Adsorbent Mass Research Articles

Reducing Ammonia (NH3) Levels in Fish Cage Water Using Activated Carbon Adsorbent Derived from Purple Corn Cob

Successfully made adsorbent of activated carbon made from purple corn cob which aims to minimize ammonia (NH3) levels found in water in fish farming with cage ponds. Activated carbon using carbonization method with a change in temperature that is between 550°C, 600°C, and 650°C and activation using Na2CO3 solution as activator. Activated carbon that has been obtained has exceeded the standard of SNI No.06-3730-1995, with characteristics including carbon yield ranging from 79.71% to 89.85%, moisture content ranging from 11.3% to 25.4%, volatile matter content ranging from 10.10% to 24.5%, ash content ranging from 9.7% to 9.9%, and fixed carbon content ranging from 65.7% to 79.7%. Then test results were obtained such as CO2 functional groups were found to enhance the adsorption process. Activated carbon displays the presence of a predominantly amorphous structure but also revealed a crystalline carbon structure. The highest peak was obtained at 29.7° with Miller index (201). The activated carbon displays the presence of pores on the scattered surface with carbon elements dominating. Adsorption mechanism to reduce ammonia (NH3) using activated carbon due to intermolecular interaction process. So that when testing the application for ammonia absorption, the best results were obtained in the sample with an adsorbent mass of 1.50 g at a carbonization temperature of 650°C with an adsorption capacity value of 546.34 mg/g and ammonia reduction of 82%. This research can open up opportunities for the potential development of new materials, especially for fish farming through cage techniques.

Adsorption Characteristics of Antibiotic Oxytetracycline on CoFe2O4@Au nanocomposite

Oxytetracycline (OTC) is a widely used broad-spectrum antibiotic for treating bacterial infections in humans and animals. Gold nanoparticles (AuNPs) and cobalt iron oxide (CFO) were combined to create composite magnetic materials designed for the selective adsorption of OTC. The strong affinity of AuNPs for the amine group in the OTC molecule allows for the preferential adsorption of OTC. Simultaneously, the high magnetism of CFO enables the efficient retrieval of materials from the sample solution. The CFO@Au nanomaterials showed an enhanced adsorption capacity of 23.75 mg/g at optimum conditions of pH 7.0; an adsorption time of 90 min, and an adsorbent mass of 0.05g. The adsorption isotherm was in accordance with a Langmuir monolayer model while the kinetic adsorption follows pseudo–second-order kinetic model.. This study provides a simple method for the effective adsorption of OTC as well as a suggestion for the adsorption of other amine-containing substances.

Green low-cost synthesis of zero-valent iron nanoparticles from Palm Petiole Extract for Cr(VI) removal from water.

One of the hottest research topics over the last decades was the valorization or/and recycling of agro-industrial wastes into different valuable liquid or solid products, which is considered a sustainable and low-cost approach. In this study, we developed zero-valent iron nanoparticles from Palm Petiole Extract (P-NZVI) using a green and straightforward approach. The as-synthesized P-NZVI was used to adsorb Cr(VI) in water. The physico-chemical characterizations of P-NZVI, including the particle size, crystalline structure, surface area, morphology, and functional groups, were investigated via several techniques such as UV-vis spectroscopy, SEM, TEM, XRD, FTIR, AFM, DLS, pHZPC measurement, and BET analysis. The adsorption performance of P-NZVI was studied under different operational parameters, including pollutant concentration, pH, temperature, and adsorbent mass. The adsorption rate was found to be 89.3% within 40 min, corresponding to the adsorption capacity of 44.47 mg/g under the following conditions: initial Cr(VI) concentration of 40 mg/L, pH 5, and a P-NZVI dosage of 1 g/L. It was found that the adsorption pattern follows the Langmuir and the pseudo-second-order kinetic models, indicating a combination of monolayer adsorption and chemisorption mechanisms. The thermodynamic study shows that the adsorption process is endothermic and spontaneous. The reusability of P-NZVI was carried out four times, showing a slight decrease from 89.3 to 87%. These findings highlight that P-NZVI's could be an effective green adsorbent for removing Cr(VI) or other types of toxic pollutants from water.

