Copper In Aqueous Solution Research Articles

Synthesis of CuO nanosheets on Cu foil via one-step wet chemical process at different reaction temperatures and their photoelectrochemical performance

Cupric oxide (CuO) nanostructures were directly grown on copper substrate via a simple one step solution-immersion process. The films were formed by the direct oxidation of copper in aqueous solution containing sodium hydroxide (NaOH) and ammonium persulfate (NH4)2S2O8. The influence of the reaction temperature on the structural, morphological, optical and photoelectrochemical (PEC) properties of the formed copper compounds nanostructures was investigated. The XRD and Raman spectroscopy results revealed the formation of Cu(OH)2/CuO composite for the samples prepared at 3 and 25 °C, and pure CuO was obtained for the samples prepared at 45 and 55 °C. The SEM micrographs showed that the formed Cu(OH)2 and CuO present a nanowire bundles and nanosheet morphology, respectively. The increase of the reaction temperature enhanced the absorbance of the CuO samples in the entire visible region. According to the photoelectrochemical measurements, the increase of the reaction temperature resulted in an improvement of the PEC response. The CuO nanosheets synthesized at 55 °C presents the highest and the most stable PEC response. A reasonable mechanism describing the formation of nanostructured copper compounds at different reaction temperatures is discussed in this paper.

Degradation Products of Rhyolitic Rocks, Adsorption Applications, Isotherm Studies

ABSTRACT Heavy metals and their toxicity are a major global concern. They are one of the major environmental problems causing serious problems for living beings. In this study, the adsorption properties of a clay sample located in nature are improved by treating with different materials, and then adsorption properties are examined. It is observed that clay sample can be used in many adsorption applications, including the adsorption of heavy metals such as copper. The clay mineral used in the study was obtained from a rhyolite type rock. Rhyolite rocks, one of the degradation products of volcanic rocks, are the volcanic counterparts of granite. In this study, rhyolite rock was crushed with suitable crushers and grinders, then sieved under 200 mesh with molecular sieve and clay minerals were obtained. The clay samples (K1,K2. K8) were synthesized by subjecting clay with acid and base. Adsorption properties of clay are due to wide surface area, surface functional groups and microporosity. Adsorption of methylene blue and iodine, adsorption from aqueous solutions of copper are done with clay samples and results were compared with samples of clay have not undergone any pre-treatment. In the study, the highest adsorption capacity was determined by applying the Freundlich isotherm. In the K6 sample treated with a base, the highest adsorption capacity was calculated as 26.98 Lg−1. In contrast, the Langmuir isotherm results were calculated in the range of 10.56 to 11.86 Lg−1. This indicates that the adsorption takes place on a heterogeneous surface. The structure and surface properties of clay were examined.

Simultaneous Determination of Iron and Copper in Aqueous Solution Using Spectrophotometry

Iron and copper mixtures were quantitatively determined in aqueous solutions for the first time using the analytical method in this approach with the aid of T60U Spectrophotometer. The method is so simple, fast, economic, and can be carried out easily on a bench. The absorbencies for iron, copper and iron-copper mixtures in aqueous solution were measured using T60U adopted with UVWin6 software UV -VIS Spectrometer (pg instruments United Kingdom) by filling two 5 ml quartz cells of dimensions 1*1*5 cm, the first is filled with the blank solution which is a solution containing all the constituents of the sample except iron and copper and the other quartz cell is filled with the stock solution iron and/or copper under investigation. Absorbency of iron was determined by setting T60U spectrometer wavelength at 504 nm, meanwhile for copper absorbency measurements the apparatus is set at 304 nm. Iron, copper, and iron-copper mixture calibration curves were of very high accuracy with the least linear regression value of ≤ 1, i, e the measured data were of relative standard deviation value (RSD) of ≤ 1.5%.

