Activated Carbon Adsorption Research Articles

Highly efficient adsorption of ciprofloxacin from aqueous solutions by waste cation exchange resin-based activated carbons: Performance, mechanism, and theoretical calculation

This study focused on the preparation of a highly efficient activated carbon adsorbent from waste cation exchange resins through one-step carbonization to remove ciprofloxacin (CIP) from aqueous solutions. Scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectrometry, and X-ray photoelectron spectroscopy were used to characterize the physicochemical properties of the carbonized materials. The CIP removal efficiency, influencing factors, and adsorption mechanisms of CIP on the carbonized resins were investigated. Density functional theory (DFT) computations were performed to elucidate the adsorption mechanisms. The CIP removal reached 93 % when the adsorbent dosage was 300 mg/L at 25 °C. The adsorption capacity of the carbonized resins to CIP gradually decreased with an increasing pH from 3.0 to 7.0 and sharply declined with a pH from 7.0 to 11.0. The adsorption process better fitted by the pseudo second-order kinetic and Langmuir models, indicating that the interaction between CIP and the carbonized resins was monolayer adsorption. The maximum adsorption capacity fitted by the Langmuir model was 384.4 mg/g at 25 °C. Microstructural analysis showed that the adsorption of CIP on the carbonized resins was a joint effect of H-bonding, ion exchange, and graphite-N adsorption. Computational results signified the strong H-bonding and ion exchange interactions existed between CIP and carbonized resins. The high adsorption and reusability suggest that waste cation exchange resin-based activated carbons can be used as an effective and reusable adsorbent for removing CIP from aqueous solutions.

Preparation and characterization of EI-Co/Zr@AC and the mechanisms underlying its removal for atrazine in aqueous solution.

Atrazine, a widely used herbicide in agriculture, is detrimental to both the ecological environment and human health owing to its extensive use, poor degradability, and biotoxicity. The technology commonly used to remove atrazine from water is activated carbon adsorption, but it has the problems of difficult recovery, secondary contamination, and a low removal rate. To efficiently remove atrazine from agricultural wastewater, in this study, a new environmental material, embedding immobilization (EI)-Co- and Zr-modified activated carbon powder (Co/Zr@AC), was prepared by immobilizing the bimetallic Co/Zr@AC via EI technique and employed to remove atrazine. When preparing EI-Co/Zr@AC, the single-factor experiment was conducted and determined the optimal preparation conditions: sodium alginate 2.5% (wt), calcium chloride 4.0% (wt), Co/Zr@AC 1.0% (wt), and bentonite 2.0% (wt). The prepared EI-Co/Zr@AC has a three-dimensional mesh structure and many pores and also possesses good mass transfer performance and mechanical properties. The removal efficiency by EI-Co/Zr@AC for the removal of 5.0 mg/L atrazine from 50 mL was 94.1% at pH 7.0 and 25°C, with an EI-Co/Zr@AC dosage of 0.8 g. The mechanistic study showed that the pseudo-second-order kinetic model could describe the removal process better than the pseudo-first-order kinetic model, and the Freundlich isotherm model fit better than other isotherm models. Additionally, the synthesized EI-Co/Zr@AC spheres demonstrated good reusability, with the atrazine removal rate remaining 70.4% after five cycles, and the mechanical properties of the spheres were stable.

Prediction of Methyl Orange (MO) Toxicity and Minimizing Its Pollution in Aquatic Environment by Activated Carbon Adsorption

Minimizing environmental pollution is an essential work of the official and scientific communities around the world, especially in water systems. In water, soluble dye works as a blockage in photosynthesis process because of its toxicity. One of these highly applicable dyes in industry is Methyl Orange (MO), documented with more than 10% released to water. Here, a new Iraqi try of converting environmental and health problems to solutions with high quantification was as done by using face tissue (Kleenex) as a carbon source. Primary in Silico testing of this anionic dye (Methyl Orange) was done based on online website confirmed MO dye is unsafe in several toxicological determinations such as foetus health (during pregnancy). Also, it is permeable material to skin, Blood- Brain system (BBB), and Human Colon Carcinoma cell line (CaCO2) compatible with Human Intestinal absorption (74.166%). In experimental section, low quality of face tissue (Kleenex) was subject to a high acidic medium (concentrated sulphuric acid), followed by addition of sodium carbonate to .increase activation of based carbon material with more structural pores yielding high removal efficiency and adsorption capacity ranged (88-98)% and (88-98) mg/g respectively. Qualitative and quantitative evaluations were based upon choosing two wavelengths in ultraviolet (272 nm) and visible (464 nm) regions. In this work, two removal steps were performed with the same adsorbent companied by multiple UV-Vis spectroscopic evaluation of several tested sections. Reviewing of published papers in MO removal presents the extraordinary performance of this prepared material towards using it as an excellent adsorbent of toxic material in aqueous solution.

