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In present research, the activated carbon was prepared by a green approach from pomegranate peel coated with zero-valent iron nanoparticles (AC-nZVI) and developed as adsorbent for the removal of amoxicillin from aqueous solution. The physicochemical properties of the AC-nZVI were investigated using XRD, FTIR, and FESEM techniques. The optimal values of the parameters for the best efficiency (97.9%) were amoxicillin concentration of 10 mg/L, adsorbent dose of 1.5 g/L, time of 30 min, and pH of 5, respectively. The adsorption equilibrium and kinetic data were fitted with the Langmuir monolayer isotherm model (qmax 40.282 mg/g, R 2 0. 0.999) and pseudo-first order kinetics ( R 2 0.961). The reusability of the adsorbent also revealed that the adsorption efficiency decreased from 83.54 to 50.79% after five consecutive repetitions. Overall, taking into account the excellent efficiency, availability, environmental friendliness, and good regeneration, AC-nZVI can be introduced as a promising absorbent for amoxicillin from aquatic environments.

Water contamination due to release of dye containing effluents is one of the environmental problems of serious concern today. The present study investigate the green synthesis of zinc oxide nanoparticles (ZnO-NPs) doped on activated carbon (AC) prepared from walnut peel extract and to estimate its efficiency in the removal of Eosin Y (Eo-Y) and Erythrosine B (Er-B) from its aqueous solution. The synthesized AC-ZnO was identified by field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and the Brunauer–Emmett–Teller. The influence of various parameters such as pH, dosage of AC-ZnO, contact time, and concentrations of Eo-Y and Er-B was also studied. The pH 3 was observed as the optimum pH while the equilibrium was noticed to reach in 30 min at dosage of 1 g/L and initial concentration 100 mg/L for Eo-Y and Er-B adsorption onto AC-ZnO. The maximum adsorption capacity of Eo-Y and Er-B onto AC-ZnO was found to be 163.9 and 144.92 mg/g (and removal efficiencies of 95.11 and 98.31 %), respectively. The process of Eo-Y and Er-B adsorption on AC-ZnO was observed to be depended on the pseudo-second-order kinetic model which indicates chemisorption processes. Langmuir adsorption isotherm model test described the removal of Eo-Y and Er-B on AC-ZnO. The thermodynamic data indicated that the adsorption was endothermic process. Also, the values, S BET and V TOTAL , for the AC-ZnO were equal to 725.65 m 2 /g and 0.6004 cm 3 /g, respectively. The results of this study exhibited that AC-ZnO was a very effective method that can be used for the removal of Eo-Y and Er-B from aqueous solutions.

The most important effect of natural organic materials in water is reacting with disinfectants and creating disinfectant by-products that are mostly carcinogenic. The aim of this study was to determine the optimum conditions for removal of humic acid (HA) by zeolite coated with nZVI nanoparticles (Zeolite/nZVI) from aqueous solutions. In this study, after synthesis of zeolite/nZVI, its structure and morphology were examined using FTIR, BET, XRF, and FESEM techniques. The effects of HA concentration, composite content, pH, and reaction time were evaluated. The experimental data were analyzed by Langmuir and Freundlich isotherm and pseudo-first-order and second-order kinetic models. Finally, the thermodynamic parameters of enthalpy (ΔΗ°), entropy (ΔS°), and Gibbs free energy (ΔG°) were calculated. The results of the analyses confirmed the accuracy of the composite structure. Its specific surface area by using BET method was 203.43 m2/g. The HA removal efficiency was obtained at 92.98% in optimum conditions of 50 mg/L concentration, 2 g/L composite dose, pH = 3, and reaction time of 60 min. The results of the isotherm and kinetic study showed that the HA adsorption process follows the Langmuir isotherm (R2 = 0.9707) and pseudo-second-order kinetic. The maximum adsorption capacity of the composite was determined at 23.36 mg/g by Langmuir model. Thermodynamic parameters indicate that the adsorption of HA endothermic and the reaction cannot be done spontaneously. Zeolite/nZVI composite had good removal efficiency after five times of recycling. The present study showed that zeolite/nZVI can be used as an effective adsorbent for removal of HA from aqueous solutions.

