (H2O2) modification in this study. The characterization results show that after oxidation treatment, the content of OFGs increased, and the textural properties of the samples do not change significantly. This indicates that the modification conditions used in this study effectively introduced OFGs while avoiding the adverse effects on physical adsorption ability of AC caused by oxidation treatment. The Pb2+ adsorption capacities of the AC modified with 10 M HNO3 and 30 wt.% H2O2 were 4.26 and 3.64 times that of the pristine AC, respectively. The experimental data can be well fitted using the Langmuir isotherm model and the Elovich kinetic model, suggesting that the adsorption of Pb2+ on AC belongs to single-layer adsorption, and chemical adsorption dominates the adsorption process. In summary, the hydrothermal-assisted HNO3/H2O2-modified coconut shell-based AC shows great potential in efficiently removing Pb2+ from solutions, offering a solution for utilizing coconut shell waste. [ABSTRACT FROM AUTHOR]

Sulfate wastewater has a wide range of sources and greatly harms water, soil, and plants. Iron-carbon microelectrolysis (IC-ME) is a potentially sustainable strategy to improve the treatment of sulfate (SO42−) wastewater by sulfate-reducing bacteria (SRB). In this study, an iron-carbon mixed micro-electrolysis bioreactor (R1), iron-carbon layered bioreactor (R2), activated carbon bioreactor (R3), and scrap iron filing bioreactor (R4) were constructed by up-flow column experimental device. The performance and mechanism of removing high-concentration sulfate wastewater under different sulfate concentrations, hydraulic retention times (HRT), and chemical oxygen demand (COD)/SO42− were discussed. The results show that the iron-carbon microelectrolysis-enhanced SRB technology can remove high-concentration sulfate wastewater, and the system can still operate normally at low pH. In the high hydraulic loading stage (HRT = 12 h, COD/SO42− = 1.4), the SO42− removal rate of the R1 reactor reached 98.08%, and the ORP value was stable between − 350 and − 450 mV, providing a good ORP environment for SRB. When HRT = 12 h and influent COD/SO42− = 1.4, the R1 reactor sulfate removal rate reached 96.7%. When the influent COD/SO42− = 0.7, the sulfate removal rate was 52.9%, higher than the control group. Biological community analysis showed that the abundance of SRB in the R1 reactor was higher than that in the other three groups, indicating that the IC-ME bioreactor could promote the enrichment of SRB and improve its population competitive advantage. It can be seen that the synergistic effect between IC-ME and biology plays a vital role in the treatment of high-concentration sulfate wastewater and improves the biodegradability of sulfate. It is a promising process for treating high-concentration sulfate wastewater. [ABSTRACT FROM AUTHOR]

As young workers prefer urban labors and migrate to USA and Canada, mango harvesting is becoming scarce on Mexican coasts. This seasonal labor is becoming expensive and when many orchards produce fruit simultaneously, grower losses increase. In this research, an innovative fruit detachment method was tested after applying a viscous paste to the pedicel of mango fruits hanging in the tree. Activated carbon or charcoal (AC), was mixed with different amounts of nitric acid to provide three AC composite blends named: light, medium, and dense. The nanomaterial was applied with a brush to the fruit pedicel/peduncle taking up to 4 h before the mango fruits felt to a net below the tree canopy. Mango detachment experiments indicated that the medium blend was the most efficient in releasing the fruit, taking an average of 2 h. The dense nano-material decreased latex exudation to 7% of the fruits. Fruit maturity emerged as a crucial factor for detachment time, followed by mango weight. [ABSTRACT FROM AUTHOR]

Although hybrid metal ion capacitors (MICs) are highly desired to achieve both high power density of supercapacitors and high energy density of rechargeable batteries, the mismatch problem of electrochemical kinetics of negative and positive electrodes in MICs hampers the realization of this goal. Here, a new hybrid capacitor concept-potassium metal capacitor (PMC) is proposed for the first time, where potassium metal and commercial activated carbon (AC) without any modification are applied as negative and positive electrodes, respectively, and the electrolyte is the same as that of non-aqueous potassium ion batteries. The simplest PMC prototype exhibits a good combination of high energy density (184.9 Wh kg−1) and power density (12.4 kW kg−1), which benefits from the synergistic effect of potassium metal and AC electrode. The former experiences fast potassium plating/striping during charging and discharging, and the later possesses complex multiple charge behaviors driven by low potential of potassium metal. Specifically, below open-circuit voltage, transportation of solvated cations in AC pores plays an important role; beyond this voltage, synergy actions of cations and anions, including adsorption/desorption of solvated cations and anions, and ions exchange between them, dominate the capacitance contribution. This work enriches the types of MICs, and deepens the understanding of the energy storage mechanism of non-aqueous hybrid metal capacitors. [ABSTRACT FROM AUTHOR]

Petroleum refinery effluents contain hazardous aromatic and polyaromatic hydrocarbons that causes environmental degradation, that is, water, land, and air pollution; therefore, it should be properly treated before its discharge into environment. Adsorption serves an efficient route to treatment of refinery wastewater; but the high production cost and selectivity of the modern adsorbent used limits their industrial scale application. On the other hand, activated carbon due to desirable adsorption characteristics and low cost seems to hold the promise if properly modified to improve its efficiency. In this study, Cu and Zn impregnated on activated carbon (AC) derived from waste tires was used for adsorption of hydrocarbon pollutants from wastewater. AC was prepared from scrap tires through thermal pyrolysis, followed by chemical activation with KOH. Cu and Zn were loaded on AC through wet impregnation method. Initial batch mode adsorption experiments were carried out using aniline and phenol as model hydrocarbons, which indicated that maximum adsorption of aniline and phenol over Zn/AC and Cu/AC occurs in 10 min contact time, temperature 30°C, pH 6, 100 ppm initial concentration, and adsorbent dose of 0.1 g/10 mL. The removal of hydrocarbon pollutants from real refinery wastewater was also investigated under optimized conditions. Results show that the COD of the refinery wastewater decreased from 963 to 73 mg/L in case of Cu/AC (92% removal) and 78 mg/L in case of Zn/AC (91% removal), respectively. The adsorbent showed many folds reusability, and in first cycle, the removal efficiency of phenol and aniline was observed to be above 95%, whereas in second, third and fourth cycles, the removal percentage was 85%, 80%, and 70%, respectively. [ABSTRACT FROM AUTHOR]