Sorption enhanced DME synthesis by one-step CO2 hydrogenation

DME synthesis by direct CO2 hydrogenation was studied on physical mixture of commercial CuZnO/Al2O3 (CZA) and in-house synthesized PTA (phosphotungstic acid)/γ-Al2O3 catalysts. Effects of PTA loading (0–50 % by mass) and relative amounts of the catalysts on CO2 conversion and DME yield were investigated. The process was intensified through integration of in-situ steam separation by Zeolite 3A (Z3A) adsorbent mixed with the catalysts. Experiments were run at 498 K, 30 bar, H2:CO2=3:1 and GHSV=1750 h−1 (based on CZA catalyst). Optimum PTA loading and CZA:PTA/γ-Al2O3 mass ratio were 30 % and 1:2, respectively, that gave ∼21 % CO2 conversion and 6.3 % DME yield. These values remained below the respective thermodynamic limits (28.5 % and 21 %), which were exceeded upon adsorbent integration. Catalytic performance depended strongly on adsorbent quantity studied at the catalyst (CZA+PTA/γ-Al2O3):adsorbent mass ratio range of 1:0.33–4. Catalysts and the adsorbent remained stable during the pressure swing driven adsorption-regeneration cycles. Sorption assistance at catalyst:adsorbent ratio=1:4 increased catalyst productivity from 5.5×10−3 to 2×10−2 kgDME h−1 kgcat−1. The latter value was comparable to those of the sorption enhanced CO2+CO hydrogenation systems due to the PTA-based dehydration catalyst with strong acidic features and was promising when the strong thermodynamic limitations of CO2-DME conversion was considered.

Used Oil Refining Process by Using Green Tea Waste for Floor Cleaner With An Addition of Pineapple Skin Extract

Used cooking oil is a waste that is produced every day and is increasing. Used cooking oil cannot be consumed again because it contains dangerous substances that will cause disease, but it also cannot be thrown away since it will pollute the environment. Therefore, it is necessary to process used cooking oil, one of which is purification using the adsorption method. The adsorption method for used cooking oil can be derived from green dregs because greens contain antioxidants which can reduce the content of dangerous substances in used cooking oil. In this study, we used variations in adsorbent mass (10 gr, 20 gr, 30 gr, 40 gr, and 50 gr) and stirring time (25 minutes, 45 minutes, 65 minutes, 86 minutes, and 105 minutes) to obtain the highest purification results. was the best and it was found that the adsorbent mass of 50 grams of green dregs and a stirring time of 105 minutes had the best results in being able to reduce the peroxide value, air content and free fatty acids. Next, the purified used cooking oil will be processed into floor cleaning liquid soap with the addition of 2 ml, 4 ml, 6 ml, 8 ml and 10 ml of pineapple peel extract. The results of the floor cleaning soap showed that the best results were 2 ml based on the alkaline number, pH and anti-bacterial test.

Bionanocomposite MIL-100(Fe)/Cellulose as a high-performance adsorbent for the adsorption of methylene blue

World production of dyes is estimated at more than 800,000 t·yr−1. The purpose of this research falls within the scope of the choice of an effective, local, and inexpensive adsorbent to remove dyes from wastewater. Adsorptive elimination of dyes by commonly accessible adsorbents is inefficient. The metal–organic frameworks (MOFs) are an important class of porous materials offering exceptional properties as adsorbents by improving separation efficiency compared to existing commercial adsorbents. However, its powder form limits its applications. One way to overcome this problem is to trap them in a flexible matrix to form a hierarchical porous composite. Therefore, in this work, we prepared MIL-100 (Fe) embedded in a cellulose matrix named MIL-100(Fe)/Cell, and used it as an adsorbent of methylene blue (MB) dye. According to the BET analysis, the specific surface area of the synthesized MOF is 294 m2/g which is related to the presence of the cellulose as efficient and green support. The structure of this composite is approximately hexagonal. Adsorption was studied as a function of contact time, adsorbent mass and pollutant load (concentration), and pH, and the effect of each of them on absorption efficiency was optimized. The MIL-100(Fe)/Cell was capable of removing 98.94% of MB dye with an initial concentration of 150 mg/L within 10 min at pH = 6.5 and room temperature. The obtained maximum adsorption capacity was 384.615 mg/g. The adsorption isotherm is consistent with the Langmuir models. The mechanism of MB adsorption proceeds through п-п and electrostatic interactions.