A Study on the Influence and Mechanism of Temperature and Dosage on PCDD/Fs Adsorption via Coal-Based Activated Carbon

Using a trace polychlorinated-ρ-dibenzodioxins and dibenzofurans (PCDD/Fs) stabilizing generator, an experimental study related to the influence of temperature (150, 165, and 180 °C) and activated carbon (AC) dosage (0.10, 0.15, and 0.20 g) on the adsorption effect of gas-phase PCDD/Fs via coal-based AC was conducted. Increasing the AC dosage is the most efficient method to improve the PCDD/Fs adsorption efficiency from 65.8% (0.10 g) to 93.0% (0.20 g) at 150 °C in an exponential trend. Both the polychlorinated-ρ-dibenzodioxins (PCDD)/polychlorinated dibenzofurans (PCDF) ratio and the Cl-PCDD/Fs value showed positive correlations, with the AC dosage under the same temperature. Increasing adsorption temperature declined the adsorption capacity of AC, resulting in the exponentially decreased average I-TEQ value adsorbed per gram of AC, from 131.3 ng TEQ/Nm3 (150 °C) to 55.9 ng TEQ/Nm3 (180 °C). The coal-based AC used in this study preferred to adsorb lower chlorinated PCDD/Fs, tetrachlorianted dibenzo-p-dioxin and dibenzofurans (TCDD/Fs), and pentachlorianted dibenzo-p-dioxin and dibenzofurans (PeCDD/Fs) than highly chlorinated PCDD/Fs, heptachlorianted dibenzo-p-dioxin and dibenzofurans (HpCDD/Fs), hexachlorinated dibenzo-p-dioxin and dibenzofurans (HxCDD/Fs), and octachlorianted dibenzo-p-dioxin and dibenzofurans (OCDD/Fs), which was aggravated by the increasing temperature. The characterization of the surface properties of AC revealed that slight oxidation occurred on the AC surface during the adsorption process, introducing oxygen to the competitive adsorption. In addition, it was found in this study that an increased temperature led to a higher content of hydrophilic carboxyl and anhydride groups and weakened π-π interactions, which were also partly responsible for the negative impact of the increasing temperature on the AC adsorption capacity. The results of this study can contribute to the operation optimization for controlling PCDD/F emissions from municipal solid waste incineration (MSWI).

Preparation of food ingredients for the PKU patients: Two‐step enzymatic hydrolysis and activated carbon adsorption for the removal of phenylalanine from whey protein hydrolysates

In this study, we developed a two‐step enzymatic hydrolysis method followed by activated carbon adsorption to remove phenylalanine (Phe) from whey protein. The results showed that the free rate of Phe after sequential enzymatic hydrolysis of trypsin and flavorzyme was 90.8%. After adsorption by activated carbon No. 1, the removal efficiency of Phe from the hydrolysates reached 89.79% at 2.19 mg/g protein equivalent. Therefore, low Phe protein hydrolysates (LPHs) can be used to prepare low Phe food for phenylketonuria patients who cannot metabolise Phe properly by themselves and need to maintain a low Phe diet for life.

