Removal Of Cadmium Ions Research Articles

Green Synthesis of CdS Nanoparticles and their Potential Application towards Adsorption of Lead and Cadmium ions

Watermelon rind aqueous extract mediated synthesis of CdS nanoparticles was investigated for its efficiency towards removal of lead and cadmium ions from aqueous solutions. Batch adsorption investigations were performed to optimise the experimental conditions. The optimised conditions were found to be pH 6, 1 g L-1, 30 min and 303 K respectively for the removal of lead and cadmium ions. The equilibrium data obtained was analysed with isotherm models and it was found that Langmuir and Freundlich isothersm explain better and the loading capacities were found to be 332.2 and 318.7 mg L-1 respectively for Pb2+ ad Cd2+ ions. Kinetic investigations suggest that pseudo second order kinetic model fits well to the experimental data suggesting that chemical reactions govern the rate limiting step. The spontaneous and exothermic nature of the present process was successfully demonstrated by the thermodynamic investigations. Desorption and regeneration studies suggest that the CdS nanoparticles can be successfully regenerated 5 times and reused in the adsorption process.

Detection and removal of cadmium ion by a neoteric polyethylenimine carbon dots @ lanthanum orthoferrite nanocomposite

In this study, a fluorescent polyethylenimine carbon dots (PEI-CDs) and an adsorbent lanthanum orthoferrite (LaFeO3) are composited as PEI-CDs/LaFeO3 (LFPC), concerning simultaneous detection and removal of cadmium (Cd) ions in the aqueous medium. The fluorescent “Off-On” mechanism is used in detecting cadmium ions and the removal of Cd ions is achieved by the adsorption method. Metal ions selectivity, optimization of the sensor with pH and time, the limit of detection, batch experiments (effect on adsorption by varying pH, initial concentration of metal ions, and adsorbent dosage), and adsorption isotherm studies are carried out in a standardized methodology for effective detection and removal of cadmium ions. The sample's pH is a significant parameter for both detection and removal, here pH 6 is an optimum condition to attain high fluorescent sensitivity and adsorption efficiency. Real sample analysis is performed to check the material's practicability. The synthesized material is characterized by X-ray diffraction, UV‐Vis spectroscopy, photoluminescence spectroscopy, Fourier transform infrared analysis, scanning electron microscopy, high-resolution transmission electron microscopy and energy dispersive X-ray analysis. The lifetime of a fluorophore and zeta potential measurements support the mechanism behind the sensing and the removal of cadmium ions.

Adsorptive performance of a new magnetic hydrochar nanocomposite for highly efficient removal of cadmium ions from water: Mechanism, modeling, and reusability studies

In this study, a novel and effective magnetic watermelon seed hydrochar (MWSHC) was successfully synthesized via hydrothermal carbonization technique and in situ co-precipitation method. The prepared magnetic watermelon seed waste hydrochar has been utilized for the elimination of cadmium ions from the aqueous environment. The structural morphology, surface properties, and thermal stability of MWSHC adsorbent were characterized using FTIR, SEM, XRD, BET surface area, and TGA analysis, which demonstrated the successful synthesis of MWSHC. An extensive study of Cd(II) adsorption was conducted by assessing the influence of contact time, adsorbent mass, pH, initial Cd(II) concentration, temperature, and coexisting cations on the adsorption process of Cd(II). The results revealed that the removal efficiency of Cd(II) was 96.60% achieved at pH 7.0, time: 300 min, and dosage: 0.01 g, T: 298 K. Adsorption isotherm and kinetic parameters were estimated. The results indicated that the Cd(II) adsorption onto MWSHC followed the Freundlich and pseudo-second-order models. Based on the Langmuir equation, the MWSHC has a maximum adsorption capacity of 347.2 mg/g at 298 K. The reusability of magnetic hydrochar nanocomposite was studied, revealing that around 84.4% Cd(II) was still removed after four cycles. In conclusion, the newly- prepared MWSHC adsorbent has the advantages of high adsorption capacity, cost-effectiveness, and easy separation, thus having promising applications in effectively removing cadmium(II) from the aqueous environment.