The exploitation and utilization of Traditional Chinese medicine have annually produced 30 million tons of waste residues including Radix Angelica Dahurica residue (RAR), which raised environmental concerns. Meantime, the non‐steroidal anti‐inflammatory drug of ibuprofen (IBP) is an emerging contaminant in the aquatic environment, annually producing up to 9000 tons in China. After extracting the active substance, RAR is prepared as activated carbon (AC) for the purification of IBP wastewater. Two kinds AC modified without (RAR‐AC) and with phosphoric acid (M‐RAR‐AC) were characterized by FT‐IR, TG, BET and SEM. The phosphoric acid activation contributed to the high BET surface area (564.9914 m2 g−1) and large total pore volume (0.4894 cm3 g−1). M‐RAR‐AC showed 7.7 folds (15 min) and 2.7 folds (30 min) higher extent of IBP removal compared to commercial activated carbon (C‐AC). The enhancement of IBP removal with M‐RAR‐AC was investigated further by varying initial pollutant concentration, absorbent dosage, temperature, pH and rotating speed. Especially, temperature nearly has no effect on IBP removal by M‐RAR‐AC. Isotherm and kinetic studies suggested IBP was adsorbed on the heterogeneous surface in multilayer form and chemisorption played the dominant role in IBP removal. IBP removal of 93.3 ± 0.1% and 64.2 ± 2.8% was achieved for first and fifth cycle, respectively. The IBP removal on M‐RAR‐AC may be accomplished by a variety of interactions such as electrostatic attraction, pore‐filling, hydrogen bonding, and π‐π interaction. These findings provide new insights into the utilization of RAR for preparing AC and highlight the potential applications for treating industrial wastewater. [ABSTRACT FROM AUTHOR]

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In this article, buckthorn twigs were used to prepare activated carbon preparation by chemical activation with a microwave technique for removing diesel oil from water. buckthorn twigs and activated carbon were characterized by field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX), and Fourier transform infrared (FTIR) analysis techniques. Design-Expert (13 Stat-Ease) with response surface methodology (RSM) was selected to identify and analyze the effects of activated carbon preparation factors. These factors include impregnation ratio, impregnation time, and microwave power with exposure time on the adsorption of methylene blue dye. Likewise, the effects of adsorption factors including; diesel oil concentration, pH, adsorption time, and adsorbent dosage on the removal efficiency were studied. The results showed that the maximum removal efficiency was 96.0823% with the significance of all adsorption factors. The adsorption data were fitted with the adsorption isotherm and kinetics models. The results showed that Freundlich and second-order kinetic models well described diesel oil adsorption, thus elucidating the applicability of multilayer and chemosorption processes. In addition, the thermodynamics parameters of diesel oil adsorption were determined, and the results demonstrated a spontaneous and endothermic adsorption process. [ABSTRACT FROM AUTHOR]

Tetracycline is the second most widely used antibiotic, and its presence in wastewater is increasing with the increasing use of TC, which is of global concern. For the removal of TC from wastewater, magnetic activated carbon (MAC) was produced from activated carbon obtained using potassium-rich wine stones in previous studies. In this study, MAC synthesis was carried out in order to obtain a cost-effective, environmentally friendly, and high-quality adsorbent for TC adsorption using the activated carbon (AC) obtained in the previous study. In the production process of MAC, chemical precipitation and hydrothermal methods were used together. To produce MAC, FeCl2.4H2O and FeCl3.6H2O solutions were mixed with AC in a 1/2 w/w ratio. Tetracycline (TC) adsorption of both MAC and AC investigated the physicochemical properties with the help of analyses such as BET, SEM, EDX, FTIR, VSM, and pH at point eo charge (pHZPC). Pseudo-first-order model and pseudo-second-order model kinetic models and Langmui, Freundlich, Temkin, and Dubinin–Radushkevich kinetic isotherms were investigated for TC adsorption of MAC and AC. With an R2 value of 0.9895, it was concluded that the Langmuir isotherm is the most suitable adsorption, which indicates that the adsorption is monolayer; 3 desorption studies were performed for both TC and MAC. It was observed that MAC had better desorption capacity in the results obtained. According to the results obtained, MAC was tested to show higher TC adsorption, although it has a lower surface area than AC, which is 1086.45 m2/g and 1814.16 m2/g, respectively. However, the average pore diameter of MAC was 4.009 nm, while that of AC was 2.2483 nm. The reason for this is thought to be that magnetite clogs the pores on the surface of the AC, reducing the surface area but increasing the active sites, resulting in better adsorption. These results indicate that the obtained MAC is an environmentally friendly and cost-effective magnetic adsorbent for TC removal. [ABSTRACT FROM AUTHOR]

In this study, adsorption, a promising technique due to its simplicity and high efficiency, was used to remove tetracycline and ciprofloxacin from water. One-step activated carbon production from lignocellulosic waste uses an environmentally friendly, effective, economical, and sustainable adsorbent. The study aimed to remove TC and CP from an aqueous solution. The effect of parameters such as pH (3–11), biosorbent dose (0.25–5 g/L), initial antibiotic concentration (10–150 mg/L), and contact time (5–240 min) on adsorption was investigated. It was observed that the adsorption process was relatively fast, and equilibrium was reached within 120 and 90 min for tetracycline and ciprofloxacin, respectively. Furthermore, it showed the best correlation with the Langmuir isotherm model. The theoretical capacities of crude activated carbon waste to adsorb tetracycline and ciprofloxacin were determined as 29.16 and 46.37 mg/g, respectively. The experimental results obtained in this study indicate that this agricultural waste can be used as an environmentally friendly and cost-effective adsorbent to remove some classes of antibiotics from aqueous solutions, thus contributing to the solution of the problem of the uncontrolled presence of these drugs in wastewater. [ABSTRACT FROM AUTHOR]

