جستجوی مقالات مرتبط با کلیدواژه « removal » در نشریات گروه « شیمی »

The biosorption properties of an agricultural waste using pineapple leaf powder as activated carbon (PLAC) were studied to remove contaminated colors from dye mixtures, including cationic and anionic dyes such as brilliant yellow (BY), malachite green (MG), methylene blue (MB), and Rhodamine B (RhB) as real samples of industrial dyes for the treatment of industrial water. The main factors such as adsorbent dosage, initial dye concentrations, solution pH, and equilibrium time that influenced the adsorption performance were investigated in all single and binary systems. The best maximum adsorption capacities (Qm) were obtained for MG, MB, BY, and Rh6G in the single system are 98.5, 88.2, 80.98, and 77.7 mg/g and removal percentage 98.11%, 93.65%, 8.12%, and 70.25%, respectively. The pH of solution has no influence on adsorption of RhB dye on to Activated carbon (AC-PL), whereas for MB dye, adsorption increases with increasing pH and the best adsorption at pH 9.0. But in the case of MG dye, the best adsorption is at pH 9.0 and the minimum is at pH 2.0 and the best solution pH of BY dye is at pH 11.0. Through the mixture of two dyes (MB with BY) and (MG with RhB), it turns out that the removal of the dye MB and MG is better and with very high efficiency compared to RhB and BY in binary system. The bio sorption was regenerated by adsorption process after the loading process and reused for several times.

With the ex-potentially increase pollutants of dyes, the purification of cationic dye waste water has been an urgent environmental problem. As a new kind of porous adsorbent, hydrogel modified activated carbon frameworks still face challenges in agglomeration, regeneration, reuse ability, and synthesis environmentally un-friendly. In this work, activated carbon was grown in situ on the surface of sodium alginate (AAc-AM) beads to fabricate (AAc-co-AM)/AC. This study works to examine the elimination of Brilliant Blue (BB), a harmful and persistent dye that could cause extensive ecological damage, from an aqueous solution via adjusting the amount of acrylamide (AM) and the degree of co-polymer cross-linking. The co-polymer of hydrogels efficiently removes BB in a brief time frame. The synthesized hydrogel was characterized via FESEM and TEM. The best adsorption efficiency of the nanocomposite was 114.4 mg.g-1. Reactivation appears to indicate that the material could be utilized repeatedly and has a better ability to resist interference. In addition, the percentage removal of BB dye by hydrogel from aqueous solution were above 91.40%. Therefore, the hydrogel appears great potential for the wastewater.

This study used an applied method to remove toluidine blue (TB) and malachite green dye (MG) via limestone residue as an adsorbent. The results showed dat the TB and MG dyes were removed at a weight (4.0 g and 2.5 g) of limestone residue, pH (10 and 7), temperature (298 oK and 303 oK), and removal rate (98.07% and 99.65%) based on an equilibrium time 40 min with a granular size of 300 µm, respectively. The recovery, RSD (%), and absorption capacity (AC) for TB and MG were obtained at (98.8, 1.4, 1.98 mg g-1) and (96.1, 0.89%, 0.55 mg g-1), respectively, by UV-Vis spectrophotometers. The adsorption isotherms of the dyes and their applicability were studied using the Lankmeyer and Freundlich equations. The results also obtained showed dat the application of the adsorption process to the Tamkin, Freundlich, and Lankmeyer equation through the values ​​of the correlation coefficient (R2), where the values ​​for TB dye were (0.96, 0.81, 0.043) and for MG dye (0.9526, 0.7193, 0.819), respectively. Due to the thermodynamic studies, the positive ∆Go values ​​for toluidine blue dye (8.986, 9.293, 10.17, 10.12) and negative ∆Ho for malachite green dye (7.756, 8.015, 8.288, 8.614) were achieved at temperatures (293, 303, 313, 323oK), respectively. So, ∆Go values indicate dat the adsorption processes were non-spontaneous and showed TB dye with positive ∆Ho values ​​is endothermic, and MG with negative ∆Ho indicates exothermic. The positive entropy values ​​indicate increased randomness when their is contact between the adsorbent surface and the dye solution.

