جستجوی مقالات مرتبط با کلیدواژه "Adsorption" در نشریات گروه "پزشکی"

This study synthesized a nanocomposite using corn cob fiber and ZnFe₂O₄, characterized by electron microscopy, X-ray diffraction, infrared spectroscopy, and surface porosity analysis. The research focused on evaluating the adsorption capacity and kinetics of this nanocomposite for removing malathion and bendiocarb, representing organophosphate and carbamate pesticides, respectively.

The nanocomposite was prepared and characterized using various techniques. Adsorption experiments assessed the removal efficiency of the pesticides under different conditions, including contact time, initial pollutant concentration, pH, and nanocomposite dosage. Kinetic studies utilized pseudo-first-order (PFO) and pseudo-second-order (PSO) models.

Rapid adsorption occurred within the first 20 minutes, with removal efficiencies of 45.4% for malathion and 40.5% for bendiocarb. Final efficiencies reached 49.3% for malathion and 47.7% for bendiocarb at 85 minutes. Optimal contact times were around 30 minutes for malathion and 40 minutes for bendiocarb. The PSO model provided a better fit, with higher equilibrium adsorption capacities (116.3 mg/g for malathion and 129.9 mg/g for bendiocarb). pH had a positive but minor effect on removal efficiency, and a dosage-dependent increase was observed, with a saturation point beyond 10 mg of nanocomposite.

The corn cob fiber and ZnFe₂O₄ nanocomposite effectively removed malathion and bendiocarb from aqueous solutions. Key factors influencing adsorption included contact time, pH, and nanocomposite dosage, highlighting the nanocomposite's potential for pesticide removal applications.

In this study, silica sands from the commune of Houéyogbé were used to synthesize silica particles by the sol-gel method, using sodium silicate as the reaction precursor. Analysis by X-ray diffraction, infrared spectroscopy, and scanning electron microscopy revealed the formation of pure amorphous silica with spherical shapes. This material was used as an adsorbent to remove 2,4-dichlorophenoxyacetic acid, one of the pesticides most widely used by farmers in Benin. The use of pesticides is a major environmental problem due to their toxicity. Pesticides pollute soils, surface, and groundwater, and it is, therefore, important to find a way of mitigating or even eliminating their effects on the environment. Adsorption tests for this pollutant were carried out in batch mode. The adsorption study showed a maximum of over 90%. The kinetic study indicates that adsorption is effective from the first five (5) minutes and becomes established after one hour. The L-type adsorption isotherm shows that pesticide adsorption takes place by progressive saturation (monolayer).

Sustainable and green adsorbents for water and wastewater treatment have gained attention worldwide in the last decades. Water contaminated with humic substances (HSs) has become an emerging human health threat due to producing disinfection by-products (DBPs) which react with chlorine and result in carcinogenic materials such as THMs. This study was conducted to remove HSs from aqueous solutions using nano-scale biosorption based on watermelon rind (WR), as a cost-efficient adsorbent. The effects of factors such as time, adsorbent dosage, pH and concentration, and then reaction kinetics and isotherms on the adsorption process were investigated. FTIR, XRD, BET analysis SEM, and also TEM were used to evaluate the structural characteristics of the adsorbent. The characteristics showed that increasing the temperature of thermal oxidation and loading of NH4Cl on the adsorbent surface increases the porosity and surface area, leading to an increase in adsorption performance. Also, given effective factors that increase the time and dose of adsorbent and reduce the initial concentration, The removal efficiency of humic acid (HA) increased with the following conditions: time 45 min and pH=4 and the adsorbent equal to 0.1 gr/L at a concentration of 50 mg/L, the removal efficiency of HSs reached 93.89%. The experiments showed that the adsorption process showed a better match with the pseudo-quadratic synthetic model with a coefficient of determination R²=0.99, while the adsorption isotherm was consistent with the Langmuir adsorption model. Studies have shown that adsorption occurs in a single layer. The thermodynamic parameters show that the process is spontaneous.

Congo red (CR), a harmful dye present in water, requires effective removal methods. This study investigated the utilization of dry green pea husk (DGPH) and its charcoal (CGPH) as economical and eco-friendly adsorbents.