Isoterm Adsorpsi Arang Kulit Jengkol Sebagai Adsorben CO2

The concentration of carbon dioxide (CO2) gas in the atmosphere continues to increase every year, mainly due to human activities such as burning fossil fuels for energy, industrial processes, and transportation. The development of CO2 gas reduction research continues to be carried out, one of which is the adsorption process using adsorbents. The research was carried out by looking at the effect of variations in activating agent and activation temperature on adsorbents as CO2 adsorbers and how N2 and pore size distribution influence CO2 adsorption. The active carbon adsorbent used comes from jengkol peel which is carbonized via the pyrolysis method. Adsorbents are made by varying the type of activating material (KOH, Urea, and KOH+urea) and activation temperature (600℃, 700℃, and 800℃). The active ingredient KOH+urea has better absorption capacity than other variations, but not too high. N2 gas does not really affect the CO2 adsorption process because it has a low N2 adsorption isotherm, so it is not worrying if the CO2 adsorption process also contains N2 in the air. Based on measurements with Belsorp-Max II, the data obtained is only specific surface area data, this is due to the small surface pores of the adsorbent. The temperature of 800℃ has a better specific surface area than other variations, this is also by the higher CO2 adsorption capacity. So it is concluded that the pore surface area influences the ability to absorb CO2. Based on the data obtained, jengkol peel charcoal is not suitable as a CO2 adsorbent because it has a low pore surface area and adsorption isotherm

Powdered activated carbon adsorbent for eosin Y removal: modeling of adsorption isotherm data, thermodynamic and kinetic studies

Abstract An investigation was conducted to examine the adsorption of eosin Y (EY) from aqueous solution using Powdered Activated Charcoal (PAC) obtained from Biochem Chemopharma (Quebec, Canada) with a surface area of 270 mg/g using the methylene blue method. The adsorption experiments showed that a contact time of 60 min resulted in a high removal efficiency of 98.25 % for EY at a concentration of 10 ppm. The study also offered insights into the effectiveness of different treatment processes and described the main physicochemical processes involved. Various parameters such as adsorbent dosage, contact time, substrate concentration, and pH were evaluated, and the data were analyzed using Freundlich, Langmuir, and Temkin isotherms. The study found that the pseudo-second-order kinetic model provided a better fit to the experimental data compared to the pseudo-first-order model. To optimize the process parameters and enhance overall efficiency, contour plots were employed in the experimental design, considering variables such as adsorbent dosage, contact time, and pH levels. These plots visually represented the relationship between the variables and the removal efficiency of EY, enabling the identification of optimal operating conditions. The investigation’s findings contribute valuable insights into the adsorption of EY using PAC and offer practical implications for improving the efficiency of EY removal in various applications. The use of contour plots in experimental design was highlighted as a crucial tool for refining adsorption process parameters.

Comparison of four pre-oxidants coupled powdered activated carbon adsorption for odor compounds and algae removal: Kinetics, process optimization, and formation of disinfection byproducts

Pre-oxidation and powdered activate carbon (PAC) are usually used to remove algae and odorants in drinking waterworks. However, the influence of interaction between oxidants and PAC on the treatment performance are scarcely known. This study systematically investigated the combination schemes of four oxidants (KMnO4, NaClO, ClO2, and O3) and PAC on the inactivation of Microcystis aeruginosa cells and removal of four frequently detected odorants in raw water (diethyl disulfide (DEDS), 2,2′-oxybis(1chloropropane) (DCIP), 2-methylisoborneol (2-MIB) and geosmin (GSM)). O3 showed highest pseudo-first-order removal rate for all four compounds and NaClO exhibited highest inactivation rates for the cell viability and Chlorophyll a (Chl-a). The Freundlich model fitted well for the adsorption of DEDS and DCIP by PAC. When treated by combined oxidation/PAC, the removal ratio of algae cells and odorants were lower (at least 1.6 times) than the sum of removal ratios obtained in oxidation or PAC adsorption alone. Among these four oxidants, the highest synchronous control efficiency of odorants (52 %) and algae (66 %) was achieved by NaClO/PAC. Prolonging the dosage time interval promoted the removal rates. The pre-PAC/post-oxidation processes possessed comparable efficiency for the removal of odorants and algae cells comparing with pre-oxidation/post-PAC process, but significantly inhibited formation of disinfection byproducts (DBPs), especially for the formation of C-DBPs (for NaClO and ClO2), bromate (for O3) and chlorate/chlorite (for ClO2). This study could provide a better understanding of improving in-situ operation of the combined pre-treatments of oxidation and PAC for source water.