The study presents of Synthetic gel beads (Orbeez balls), specifically targeting their application in the adsorption of Direct yellow (DY) dye. Advanced characterization techniques like FTIR, FESEM, and TEM were employed, revealing significant findings. FTIR analysis showed changes in band intensities after dye adsorption, indicating gel beads -dye interactions. FESEM analysis revealed a more porous surface post after adsorption, enhancing adsorption efficiency. TEM corroborated the uniform distribution of gel beads. The study also explored the impact of gel beads on dye adsorption, identifying an optimal concentration for maximum capacity. An inverse relationship between adsorbent surface weight and dye adsorption per unit weight was observed, underlining the importance of surface weight in dye removal efficiency. The equilibrium time for DY dye adsorption was found to be around 2 hr, with a rapid initial adsorption rate that slowed over time. The study also found that adsorption efficiency decreases with increasing pH. The maximum adsorption capacity (Qe mg/g) determined for gel beads was determined to be 110.56 mg/g. increase adsorbent dosage increase removal percentage (E %) of 64.76% to 95.9 %, but decrease adsorption capacity (650.76 mg/g to 95.66 mg/g), for gel beads of DY dye. Adsorption isotherms indicate a multilayer process on a heterogeneous surface.

The field of nanotechnology has demonstrated remarkable potential in effectively addressing environmental issues through remediation, particularly in extracting and removing pollutants from water, air, and human samples. The unique properties of nanomaterials, such as their high surface area (HSA) to volume ratio, size, and optical and magnetic behavior, make them well-suited for various applications in pollution control in different matrixes. Nanotechnology-based adsorbents are utilized in multiple fields such as water wastewater treatment, air purification filters, photocatalysis, environmental monitoring, electrochemical sensors, industrial, human sample analysis, and bioanalysis. Nanoadsorbents such as carbon nanotubes (CNTs), graphene (G), metal oxide nanoparticles, metal-organic frameworks (MOFs), nanocomposites, magnetic nanoparticles, and silica-based nanomaterials are materials at the nanoscale that can remove pollutants by solvent extraction, membrane separation, photocatalysis, sorption, filtration, adsorption, precipitation, ion exchange, bioremediation, phytoremediation, coagulation, flocculation, and chemical oxidation/reduction technique. These nanomaterials are designed to have high surface areas and unique properties that effectively absorb various contaminants. The choice of nano adsorbent depends on the specific pollutants targeted, the environmental conditions, the physicochemical characteristics of the pollutant, and the desired application. Ongoing research is exploring new nanomaterials and optimizing existing ones to improve efficiency and address potential environmental and safety concerns. In summary, nanotechnology holds great potential for extracting and removing pollutants in water, air, soil, and human samples, using innovative methods for environmental protection and public health.

Electrocoagulation has demonstrated its efficacy in treating industrial effluents by effectively removing pollutants, particularly metallic contaminants. The electrochemical processes occurring at aluminum electrodes have shown excellent performance in this regard. In this study, electrocoagulation experiments were conducted on an industrial effluent originating from an electroplating bath situated in Casablanca, Morocco. The primary objective was to eliminate chromium in the effluent and reuse the processed water for other applications within our  facility. To achieve this goal, we systematically optimized various operational parameters influencing the electrocoagulation efficiency, including electrical voltage, electrode material, stirring speed, and electrode spacing. Additionally, we assessed their impact on pH, conductivity, and chromium concentration. The experiments were conducted in a well-mixed reactor using an industrial solution containing a high concentration of chromium, specifically 1 g/l of Cr (VI). The chromium removal efficiency was evaluated under specific operational conditions, including the use of aluminum electrodes, regulated voltages of 6 volts and 12 volts, an optimal stirring speed of 600 rpm, and an electrode spacing of 2 cm.