In this work, comparative studies on the activated carbons (ACs), derived from of Sabal palmetto and Pterospermum acerifolium trees, are presented for electric double-layer capacitor (EDLC) application. The objective of this work is to obtain ACs from a novel biomass using a cost-effective synthesis approach. In this work, we have used Sabal palmetto and Pterospermum acerifolium leaves (dead leaves) as precursors for ACs for the first time. Both dead leaves and fresh precursors are available in huge amounts. In order to reduce the production cost, no specific gaseous environment is used during any synthesis step. The obtained ACs are found to show respectably high surface area and porosity. The respective ACs were synthesized in a cost-effective way via carbonization of the leaves followed by chemical activation with ZnCl2 and thermal activation at ambient conditions. The structural and morphological studies were done using X-ray diffraction (XRD), scanning electron microscope (SEM), and Brunauer–Emmett–Teller (BET) techniques. The electrochemical performance of the ACs, as electrodes in EDLC, was studied by using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS). The Sabal palmetto (SP) and Pterospermum acerifolium (PA) based nanostructured ACs display high specific surface area of 971 m2 g−1 and 1151 m2 g−1 and crystallite size of ~ 47.45 nm and ~ 67.83 nm respectively. The Sabal palmetto–derived AC possesses higher value of mesopore/micropore volume ratio (Vmeso/Vmicro) as ~ 0.89 than that of derived from Pterospermum acerifolium (Vmeso/Vmicro ~ 0.64). The EDLC fabricated using Sabal palmetto–derived AC delivers specific capacitance of 90.98 F g−1, which is about twice of Pterospermum acerifolium–derived activated carbon. The EDLC utilizing the Sabal palmetto–derived AC demonstrates superior capacity retention of 98.7% after 10,000 charge–discharge cycles. [ABSTRACT FROM AUTHOR]

BACKGROUND: Utilizing biowaste‐derived carbon (C) materials to remediate antibiotic‐rich wastewater has considerable ecological significance in the broader ecological cycle. In this study, coconut shell activated carbon (AC) was modified using a potassium hydroxide (KOH) hydrothermal method, and the influence of modified coconut shell AC on the adsorption of amoxicillin at different particle sizes and treatment temperatures was investigated. In addition, the adsorption kinetics of amoxicillin on different modified coconut shell AC was studied. RESULTS: The study found that unmodified coconut shell AC itself had a certain adsorption capacity for amoxicillin, with a maximum adsorption capacity of 22.43 mg g−1. After hydrothermal‐alkali modification, the adsorption capacity of coconut shell AC for amoxicillin was greatly improved, with an adsorption capacity increase of 221%. In addition, the adsorption kinetic fitting results showed that the adsorption process of amoxicillin on coconut shell AC was more consistent with the pseudo‐second‐order kinetic model. CONCLUSION: The optimal modification condition for coconut shell AC was to treat coconut shell AC with a particle size of 80–120‐mesh at 160 °C. The findings of this study could offer a green and environmentally sustainable approach for amoxicillin‐contaminated wastewater treatment, and also could provide a certain theoretical basis for the application of biowaste resources in organic wastewater treatment. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

BACKGROUND: The precise detection of nitrogen dioxide (NO2) requires the conversion of NO2 to nitric oxide (NO) using a molybdenum conversion furnace. Currently, molybdenum wire is utilized as the conversion agent for the molybdenum furnace; however, the high operating temperature of the molybdenum wire can inadvertently convert ammonia (NH3) in industrial exhaust gas to NO, potentially impacting the accuracy of the detection process. Consequently, there is a pressing need to develop low‐temperature conversion agents. The study aims to establish a correlation between the iodine value, which characterizes the liquid‐phase adsorption properties of activated carbon (AC), and its capacity for NO2 conversion, with the potential to provide valuable theoretical insights supporting the development of commercial molybdenum furnace conversion agents. RESULTS: The iodine value of coconut shell carbon (C) is closely related to their reaction performance for NO2‐to‐NO among three samples with different iodine values. AC‐900, AC‐1200 and AC‐1500 exhibited notable NO2‐to‐NO conversion capabilities. Specifically, AC‐900 demonstrated significantly superior reaction performance compared to AC‐1200 and AC‐1500. Under conditions of 175 °C and 1 L min−1, the NO2 conversion rates for AC‐900, AC‐1200 and AC‐1500 were measured at 97.3%, 88.2% and 86.4%, respectively. Furthermore, the evaluation of AC‐1200 and AC‐1500 at different flow rates at 125 °C revealed a decrease in NO2 conversion with increasing gas flow rate. AC‐1200 exhibited better reaction performance compared to AC‐1500. CONCLUSION: The structure–activity relationship between iodine value of coconut shell C and their NO2‐to‐NO performance is revealed. The capacity of AC to convert NO2 is significantly influenced by the presence of oxygen (O) functional groups and the proportion of micropores. The content of micropores and O‐containing functional groups, especially phenolic hydroxyl groups, decreases with the increase of iodine value, leading to a decrease in the reaction performance of the conversion agent. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

BACKGROUND: In order to investigate the correlation between the pore size distribution of biomass activated carbon adsorbents (BACAs) and VOCs (volatile organic compounds) adsorption/desorption performance. Four BACAs with same specific surface area but different pore size distribution were prepared under different experimental conditions and processes. RESULTS: The impact of the pore size distribution of BACAs on the adsorption/desorption performance of benzene, toluene and xylene was investigated. The results indicated that the adsorption ability of the prepared BACAs for benzene, toluene and xylene was mostly affected by the pore sizes distributed in the 2.60 ~ 3.25, 2.68 ~ 3.35and 4.20 ~ 4.90 nm ranges, respectively, when the studied BACAs had similar specific surface area (SBET ≈ 1080 m2 g−1). However, the desorption amount of adsorbed benzene molecules mainly relied on the pore structures of BACAs having pore sizes in the 3.95 ~ 4.60 nm range. CONCLUSION: The pore structures of BACAs distributed in different pore size ranges have various effects on the phenyl VOCs adsorption capacity. Benzene adsorption on the BACAs was mainly affected by the microporous structures. The pore structure with larger pore size was more favorable for the desorption of the adsorbed toluene and xylene molecules compared to the adsorbed benzene molecules. Benzene, toluene and xylene had low residual rates in the studied activated carbon adsorbents attesting to their superior regenerative properties. This work could provide an important reference for the design, preparation, and selection of activated carbon adsorbents for the adsorption capacity of benzene, toluene and xylene. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