Bio-inspired adsorption sheets from waste material for anionic methyl orange dye removal

Nano zero-valent iron (nZVI), bimetallic nano zero-valent iron-copper (Fe0–Cu), and Raw algae (sargassum dentifolium) activated carbon-supported bimetallic nano zero-valent iron-copper (AC-Fe0–Cu) are synthesized and characterized using FT-IR, XRD, and SEM. The maximum removal capacity is demonstrated by bimetallic activated carbon AC-Fe0–Cu, which is estimated at 946.5 mg/g capacity at the condition pH = 7, 30 min contact time under shaking at 120 rpm at ambient temperature, 200 ppm of M.O, and 1 g/l dose of raw algae-Fe0–Cu adsorbent. The elimination capability of the H3PO4 chemical AC-Fe0–Cu adsorbent is 991.96 mg/g under the conditions of pH = 3, 120 min contact time under shaking at 120 rpm at room temperature, 200 ppm of M.O, and 2 g/l doses of H3PO4 chemical AC-Fe0–Cu adsorbent. The Bagasse activated carbon adsorbent sheet achieves a removal capacity of 71.6 mg/g MO dye solution. Kinetic and isothermal models are used to fit the results of time and concentration experiments. The intra-particle model yields the best fit for bimetallic Fe0–Cu, AC-Fe0–Cu, H3PO4 chemical AC-Fe0–Cu and bagasse activated carbon(CH), with corrected R-Squared values of 0.9656, 0.9926, 0.964, and 0.951respectively. The isothermal results emphasize the significance of physisorption and chemisorption in concentration outcomes. Response surface methodology (RSM) and artificial neural networks (ANN) are employed to optimize the removal efficiency. RSM models the efficiency and facilitates numerical optimization, while the ANN model is optimized using the moth search algorithm (MSA) for optimal results.HighlightsThe Fe0–Cu composite, when combined with activated carbon from Bagasse Pulp (CH), exhibited the most effective decolorization effectiveness for anionic colours present in wastewater.The utilization of composites presents a promising opportunity for efficient dye removal due to its cost-effectiveness and environmentally sustainable nature. The utilization of response surface approach and artificial neural network modelling improves the efficacy of removal processes and treatment techniques.

Numerical simulation and optimization analysis of low temperature adsorption hydrogen storage

In this paper, a two-dimensional axisymmetric hydrogen storage tank model is established based on the D-A model using software to simulate the activated carbon adsorption hydrogen storage filling process numerically. The distribution of pressure inside the tank under the boundary conditions of 0.5 atm–1 atm is obtained, and the trends and rates of pressure changes inside the tank under different boundary conditions are compared. The temperature distribution inside the tank is investigated under the initial temperature of 293.15 K, the external condition of 77 K, and the convective heat transfer coefficient inside and outside the tank is 20 W/(m2·K), and the influence of adsorption materials on the temperature distribution inside the tank is compared with that of different thermal conductivity coefficients, and the general trend is that the temperature is higher and then lower, the temperature inside the tank is relatively high near the center axis, and the temperature near the tank wall is relatively low, and the addition of ribs can The addition of ribs can reduce the temperature inside the tank. This paper also calculates the adsorption amount of hydrogen at different pressures (0–7 MPa) and temperatures (80 K–260 K), and finds that the adsorption amount is the largest at 80 K and 7 MPa, with a value of 39.3 mol/kg. The novelty of this study is the coupling of many different physical fields to bring the results closer to reality and to give directions for optimization.

Regeneration of granular activated carbon adsorbent by peroxymonosulfate activation with MnO2/MnFe2O4

The regeneration of spent adsorbent is crucial in terms of environmental and economic aspects. In this study, MnO2/MnFe2O4 was synthesized by an impregnation-precipitation method and investigated as a peroxymonosulfate (PMS) catalyst for the regeneration of granular activated carbon (GAC) after adsorption of ofloxacin (OFL). MnO2/MnFe2O4 exhibited high catalytic activity for the regeneration of GAC with PMS, and the adsorbed OFL was effectively removed from GAC surface. Singlet oxygen was found to be the dominant reactive species in this process, while O2•− and SO4•− participated in the degradation of intermediates. At neural pH, the regeneration efficiency of the spent GAC after the adsorption of OFL, tetracycline hydrochloride, ciprofloxacin and methylene blue reached 100 %, 100 %, 87.2 % and 84.2 %, respectively. MnO2/MnFe2O4 and GAC exhibited good stability and reusability in this process, and the regeneration efficiency was still above 90 % in the fifth cycle. The results suggest the potential application of PMS activation with magnetic catalyst in the regeneration of GAC after adsorption of organic pollutants.