It is always a concern to ensure personnel and environment safety in the field of chemistry which has caused to development of green analytical chemistry methods. Green chemistry aims to create an eco-friendly environment in laboratories by using various analytical methods/strategies to reduce the use of toxic solvents which are harmful to humans and the environment. It is a way that protect the environment by using green solvents and methods. Green analytical chemistry is a rapid analytical technique that describes the separation, identification, and quantification of an analyte in drugs, environments, and humans. Various green methodologies such as automation, miniaturization, precipitations, and passivation are utilized in the recovery of solvents and reagents. Green analytical chemistry aims to create an eco-friendly environment in the laboratories by using various analytical methods/strategies to reduce the use of toxic solvents which are harmful to the environment/humans as well as to decrease the amount of waste generated. In this review, we explore different green solvents that can replace other toxic solvents used during extraction processes. In this review, the various extraction methods and analytical techniques used to analyze different components have been discussed.

In the present work, a copper nanowire loaded on activated carbon (Cu-NW-AC) was fabricated and applied as an effective adsorbent for the removal of bromophenol blue (BPB) dye from aqueous solutions and then the percentage of removal was evaluated by UV–Vis spectrophotometer. The synthesized adsorbent was characterized and identified using techniques like Transmission electron microscopy (TEM) and Brunauer–Emmett–Teller (BET). The effective parameters of the removal process were investigated and optimized by experimental design methodology (EDM) based on response surface methodology (RSM) as a powerful optimization method. EDM is a unique method for following the effects of different factors on the removal process simultaneously. Analysis of variance (ANOVA) was used based on p-values and F-tests to investigate the accuracy and reliability of the used method. The optimized parameters were obtained as BPB concentration of 15 mg L-1, ultrasonic irradiation time of 14 min, adsorbent dosage of 0.018 g and pH= 5.5 under the desirability function. To evaluate the adsorption mechanism and calculation of maximum adsorption capacity, different adsorption isotherms were studied and according to the results, the Langmuir isotherm model showed the highest compatibility due to its higher R2 (0.9905). Also, the proposed adsorbent represented good adsorption capacity (123.45 mg g-1).

In this work, a coal fly ash (CFA) as a waste generated from chimney furnaces was tested as a low-cost adsorbent to streptomycin (SPM) drug removal from aqueous solution. Treatment of the samples coal fly ash was performed to reduce cost the of end use. CFA composition depends on the kind of coal utilized and has crystalline and no crystalline character. CFA is a valuable material and extensively utilized in cement production and as a higher adsorbent for water treatment. The physical properties like surface area, morphology, porosity, and chemical composition (alumina, iron oxide, silica, and titania) make CFA efficient material for wastewater treatment. The CFA was characterized via chemical and physical techniques, like FE-SEM, TEM, and EDX. The best optimum condition of adsorption method for SPM drug removal onto CFA, several factors were studied like, effect of contact time solution pH, concentration of drug, adsorbent dosage, and solution temperature. The percentage removal of SPM drug increased while the modified CFA dosage increased. The removal percentage % of drug increased with decreased drug concentration, also increased with increase quantity of CFA. The best of SPM drug removal found 91.76 % at concentration of drug 10 g/mL, adsorbent dosage 0.05 g, temperature 25 oC, and solution pH of 6.6. The adsorption models were tested with two isotherms like isotherm Langmuir, and isotherm Freundlich, the adsorption model was found to follow the model Freundlich.

This study demonstrates peanut shells as a potential inexpensive and ecofriendly adsorbent for adsorption of streptomycin drug from aqueous solution via batch adsorption method. Reaction isotherm studies were carried out at several experimental conditions of concentration of streptomycin drug (10-100 mg/g), adsorbent dosage (0.1-2 g), equilibrium time (5-60 min), and solution pH (3-10). The adsorbent surface was characterized via field emission scanning electron microscopes (FE-SEM) and transmission electron microscopy (TEM). The best adsorption efficiency of drug on to peanut shells was observed as high as 1.677 mg/g. The removal percentage % of streptomycin drug rise with increasing weight of peanut shells as well as solution of pH. Equilibrium of streptomycin drug on to peanut shells rind is found to be quick, and equilibrium to reached in 60 min. Langmuir isotherm and Freundlich isotherm models were useful to fit the result of equilibrium peanut shells, and it was noticed that isotherm Freundlich fits the multilayer peanut shells ability for drug was 1.455 mg/g. These data demonstrated that peanut shells are locally available, ecologically, effective and inexpensive adsorbent for the adsorption of Streptomycin drug from aqueous solution.