The environment is threatened by a diversity of pollutants, and synthetic dyes are considered a foremost environmental pollutant among them. The characteristics detected for the dye, e.g., toxicity and carcinogenicity, have brought severe problems for humans and aquatic organisms. The present study was done to clarify the potential of activated carbon made from cherry tree wood (CWAC) in the adsorption of cationic red 14 dye. In our experimental-laboratory study, the changes in removal efficiency were assessed by considering the changes in values of pH, concentration, adsorbent dose, contact time, and temperature. In addition, the nature of our prepared adsorbent was defined based on scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET), X-ray diffraction (XRD), and Fourier-transformed infrared (FTIR) spectroscopy techniques. The concentration of dye after the completion of experiments was recorded using a spectrophotometer at 514 nm. Evaluating the attained data by isotherm and kinetic models were also considered. Our results demonstrated the enhancement in the efficiency of the studied process at higher contact times, temperatures, and pH and its decline at higher initial dye concentrations. pH = 11, time of 45 min, dye concentration of 50 mg/L, and AC mass of 0.25 g/l were optimal values in obtaining the highest removal of the studied dye. Langmuir isotherm and pseudo-second-order (PSO) with ( R 2  = 0.9972) and ( R 2  = 0.9947) were the best isotherms and kinetic models in the description of the observed data, respectively. Considering the results, CWAC could be effectively utilized for the adsorption of cationic red 14 dye from solutions.

Diazinon (DZN) has been reported as an important pesticide with wide application in agriculture. The entry of these compounds into water resources has brought serious environmental problems due to their resistance to biodegradation; thus, this study was considered to be done to explore the process of DZN uptake and the influence of effective parameters. The study was performed experimentally and on a laboratory scale. Investigating the structure and morphology of the nanocomposite was done based on different analyses, i.e., FE-SEM, FTIR, and XRD. The experiments based on the Box–Behnken scheme were performed by surveying four important operating parameters (pH, contact time, nanocomposite dose, and DZN concentration). Optimization was performed by experiment design software and using the response surface method and analysis of the proposed model. The DZN removal efficiency was obtained 100% under optimal conditions including pH = 5, nanocomposite dose = 0.83 g/L, reaction time = 55 min, and DZN concentration = 5 mg/L. Considering the high correlation coefficient R 2  = (0.9873) and R Adj 2 = (0.9725), the proposed model (quadratic) was approved. The results were indicative of conforming the reaction kinetic to the pseudo-second-order model and the correspondence of reaction isotherm to the Freundlich model ( R 2  = 0.997). Based on the obtained results, the adsorption process with AC–ZnO nanocomposite could be introduced as an efficient and eco-friendly technique to remove DZN.

This article was aimed at investigating the removal of metronidazole (MNZ) from aquatic solutions by modified activated carbon (MAC) with amine groups. The effect of various parameters on the adsorption rate such as the initial pH, adsorbent dose and initial concentration of MNZ and contact time were scrutinized. MAC was characterized by Fourier transform infrared spectroscopy and Brunauer–Emmett–Teller techniques. The obtained results illustrated that under the optimum conditions (pH = 3, contact time = 50 min, initial MNZ concentration = 5 mg/L and MAC dose = 0.5 g/L), the maximum adsorption efficiency was 95%. Furthermore, the kinetic studies indicated the applicability of the pseudo-second-order kinetic model, whereas the adsorption isotherm fitted well with the Freundlich model (0.996), and the maximum adsorption capacity was 66.22 mg/g. The SBET and the total pure volume of MAC were 706.92 m2/g and 0.532 cm3/g, respectively. Also, the regeneration tests demonstrated that MAC had good stability after five cycles (73%). It can be concluded that MAC, as an effective adsorbent, has a high ability to remove MNZ from aqueous solutions.

The chlorination of surface waters leads to the formation of thrihalomethans (THMs) and haloaceticacids (HAAs) due to the presence of natural organic matters. Thus, the removal of fulvic acid (FA) as one of the most prominent natural organic matters in water is necessary. Therefore, this study was aimed to evaluate the efficiency of catalytic ozonation of FA in the presence of the local montmorillonite (Mnt). The soils were collected from the Ardabil Sarcham area and used as a catalyst, after the required preparation. The variables in this study including initial solution pH, catalyst dosage, reaction time, and initial pollutant concentration were examined. For the ozonation of the samples, an ozone generator with a capacity of 5 g/h was used. It was found that, with increasing contact time, pH, and catalysts dosage, as well as decreasing initial FA concentration, the performance of the catalytic ozonation process increased significantly. The results demonstrated that radical scavengers like nitrate, chloride, sulfate, and carbonate a high concentration had very low effect on the efficiency of this process compared to conventional ozonation. The kinetic data was found to fit into the pseudo-first-order kinetic model ( R 2 = 0.98) than the zero and pseudo-second-order model. The Green Mnt was more effectual than the Red Mnt at pH: pH = 7, FA concentration = 25 mg/L, time = 30 min, catalyst dosage = 1.25 g/L, inlet ozone concentration = 2.2 mg/L-min; which gave COD removals of 84.68 and 78.25%, respectively. As a whole, green and red soils increase highly the efficiency of FA removal in the catalytic ozonation process, because of low costs and availability of these soils.