This study utilized palm kernel shells (PKS), a type of biomass, to synthesize chemically modified activated carbon in order to enhance its efficacy in adsorbing carbon dioxide (CO2). To enhance the adsorption efficiency, the activated carbon derived from PKS has undergone chemical activation with potassium hydroxide (KOH) and impregnated with magnesium oxide (MgO). The physicochemical characterization, CO2 adsorption performance, isotherm and thermodynamics properties were evaluated. The characterization analysis shows that PKS-MgO exhibited a surface area of 418 m2 g−1 and a well-formed mesopores structure with pore diameter and volume of 2.8 nm and 0.294 cm3 g−1, respectively. The FTIR analysis shows the presence of hydroxyl group (–OH), amino group (–NH2), carbonyl group (C=O), metal–oxygen bond (Mg–O). The result revealed that PKS-MgO has the highest CO2 adsorption capacity of 104.74 mg g−1 at lowest temperature of 25 °C and 5 bar. Subsequently, the adsorption capacity has been determined as 74.37 mg g−1 at 50 °C and 51.93 mg g−1 at 75 °C, respectively. Langmuir model fitted the data the best at 25 °C (R2 = 0.978). On the other hand, he Temkin isotherm showed the best accuracy at 50 °C (R2 = 0.986) and 75 °C (R2 = 0.989). The isotherm study suggests that adsorption primarily occurs by homogeneous monolayer adsorption. In summary, the findings suggest that chemically modified palm kernel shells show potential for CO2 adsorption. This approach also aligns with circular economy principles, emphasizing the sustainable utilization of biomass resources and provide solutions for environmental concerns. [ABSTRACT FROM AUTHOR]

Overuse of antibiotics causes environmental pollution, and activated carbon adsorption is an effective way to remove antibiotics from polluted water. Herein, a cost-effective biomass carbon adsorbent for the adsorption of chloramphenicol (CHL) was prepared from pomelo peel using KHCO3 activator. The activated carbon boasted a significant specific surface area (SBET) of 1608 m2 g−1 with a maximum adsorption capacity (Qmax) for CHL reaching 549.5 mg g−1. The effect of adsorption behavior on adsorption capacity was studied. The adsorption process followed the pseudo-second-order kinetic and Langmuir models. From combined FT-IR and XPS data, the adsorption action included both physical adsorption and chemical adsorption. The rate-limiting step was diffusion through the boundary layer. The adsorption mechanism mainly included the processes of pore filling, functional group binding, and hydrogen bond and π–π interactions. Thermodynamic parameters demonstrated spontaneous and exothermic properties. This work demonstrated the rational application of waste biomass carbon for efficient adsorption of antibiotics to provide new help for antibiotic removal from polluted water. [ABSTRACT FROM AUTHOR]

In this study, activated carbon cloth (ACC) derived from cypress fruit was employed to investigate the adsorption of Pb2+, Cd2+, and Co2+ from synthetic aqueous systems. The correlation between adsorption features (pH, adsorbent dosage, temperature, initial ion concentration, and contact time) and adsorbent removal efficiency was investigated. Analysis by FT-IR, SEM, and EDS was employed to confirm the adsorption of metal ions onto the ACC. Results revealed the best adsorption efficiencies for heavy metal ions were attained at pH = 7, 11, 6; the adsorbent dosage of 0.06, 0.08, and 0.04 g for Pb2+, Cd2+, and Co2+, respectively; the ion initial concentration of 50 mg·L−1 for Pb2+ and 70 mg·L−1 for both Co2+ and Cd2+; and contact time of 90 minutes for both Pb2+ and Co2+ and 120 minutes for Cd2+. Kinetic studies exposed the second-order adsorption of all aforementioned heavy metal ions. Additionally, the equilibrium data were fitted by Langmuir and Freundlich's isotherms, while the former performed better than the latter. The maximum adsorption capacity values for Pb2+, Co2+, and Cd2+ were attained to 81.87, 55.30, and 117.3 mg·g−1, respectively. Considering the thermodynamic data, the studied processes were exothermic and spontaneous. [ABSTRACT FROM AUTHOR]

Porous carbons have been extensively studied in electrochemical capacitors (ECs). However, low capacitance remains a limitation due to the electrical double layer (EDL) storage mechanism when porous carbons are used in ionic liquids (ILs) based ECs. Herein, the nitrogen‐derived vacancy defects in porous carbon nanospheres are found which can boost capacitive charge storage and present reversible high capacitance of 427 F g−1 in pure IL electrolyte, equal to a normalized area capacitance (CA) of 16 µF cm−2, surpassing the theoretical EDL CA (≈11 µF cm−2). When used as capacitive cathode, the assembled Lithium hybrid capacitor express high energy density of 635 Wh kg−1 based on active material under much high‐power density of 14.5 kW kg−1. A combination of control experiments and density functional theory investigation indicate that the EC's performance improvement mostly stems from strong interactions at vacancy defects, triggering extraordinary faradaic capacitance. The results shed light on defect engineering for realizing extra faradaic capacitance of carbon materials, and open up new opportunities for improving EC's energy density. [ABSTRACT FROM AUTHOR]

According to green analytical chemistry principles, the use of agricultural byproducts as sorbent phases is an interesting topic due to their lignocellulosic origin, as they are biodegradable and inexpensive. To the best of our knowledge, this is the first study in which avocado seed and avocado seed activated carbon are proposed as sustainable sorbents for solid-phase microextraction technologies, which were used to assess the proof of concept. Rotating disk sorptive extraction (RDSE) was used as a model technology and ibuprofen (Ibu) and 1-hydroxy-ibuprofen (1-OH-Ibu) as representative analytes. It was found that activated carbon (AC) prepared at 600 °C with an impregnation ratio (raw material/activating agent (ZnCl2), w/w) of 1:1.2 had better extraction efficiency than other ACs obtained at different temperatures, impregnation ratios, and activating agents (K2CO3). Characterization revealed several differences between natural avocado seed, biochar prepared at 600 °C, and selected AC since the typical functional groups of the natural starting material begin to disappear with pyrolysis and increasing the surface area and pore volume, suggesting that the main interactions between analytes and the sorbent material are pore filling and π-π stacking. By using this AC as the sorbent phase, the optimal extraction conditions in RDSE were as follows: the use of 50 mg of sorbent in the disk, 30 mL of sample volume, pH 4, 90 min of extraction time at a rotation velocity of the disk of 2000 rpm, and methanol as the elution solvent. The extracts were analyzed via gas chromatography coupled to mass spectrometry (GC–MS). The method provided limits of detection of 0.23 and 0.07 µg L−1 and recoveries of 81% and 91% for Ibu and 1-OH-Ibu, respectively. When comparing the extraction efficiency of the selected activated carbon with those provided by Oasis® HLB and C18 in RDSE, nonsignificant differences were observed, indicating that avocado seed activated carbon is a suitable alternative to these commercial materials. [ABSTRACT FROM AUTHOR]