Magnetic surface-imprinted polymer microspheres coupled with HPLC-MS/MS for sensitive detection of amphetamine-type drugs in water

Magnetic surface imprinted polymer microspheres (Fe3O4@MIPs) were successfully synthesized via Pickering emulsion polymerization, utilizing N-Methylphenethylamine as a surrogate template for amphetamine-type drugs. Fe3O4@MIPs not only possessed excellent dispersibility and enough magnetic properties in aqueous solutions, but also displayed good selectivity towards six amphetamines, with an imprinting factor ranging from 1.8 to 2.6. The adsorption kinetics closely aligned with the pseudo-second-order model, and the adsorption efficiency exceeds 80 % for each amphetamine at equilibrium. Fe3O4@MIPs were then employed as the efficient adsorbents for the extraction of amphetamine drugs. Extraction parameters, including sample pH, the mass of adsorbent, and the type and volume of eluting solvent, were carefully optimized. In combination with the high performance liquid chromatography tandem triple quadrupole mass spectrometry (HPLC-MS/MS), a selective magnetic solid-phase extraction (MISPE) method utilizing Fe3O4@MIPs was developed for the detection of six amphetamines in water samples. The limits of detection and limits of quantitation were determined to be 5.2∼23 ng L−1 and 17∼77 ng L−1, respectively. Recoveries for the six target drugs from lake water and sewage samples fell within the range of 87.2∼110 %. Additionally, the MISPE-HPLC-MS/MS method exhibited excellent repeatability, with a precision below 8.5 % at two spiking levels. The prepared Fe3O4@MIPs possessed the advantages of high selectivity, straightforward preparation, facile separation and good reusability, and was highly suitable for the efficient extraction of amphetamine-type substances in complex environmental water.

Computational intelligence for empirical modelling and optimization of methylene blue adsorption phenomena utilizing an activated carbon‐supported [Co(NH3)6]Cl3 complex

AbstractThe study focuses on the efficiency of hexaamminecobalt (III) chloride (HACo, [Co(NH3)6]Cl3) immobilized on activated carbon for removing methylene blue (MB) from water solutions. The primary objective of this study was to assess the sorption performance of HACo immobilized on activated carbon in removing MB from water solutions. Additionally, predictive models were developed to optimize the MB removal percentage. Lastly, the study aimed to determine the optimal conditions for achieving maximum MB removal. Samples were characterized using scanning electron microscopy. Batch sorption experiments were conducted to analyze the impact of MB concentration, adsorbent mass, pH, temperature, and contact time. Predictive models were built using multiple linear regression and neural network techniques, specifically artificial neural networks (ANN) and hybrid ANN–particle swarm optimization (ANN‐PSO). The PSO‐ANN model with a single hidden layer of eight neurons trained using the Levenberg–Marquardt algorithm demonstrated high accuracy in predicting MB removal percentage, with mean absolute percentage error (MAPE) = 0.083788, root mean square error (RMSE) = 0.11441, and R2 = 0.99693. The MB adsorption process followed a mono‐layer with one energy model and a pseudo‐first‐order kinetic model. Optimization using the genetic algorithm revealed that the maximum MB removal percentage of 99.56% is achievable at an MB concentration of 9.36 mg/L, adsorbent mass of 15.72 mg, and temperature of 311.2 K. The study confirms the effectiveness of HACo immobilized on activated carbon for MB removal. The PSO‐ANN predictive model proved superior in accuracy compared to empirical models. Optimization results provide the optimal conditions for maximizing MB removal, offering valuable insights for practical applications.