Поисковые исследования по гидрометаллургической переработке медьсодержащей руды месторождения Кеншокы-1

The main purpose of these studies was to study the chemical and mineralogical composition of the ore of the Kenshoky-1 deposit with subsequent search experiments on the extraction of copper from ore material by sulfuric acid leaching. During the research it was established that the ore belongs to the type of oxidized cuprous sandstone and along with copper it contains a significant amount of lead and a small amount of zinc. The main minerals of copper and lead in this ore are carbonate – malachite and cerussite. A fairly significant amount of the lead phosphate mineral pyromorphite is present. The main minerals in the waste rock are quartz, orthoclase, and clinochlorine. Iron, according to diffractometric analysis, is bound in clinochlore. The search experiments on copper leaching from the mentioned ore by sulfuric acid solutions showed that even at room temperature and sulfuric acid concentration in the solution of 11.3 g/dm3 extraction of copper in aqueous solution of more than 60% is achieved, and the main technological factors influencing the process of copper leaching are duration, concentration of sulfuric acid in the initial solution, intensity of agitation and the ratio of solid and liquid phases. The concentration of copper in the resulting pregnant solution was, depending on the concentration of sulfuric acid from 6.32 to 10.15 g/dm3 , which is insufficient for further processing of solution by electrolysis, therefore, productive solutions must be additionally saturated with copper by returning pregnant solution to the head of the process. Lead behavior during prospecting studies was not studied, but due to low solubility of lead sulfate in aqueous solutions, the main part of lead should remain in the cake

Enhanced Adsorption of Cu2+ from Aqueous Solution by Sludge Biochar Compounded with Attapulgite-Modified Fe

Three types of modified sludge biochar were produced for the adsorption of copper in aqueous solutions via the calcium-based magnetic (CaCO3, Fen+) treatment (CA–BC), nanozero-valent iron (nZVI) treatment (nZVI–BC), and iron (Fe3+) treatment (FA–BC) of raw biochar. The results suggested that the adsorption capacity for Cu2+ of calcium-based magnetic attapulgite/sludge biochar (CA–BC) prepared from CaCO3, FeCl3, and FeSO4 is 38.01% greater than that of unmodified biochar and 6.41% to 17.5% greater than that of the other biochar. The CA-BC contained a variety of ferrite-containing and hydroxide-functional groups, as well as a more developed pore structure. The existence of H+ reduced the adsorption capacity of the biochar for Cu2+. A high initial concentration of Cu2+ could increase Cu2+ adsorption on CA–BC. Combined with theoretical calculations, the adsorption efficiency of CA–BC in different systems was explored. The results revealed that CA–BC achieved a maximum removal rate of 92.644% at a pH of 6 with a reaction time of 157 min and an initial Cu2+ concentration of 2.813 mg/L. These results suggest that CA–BC shows great potential for removing Cu2+ from aqueous solutions.

Inspired dual functional adsorption films of armed molecules on copper

AbstractIn this study, double norfloxacin skeletons including the target armed molecules (DNs) displaying antibacterial and anticorrosion properties for copper in aqueous solutions were presented. The molecular modelling and material simulation calculations suggest that the target molecules could be adsorbed to copper surface, which was further demonstrated by attenuated total reflection infrared spectroscopy (ATR‐IR), X‐ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and scanning electron microscopy (SEM). The experimental results show that the copper surface which adsorbed the target armed molecules exhibited an excellent inhibitory effect on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The potentiodynamic polarization plots and electrochemical impedance spectroscopy demonstrate that the DNs of 0.100 mM achieved over 95% corrosion inhibition efficiency for copper in 0.5 M H2SO4 solution at 298 K. The results given in this study may guide us to achieve bacterial and corrosion resistances for copper based on the drug‐included armed molecules.

A New Pyrrole-2-carboxaldehyde Functionalized Chitosan-Cu(II) Complex-based Chemosensor for Iodide Anion in Aqueous Media

Iodine is an essential ingredient in thyroid hormones of which both low and high intakes may cause thyroid disease. This study develops a Pyrrole-2-Carboxaldehyde functionalized chitosan-Cu(II) Complex [PCAFC-Cu(II)] chemosensor, for quick and easy detection of iodide ions from its aqueous solutions. PCAFC-Cu(II) complex was synthesized from a simple condensation reaction of chitosan (CS) and pyrrole-2-carboxaldehyde (PCA) along with an aqueous solution of copper(II) salt. The starting materials and the products were characterized by spectroscopic (FT-IR and UV-Visible), X-ray powder diffraction, and microscopic methods (Scanning Electron Microscopy). The PCAFC-Cu(II) colorimetric sensing of I- revealed a color change adduced to the formation of a hydrogen bond or deprotonation of the complex matrix. Colorimetric detection for I- ions was obtained with a detection limit (LoD) of 0.005 M and the complex has high specificity for I- ions detection from a solution consisting of several anions. The synthesized complex [PCAFC-Cu(II)] could serve as an on-site reagent for the qualitative detection of iodide ions.