Hydrothermal carbonization is one of the effective methods of converting wet lignocellulosic biomass into carbon-rich hydrochar. Due to its characteristic application on CO2 capture and storage, many researchers have studied the CO2 uptake on activated hydrochar. The present work studies the CO2 uptake from banana-peel-derived activated hydrochar which is not presented in the literature. Hydrochar is obtained at three different temperatures (180, 200, and 220 °C) and activated using KOH. Characterization studies including SEM, XRD and FTIR were performed to examine the structure and chemistry of the derived activated hydrochar. The hydrochar sample (BP-180) when activated with a KOH/hydrochar ratio of 3 and an activation temperature of 700 °C has a well-developed microstructure with a surface area and pore volume of 243.4 m2/g and 0.0931 cm3/g, respectively. Samples obtained at higher process temperatures (BP-200 and BP-220) showed much lower porosity. Similarly, the maximum CO2 adsorption is recorded for BP-180 (3.8 mmol/g), followed by BP-200 and BP-220 with maximum adsorption capacities of 3.71 and 3.18 mmol/g, respectively, at 1 bar and 25 °C. [ABSTRACT FROM AUTHOR]

Transition metal sulfides have attracted much attention due to their excellent electrochemical properties. However, their preparation process often requires multiple steps to be completed, which poses difficulties for their application. In this paper, a NiCo2S4(NCS)@NiCo-LDH material was successfully prepared as the cathode material for the prepared supercapacitor by a one-step hydrothermal method using a MOF as a sacrificial template. The electrode material exhibits good electrochemical performance due to the regular microstructure with abundant active sites. The electrode material exhibits a specific capacitance as high as 4191.25 mF cm−2 in the three-electrode system at a current density of 2 mA cm−2. This is much higher than the sum of the capacitances of the NiCo2S4 and NiCo-LDH materials. To further validate its practical application, it was assembled with an activated carbon negative electrode to prepare a high-performance supercapacitor with a scalable voltage window of up to 1.6 V. The device was able to maintain 90% capacity retention after 5000 cycles and showed excellent performance. This work provides a new way to design and fabricate electrode materials with high performance and lifetime. [ABSTRACT FROM AUTHOR]

Supercapacitors often deliver a significantly high-power density with a long cycling life but low energy density. An exceedingly promising approach is to construct asymmetric supercapacitors (ASCs) reconciling the compromise between power density and energy density. However, ASCs combining transition metal oxides (TMOs) and activated carbon (AC) struggle to improve energy density due to a vast difference in their specific capacitance. To cross this hurdle, we first proposed a new strategy to construct the ASCs with α-MoO3 as the anode and conductive polymer polypyrrole (PPy) as the cathode. The remarkable features of α-MoO3, including its layered structure and ultra-high specific capacitance, along with the stability and fast charge–discharge ability of PPy, have contributed significantly to the augmentation of power density and energy density in ASCs. Taking advantage of these bright features, the operation voltage for α-MoO3//PPy is effectively expanded to 2.0 V, exhibiting a high energy density of 25.9 W h kg−1 at 1538 W kg−1. Furthermore, the energy density presented a remarkable recovery rate, reaching 91.04% of its initial state after undergoing full rate tests. These conclusions reveal that the construction of α-MoO3//PPy can effectively enhance the energy density and power density of supercapacitors. [ABSTRACT FROM AUTHOR]

This study aims to develop a mesoporous forsterite spheres-based scaffold for bone tissue regeneration. To achieve this goal, mesoporous forsterite spheres were fabricated using alginate (gel-forming agent) and activated charcoal (porogen). The impact of carbon concentration (2, 5, 10, and 20 wt %) and sintering temperature (1100 and 1200 °C) on the structural properties of mesoporous forsterite spheres was investigated. Additionally, gelatin coatings were applied to modify these spheres. Forsterite microspheres with a particle size of 2.43 ± 0.22 mm were successfully produced, exhibiting varying pore sizes based on the sintering temperature and carbon content. Notably, mesoporous forsterite spheres synthesized using 5 wt% carbon and sintered at 1200 °C displayed uniform morphology, a minor average diameter (2.4 ± 0.3 mm(, and an average pore size of 2.7 ± 0.9 μm. These optimized forsterite spheres exhibited mesoporous structures with superior surface area (2.93 m2g-1) and pore volume (0.009–0.048 cm3g-1). Furthermore, the gelatin coating, with an average thickness of 160 μm, was effectively applied to the forsterite spheres. The gelatin coating reduced the surface area (1.40 m2g-1), pore volume (0.003 cm3g-1), and average pore diameter to 9.26 nm, maintaining the mesoporous structure. Both mesoporous forsterite spheres successfully induced bone-like apatite formation in vitro during a 21-day immersion in simulated body fluid. Moreover, while both forsterite-based spheres exhibited cytocompatibility with MG63 cells (cell viability >80 %), the gelatin coating significantly enhanced osteogenic differentiation (1.29 times). In conclusion, gelatin-coated mesoporous forsterite spheres exhibit promising potential as bioactive filling scaffolds for bone tissue regeneration. [ABSTRACT FROM AUTHOR]

While carbon in itself appears as simple an element as it could possibly get, the undeniable truth is that carbon materials represent a plethora of possibilities both from the perspective of their structure and their applications. While we may believe that carbon is "just another element", one should never forget that its special ability to coordinate through different hybridizations with apparent ease grants the element properties that no other element may even match. Taking this one step further into the materials realm opens up numerous avenues in terms of materials dimensionality, surface and bulk functionalization, or degree of structural order just to mention a few examples. If these properties are translated into the properties and applications field, the results are just as impressive, with new applications and variants appearing with growingly larger frequency. This has resulted in over a million scientific papers published in the last decade in which the term "carbon" was used either in the title, abstract or keywords. When the search is narrowed down to the field "title" alone, the results drop to just over 318.000 scientific papers. These are figures that no other element in the periodic table can equal, which is a clear indicative that the story of carbon materials is still under constant evolution and development. This review will present an overview of the works published in the Frontiers in Carbon-based materials section during its 10 years of life that reflect the advancements achieved during the last decade in the field of carbon materials. [ABSTRACT FROM AUTHOR]