Cyclic stability evaluation of a novel CO2 absorption-microalgae conversion (CAMC) system

CO2 absorption-microalgae conversion (CAMC) system is a promising alternative to simultaneous CO2 capture and utilization. However, it is necessary to explore the stability of recycled absorption solvent for subsequent culture of CAMC system. In this work, dilution, activated carbon adsorption and H2O2/UV photocatalytic treatment were used to treat the absorption solution that had been run once in CAMC system and then the subsequent culture was performed and its performance was evaluated. It was found that these treatments could restore the performance of circulating absorption solution and H2O2/UV photocatalytic treatment showed the best effect. The biomass concentration, NADPH content and RubisCO enzyme activities increased by 18 %, 92.0 %, and 26.5 % by H2O2/UV photocatalytic treatment. H2O2/UV photocatalytic treatment enhanced carbon fixation rate, which was 7.05 % higher than untreated group. H2O2/UV photocatalytic treatment could improve the yield of lipid and protein. These results showed that H2O2/UV photocatalytic treatment could restore the performance of circulating solution to the level of primary culture and maintain the cyclic stability of CAMC system. Therefore, this study provided a certain guiding significance for the application of CAMC system.

Scalable production of wood carbon microspheres for high-efficiency carbon dioxide capture

Utilizing abundantly available biomass materials to prepare adsorbent substances is a simple and cost-effective method for CO2 adsorption, which, however, is often hampered by low adsorption capacity. Here, we demonstrate near-spherical active carbon (C-DWP/Zn) with high CO2 adsorption ability, employing delignification combination with ZnCl2 activation of natural wood powder. Removing lignin from wood cell walls facilitates easy absorption of Zn ions by the cellulose nanofibers (CNFs), thereby promoting micro/nano pores formation. Moreover, rapid dehydration of cellulose molecular chains alters the morphology of activated carbon, resulting in a transition from a granular to a near-spherical shape. Consequently, C-DWP/Zn with high specific surface area of 1769 m2 g−1, shows a significantly higher microporous volume than that of a control sample without delignification. The CO2 adsorption capacity of C-DWP/Zn, with values of 3.51 mmol g−1 and 5.12 mmol g−1 at 1 bar, 25 °C and 0 °C, respectively, is superior to that of commercial activated carbon. Attributable to its optimal micropore structure, C-DWP/Zn exhibits high CO2/N2 selectivity. Furthermore, the high carbon dioxide adsorption efficiency of C-DWP/Zn was maintained and the substance could be reused at least 20 times. Near-spherical active carbon adsorbents prepared from low-value wood powders, all featuring high CO2 adsorption performances, reasonable CO2/N2 selectivity, good recoverability, suitable heat of adsorption, and fast adsorption kinetics, which are promising candidates for practical CO2 adsorption.

Enabling in situ electro-regeneration systems for PFOA-laden spent activated carbon adsorbents reuse

Adsorption is the main commercially used water treatment technology to remove per-and polyfluoroalkyl substances (PFAS) from water. Despite the high performance of this physical separation treatment, the endpoint of this technology is the production of PFAS-laden spent activated carbon. So far, several regeneration techniques have been used for spent activated carbon. However, activated carbon regeneration techniques remain challenging due to a limited understanding of cost/benefit analysis. In the present study, we developed the first proof of concept in situ electro-regeneration technique for the regeneration of perfluorooctanoic acid (PFOA, as a model long chain PFAS compound) laden-F400 using electro-assisted up-flow rapid small-scale column test (RSSCT) setup. The laboratory column experiments were conducted exploring sequential adsorption and electro-regeneration cycles. The results showed that the electro-regeneration of saturated F400 reinstated up to ∼60% of initial capacity. After the 1st regeneration cycle, the regeneration efficiency of spent F400 remained similar following 4 consecutive adsorption/regeneration cycles. The calculated operational cost for electro-regeneration was 0.70 kWh/kg, which is more competitive than current regeneration techniques. Overall, this novel proof-of-concept approach can be used as a promising alternative regeneration technique to existing ones to minimize waste PFAS-laden adsorbents in landfills and decrease the amount of CO2 emissions associated with the incineration of these sorbents.