Non-dispersive solvent extraction as an alternative for sulfuric acid and copper recycling from membrane distillation concentrate of gold mining wastewater

The wastewater from the pressure oxidation process is a complex stream enriched in sulfuric acid and dissolved metallic species, conventionally treated by neutralization, a technique that does not allow for by-product recovery. Previous studies focused on water recovery from the wastewater by membrane distillation and the concern related to concentrate production after water is recovered is now addressed by using hollow-fiber membrane contactors in non-dispersive solvent extraction processes intended for sulfuric acid and copper recycling. Tris(2-ethylhexyl)amine (TEHA), Aliquat 336, and Lix 84-I were used as extractants, the first two for acid recovery and the latter for copper. It was investigated the contribution of different organic phases flow rate (4–12 cm3/s), organic phase composition (5–15 wt%), and temperature (30–60 °C) on the performance of hollow fiber membrane contactors, with an in-depth disclosure of mass transfer phenomena limiting the extraction efficiency. For both acid and copper recovery, a reduction in viscosity forces prevails over the decrease in inertial forces, improving the flow regime. Even so, the predominant mechanism was the diffusive transport of both solutes into the fluid, across the membrane pores, rather than being carried along by the aqueous phase flow. The acid and copper recovery from membrane distillation concentrate achieved values greater than 91%, which represents an acid stream containing 5.86 g-H2SO4/L and an aqueous copper solution with a concentration of 269.0 mg/L, both at high purity. It was discussed different opportunities for their reuse within the gold ore processing circuit and challenges related to their external commercialization. Preliminary economic analysis suggested that the mineral acid would present slightly higher costs than currently practiced (0.54 US$/kgH2SO4; market prices: 0.03–0.11 US$/kgH2SO4), although the operational costs related to copper were comparable with market prices (11.58 US$/kgCu; market prices: 10.31 US$/kgCu). In a broad context, the opportunity for acid and sulfuric acid recycling has the potential to extend sustainability in the mining sector.

Synthesis, structure characterization and antitumor activities of copper and cobalt thiocyanate complexes with 3-acetlpyridine ligand

Complexes of [Cu(SCN)2(3-Acpy)2], (1) and [Co(SCN)2(H2O)2(3-Acpy)2], (2) were synthesized at ambient temperature by adding an aqueous solution of copper(II) or cobalt(II) chloride to H2O/CH3CN solution of 3-acetlpyridine (3-Acpy) and potassium thiocyanate. Elemental analysis, FT-IR and UV–vis spectra were used to comprehensively characterize complexes 1 and 2. Single crystal X-ray diffraction was used to analyze the crystal structure of complexes 1 and 2. In complex 1, the copper is bonded to two 3-Acpy ligands and two thiocyanates groups in trans mode giving square planer geometry. While, in complex 2, the cobalt ion is coordinated to two water molecules, two 3-Acpy ligands and two thiocyanates ions in trans mode giving an octahedral structure. Through hydrogen bonding, the discrete units of complexes 1 and 2 extend to form a 3D supramolecular network. Additionally, the luminescence spectra of complexes 1 and 2 were investigated. Complexes 1 and 2 were evaluated to determine whether they were able to inhibit the growth of liver cancer (HepG2 cells) and breast cancer (MCF-7 cells). Complex 1 exhibits lower IC50 values than complex 2 against both of the two human cell lines. In HepG2 cells treated with complexes 1 and 2 at dosages roughly half of the IC50, apoptosis of complexes 1 and 2 is triggered by 18% and 22%, respectively. It was found that copper complex 1 has a greater cytotoxic effect on MCF-7 and influences on late apoptosis of HepG2.