The substantial amount of mercury emissions from coal-fired flue gas causes severe environmental contamination. With the Minamata Convention now officially in force, it is critical to strengthen mercury pollution control. Existing activated carbon injection technologies suffer from poor desulfurization performance and risk secondary-release risks. Therefore, considering the potential industrial application of adsorbents, we selected cost-effective and readily available activated coke (AC) as the carrier in this study. Four metal selenides—copper, iron, manganese, and tin—were loaded onto the AC to overcome the application problems of existing technologies. After 120 min of adsorption, the CuSe/AC exhibited the highest efficiency in removing Hg0, surpassing 80% according to the experimental findings. In addition, the optimal adsorption temperature window was 30–120 °C, the maximum adsorption rate was 2.9 × 10−2 mg·g−1·h−1, and the effectiveness of CuSe/AC in capturing Hg0 only dropped by 5.2% in the sulfur-containing atmosphere. The physicochemical characterization results indicated that the AC surface had a uniform loading of CuSe with a nanosheet structure resembling polygon and that the Cu-to-Se atomic ratio was close to 1:1. Finally, two possible Hg0 reaction pathways on CuSe/AC were proposed. Moreover, it was elucidated that the highly selective binding of Hg0 with ligand-unsaturated Se− was the key factor in achieving high adsorption efficiency and sulfur resistance in the selenium-functionalized AC adsorbent. This finding offers substantial theoretical support for the industrial application of this adsorbent. [ABSTRACT FROM AUTHOR]

A nitrogen-phosphorus dual-doped porous spore carbon (NP-PSC) positive electrode matrix was prepared using native auricularia auricula as solid medium based on the principle of biomass rot. Yeast was introduce and cultured by the auricularia auricula solid medium. The freeze-drying and carbonization activation processes made the materials present a three-dimensional porous spore carbon aerogel properties. Yeast fermentation transformed auricularia auricula from blocky structure to porous structure and introduced nitrogen-phosphorus dual-doping. The physical and chemical properties of the prepared materials were characterized in detail. Electrochemical performance of NP-PSC in Li-S batteries was systematically investigated. Porous structure and heteroatom-doping improved the electrochemical performance, which is much superior to conventional activated carbon materials. [ABSTRACT FROM AUTHOR]

As an important branch of hydrogen storage materials, adsorptive materials have unique advantages such as high reversibility, fast adsorption rate and mild release conditions, etc. At present, the research on adsorptive hydrogen storage materials mostly focus on the pressure conditions of 30–300 bar, while the atmospheric hydrogen storage performance of adsorptive materials needs to be further enhanced. Based on the sonication-assisted activation process, micro-nano scale synchronous "carving" of viscose fiber was achieved in activation process for viscose fiber after carbonization, and petaloid activated carbon fibers (FL-VACFs) and rod-shaped activated carbon fibers (RL-VACFs) were constructed. Specific surface area of FL-VACFs and RL-VACFs can reach 1085.77 m2 g−1 and 956.81 m2 g−1 respectively, and the ultramicropore relative contents can reach 44% and 52.08% respectively. Under the synergistic action of abundant ultramicropores and oxygen-containing functional groups, FL-VACFs and RL-VACFs exhibit excellent hydrogen storage density of 2.04 wt% at77 K, 1 bar. Additionally, Multisite-Langmuir model (N = 3) model is discovered more suitable for accurate describing the hydrogen adsorption process of FL-VACFs and RL-VACFs under atmospheric pressure. [Display omitted] • Micro-nano scale synchronous "carving" of viscose fiber surface was achieved by sonication-assisted activation process. • Petaloid and rod-shaped activated carbon fibers are constructed with high specific surface area. • It exhibit excellent hydrogen storage density of 2.04 wt% under atmospheric pressure. [ABSTRACT FROM AUTHOR]

Biowaste conversion into activated carbon is a sustainable and inexpensive approach that relieves the pressure on its disposal. Here, we prepared micro-mesoporous activated carbons (ACs) from cucumber peels through carbonization at 600 °C followed by thermal activation at different temperatures. The ACs were tested as supercapacitors for the first time. The carbon activated at 800 °C (ACP-800) showed a high specific capacitance value of 300 F/g at a scan rate of 5 mV/s in the cyclic voltammetry and 331 F/g at the current density of 0.1 A/g in the galvanostatic charge–discharge analysis. At the current density of 1 A/g, the specific discharge capacitance was 286 F/g and retained 100% capacity after 2000 cycles. Their properties were analyzed by scanning electron microscopy, energy-dispersive X-ray analysis, porosity, thermal analysis, and Fourier-transform infrared spectroscopy. The specific surface area of this sample was calculated to be 2333 m2 g−1 using the Brunauer–Emmett–Teller method. The excellent performance of ACP-800 is mainly attributed to its hierarchical porosity, as the mesopores provide connectivity between the micropores and improve the capacitive performance. These electrochemical properties enable this carbon material prepared from cucumber peels to be a potential source for supercapacitor materials. [ABSTRACT FROM AUTHOR]

Hydrothermal carbonization (HTC) has recently emerged as a promising technology for converting diverse forms of waste with a high moisture content into value-added products such as biofuel, biochar, and activated carbon. With an increasing demand for sustainable and carbon-neutral energy sources, HTC has attracted considerable attention in the literature. However, a successful transition from laboratory-scale to large-scale industrial applications entails notable challenges. This review critically assesses the upscaling of hydrothermal carbonization processes, emphasizing the challenges, innovations, and environmental implications associated with this transition. The challenges inherent in upscaling HTC are comprehensively discussed, including aspects such as reactor design, process optimization, and the current treatment technology for process water. This review presents recent innovations and technological advancements that address these challenges and explores integrated solutions to enhancing hydrothermal carbonization's scalability. Additionally, this review highlights key companies that have developed and implemented HTC plants for commercial purposes. By overcoming the obstacles and achieving advancements in the upscaling of hydrothermal carbonization, this review contributes to the ongoing efforts to realize the full potential of HTC as a sustainable and scalable biomass conversion technology and proposes future directions. [ABSTRACT FROM AUTHOR]