Recovery of gold from electronic waste by the synthesis of Pinus Brutia tannin polymer

Electrical and electronic waste (e-waste) is one of the most common waste problems today and contains many recyclable materials such as gold and palladium. In this study, an adsorption material was prepared by reacting tannin from Pinus Brutia bark with formaldehyde to recover gold from e-waste. The produced Pinus Brutia tannin (PBTR) polymer was characterized using TGA, BET, and FTIR. The adsorption efficiency was investigated using solutions containing gold ions with different pH values, adsorbent masses, initial concentrations, times, and temperatures. The results of these experiments were used to perform adsorption isotherm, kinetics, and thermodynamics calculations. The pseudo-second-order kinetic equation and the Langmuir isothermal equation were found to fit the experimental data best. The Au(III) ion saturation capacity of the PBTR particle monolayer was calculated to be 1771.73 mg/g at 328 K using the Langmuir isotherm. XRD and XPS analyses showed that most of the Au(III) ions were reduced to metallic gold after adsorption on the surface of the PBTR particles. Observations show that the adsorbent effectively removes Au(III) from the leaching solution generated by e-waste.

Performance evaluation of calcined eggshell waste (Sorbent) for biogas upgrading: Adsorption isotherms, adsorption kinetics, and fixed bed studies

The use of non-renewable energy resources such as fossil fuels accelerates climate change and environmental degradation necessitating a shift to renewable energy sources. Biogas is a renewable energy resource with great potential. However, its application is limited by the presence of contaminants such as carbon dioxide, which reduces its energy value, and density. Upgrading biogas using locally available materials solves waste management and energy sustainability challenges. In the present study, calcined eggshell waste was employed as an adsorbent for carbon dioxide. The effect of calcination temperature, adsorbent mass and adsorbent particle size was evaluated. The experimental data was fitted to adsorption isotherms, adsorption kinetic models, and breakthrough curves. Eggshells with a particle size of 280 μm, calcined at 850 °C, and mass of 75 g showed the best performance in removing carbon dioxide from biogas. It was noted that data from the experiment fitted Langmuir isotherm with RL 0.00216 while its R2 was 0.97 and Freundlich n = 0.6 while R2 = 0.97. Regarding adsorption kinetics, the intra-particle diffusion model shows good conformity with kid of 34, C of 98, and R2 of 0.977. Breakthrough analysis proved that Yoon Nelson's Model fitted well with the experimental data with an R2 of 0.989. Thus, calcined eggshell waste is a good sorbent for biogas upgrading that can solve the twin challenges of waste disposal and management and energy sustainability.

Comparative Analysis of Nickel Adsorption by Natural Sisal Fiber and Treated with Citric Acid

Introduction: Removing nickel from wastewater is complex and costly, requiring research into alternatives with technical and economic solutions. An alternative would be the use of plant biomass. In the Northeast region of Brazil, one of these alternatives, with a large cultivation area, is sisal (Agave Sisaliana), which may have greater yields for this purpose through surface chemical treatment with citric acid, which inserts carboxylic groups into the structure of the plant fiber. Thus, the objective was to analyze the ability to remove nickel in solution by sisal fibers. Methodology: For this purpose, part of the sisal fibers was cut into 0.5 cm, washed and dried; initially treated with NaOH (0.1 mol/L); washed with distilled water and treated with citric acid (1.2 mol/L). The fibers were identified by FTIR; XRD; XRF and SEM. Adsorption tests were carried out with nickel solution for the parameters: kinetics, balance, influence of pH and adsorbent mass. Results: The XRF analysis demonstrated a greater presence of NiO adhered to the treated fiber (55.74%); FTIR confirmed the presence of non-ionized carbonyl in the region from 1700 to 1750 cm-1; the adsorption kinetic test demonstrated greater effectiveness of the treated fiber > 80%; an ideal adsorbent mass was observed to be 0.1g; the ideal pH for removal was 5.0 while the equilibrium test has the best Languimuir isotherm, the uncontrolled fiber obtained R2 = 0.9810 and the controlled fiber R2 = 0.9643. Conclusion: Therefore, it was observed that the treatment of sisal fiber with citric acid increases the removal efficiency of nickel ion in aqueous solution, presenting itself as a low-cost and widely available material.