Thermochemistry of the Dissolution of Tetra-4-(4'-carboxyphenyoxy)- and Tetra-4-(4'-carboxyphenylthio)phthalocyanines of Copper in Aqueous Solutions of KOH at 298.15 K

Thermochemistry of the Dissolution of Tetra-4-(4'-carboxyphenyoxy)- and Tetra-4-(4'-carboxyphenylthio)phthalocyanines of Copper in Aqueous Solutions of KOH at 298.15 K

Thermochemistry of the Dissolution of Tetra-4-(4'-carboxyphenyoxy)- and Tetra-4-(4'-carboxyphenylthio)phthalocyanines of Copper in Aqueous Solutions of KOH at 298.15 K

The authors obtain complexes CuPc(4-S-C6H4-COOH)4 and CuPc(4-O-C6H4-COOH)4 that are insoluble in water. The standard enthalpies of formation of these compounds are calculated using additive groups based on group systematics with Benson-type classification of fragments, allowing for the influence of the atoms’ primary environment. Thermal effects of the dissolution of crystalline phthalocyanines in aqueous solutions of various KOH concentrations at a temperature of 298.15 K were determined via direct calorimetry. Thermal effects of the stepwise dissociation of CuPc(4-S-C6H4-COOH)4, CuPc(4-O-C6H4-COOH)4 are calculated using the HEAT computer program. Standard enthalpies of formation are calculated for products of the dissociation of CuPc(4-S-C6H4-COOH)4 and CuPc(4-O-C6H4-COOH)4 in an aqueous solution.

Green Synthesis and Characterization of Copper Oxide Nanoparticles Using Tecoma Stans

Aims: An eco-friendly approach utilizing biologically-mediated processes has been developed for the fabrication of CuO nanoparticles using Tecoma stans leaves.
 Methodology: The synthesis of CuO nanoparticles was carried out using an environmentally friendly method, which involved the use of an aqueous solution of copper (II) sulfate and a leaf extract derived from Tecoma stans. The synthesized CuO nanoparticles were characterized using various instruments, including a UV-visible spectrophotometer, scanning electron microscopy, X-ray Diffraction Spectrometer, and Fourier-transform infrared spectroscopy.
 Results: The UV-Vis spectrum showed a characteristic absorption peak of CuO nanoparticles at 296 nm. The green-synthesized CuO nanoparticles were characterized using SEM, which revealed their morphological and structural characteristics and showed a mean particle size ranging from 20 nm to 200 nm. The FTIR spectrum, ranging from 584.63 cm-1 to 3430.41 cm-1, indicated the presence of various functional groups. X-ray powder diffraction (XRD) analysis confirmed the formation of monoclinic CuO with a crystalline nature, and an average particle size of 27.67 Å.
 Conclusion: The present study reports the development of a simple, low-cost, and biologically-mediated method for synthesizing CuO nanoparticles using an extract obtained from Tecoma stans leaves. The effectiveness of these nanoparticles can be evaluated through various biological activities, including antibacterial, antifungal, and cytotoxic assays.

Immobilizing lead and copper in aqueous solution using microbial- and enzyme-induced carbonate precipitation.

Inappropriate irrigation could trigger migration of heavy metals into surrounding environments, causing their accumulation and a serious threat to human central nervous system. Traditional site remediation technologies are criticized because they are time-consuming and featured with high risk of secondary pollution. In the past few years, the microbial-induced carbonate precipitation (MICP) is considered as an alternative to traditional technologies due to its easy maneuverability. The enzyme-induced carbonate precipitate (EICP) has attracted attention because bacterial cultivation is not required prior to catalyzing urea hydrolysis. This study compared the performance of lead (Pb) and copper (Cu) remediation using MICP and EICP respectively. The effect of the degree of urea hydrolysis, mass and species of carbonate precipitation, and chemical and thermodynamic properties of carbonates on the remediation efficiency was investigated. Results indicated that ammonium ion (NH4 +) concentration reduced with the increase in lead ion (Pb2+) or copper ion (Cu2+) concentration, and for a given Pb2+ or Cu2+ concentration, it was much higher under MICP than EICP. Further, the remediation efficiency against Cu2+ is approximately zero, which is way below that against Pb2+ (approximately 100%). The Cu2+ toxicity denatured and even inactivated the urease, reducing the degree of urea hydrolysis and the remediation efficiency. Moreover, the reduction in the remediation efficiency against Pb2+ and Cu2+ appeared to be due to the precipitations of cotunnite and atacamite respectively. Their chemical and thermodynamic properties were not as good as calcite, cerussite, phosgenite, and malachite. The findings shed light on the underlying mechanism affecting the remediation efficiency against Pb2+ and Cu2+.