The aim of this study was to obtain nitrogen-enriched activated carbons from orthocoking coal. The initial material was subjected to a demineralisation process. The demineralised precursor was pyrolysed at 500 °C and then activated with sodium hydroxide at 800 °C. Activated carbon adsorbents were subjected to the process of ammoxidation using a mixture of ammonia and air at two different temperature variants (300 and 350 °C). Nitrogen introduction was carried out on stages of demineralised precursor, pyrolysis product, and oxidising activator. The elemental composition, acid-base properties, and textural parameters of the obtained carbon adsorbents were determined. The activated carbons were investigated for their ability to remove nitrogen dioxide. The results demonstrated that the ammoxidation process incorporates new nitrogen-based functional groups into the activated carbon structure. Simultaneously, the ammoxidation process modified the acid-base characteristics of the surface and negatively affected the textural parameters of the resulting adsorbents. Furthermore, the study showed that all of the obtained carbon adsorbents exhibited a distinct microporous texture. Adsorption tests were carried out against NO2 and showed that the carbon adsorbents obtained were highly effective in removing this gaseous pollutant. The best sorption capacity towards NO2 was 23.5 mg/g under dry conditions and 75.0 mg/g under wet conditions. [ABSTRACT FROM AUTHOR]

Formed activated carbon (AC) is a multipurpose product with developed adsorption properties that is widely used in various areas of life. To create AC, hard coal has to go through various processes: grinding, granulation, carbonization, physical and/or chemical activation. Presented research was conducted in the professional company manufacturing activated carbons. Studied AC reached the demanded shape of grains thanks to binders added to granulation process. Research on the AC formed using new polymeric binders (applied so far in other branches: pharmacy and construction materials) is presented in this manuscript. Tested binders were not used before to manufacture ACs in the professional technological line. Such polymers as: sodium carboxymethylhydrocellulose (CMHC), poly[1-(2-oxo-1-pyrrolidinyl)ethylene] (POPE) and enriched methyl-hydroxypropyl cellulose MHPC were studied in this work. Conducted research has proven efficiency of 8% CMHC which allowed for proper granulation and carbonization and reached the best parameters. Single- and double-stage activation was investigated for AC with this binder. For newly manufactured AC BET surface and pore volume increased accordingly from 774 m2/g and 0.58 cm3/g (1-stage) to 968 m2/g and 0.72 cm3/g (2-stage). Chemical elemental features of surface of the best AC showed beside elementary carbon also calcium, silicon and aluminum ions as well as groups with an acidic character, phosphates, sulphates and chlorides. The new AC had a higher Mechanical Strength reaching 99.9% and a lower Ash content and Volatile Matter than AC manufactured with previous binder—molasse. The new AC is intended to be directed for full production line and implementation to usage after positive certification. It may be useful in water treatment. It will also find application in the treatment of industrial and municipal wastewater. [ABSTRACT FROM AUTHOR]

The development of bone-filling biomaterials capable of delivering in situ bone growth promoters or therapeutic agents is a key area of research. We previously developed a biomaterial constituting biphasic calcium phosphate (BCP) microparticles embedded in an autologous blood or plasma clot, which induced bone-like tissue formation in ectopic sites and mature bone formation in orthotopic sites, in small and large animals. More recently, we showed that activated carbon (AC) fiber cloth is a biocompatible material that can be used, due to its multiscale porosity, as therapeutic drug delivery system. The present work aimed first to assess the feasibility of preparing calibrated AC microparticles, and second to investigate the properties of a BCP/AC microparticle combination embedded in a plasma clot. We show here, for the first time, after subcutaneous (SC) implantation in mice, that the addition of AC microparticles to a BCP/plasma clot does not impair bone-like tissue formation and has a beneficial effect on the vascularization of the newly formed tissue. Our results also confirm, in this SC model, the ability of AC in particle form to adsorb and deliver large molecules at an implantation site. Altogether, these results demonstrate the feasibility of using this BCP/AC/plasma clot composite for bone reconstruction and drug delivery. [ABSTRACT FROM AUTHOR]

A static batch arrangement composed of anti-leak vials coupled to gas chromatography is proposed as a complementary system for performance assessment of biogas desulfurization by adsorption. For testing, a modified commercial activated carbon produced by controlled thermal treatment in the presence of iron(III) species improved biogas desulfurization. The adsorbents showed a superior hydrogen sulfide removal compared to ordinary one. Pseudo-first-order, pseudo-second-order, and Bangham's kinetic models were used to fit experimental data. All studied samples followed pseudo-first-order model, indicating the predominance of physisorption, and Bangham's model, confirming that the micropores structure played an important role for gases diffusion and adsorbent capacity. Additionally, the materials were characterized by N2 adsorption–desorption, X-ray diffraction, infrared spectroscopy, scanning electron microscopy and energy-dispersive spectroscopy. The thermal treatment associated with iron impregnation caused significant modifications in the surface of the materials, and the iron species showed two main benefits: an expressive increase in the specific area and the formation of specific adsorption sites for hydrogen sulfide removal. The results reinforce the advantages of iron-modified adsorbents in relation to their non-modified counterparts. The analytical methodology based on the confinement of multiple gases contributes to improving the understanding of the hydrogen sulfide adsorption process using pressure swing adsorption technology. [ABSTRACT FROM AUTHOR]

• Thermodynamic analysis guided experiments for favorable reactions and operating conditions. • Thermogravimetry produced crystalline SiC, Si, and Fe, and showed reactions with Ti- compounds. • Ultra-high vacuum experiments identified elements of produced volatiles at varying temperatures. The carbothermal reduction of JSC-1A lunar simulant with activated carbon was investigated for producing metals and metalloids. Chemical equilibrium compositions were examined using Gibb's free energy minimization to identify favorable operating temperatures at 0.1, 10-8, and 3 × 10-15 bar for Fe and Si production. Complete conversion of Fe 2 O 3 to Fe(g) was predicted at temperatures above 850 °C and about 90 % conversion of SiO 2 to Si(g) was predicted at temperatures above 1000 °C for lunar surface pressure of 3 × 10-15 bar. Thermogravimetry was used to examine the reactions with mixtures of JSC-1A and stoichiometric activated carbon in 100 % Ar up to 1500 °C, and comparisons between temporal mass losses and CO evolution were used to estimate volatile production. The results were compared to ultra-high vacuum experiments at ∼ 10-12 bar with temporal CO measured. Solid-state surface material characterization was performed using scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, X-ray diffractometry, and transmission electron microscopy to identify elemental distributions and particle morphology of sample surface before and after experiment as well as chemical compositions present after experiment. Changes in elemental distributions and morphologies of Si-, Fe-, and Ti- in the sample before and after the experiment provided strong evidence of reactions of Si-, Fe-, and Ti- compounds in JSC-1A. Characterization of the loose sample after TGA confirmed the presence of crystalline SiC, Si, and Fe. Deposits collected on Cu foils mounted above the sample in the ultra-high vacuum experiments were found to contain Fe-, Al-, Mg-, and Si- volatiles. [ABSTRACT FROM AUTHOR]