Adsorptive decolorization of brilliant green dye in aqueous media using various modified MOF-5 adsorbents

Dye pollution in environmental water is a serious problem worldwide, posing significant environmental and health concerns. To effectively address this problem, this study investigates the adsorptive decolorization of brilliant green (BG) dye in aqueous media by using various metal-organic frameworks (MOF-5)-based adsorbents modified with industrial wastes (coal fly ash (CFA) and rice husk ash (RHA)). The adsorption experiments were conducted to evaluate their performance under varying conditions, and the synthesized and spent adsorbents (selected) were characterized. The results showed that the adsorbent samples possessed the characteristics of a good adsorbent. MOF-5 coated with thermally treated RHA at 900 °C (MOF-5@ RHA900 – with BET surface area = 91.6810 m2 g−1) has the highest observed BG dye adsorption efficiency (92%) and adsorption capacity (30.22 mg g−1) at adsorbent mass of 1.4 g, contact time of 2 h, and initial dye concentration of 20 mg L−1. BG dye removal increased with an increase in contact time and adsorbent amount and decreased with an increase in initial dye concentration. The adsorption kinetics and isotherm equilibrium studies revealed that the adsorption data were best fitted to the pseudo-second-order kinetic model (R2 = 0.9507) and Langmuir isotherm model (R2 = 0. 0.9929), respectively. These findings highlight the potential of mesoporous MOF-5@ RHA900 as an effective adsorbent for BG dye decolorization in aqueous media, with implications for water treatment and the utilization of industrial waste materials.

Gaussian process regression with levy flight optimization: Advanced AR66 adsorption studies

The coal fly ash (CFA), which is the residue generated by coal-fired power plants, was converted into a valuable zeolite material known as zeolite P (ZNa-P) through thermal and acid pretreatments followed by microwave radiation. Various analytical techniques were utilized to analyze the resulting zeolite, including X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, BET analysis, and zeta potential measurement. The efficiency of ZNa-P in eliminating anionic dyes from aqueous solutions was exhibited by successfully removing acid red dye 66 (AR66) from a solution composed of water. To optimize the removal process, Central Composite Design (CCD) was applied to investigate the impact of four main parameters: solution pH, initial dye concentration, adsorbent mass, and contact time. The generated CCD database was modeled using Gaussian process regression (GPR) with the Lévy flight distribution (LFD) optimization algorithm. The GPR model was then used to determine optimal conditions for maximum AR66 absorption (3405.3 mg/g), with a pH of 2, initial dye concentration of 1000 mg/L, adsorbent mass of 0.2 g/L, and contact time of 11 minutes. Furthermore, the GPR model exhibited significantly lower error (32.58 mg/g) in predicting the experimental values compared to the CCD model (204.92 mg/g), highlighting the efficiency and superiority of the GPR model in this study.

Linker-induced hollow MOF embedded into arginine-modified montmorillonite for efficient urea removal: Adsorption behavior and mechanism analysis