Conocarpus lancifolius Leaves as Low-Cost, Green and Sustainable Sorbent Material for Simultaneous Removal of Cadmium, Chromium, and Lead Ions from Aqueous Samples

Conocarpus lancifolius Leaves as Low-Cost, Green and Sustainable Sorbent Material for Simultaneous Removal of Cadmium, Chromium, and Lead Ions from Aqueous Samples

Toxic heavy metal ions removal from wastewater by ion flotation using a nano collector

Industrial wastewater treatment containing heavy metal ions has been a challenge in the ion flotation process development in recent years due to the high collector consumption required to achieve maximum ion removal. To address this issue, a nano collector consisting of functionalized graphene oxide (FGO) was synthesized and applied to increase the removal of heavy metal ions (lead, copper, nickel, cadmium, and zinc) from wastewater. This study evaluated the effect of various critical operating conditions including pH, collector/frother type and concentration, gas type, gas flowrate, and energy input on ion flotation performance to improve the efficiency of the process in this investigation. It was found that using FGO not only increased the ion removal percentage but also decreased collector consumption and water recovery, all of which improved the ion flotation process performance. Under the optimum chemical and hydrodynamic conditions using FGO with much lower concentration than stoichiometry concentration resulted in the maximum removal of lead, copper, nickel, cadmium, and zinc ions with percentages of 97.07, 99.02, 98.38, 95.20, and 98.94, respectively. In optimum condition, water recovery was 8 %. The use of FGO in the ion flotation process for wastewater treatment offered significant benefits, including high adsorption efficiency, low collector consumption, recyclability, and the absence of critical micelle concentration (CMC) and frothing properties.

Removal of lead and cadmium ions from wastewater using magnetic alginate impregnated sulfur

A new adsorbent, magnetic Fe3O4 sulfonated nanoparticle caged alginate microbeads (S.MNPs@Alg), was developed for Cd(II) and Pb(II) ions removal from water, which could be effectively separated from the solution owing to the superparamagnetic property. This adsorbent was characterized using FTIR, FESEM, XRD, SEM, and VSM. The effect of parameters affecting sorption potential including pH, contact time, and adsorbent dosage was carried out. Under the best experimental condition, the Cd(II) and Pb(II) ions removal efficiencies were reported to be over 95%. To understand the nature of the sorption process, adsorption isotherms including Freundlich and Langmuir models were precisely investigated. The process is fitted well with the Langmuir model and the maximum adsorption capacity obtained was 37 mg. g−1 and 85 mg. g−1 for Cd(II) and Pb(II) ions, respectively. The as-prepared S.MNPs@Alg is easy to prepare and effective in the uptake of Cd(II) and Pb(II) ions with a physisorption mechanism, which adsorption rate is limited with the pseudo-second-order model. The adsorbent lost<5% of its removal efficiency in five adsorption–desorption cycles. Finally, the existence of sulfur groups increased adsorption capacity and decrease the toxicity of magnetic nanoparticles (MNPs) and the presence of magnetism part can facilitate the separation of the adsorbent from the solution.

Response Surface Methodology for the Optimization of Cadmium Ion Adsorption using Activated Carbon

Adsorption refers to the process of chemical species adhering to the surface of particles. Activated carbon, also known as activated charcoal, is a type of carbon widely utilized for purifying water and air by filtering out various contaminants. One of the transition metals, Cadmium (Cd), situated in the dblock and 12th group of the periodic table, possesses toxic and poisonous properties. Absorbent material was prepared using standard method. The absorbate was prepared by dissolving cadmium nitrate in distilled water. Different volume of the solution was added absorbate and later filtered and atomic adsorption Spectroscopy (AAS) was carried out. The potential of Activated carbon for removal of cadmium from contaminated water, it was found that highest efficiency in terms of percentage removal was achieved at 50 ppm initial metal ion concentration of Cadmium. The highest percentage removal was 98.5% confidence level. Therefore, the hypothesis that Activated carbon adsorbents are effective in removal of cadmium (II) ion from contaminated water at different experimental conditions is upheld

Ultrasound assisted removal of cadmium ions from wastewater using ionic liquid modified aluminium isopropoxide

Ultrasound assisted removal of cadmium ions from wastewater using ionic liquid modified aluminium isopropoxide

Optimization of Response Surface Methodology for Removal of Cadmium Ions from Wastewater using Low Cost Materials

Optimization of Response Surface Methodology for Removal of Cadmium Ions from Wastewater using Low Cost Materials

Development of ZnO-GO-NiO membrane for removal of lead and cadmium heavy metal ions from wastewater