[Display omitted] Surface-enhanced Raman spectroscopy (SERS) is an analytical technique with a broad range of potential applications in fields such as biomedicine, electrochemistry, and hazardous chemicals. However, it is challenging to develop SERS substrates that are both good sensitive and signal stable. Here we designed a superhydrophobic Nd doped MoS 2 uniformly assembled on the activated carbon fiber cloth (CFC) to avoid the coffee ring effect and enrich the analyte, improving the enhancement factor (EF) to 3.9 × 109 and pesticide endosulfan (<10−10) analyte detection. We demonstrate our strategy by density-functional theory (DFT) calculations confirming that both adsorption energy and density of states are enhanced after doping Nd leading to SERS enhancement. Beside DFT calculations, our experiments also provide an effective means to demonstrate that the high SERS sensitivity is based on multiple charge transfer processes combined with the activated carbon cloth. Our results address the limitations of low sensitivity and limit of detection (LOD) of semiconductor SERS substrates for trace analysis and are a step towards practical applications. [ABSTRACT FROM AUTHOR]

The adsorption of ammonium from water was studied on an activated carbon obtained using raw oil palm shell and activated with acetic acid. The performance of this adsorbent was tested at different operating conditions including the solution pH, adsorbent dosage, and initial ammonium concentration. Kinetic and equilibrium studies were carried out, and their results were analyzed with different models. For the adsorption kinetics, the pseudo-first order equation was the best model to correlate this system. Calculated adsorption rate constants ranged from 0.071 to 0.074 g/mg min. The ammonium removal was 70–80% at pH 6–8, and it was significantly affected by electrostatic interaction forces. Ammonium removal (%) increased with the adsorbent dosage, and neutral pH condition favored the adsorption of this pollutant. The best ammonium adsorption conditions were identified with a response surface methodology model where the maximum removal was 91.49% with 2.27 g/L of adsorbent at pH 8.11 for an initial ammonium concentration of 36.90 mg/L. The application of a physical monolayer model developed by statistical physics theory indicated that the removal mechanism of ammonium was multi-ionic and involved physical interactions with adsorption energy of 29 kJ/mol. This activated carbon treated with acetic acid is promising to depollute aqueous solutions containing ammonium. [ABSTRACT FROM AUTHOR]

Flow electrode capacitive deionization (FCDI) is a promising technology for efficiently treating industrial brine with high salt content. However, its desalination performance is currently limited by internal resistance. Achieving an effective FCDI system relies on active electrode materials with high conductivity. This study compares the desalination performances of the widely used flow electrode activated carbon (AC) with more conductive materials, reduced graphene oxide (rGO), and ZnO/rGO composite. Additionally, the lack of particle-to-particle contact in the flow electrode contributes to internal resistance and to address this, a cationic surface-active agent is introduced. This agent forms a stable dispersion, creating a space for enhanced mass loading of the active material. This modification enhances the conductive network and particle contact, reducing the diffusion path and promoting rapid ion transport. With a 5 wt% loading, ZnO/rGO achieved a 73% salt removal efficiency, surpassing AC at 63%. Furthermore, the surfactant-modified ZnO/rGO flow electrode with a 7 wt% loading demonstrated an 81% salt removal efficiency. [ABSTRACT FROM AUTHOR]

Herein, microwave-assisted activated carbon (MW-AC) was fabricated from peanut shells using a ZnCl2 activator and utilized for the first time to eliminate benzene vapor as a volatile organic compound (VOC). During the MW-AC production process, which involved two steps—microwave treatment and muffle furnace heating—we investigated the effects of various factors and achieved the highest iodine number of 1250 mg/g. This was achieved under optimal operating conditions, which included a 100% impregnation ratio, CO2 as the gas in the microwave environment, a microwave power set at 500 W, a microwave duration of 10 min, an activation temperature of 500 °C and an activation time of 45 min. The structural and morphological properties of the optimized MW-AC were assessed through SEM, FTIR, and BET analysis. The dynamic adsorption process of benzene on the optimized MW-AC adsorbent, which has a significant BET surface area of 1204.90 m2/g, was designed using the Box-Behnken approach within the response surface methodology. Under optimal experimental conditions, including a contact duration of 80 min, an inlet concentration of 18 ppm, and a temperature of 26 °C, the maximum adsorption capacity reached was 568.34 mg/g. The experimental data are better described by the pseudo-second-order kinetic model, while it is concluded that the equilibrium data are better described by the Langmuir isotherm model. MW-AC exhibited a reuse efficiency of 86.54% for benzene vapor after five consecutive recycling processes. The motivation of the study highlights the high adsorption capacity and superior reuse efficiency of MW-AC adsorbent with high BET surface area against benzene pollutant. According to our results, the developed MW-AC presents itself as a promising adsorbent candidate for the treatment of VOCs in various industrial applications. [ABSTRACT FROM AUTHOR]

Orange peels (OPs) were valorized in a lab-scale biorefinery loop for the recovery of limonene and the subsequent production of volatile fatty acids (VFAs) and activated carbon (AC). Solid/liquid extraction of limonene was optimized using n-hexane at 85 °C with an OPs-to-solvent ratio of 2:1, allowing for a limonene recovery yield of 1.20% w/w. Then, post-extraction OPs were used for the production of both VFAs and AC. For VFA production, a hydraulic retention time (HRT) of 5 days and a total solid (TS) inlet content of 10% w/w were adopted leading to a VFA yield of about 43% gVFAs/gTS. Adsorption tests revealed that, among all the solid matrixes tested, only powdered activated carbon (PAC) was able to discriminate no-VFA compounds and allowed for VFA purification. For AC production, post-extraction OPs were firstly converted into biochar through slow pyrolysis at 550 °C for 1 h and then physically activated with CO2 at 880 °C for 1 h. Extraction did not appreciably affect OP properties, while pyrolysis increased the carbon content (from 43 to 83%) and the heating value (from 17 to 29 MJ/kg) of the material. Physical activation of OP biochar increased its surface area by almost ten times, from 40 to 326 m2/g, proving the effectiveness of the treatment. [ABSTRACT FROM AUTHOR]