The precise regulation of hollow metal–organic framework (HMOF) and the effective assembly with excellent guest materials present limitless potential for pollutant removal. In this work, the arginine-modified montmorillonite (AMMT) was preferentially prepared via room temperature impregnation approach, and then the AMMT-HMOF composite was effectively constructed through a one-pot method. During this process, linker-induced MOF to MOF route was proposed, i.e., solid ZIF-67 transformed into hollow MOF-74 (thicknesses: ∼25 nm). Of note, this route involves the transition from solid to hollow structures, as well as the change between different topologies. Next, the AMMT-HMOF composite was evaluated for adsorption experiments with urea in aqueous solution as the target molecule. Further speaking, the optimization experiments were conducted to analyze the impact of pH, contact time, adsorbent mass and original urea concentration towards the adsorption process. The as-fabricated absorbent presented a maximum adsorption capacity of 298.5 mg/g within 1 h, demonstrating adherence to pseudo-second-order kinetics and the Langmuir model. The excellent adsorption performance can be ascribed to the enlarged layer spacing of AMMT, as well as the fast mass transport and abundant diffusion channels in HMOF. Additionally, the mechanistic analyses revealed the existence of hydrogen bonding interactions between the adsorbent and urea. Meanwhile, the adsorbent displayed the outstanding morphological and structural stability after usage. According to our survey, this is the first time to use this linker-induced MOF-to-MOF strategy and predictably assemble with functionalized montmorillonite to construct the hollow MOF composite for urea adsorption.

Peach seed shell and Aspergillus oryzae as adsorbents for the uptake of acid violet 90 dye from wastewater

In this study, Aspergillus oryzae (A. Oryzae) biomass and waste peach seed shells (PPSS) were used to create alternative and effective adsorbents. Acid Violet 90 (AVD) dye was removed from wastewater using the as-prepared adsorbents. Different process variables like pH (2–11), contact period (0–180 min), and adsorbent mass (0.2–2.0 g/L) were examined. The solution pH had a synergistic effect on the improved removal of AVD and the optimal adsorption removal for the PPSS and the A. Oryzae adsorbent occurred at pH 2.0 and pH 5.0, respectively. The findings demonstrated that, in comparison to A. Oryzae, PPSS reported a greater AVD adsorption (mg/g). The equilibrium time for the adsorption process was attained within 180 min for both adsorbents. The adsorption kinetics modelling results showed a good fit with pseudo-second-order kinetics, for both adsorbents, with average R2 values of 0.999 (for PPSS) and 0.997 (for A. Oryzae). Similarly, the isotherm modelling results confirmed the good fitting of the Langmuir isotherm model for A. Oryzae (R2 = 0.999) and the Freundlich model for PPSS (R2 = 0.997). The maximum adsorption capacity (qmax) of 55.0 and 94.92 mg/g was recorded for A. Oryzae and PPSS, respectively. Mechanistic investigation of the present system suggests that both intraparticle diffusion and surface sorption mechanisms control the adsorption rate. As agro materials, both adsorbents are composed of mostly oxygen-based surface functional groups like the –OH, –C = O, -C-O-C, and multiple carbon-carbon bonds, all contributed to the synergistic mechanism interaction between the adsorbent and AVD dye in this study. This study, therefore, revealed that the PPSS and A. Oryzae may be very helpful for removing anionic dye from contaminated wastewater, indicating its potential for useful application in the removal of other major pollutants.

Conversion of secondary aluminum dross into hierarchical carbonate-intercalated Mg-Al layered double hydroxide for efficient CO2 capture

This paper explores the preparation of hierarchical Mg-Al layered double hydroxide (LDH) from secondary aluminum dross waste for the first time. The aluminum content of the waste was initially extracted in the form of a sodium aluminate solution using a multistep wet chemical process. CO3-intercalated Mg-Al LDH was then prepared at pH values of 9 and 11 by adding magnesium chloride to a mixed solution of sodium aluminate and sodium carbonate. The X-ray diffraction (XRD) analysis revealed that a pure LDH structure could be formed at pH 11. The quantification of the XRD data revealed that the synthesized LDH had an interlayer spacing of 3.1 Å. The microstructural porosity was 0.76 cm3/g, and the specific surface area was 134 m2/g. The field emission scanning electron microscopy (FESEM) analysis revealed a hierarchical layered structure composed of flake-like particles in the microstructure. The elemental mapping of the synthesized LDH showed a proper distribution of Mg, Al, C, and O. The synthesized Mg-Al-CO3 LDH was then used for a study on CO2 capture. The CO2 capture experiments demonstrated that the amount of CO2 adsorption is influenced by temperature, gas pressure, adsorbent mass, and exposure duration. Investigating the effects of time and temperature revealed that a CO2 adsorption of 0.94 mmol/g can be achieved at a temperature of 25 °C during a 90-minute exposure period. Varying the gas pressure from 1 to 2.5 bar, while maintaining a constant temperature of 25 °C and an adsorbent mass of 1.5 g, resulted in an increase in CO2 adsorption from 1.7 to 2.3 mmol/g. Reusability tests showed that the LDH could maintain a satisfactory adsorption value of 0.84 mmol/g after 5 cycles, indicating its potential for repeated use.