Todays, activated carbon derived from biomass sources has wide applications. In this study, activated carbon of tea waste has been considered for adsorption of phenylephrine hydrochloride drug from aqueous solution via batch adsorption process. The adsorption tests were carried out under several conditions such as equilibrium time, pH, adsorbent dose, and temperature. FESEM, TEM, and EDX techniques applied for characterization of activated carbon of tea waste before and after adsorption. The equilibrium results fitted to Langmuir and Freundlich isotherm models and it has been described as well via Freundlich model with best multilayer adsorption efficiency. According to analyses and experimental data, activated carbon of tea waste as a low cost, economically feasible and abundantly available adsorbent has great potential to high removal efficiency for phenylephrine hydrochloride drug.

This s tudy developed an applied method based on the degradation to remove ethylene bisdithiocarbamate (EBDC) fungicides from was tewater and agricultural runoff by zinc oxide nanoparticles (ZnONPs). The synthesized ZnONPs were characterized using XRD for material crys tallinity, scanning electron microscope (SEM) and particle size analysis (PSA) for surface s tructure, morphology and particle size (nm), respectively. The energy-dispersive X-ray spectroscopy (EDX) spectra confirmed the presence of zinc and showed that the synthesized zinc oxide nanoparticles were pure. Determination of the adsorption and photocatalytic degradation of Mancozeb (MCZ) fungicides based on ZnONPs was performed. Different amounts of ZnONPs were loaded into an MCZ fungicide solution in different concentrations. High-performance liquid chromatography (HPLC) and UV-Vis spectroscopy were used to determine the dithiocarbamate residue and the degradation efficiency of the synthesized particles. The particle size dis tribution of the synthesized ZnONPs was found to be in the range of 50-95 nm. At optimum conditions, with a ZnONPs dosage of 10 mg, (MCZ) fungicide concentration of 9.37 mg L-1, and a duration of 60 minutes, the degradation efficiency was surpassed at more than 95%. Additionally, the nanoparticles demons trated excellent reusability and maintained efficient activity for up to three cycles. It is crucial and significant to keep on exploring the intrinsic capabilities of abundant metal oxides like zinc oxide nanoparticles for environmental remediation and other applications.

In this s tudy, manganese (Mn II) was determined in aqueous media by an electrochemical method, and its removal was evaluated using the aeration-filtration process (AFP). An electrochemical sensor based on carbon pas te (EPC) modified with the 5-Br-PADAP ligand was used to measure Mn (II) in aqueous media. Through the optimization of analytical parameters in cathodic s tripping voltammetry (CSV), real boreholes and well water samples could be analyzed for manganese content. The optimum parameters such as preconcentration potential (1100 mV), preconcentration time (240s), 5-Br-PADAP ligand concentration (20 μmol L-1), and electrode rotation speed during pre-concentration (1000 rpm) were s tudied and optimized. The detection limit (LOD) is es timated at 3 ×10-7 mol L-1 with a relative s tandard deviation (RSD) of 3.36%. The real samples showed that some water points have more concentration than the s tandard. A simple, effective, inexpensive, and rural-friendly method was used for treating manganese-rich water. Following the aeration phase, the sand and gravel column was filtered toremove manganese (II) from the water. The removal efficiency of Mn was obtained at a rate of 74.8- 84.5% and more than 95% after two hours of aeration and 1 hour at pH 8 for real samples.