The presence of heavy metal (HM) ions, such as lead, cadmium, and chromium in industrial wastewater discharge are major contaminants that pose a risk to human health. These HMs should separate from the wastewater to ensure the reuse of the discharged water in the process and mitigate their environmental impacts. The distinctive mechanical properties of 2D graphene oxide (GO), and the antifouling characteristics of metal oxides (ZnO/NiO) nanoparticles combined to produce composites supporting special features for wastewater treatment. This study employed solution casting and phase inversion methods to synthesize PSF-based GO, ZnO-GO, and ZnO-GO-NiO mixed matrix membranes and the effects of variation in composition on the removal of lead (Pb2+) and cadmium (Cd2+) ion was examined. Several characterization techniques including X-ray diffraction analysis, scanning electron microscopy, energy dispersive X-ray, and Fourier transform infrared spectroscopy were applied to analyze the synthesized NPs and MMMs. The composite membranes were also analyzed in terms of their porosity, permeability, hydrophilicity, surface roughness, zeta potential, thermal stability, mechanical strength, and flux regeneration at various transmembrane pressures (2–3 kgcm−2), and pH value (5.5). The highest adsorption capacities were measured to be 308.16 mg g−1 and 354.80 mg g−1 for Pb (II) and Cd (II), respectively, for membrane (M4_A) having 0.3 wt% of ZnO-GO-NiO nanocomposite, at 200 mg L−1 of feed concentration and 1.60 mL min−1 of permeate flux. The Pb (II) and Cd (II) adsorption breakthrough curves were created, and the results of the experiment were compared with the data of the Thomas model.

Removal of Cadmium Ions from Simulated Wastewater Using Rice Husk Biosorbent

Biosorption of cadmium ions from simulated wastewater using rice husk was studied with initial concentration of 25 mg/l. Equilibrium isotherm was studied using Langmuir, Freundlich, BET and Timken models. The results show that the Freundlich isotherm is the best fit model to describe this process with high determination coefficient equals to 0.983. There was a good compliance between the experimental and theoretical results. Highest removal efficiency 97% was obtained at 2.5g of adsorbent, pH 6 and contact time 100 min.

Composite Material of Clay-biochar for Cadmium Ion Removal from Water

A research study of the synthesis of nanocomposite of clay-biochar material acquired from normal clay and biomaterial of Prosopis Juliflora for cadmium ion removal from aqueous solutions is reported. Composite materials were prepared by heating of ordinary clay and biomaterial of Prosopis at 500°C temperature and the synthesis was established with XRF, EDX, FTIR, XRD and SEM characterization. The results of characterized material showed that clay minerals successfully permeated the surface of biochar materials to form composites. The effectiveness of the composites in removing cadmium metal was determined by a batch adsorption procedure. The composite material produced a removal efficiency of 99% of cadmium ions. Adsorption was investigated using the adsorption isotherms of Freundlich and Langmuir which showed correlation r2 values of 0.924 and 0.932 respectively for the removal of cadmium ions from water. The results also revealed a pseudo second-order reaction for cadmium ions removal.

Adsorption Studies of Pb(II) and Cd(II) Heavy Metal Ions from Aqueous Solutions Using a Magnetic Biochar Composite Material

Heavy metal toxicity in water is a serious problem that may have harmful effects on human health and the ecosystem. Lead [Pb(II)] and cadmium [Cd(II)] are two such heavy metal ions, present in water, whose severity is well-known and well-studied. In the current research, magnetic biochar composite (MBC) is studied as an adsorbent material for the effective removal of lead and cadmium ions from water solutions. Magnetite (Fe3O4) nanoparticles and pine-needle-derived ultrasonicated magnetic biochar were used in different weight ratios to prepare APTES (3-aminopropyl triethoxysilane)-functionalized MBC (FMBC). An average crystalline size of ~10 nm for magnetite NPs was obtained via XRD analysis. The adsorption characteristics of both Pb(II) and Cd(II) ions were investigated in a batch experiment. The FTIR spectra of raw biochar, MBC, FMBC, and metal-loaded FMBC were obtained at different stages. The decrease in the intensity of the –NH2 functional group in the FTIR spectra of the residue confirmed the successful adsorption of heavy metal ions. The SEM-EDX spectra of the residue showed the uniform adsorption of Pb(II) and Cd(II) heavy metal ions onto the surface of the adsorbent. Magnetic biochar composite (MBC) was found to be a very effective adsorbent at basic pH, as a maximum of 97% instantaneous heavy metal removal was observed for both ions in synthetic water solutions. The Langmuir isotherm model predicted the monolayer adsorption and good affinity between the metal ions and adsorbent. The prepared MBC is low-cost, environmentally friendly, and it has shown good adsorption performance. Therefore, our study suggests that the magnetic biochar composite under study is an effective adsorbent for lead and cadmium metal ion removal from aqueous solutions at normal room temperature. Only a few hundred milligrams of the adsorbent dose is sufficient to remove higher concentrations (~100 ppm) of lead and cadmium at basic pH conditions of aqueous solutions.