Adsorption of antiretroviral drugs, abacavir, nevirapine, and efavirenz from river water and wastewater using exfoliated graphite: Isotherm and kinetic studies

In this work, exfoliated graphite was used to adsorb antiretroviral drugs from river water and wastewater. The exfoliated graphite was prepared from natural graphite by intercalating it with the acids and exfoliating it at 800 °C. It was characterized using Fourier Transform Infrared Spectroscopy which showed phenolic, alcoholic, and carboxylic functional groups between 1000 cm-1 and 1700 cm-1. Energy-dispersive X-ray spectroscopy results showed carbon as the main element with splashes of oxygen. The Scanning Electron Microscopy images showed increased c-axis distance between graphene layers after intercalation, which further increased after the exfoliation. The exfoliation resulted in elongated distorted cylinders, which were confirmed by the lower density (0.0068 g/mL) of exfoliated graphite material compared to the natural graphite (0.54 g/mL). The X-ray diffraction pattern showed the characteristics of hexagonal phase graphitic structure by the diffraction plane (002) at 26.74°. Raman spectroscopy results showed the natural graphite, graphite intercalated, and exfoliated graphite contained the D, G, D′, and G′ peaks at about 1350 cm-1, 1570 cm-1, 2440 cm-1, and 2720 cm-1, respectively indicating that the material's crystallinity was not affected by the modification. The highest antiretroviral drugs removal (95–99%), from the water was achieved with a solution pH of 7, an adsorbent mass of 30 mg, and an adsorption time of 30 min. The kinetic model and adsorption isotherm studies showed that the experimental data fit well in pseudo-second-order kinetics and is well explained by Freundlich's adsorption isotherm. The maximum adsorption capacity of the exfoliated graphite for antiretroviral drugs ranges between 1.660 and 197.0, 1.660–232.5, and 1.650–237.7 mg/g for abacavir, nevirapine, and efavirenz, respectively. The obtained removal percentages were 100% in river water, 63–100% in influent and 70–100% in effluent wastewater unspiked samples.

Adsorption simulation of 2,4-D pesticide on novel zinc-based 2-amino-4-(1H-1,2,4-triazole-4-yl)benzoic acid coordination complexes using machine learning approach.

The capacity of zinc-based 2-amino-4-(1H-1,2,4-triazole-4-yl)benzoic acid coordination complex (Zn(NH2-TBA)2) and modified Zn(NH-TBA)2COMe complex for removal of 2,4-dichlorophenoxyacetic acid (2,4-D) from aqueous solutions was investigated through adsorption modeling and artificial intelligence tools. Analyzing the adsorption characteristics of pesticides helps in studying the groundwater pollution by pesticides in agriculture area.In this study, Zn(NH2-TBA)2 was synthesized using Schiff base and its surface was modified using acetic anhydride group and their physical characteristics were identified using proton NMR, FTIR, and XRD. NMR results showed maximum modification yield obtained was 65% after 5days. The porous structure and surface area monitored using nitrogen isotherm and BET surface area analysis presented relatively less surface area and porosity after modification. Adsorption modelling indicated that Toth model with a maximum adsorption capacity of 150.8mg/g and 100.7mg/g represents the homogenous adsorption systems which satisfy both low- and high-end boundary of adsorbate concentration in all settings according to the optimum point, while the kinetics and rate of 2,4-D adsorption follow the pseudo-first-order kinetic model in all situations. Artificial neural network (ANN), support vector regression, and particle swarm optimized least squares-support vector regression (PSO-LSSVR) were used for the optimization and modelling of adsorbent mass, adsorbate concentration, contact time, and temperature to develop predictive equations for the simulation of the adsorption efficiency of 2,4-D pesticide. The obtained results exhibited the better performance of ANN and PSO-LSSVR for prediction of adsorption results. The mean square error values of ANN (0.001, 0.012) and PSO-LSSVR (0.121, 0.105) were obtained for Zn(NH2-TBA)2 and Zn(NH-TBA)2COMe, respectively, while their respective coefficient of determination (R2) obtained were 0.999 and 0.988 for ANN and 0.980 and 0.825 for PSO-LSSVR. The study specified that machine learning predictive behavior performed better for Zn(NH2-TBA)2 compared to Zn(NH-TBA)2COMe that is also supported by theoretical kinetics and isotherm models. The research concludes that artificial intelligence models are the most efficient tools for studying the predictive behavior of adsorption data.