Traditional techniques for adding chelating agents to solids take time, energy, and materials. This study focuses on the preparation of a quick and easy solid-phase extraction approach using microwave-enforced green synthesis. CuFe2O4 magnetic nanoparticles (CFO-NPs) were modified chemically by bis(salicylaldehyde) phenylenediamine (BSAPhD) investigated for Cu(II) removal from aqueous solutions. The modification conditions (power and time) of the process are optimized. The performance of the resulting magnetic composite nanoparticles (BSAPhD@CFO-NPs) was compared with that of those prepared using a conventional reflux method (BSAPhD/reflux@CFO). BSAPhD@CFO-NPs was characterized using Fourier-transform infrared spectroscopy (FT-IR) and transmission electron microscopy (TEM). All the data confirmed the success of the preparation of BSAPhD and modification for CFO with BSAPhD via microwave synthesis. The experimental adsorption conditions: pH, contact time, adsorbent mass, and Cu(II) concentration were also optimized. BSAPhD@CFO-NPs has an adsorption capacity of 429.8 mg-Cu(II) g–1, which is more than that of BSAPhD/reflux@CFO (287 mg g-1) at pH = 8 with 15 min contact time. The Freundlich, Langmuir, and Temkin isotherms are used to describe adsorption equilibrium. It was found that the Langmuir model (R2 = 0.9988) best fits Cu(II) adsorption on the BSAPhD@CFO-NPs adsorbent surface. The application of the BSAPhD@CFO-NPs adsorbent for the removal of Cu(II) from various water samples was performed. The results showed good recovery with high sensitivity.

In the present study, HKUST-1 (Hong Kong University of Science and Technology), HKUST-1@PVA, and Fe3O4@HKUST-1, metal-organic framework, were synthesized by hydrothermal, post-synthetic modification and pre-synthetic modification methods, respectively. These sorbents were applied to remove the meloxicam drug as the model drug from aqueous solutions. The adsorption isotherm, kinetic, and thermodynamic experiments were done and confirmed that the adsorption behaviors of HKUST-1, Fe3O4@HKUST-1, and HKUST-1@PVA are based on Langmuir isotherm (the values of qmax were obtained as 883.33, 2.50E+03 mg/g for HKUST-1@PVA and Fe3O4@HKUST-1, respectively) and Freundlich isotherm (the values of KF were obtained as 3.02E+03 (n=0.74), 7.24E+03 (n=0.99) and 7.99E+04 (n=1.49) for HKUST-1, Fe3O4@HKUST-1 and HKUST-1@PVA, respectively), with an endothermic mechanism and enthalpy-driven process. The kinetic results showed well-fitting with the pseudo-second-order kinetic model for all of them. The speed of the adsorption process, low cost, high efficiency, and high surface area are the main advantages of the proposed compounds as sorbents. The functionalization of HKUST-1 with magnetic nanoparticles decreased the adsorption time, and with PVA provides more functional group on the surface of HKUST-1 and increases its adsorption efficiency. Further, an easy separation with an external magnet in 30 seconds is another advantage of magnetic functionalization. The aforementioned features make these adsorbents appropriate candidates for cost-effective water treatment.

In this study, removal of three toxic chemical pollutants, such as crystal violet (CV) dye, tetracycline (TC) drug, and phenol (PH) using sodium alginate-g-poly (acrylicacid-co-sodium, 4-ethenylbenzenesulfonate, hydrate)/Zinc oxide, and SA-g-poly(AC-co-EBS)/ZnO hydrogel composite was prepared by co-polymerization method by addition of free radicals. The hydrogel composite was characterized by TEM, FESEM, and XRD. Removal of laboratory sample aqueous pollutants (dyes, drugs, and phenol) using hydrogel composite to give low absorbance (0.0001) utilizing UV-Vis spectrophotometer for at a chosen wavelength for 2 h. Comparative between ((SA-g-(PAAc-co-EBS)/ZnO, (SA-g-(PAAc-co-EBS), and ZnO NPs) surfaces as adsorbents. The best results of the percentage of removal (E%) of three pollutants arrange in order increasing (SA-g-(PAAC-co-EBS)/ZnO NPs > SA-g-(PAAC-co-EBS) > ZnO NPs), the good results of the percentage removal (E%) of hydrogel composite, (92, 451%, 87.56%, and 82.56%) for CV, TC, and PH, respectively. Likewise, comparative between the amount of Zinc oxide nanoparticles (ZnO NPs) decorated of (SA-g-(PAAC-co-EBS) using (0.05, 0.08, 0.1, and 0.15 g). The good results of the percentage of removal (E%) of three pollutants about 0.1 g ZnO NPs. Re-cyclability and desorption studies indicated the best re-cycling performance of the prepared composite. Based on the results, the prepared hydrogel composites can be useful as a promising, ecological, cost-effective, and efficient material for dyes decontamination. Studies was carry out using several desorption agents at concentration (0.01 N) like HNO3, NaOH, H3PO4, H2SO4, HCl, and water. The hydrogel composite, was regeneration with 100% can be desorbed in diluted hydrochloric acid (0.01 N). The isotherm Freundlich and Langmuir models are also introduced, it has been found that all results follow the Freundlich model in the presence of three pollutants; this nonlinearity is higher when using the Freundlich model.