Sonochemical Removal of Highly Toxic Aqueous Cd2+ and Cr6+ Ions Using Dandelion-like Co3O4 Nanoflowers

In this work, cobalt(II/III) oxide (Co3O4) nano/microflowers were practically synthesized in laboratory conditions. Adsorbence properties of the nanoflowers were investigated for the removal of cadmium and chromium heavy metal ions. To assess the chemical and morphological characteristics of Co3O4 nanoflowers, Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), field emission electron microscopy (FESEM), Energy dispersive spectroscopy (EDS), and was used. To determine the adsorbence mechanism in detail, eluent concentration, eluent type, solution pH, adsorbent amount, solution volume, and adsorption duration were studied. In these assessments, flame atomic absorption spectroscopy (FAAS) was used. For Cr6+, adsorption optimum parameters were determined as 3M HNO3, pH 6.5, 150mg, 30mL, 60min. For Cd2+, optimum parameters were determined as 3M HNO3, pH 6.0, 100mg, 10mL, 30min. Co3O4, nanoflowers are eco-friendly adsorbent materials for the adsorption of Cd6+ and Cd2+ heavy metal ions since the production method is affordable and practical.

Modeling and Simulation of Cadmium Removal from the Groundwater by Permeable Reactive Barrier Technology

The removal of cadmium ions from simulated groundwater by zeolite permeable reactive barrier was investigated. Batch tests have been performed to characterize the equilibrium sorption properties of the zeolite in cadmium-containing aqueous solutions. Many operating parameters such as contact time, initial pH of solution, initial concentration, resin dosage and agitation speed were investigated. The best values of these parameters that will achieved removal efficiency of cadmium (=99.5%) were 60 min, 6.5, 50 mg/L, 0.25 g/100 ml and 270 rpm respectively. A 1D explicit finite difference model has been developed to describe pollutant transport within a groundwater taking the pollutant sorption on the permeable reactive barrier (PRB), which is performed by Langmuir equation, into account. Computer program written in MATLAB R2009b successfully predicted meaningful values for Cd+2 concentration profiles. Numerical results show that the PRB starts to saturate after a period of time (~120 h) due to reduce of the retardation factor, indicating a decrease in percentage of zeolite functionality. However, a reasonable agreement between model predictions and experimental results of the&#x0D; total concentration distribution of Cd2+ species across the soil bed in the presence of zeolite permeable reactive barrier was recognized.

Enhanced removal of Pb (II) and Cd (II) ions from aqueous systems using coated magnetic nanoparticles in activated carbon derived from corncob waste

The study investigated the use of a cheap, high-efficiency, and eco-friendly adsorbent as an alternative to activated carbon coated Maghemite nanoparticles (γ-Fe3O4) for removing lead and cadmium ions from aqueous solutions. The Maghemite nanoparticles were synthesized using a sol-gel method. The characteristics of the adsorbent SEM, FT-IR, XRD and pHZPC, were analysed. The adsorption isotherm data were examined, and the data showed good fit with the Langmuir, Temkin and Freundlich isotherm models. The maximum adsorption capacity for Pb (II) and Cd (II) ions, as determined by the Langmuir isotherm, was found to be 127 mg/g and 100 mg/g, respectively. The kinetics of adsorption were studied using four kinetic models: pseudo-first order, pseudo-second order and Elovich model. Among these, the pseudo-second order kinetic model showed a good fit with high correlation values. Thermodynamic parameters such as the change in free energy (ΔG°), enthalpy (ΔH°), and entropy (ΔS°) were calculated. These parameters indicated that the sorption of Pb (II) and Cd (II) ions is feasible, spontaneous, and endothermic. Overall, the results demonstrated that Maghemite nanoparticle coated activated carbon derived from agricultural biomass could be an attractive option for removing metals from industrial effluents. This alternative adsorbent offers advantages such as cost-effectiveness, high efficiency, and environmental friendliness in the removal of lead and cadmium ions from aqueous solutions.

Efficient Adsorption Capacity of MgFe-Layered Double Hydroxide Loaded on Pomelo Peel Biochar for Cd (II) from Aqueous Solutions: Adsorption Behaviour and Mechanism.