Various factors, including contact time, pH, adsorbent dosage, initial concentration, and temperature, were investigated to assess their impact on the adsorption process. Also, different models (isotherms, kinetics, and thermodynamics) were compared to describe the adsorption phenomenon.

Equilibrium adsorption was achieved within 30 minutes for both adsorbents. The optimum pH for CR removal was determined to be 2. The adsorption capacity decreased by increasing the adsorbent dosage, whereas it increased by increasing the initial dye concentration. The Langmuir isotherm model demonstrated the best fit for DGPH, while the Freundlich model exhibited the best fit for CGPH. The pseudo-second-order model displayed a superior fit for both adsorbents. To assess the spontaneity and feasibility of the adsorption process, thermodynamic parameters including enthalpy, entropy, and Gibbs free energy were computed. The results indicated that the adsorption of CR on DGPH was endothermic and favorable at lower temperatures, whereas the adsorption on CGPH was exothermic and favorable at higher temperatures. The negative values of Gibbs free energy for the CGPH adsorbent confirmed the spontaneous nature of the adsorption process.

The study establishes that green pea husk and its charcoal are effective and environmentally friendly alternatives for the removal of CR from water.

Pollution caused by heavy metals, due to their toxicity and harmful effects on plant species, is considered one of the fundamental problems. The unique properties of graphene oxide (GO) in adsorbing heavy metals from contaminated soil systems have garnered attention in the past decade. This study evaluates the effects of different doses of graphene oxide (0.5 and 1.5 g kg-1) on the adsorption and distribution of heavy metals, including Cadmium (Cd) and Copper (Cu) fractions, in soil contaminated with two rates (2% and 10%) of sewage sludge (SS) over a 92-day period. Subsamples were collected from the soils at intervals of 5, 15, 29, 57, and 92 days, air-dried, and subjected to metal fractionation. The aim was to evaluate the separation of Cd and Cu by employing a five-stage sequential extraction technique, where each stage involved 2 grams of air-dried soil as a sample. The overall metal quantity in the treatments was determined by utilizing aqua regia digestion. The recovery rate was determined by calculating the percentage of the total metal concentration obtained from acid digestion, involving the summation of the concentrations of the five metal fractions. The results showed that the F1 fraction of heavy metals in the soil with a 2% SS rate decreased with an increase in GO dosage. The calculated mobility factor of the metals at five incubation times (5, 15, 29, 57, and 92 days) was found to be in the range of 28.1-60.9 for Cd and 14.4-25.3 for Cu, indicating a higher mobility of Cd. The findings suggest that the presence of GO as an adsorbent and the incubation time were critical parameters in stabilizing heavy metals in the soil with different rates of SS. Additionally, the nature of the applied SS was found to influence the fractionation of heavy metals in the soil, besides providing elements.

Ensuring access to safe drinking water is a significant health issue in contemporary society. Industrial dyes, such as Methylene Blue (MB), play a substantial role in water pollution, making water unsuitable for consumption. In this research, the three-dimensional sponge-like mesoporous material TUD-1, doped with two different metals (Sn and Al) at two Si-to-metal ratios (25 and 50), was synthesized and utilized as an adsorbent for the removal of MB via the adsorption method. The adsorption data underwent analysis using the Langmuir and Freundlich isotherm models. Notably, for Sn25-TUD-1, Sn50-TUD-1, and Al50-TUD-1 adsorbents, the Langmuir model exhibited a better fit than the Freundlich model. Conversely, for Al25-TUD-1, the Freundlich model provided more accurate predictions. All adsorbents were assessed using the pseudo-second-order kinetic model. Remarkably, all prepared adsorbents effectively removed MB from water. Particularly, Sn50-TUD-1, with a remarkable BET surface area of 866 m² g⁻¹, demonstrated the highest performance with the removal capacity of 1785.6 mg g-1, at pH 7-10 and reached 1689.6 mg g-1 after five cycles of recycling. A possible mechanism for the adsorption of MB on M-TUD-1 is proposed. This research highlights the potential of TUD-1 adsorbents for efficient MB removal from wastewater.