Research on the adsorption rule of porous media on supersaturated total dissolved gas

AbstractDischarge of high dams may result in supersaturated total dissolved gas (TDG) in water, which could cause fish that live downstream river to suffer from gas bubble disease. If supersaturated TDG water was taken as a water source for breeding and proliferation stations, farmed fish was confined and may face more severe problems than fish living in the river. Therefore, it is critical to develop strategies to reduce the negative effects of supersaturated TDG. In this research, the adsorption effect of porous media on supersaturated TDG was explored, including biofilter adsorption experiments and previously existing activated carbon adsorption experiments. The experimental results showed that adding porous media to the water effectively accelerated the dissipation of supersaturated TDG, and the adsorption effect was associated with the specific surface area, mass density, and initial TDG saturation. To quantitively evaluate the adsorption effects of the porous media, the porous adsorption coefficient was proposed to express the adsorption rate of porous media on supersaturated TDG. The porous adsorption coefficient was related to the initial TDG saturation and the specific surface area of the porous media. The porous adsorption coefficient increased with increasing the specific surface area and decreasing initial TDG saturation. Based on this, an equation related to the specific surface area, initial TDG saturation, and the porous adsorption coefficient was developed. This equation may be used to evaluate the adsorption effect of porous media on supersaturated TDG. This study could serve as a crucial resource in reducing the adverse impacts of supersaturated TDG.

Removal of aflatoxins in peanut oils by activated carbon functionalized with sodium dodecyl sulfonate

In this study, three kinds of novel modified activated carbon adsorbent were prepared by different concentrations of sodium dodecyl sulfonate solution, and carried out by FTIR, XRD, TGA, SEM, and N2-adsorption-desorption analytical techniques. The adsorption mechanism of aflatoxins on three types of modified activated carbon had been systematically investigated by isotherm, kinetic, and thermodynamic studies. The optimized adsorption conditions (amount, temperature, time) were determined by combining different types of aflatoxins (AFB1, AFB2, AFG1 and AFG2) removal efficiency in peanut oil. Notably, the modification of activated carbon using a 2-fold critical micelle concentration sodium dodecyl sulfonate solution not only remove 93.5% of AFB1 from peanut oils containing four aflatoxins (58.89 μg/kg), but also remain nearly unchanged in the phytosterol content in oils. In conclusion, the modified activated carbon with low cost and high efficiency showed a great potential for application in the adsorption of four aflatoxins from contaminated edible oils.

Synthesis, characterization and adsorption studies on activated carbon adsorbent synthesized from Kigelia africana for removal of acid blue 113 dye from synthetic solution

The need for waste water treatment, which can be accomplished via adsorbents, is growing today. Adsorbents are inexpensive, environmentally responsible, and made of biodegradable materials that can be replenished. In this work, chemical activation is used to create powdered activated carbon from Kigelia africana. The raw material was chosen because this fruit has not been the subject of any significant research on dye removal. It is also a poisonous fruit, abundantly available in nature, has high cellulose content, carbon rich and possesses less ash content thus making it a low cost activated carbon. After activation, the surface area has increased from 5 m2/g to 400 m2/g, morphology studies with SEM analysis and also analyzed the functional groups with FT-IR. These properties have made our adsorbent highly efficient for dye removal. The batch adsorption studies have been carried out for the removal of acid blue 113 using various combinations of synthetic dye solution concentrations (50–300 mg/L), adsorbent dosage 0.4–7 g/L), contact time (30–300 min), and pH (2–10). The removal % efficiency and capacity (mg/g) are obtained from this work as 99.79 % and 188.89 mg/g, respectively.