In this study, the removal of vitamin B2 from the aqueous solution using a synthesized multi-component nano-magnetic adsorbent modified by orange peel was studied. The structure and the morphology of the prepared nanocomposite were characterized using Fourier Transform InfraRed (FT-IR), X‐Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Brunauer–Emmett–Teller (BET), and Dynamic Light Scattering (DLS) techniques. The average size of the synthesized nanoparticles was 80 nm. The effect of experimental parameters such as pH, amount of adsorption, and contact time on vitamin B2 adsorption was investigated. Response Surface Methodology (RSM) based on the Central Composite Design (CCD) was used to obtain the optimum conditions for removing vitamin B2. Results revealed that the pH=5, adsorbent dosage of 0.4 g, and contact time of 180 min were obtained as optimum conditions. The isotherms (Langmuir, Freundlich, Temkin) and kinetic (pseudo-first-order, pseudo-second-order) studies were assessed. The data were fitted well with Langmuir (R2=0.9984) with qmax=53.47 mg/g and pseudo-second-order (R2=0.9984) models. The results showed that the two-component magnetic nanoparticle modified with orange peel, as an adsorbent, was suitable for the process of vitamin B2 adsorption from the aqueous solution.

In this study, the PVP/NiO nanocomposite was synthesized using the solution cast technique and characterized by Fourier transform infra-red (FT-IR), X-ray powder diffraction (XRD), thermogravimetric analysis (TGA), differential thermal analysis (DTA), energy-dispersive X-ray spectroscopy (EDS), and scanning electron microscope (SEM). The results confirmed the successful preparation of PVP/NiO. The as-prepared PVP/NiO was used as a new adsorbent for the removal of eosin Y (EY) dye from aqueous solution at room temperature. The effect of different important parameters such as solution pH, adsorbent dose, and contact time on the adsorption efficiency of EY was investigated. The maximum adsorption capacity was found to be 101.58 mg/g at the initial pH solution of 3, 0.025 g adsorbent dose, and 90 min of contact time. The kinetic study indicated that the remove of EY was followed by a pseudo second-order (PSO) model. Then, the as-prepared PVP/NiO possessed well adsorption potential for the removal of other organic dyes from aqueous solution.

Polymer-based antimicrobial nanocomposite adsorbents have emerged as promising materials for water purification due to their unique properties, including high surface area, low cost, abundance, and ease of interaction with contaminants. These materials can be prepared using a variety of methods, including solvent casting, in situ polymerization, and electrospinning. The application of polymer-based antimicrobial nanocomposite adsorbents in water purification has been widely reported in the literature, with promising results for the removal of a wide range of pollutants, including heavy metals, organic dyes, and bacteria. This review manuscript aims to provide a comprehensive overview of polymer-based antimicrobial nanocomposite adsorbents for water purification. The review will begin with a discussion of the different types of polymer-based antimicrobial nanocomposites and the methods used to prepare them. The next section will review the application of these materials in water purification, with specific examples of their use to remove various pollutants. Finally, the review will conclude with a discussion of the challenges and opportunities for the future development of polymer-based antimicrobial nanocomposite adsorbents for water purification. This review will be of interest to researchers and practitioners in the field of water purification, as well as those working on the development of new materials for environmental remediation.