The research carried out an inquiry into the efficiency of C8B6N6 nanoclusters as both an adsorbent and a sensor for the elimination and identification of sulfamethoxazole (SMZ) using density functional theory computations. The results of the study showed that the interaction between SMZ and C8B6N6 is not only possible but also releases heat and occurs naturally, indicating the potential of C8B6N6 as a very effective adsorbent for eliminating SMZ. Additionally, the study explored the impact of water as the solvent and different temperatures on the thermodynamic parameters, ultimately revealing that these factors did not have a significant effect on the connections. Moreover, the analysis of Frontier Molecular Orbital (FMO) uncovered significant alterations in the bandgap of C8B6N6, from 8.101 (eV) to 4.875 (eV) (-40.933%) during the adsorption process, hinting at its likelihood to be a helpful electrocatalytic modifier for the electrochemical detection of SMZ. The study also thoroughly examined several other FMO parameters. In conclusion, this investigation offers valuable insights into the promising capabilities of C8B6N6 as a highly effective adsorbent and sensor for the elimination and detection of SMZ.

In the current investigation, the utilization of sawdust was modified through chemical means employing diethylenetriamine. This modified form of sawdust served as an effective adsorbent for the purpose of adsorbing Eosin Y dye from aqueous samples. The chemical modification procedure was thoroughly examined, comparing the fourier transform of infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) before and after the modification. Various factors including solution pH (ranging from 2 to 6), adsorbent dosage (ranging from 0.2 to 2.0 g L-1), contact time (ranging from 5 to 35 min), agitation rate, and initial dye concentration (ranging from 20 to 1000 mg L-1) were investigated. Remarkably, the modified sawdust exhibited a notable uptake capacity at ambient temperature and successfully removed approximately 96% of the Eosin Y dye with a mere 1.2 g L-1 of adsorbent in just 5 minutes. Moreover, it was discovered that the adsorbent maintained its promising adsorption ability even after undergoing ten cycles of adsorption and desorption. The Freundlich isotherm model was employed to determine the adsorption parameters. This methodology was also implemented to eliminate dye from authentic samples of diverse water sources.

An Eco-friendly and low-cost adsorbent surface was prepared from oxidized black tea leaves for adsorption of Malachite Green (MG) dye by batch equilibrium adsorption technique and investigated the optimum conditions that include dose of adsorbent, contact time, adsorbent particle size, pH, and initial concentration of the dye. All adsorption measurements were performed using spectrophotometry at 618 nm, the maximum wavelength of MG. Maximal adsorption was obtained at 1.0 g of oxidized black tea leaves with a contact time of 120 min. The optimal pH was 8. The maximum adsorption capacity was 97.8 mg g-1. The physic processes were used to prepare the adsorbent surface from oxidized black tea leaves. These included boiling the oxidized black tea leaves for 10 hours using distilled water, filtering, washing, and drying at 80°C. Physic preparation gave a suitable surface for the adsorption process. The adsorption of MG on the surface of tea leaves obeyed the Freundlich and Langmuir equations in adsorption. Isotherm parameters of Freundlich and Langmuir modules were estimated.

Water is the most essential natural resources in the ecosystem and vital for the existence of all living beings as well as humans growth. Due to the rapid industrialization, water pollution is now the most vital matter of concern. A common ecological issue is water pollution with heavy metals, such as lead (Pb) and mercury (Hg), which has become a major environmental problem due to the detrimental consequences on human health and ecosystems. Additionally, research into new and more effective water treatment methods is being driven by the persistence, toxicity, and accumulation of Pb and Hg in the human body. This is done to reduce the amount of Pb and Hg in water. To remove or lower the amount of Pb and Hg in water, several researchers make substantial use of the adsorption. Adsorption continues to be a practical method with flexible design and execution. In the past few years, nanotechnology has come to be a promising approach for the remediation of water polluted with these hazardous metals by adsorption. It will become more and more difficult to deploy technologically sophisticated alternative water treatments to meet the growing demand for lower levels of Pb and Hg in drinking water using current methods. Compared it to alternative approaches, nanotechnology has a lot of benefits. Nanoparticles, owing to their unique physicochemical properties, have garnered attention as competent adsorbents for Pb and Hg removal from water. This review gives an in depth account of several nanoparticle preparation methods. The review also highlights the recent advancements in the application of different nanoparticles for the remediation of Pb and Hg from aquatic environments.