Using predictive models unravel the potential of titanium oxide-loaded activated carbon for the removal of leachate ammoniacal nitrogen.

The TiO2 nanocomposite efficiency was determined under optimized conditions with activated carbon to remove ammoniacal nitrogen (NH3-N) from the leachate sample. In this work, the facile impregnation and pyrolysis synthesis method was employed to prepare the nanocomposite, and their formation was confirmed using the FESEM, FTIR, XRD, and Raman studies. In contrast, Raman phonon mode intensity ratio ID/IG increases from 2.094 to 2.311, indicating the increase of electronic conductivity and defects with the loading of TiO2 nanoparticles. The experimental optimal conditions for achieving maximum NH3-N removal of 75.8% were found to be a pH of 7, an adsorbent mass of 1.75mg/L, and a temperature of 30°C, with a corresponding time of 160min. The experimental data were effectively fitted with several isotherms (Freundlich, Hill, Khan, Redlich-Peterson, Toth, and Koble-Corrigan). The notably elevated R2 value of 0.99 and a lower ARE % of 14.61 strongly support the assertion that the pseudo-second-order model compromises a superior depiction of the NH3-N reduction process. Furthermore, an effective central composite design (CCD) of response surface methodology (RSM) was employed, and the lower RMSE value, precisely 0.45, demonstrated minimal disparity between the experimentally determined NH3-N removal percentages and those predicted by the model. The subsequent utilization of the desirability function allowed us to attain actual variable experimental conditions.

Factorial experimental design optimisation of adsorption process for removing chrome ion using crude biomass

ABSTRACT The pollution of water and the environment by heavy metals has recently increased dramatically, creating a severe environmental problem due to their non-biodegradability and high toxicity. Among these metals, we are interested in chromium (Cr), essential for human life but can be toxic in large quantities. It is vital to develop a simple, effective, and inexpensive method for its removal from aqueous media. This work aims to combine two aspects: environmental protection and waste recovery. We studied the adsorption capacity of Cr(VI) by biomass consisting of a mixture of walnut shells, pecan nuts, and peanuts. The ion was quantified using high-resolution magnetic sector inductively coupled plasma mass spectrometry, and several techniques characterised the raw adsorbent. To optimise the removal of Cr(VI), four factors were optimised using a 24-full factorial design, enabling us to determine the optimum adsorption conditions: a contact time of 360 min, an adsorbent mass of 30 mg, an initial ion concentration of 50 mg/L, and a pH of 6. The response efficiency Y (Qe) achieved its optimum at 58.47976 ± 4.168804 (mg/g), resulting in a maximum desirability of 0.957419. The adsorption phenomenon was studied kinetically, and it was found to follow the pseudo-first-order reaction (R 2 = 0.9894); concerning adsorption isotherms, the Freundlich isotherm proved to be the best (R 2 = 1). Overall, the present biosorbent demonstrates excellent capacity to remove Cr (VI) from water and can be used on a large scale.