High amounts of dyes in receiving waters are dangerous to the ecosystem due to their specific properties, such as high alkalinity, high organic compound content, and robust structure. The present article aims to investigate the efficiency of the Fe 3 O 4 /zeolite process in removing methylene blue dye (MB) from aqueous solutions, as well as to optimize the factors influencing the efficiency of removal. Initially, a Fe 3 O 4 /zeolite nanocomposite was prepared and characterized using Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) techniques. The impact of various parameters such as pH of the aqueous solution, nanocomposite dosage, contact time, and initial dye concentration on the adsorption efficiency was systematically investigated. FTIR shows presence of iron disrupts the hydrogen bonds in the zeolite structure. Additionally, SEM analysis reveals the pronounced microporosity of the Fe 3 O 4 /zeolite nanocomposite. Optimal conditions were determined to be a pH of 9.0, an adsorbent dosage of 0.75 g/L, a contact time of 45 min, and a methylene blue concentration of 50 mg/L, resulting in a removal efficiency of 96.92%. Adsorption isotherm and kinetic studies revealed that the adsorption process of methylene blue followed the Freundlich isotherm (R 2  > 0.984) and pseudo-second-order kinetic models (R 2  > 0.9958), respectively. The qm (sorption capacity) of the Fe 3 O 4 /zeolite nanocomposite was 113.64 mg/g. Furthermore, the reusability of the adsorbent was assessed through five consecutive experiments, demonstrating only a marginal decrease (approximately 7.9%) in methylene blue removal efficiency. These findings underscore the potential of the magnetic nanocomposite based on zeolite as a highly effective adsorbent for methylene blue removal applications. Highlights A zeolite-based magnetic nanocomposite was synthesized and characterized using FT-IR and SEM techniques for the removal of methylene blue dye from water. The study determined optimal conditions for dye removal as a pH of 9.0, an adsorbent dosage of 0.75 g/L, a contact time of 45 min, and an initial dye concentration of 50 mg/L, achieving a removal efficiency of 96.92%. The adsorption process followed the Freundlich isotherm and pseudo-second-order kinetic models, with high correlation coefficients (R 2  > 0.984 and R 2  > 0.9958, respectively). The adsorbent demonstrated good reusability with only a 7.9% decrease in removal efficiency over five consecutive uses, highlighting its effectiveness for repeated applications.

Furfural is one of the industrial pollutants, and uncontrolled discharge of it into the receiving water bodies of industrial wastewater can cause various problems for the ecosystems downstream of these receiving streams. At present, nanoscale metals are mainly synthesized by chemical methods with unintended effects such as environmental pollution, large energy consumption, and potential health problems. Green synthesis is more beneficial than traditional chemical synthesis because it costs less, reduces pollution, and enhances environmental and human health safety. This research was conducted to remove furfural from aqueous solutions using modified nanoclay (nC) with zero-valent iron nanoparticles (nZVI) in a batch reactor. Additionally, X-ray fluorescence (XRF), Fourier Transform Infrared Spectroscopy (FTIR), and Field Emission Scanning Electron Microscopy (FE-SEM) analysis were performed to identify the properties of the nanoparticles. The adsorption of furfural was measured with a spectrophotometer at a wavelength of 278 nm. The efficiency of furfural removal has a direct and inverse relationship with the adsorbent dose and furfural concentration, respectively. The obtained results showed a better fit with the pseudo-second-order kinetic model and the Langmuir isotherm (R 2  = 0.9885). The nC/nZVI adsorbent was effectively regenerated and reused for several cycles. Under ideal conditions, 46.1% of the used adsorbent was recovered after five cycles. These results demonstrate that locally modified nanoclay with nZVI nanoparticles is a promising and effective adsorbent for eliminating furfural. Highlights In this work, modified nanoclay with zero-valent iron nanoparticles (nC/nZVI) nanocomposite synthesized and used for adsorption of furfural. A modified nanoclay with zero-valent iron nanoparticles (nC/nZVI) nanocomposite was synthesized and characterized using XRF, FTIR, and FE-SEM techniques for the removal of furfural. The adsorbent demonstrated good reusability with only a 16.5 % decrease in removal efficiency over five consecutive uses, highlighting its effectiveness for repeated applications. The study determined optimal conditions for furfural removal as a pH of 7, an adsorbent dosage of 8 g/L, a contact time of 150 min, and an initial furfural concentration of 10 mg/L, achieving a removal efficiency of 62.6%. The adsorption process followed the Langmuir isotherm (R2= 0.9886) and pseudo-second-order kinetic models.