The research investigated the performances of pristine and Si-doped fullerenes (C20 and SiC19) as an adsorbent and sensor for the removal and detection of methyl paraben (MP) using density functional theory computations. The results indicated that MP interaction with C20 is experimentally impossible, endothermic, and non-spontaneous, suggesting that C20 is not an effective adsorbent for the removal of MP. On the other hand, MP adsorption on the surface of SiC19 is experimentally feasible, exothermic, spontaneous, and thermodynamically reversible, indicating that SiC19 could be a potential adsorbent for the removal of MP. The study also scrutinized the effects of water as the solvent and changing temperature on the thermodynamic parameters. The findings revealed that both parameters do not have any meaningful effects on the interactions in the case of both adsorbents. Additionally, the Frontier Molecular Orbital (FMO) analysis showed that SiC19is more conductive than C20. Moreover, the bandgap of C20 did not experience significant changes during the adsorption process, while the bandgap of SiC19 decreased from 5.840 eV to 3.270 eV. This implies that Si-doped fullerene can be utilized as a good electrocatalytic modifier for the electrochemical detection of methyl paraben. In conclusion, the research provides valuable insights into the potential use of Si-doped fullerene (SiC19) as an effective adsorbent and sensor for the removal and detection of methyl paraben.

Heavy metals are known to be toxic for living organisms even if they are present at low levels. Water pollution by heavy metals from industries is a dangerous environmental problem. Due to the ease, flexibility, and cost-effectiveness of the remediation process, adsorption has been widely implemented in heavy metal wastewater treatment. In the present study, nanostructured manganese oxide was used for the removal of the heavy metal ions from aqueous solutions by a batch adsorption method and have been modelled using classical Langmuir and Freundlich adsorption isotherms. we have successfully synthesized an efficient adsorbent through a cost-effective and eco-friendly method. Bio synthesis is widely applied for the synthesis of nano materials . Various techniques such as XRD, FTIR, SEM EDX ,TEM and UV–VIS spectroscopy have been used to characterize the nanometal oxide. The obtained nano manganese oxide rods have very good adsorption efficiency due to the presence of some functionalities associated with the oxide material.

In recent years, the presence of various pharmaceutical residues such as cefixime (CFX) in aquatic environments has been gaining attention due to its adverse effects on health and ecosystems. Since conventional treatment methods are unable to remove antibiotics, sustainable and efficient approaches are needed to remove these compounds from aquatic environments. In this study, granular ferric oxide (GFO) was used to remove CFX, and the experiments were designed using Design Expert software. The findings were then analyzed using ANOVA test. The results showed that the proposed regression model fit the experimental condition (R2=0.9701, R2 adjusted=0.9432, R2 predicted=0.83). Several residual plots were used to confirm the suitability of the model. The initial concentration of 1.84 mg/L, GFO dose of 3.05 mg/L, and contact time of 24.32 minutes were found to be the ideal conditions for CFX adsorption. Moreover, the findings showed that GFO can be effective in absorbing and removing CFX from aqueous environments.

Here we report a simple and eco-friendly solvothermal synthesis of graphitic carbon nitride nanospheres (g-CNNS) at 180 oC. The synthesized g-CNNS is characterized by various analytical techniques such as FESEM, PXRD, BET isotherm, Zeta potential, EDX and FT-IR spectroscopy. The adsorption property of g-CNNS is studied using four different dyes in aqueous medium and found that g-CNNS is an efficient material for cationic dye adsorption. A Comprehensive investigation of the kinetics, isotherms and thermodynamics of methylene blue (MB) adsorption, is carried out. The adsorption of MB on g-CNNS is well described by Langmuir isotherm model, and the experimental data fits well with pseudo-second order kinetics. The high rate of adsorption (94.92% MB removal in 120 minute at neutral pH) is attributed to electrostatic interaction between negative charged g-CNNS and cationic organic dye molecule. Additionally, g-CNNS demonstrated good reusability, retaining its efficiency for at least three cycles. Over all our findings suggests that g-CNNS has potential as an efficient adsorbent for wastewater treatment.