A novel pomelo peel biochar/MgFe-layered double hydroxide composite (PPBC/MgFe-LDH) was synthesised using a facile coprecipitation approach and applied to remove cadmium ions (Cd (II)). The adsorption isotherm demonstrated that the Cd (II) adsorption by the PPBC/MgFe-LDH composite fit the Langmuir model well, and the adsorption behaviour was a monolayer chemisorption. The maximum adsorption capacity of Cd (II) was determined to be 448.961 (±12.3) mg·g-1 from the Langmuir model, which was close to the actual experimental adsorption capacity 448.302 (±1.41) mg·g-1. The results also demonstrated that the chemical adsorption controlled the rate of reaction in the Cd (II) adsorption process of PPBC/MgFe-LDH. Piecewise fitting of the intra-particle diffusion model revealed multi-linearity during the adsorption process. Through associative characterization analysis, the adsorption mechanism of Cd (II) of PPBC/MgFe-LDH involved (i) hydroxide formation or carbonate precipitation; (ii) an isomorphic substitution of Fe (III) by Cd (II); (iii) surface complexation of Cd (II) by functional groups (-OH); and (iv) electrostatic attraction. The PPBC/MgFe-LDH composite demonstrated great potential for removing Cd (II) from wastewater, with the advantages of facile synthesis and excellent adsorption capacity.

Biocomposite of hydrochar and Lindnera jadinii with magnetic properties for adsorptive removal of cadmium ions

The aim of the work was to check the possibility of obtaining a biocomposite with magnetic properties capable of removing cadmium ions from aqueous solutions. The biocomposite consists of hydrochar obtained by hydrothermal carbonization of raffia fibers, Lindnera jadinii yeast and Fe3O4 nanoparticles. The obtained biocomposite was characterized by SEM, FTIR, VSM, XRD, TGA and BET analysis. The study examined the effect of sorption time, initial concentration of cadmium ions, temperature, the pHZPC and the reusability of the biocomposite. Based on the obtained results, non-linear equilibrium and kinetic models were selected. The equilibrium model with the highest matching factor describing the sorption of Cd(II) by the bionanocomposite was the Temkin isotherm model R2 = 0.9960 and ARE = 2.06%, while the kinetic model with the best fit was the Elovich model R2 = 0.9928 and ARE = 5.44%. The results showed that the maximum Cd(II) adsorption capacity of the biocomposite was equal to 16.34 mg/g at 25 °C and increased with increasing temperature up to 26.22 mg/g at 40 °C. The performed Cd desorption tests showed a significant efficiency of the biocomposite for five successive cycles of the sorption-desorption process with the use of HNO3, obtaining a leaching degree of 96–98.8%. The conducted research provides new data on the use of composites obtained from biomass, microorganisms and Fe3O4 in the bioremediation of heavy metals from water media and proves the effectiveness of removal and potential use in real environmental conditions of the biocomposite due to its easy recovery from contaminated aqueous solutions.

Multicomponent Biosorption of Heavy Metals Using Fluidized Bed of Algal Biomass

This paper aims to study the biosorption for removal of lead, cadmium, copper and arsenic ions using algae as a biosorbent. A series of experiments were carried out to obtain the breakthrough data in a fluidized bed reactor. The minimum fluidization velocities of beds were found to be 2.27 and 3.64 mm/s for mish sizes of 0.4-0.6 and 0.6-1 mm diameters, respectively. An ideal plug flow model has been adopted to characterize the fluidized bed reactor. This model has been solved numerically using MATLAB version 6.5. The results showed a well fitting with the experimental data. Different operating conditions were varied: static bed height, superficial velocity and particle diameter. The breakthrough curves were plotted for each metal. Pb2+ showed the largest breakthrough time compared with others, while Cd2+ had the lowest value

Reduction of cadmium content in 29 % and 54 % P2O5 phosphoric acid by manganese oxide material birnessite-type Na-MnO2

This paper presents a new approach for the purification of 29% and 54% P2O5 phosphoric acid contaminated with cadmium ions using synthesized lamellar material based on manganese (Na-MnO2). The removal efficiencies of cadmium ions were 35 % and 31 % for 54% and 29% P2O5 phosphoric acid. The kinetic and isotherm studies of cadmium adsorption were performed. After the phosphoric acid purification process, Na-MnO2 material was characterized by XRD, SEM, and TGA-DTA. All the results enable the refinement of the final phase by the Rietveld method. A proposed mechanism of cadmium ion removal by Na-MnO2 was given. The stability of the material was also controlled in the acid medium 29 % and 54 % P2O5. The results confirmed that Na-MnO2 material could be a potential sorbent for the efficient removal of heavy metals from phosphoric acid solutions. This simple process can be further developed and thus opens an avenue in the industrial sector to process larger quantities using high-performance materials based on manganese. Self-consistent ab initio calculations, based on DFT (Density Functional Theory) approach and using the FLAPW method (Full potential Linear Augmented Plane Wave), were performed to investigate both the electronic and magnetic properties of materials.