Quantitative simulationSimulation of nitrogen doping effects on benzene selective adsorption by activated carbon in aqueous conditions

Investigating the impact of nitrogen doping on the selective adsorption of benzene on activated carbon under aqueous conditions holds significant importance in regulating nitrogen content on activated carbon precisely and enhancing benzene adsorption in the air. This study utilizes quantum chemical simulation to systematically compute the pairwise interactions of pyridine nitrogen, pyrrole nitrogen, graphite nitrogen, and their coexistence on carbon materials, including electrostatic potential, van der Waals potential, and polarity changes. We examine the adsorption of benzene and water on nitrogen-doped carbon materials and calculate the type and proportion of weak interactions in the adsorption process through energy decomposition analysis. Visual analysis of weak interactions is conducted via independent gradient scatter plots and isosurface plots. Based on this research, we investigate the influence of nitrogen doping on the competitive adsorption of benzene and water on carbon materials using adsorption energy and configuration changes. Our findings reveal that nitrogen doping disrupts the uniform electrostatic potential distribution and polarity of carbon materials. Specifically, graphite nitrogen inhibits water molecule adsorption by enhancing mutual repulsion and weakening dispersion and electrostatic interactions, consequently promoting benzene adsorption on carbon materials. Moreover, hydrogen bonds form between pyridine nitrogen, pyrrole nitrogen, and water, making carbon materials more hydrophilic. However, when combined with graphite nitrogen, this increases the negative van der Waals potential of carbon materials, further enhancing benzene adsorption. Experimental results align with the simulation, reinforcing the significance of this research in developing efficient activated carbon adsorbents for benzene under aqueous conditions.

Pharmaceutically active compounds in aqueous environment: recent developments in their fate, occurrence and elimination for efficient water purification.

The existence of pharmaceutically active compounds (PhACs) in the water is a major concern for environmentalists due to their deleterious effects on living organisms even at minuscule concentrations. This review focuses on PhACs such as analgesics and anti-inflammatory compounds, which are massively excreted in urine and account for the majority of pharmaceutical pollution. Furthermore, other PhACs such as anti-epileptics, beta-blockers and antibiotics are discussed because they also contribute significantly to pharmaceutical pollution in the aquatic environment. This review is divided into two parts. In the first part, different classes of PhACs and their fate in the wastewater environment are presented. In the second part, recent advances in the removal of PhACs by conventional wastewater treatment plants, including membrane bioreactors (MBRs), activated carbon adsorption and bench-scale studies concerning a broad range of advanced oxidation processes (AOPs) that render practical and appropriate strategies for the complete mineralization and degradation of pharmaceutical drugs, are reviewed. This review indicates that drugs like diclofenac, naproxen, paracetamol and aspirin are removed efficiently by conventional systems. Activated carbon adsorption is suitable for the removal of diclofenac and carbamazepine, whereas AOPs are leading water treatment strategies for the effective removal of reviewed PhACs.

Reduction of Heavy Metal (Pb) ions in industrial waste using activated carbon based on used catalysts

Used catalyst-based activated carbon is activated carbon made from used catalysts from the crude oil cracking process. The used catalyst used is a type of crystalline Zeolite with a regular structure, which contains elements of Silica Oxide, Alumina Oxide, and Calcium Oxide. The use of organic activated carbon to treat waste has been widely used, the use of used catalyst waste as activated carbon is very potential because the catalyst used for oil company cracking is no longer used. Tofu industry is one of Indonesia's industries dominated by small-scale businesses with limited capital, so most tofu industries do not have waste treatment units, where liquid waste is directly discharged into sewers or water bodies without treatment first. Tofu industrial waste contains pollutants both organic and inorganic. Initial analysis of tofu industry liquid waste containing Pb metal. This study aims to determine the effect of mass variation and stirring time of used catalyst-based activated carbon adsorbent on reducing Heavy Metal Ions (Pb) in tofu industry liquid waste. The adsorption process is carried out with mass variations of activated carbon of 5, 10, 15, 20, and 25 grams. Stirring time variations are 30, 60, 90, 120, and 150 minutes. From the results of the study, it is known that the best condition for reducing Pb content was obtained at a stirring time of 60 minutes and a large catalyst-based activated carbon mass of 66.33%