Low-voltage anodizing of copper in sodium bicarbonate solutions

The low-voltage (< 5 V) anodization of copper in aqueous solutions of sodium bicarbonate was studied for the first time. As demonstrated, this method leads to the formation of microstructures on a copper surface, that are composed of malachite (CuCO3·Cu(OH)2). Moreover, by tuning the operating conditions, i.e., applied cell voltage and electrolyte concentration, different surface morphologies can be grown. As shown by electron microscopy investigation, clusters of ribbons corrosion pits or nonuniformly located powdery precipitates are formed when the low anodizing voltage is applied. Anodization at 1.0 V in 0.4 M sodium bicarbonate solution led to the formation of a velvet-like, deep black anodic layer that covered the whole metal surface with ribbon-resembling structures. A thorough investigation of the obtained anodic layers with X-ray diffraction (XRD), X-ray adsorption (XAS), Raman, and X-ray Photoelectron Spectroscopy (XPS) uncovered the mixed crystalline-amorphous nature of the anodic copper species. Besides dominating the crystalline malachite phase, the amorphous cupric oxide was also identified. This composition offers promising features for catalytic applications, hence, low-voltage anodized copper was tested in an electrochemical CO2 reduction reaction to explore one possible application of the presented material. The current density of 4.7 mA cm−2 was registered for the selected sample.

Стресс-тесты антраценпроизводных растительного происхождения

Objective: to study the stability of solutions of standard samples of sennoside B and glucofrangulin A by stress tests using high performance liquid chromatography (HPLC). Materials and methods. The objects of the study were solutions of standard samples of sennoside B, as well as glucofrangulin A. Stress agents were 0.5M aqueous solution of copper (II) chloride (CuCl2), 0.5M aqueous solution of iron (III) chloride (FeCl3), 0.1M aqueous solution of hydrochloric acid (HCl), as well as 0.1M aqueous solution of sodium hydroxide (NaOH) and a solution of hydrogen peroxide (H2O2) 3%. The study was carried out using an Agilent 1100 liquid chromatograph. For this purpose, a Zorbax SB-C18 reverse-phase column (4.6×250 mm, 5 µm) was used. Elution of the mobile phase (acetonitrile and highly purified water, which was adjusted to pH 2 with phosphoric acid) was carried out in a gradient mode. Detection was carried out at wavelengths of 360 nm and 435 nm. Results. It was found that a solution of a standard sample of glucofrangulin A is stable for 14 days under the influence of 0.1M aqueous solution of HCl and 0.1M aqueous solution of NaOH, as well as 0.5M aqueous solution of FeCl3 and 3% H2O2 solution. When a solution of a standard sample of glucofrangulin A interacts with a 0.5M aqueous solution of CuCl2, its destruction is observed. When a standard sample of sennoside B reacts with a 3% H2O2 solution and a 0.5M aqueous CuCl2 solution, it remains stable. When interacting with other stress agents, its destruction occurs. Conclusion. The results obtained on the stability of solutions of standard samples of anthracene derivatives determine the main physico-chemical factors that cause their destruction, which can be taken into account when validating analytical methods, justifying the conditions of storage, packaging and processing of medicinal plant materials that contain anthracene derivatives.

On the flotation activity of reagents with a nitrile group in the flotation of copper-nickel ores

This paper considers the use of compounds having a nitrile group, such as Tecflote S10, S11, S12, and S13, as potential collectors in the flotation of sulfide copper-nickel ore. Tecflote S12, S10, and S13 reagents are substituted aminonitriles with one or two nitrile groups, differing by the hydrocarbon radical R, with its length in the range of C10&ndash;18. Tecflote S11 is a dimer with only two nitrile groups. Respective copper- and nickel-containing minerals were subjected to test hydrophobization when exposed to these reagents in frothless flotation using two ore samples characterized by higher chalcopyrite/pentlandite and nickel-bearing pyrotine grades. This paper shows the distribution of copper and nickel in the resulting frothless flotation products. A comparison of the results obtained when using aqueous and hexane solutions of the collector has demonstrated that Tecflote S12 is more efficient for nickel-containing minerals due to the possibility of direct interaction of the mineral particle with the collector in the volume of the solution. The formation of a Tecflote S12 complex with non-ferrous metal atoms is evidenced by the presence of broad bands corresponding to copper and nickel ions in the region of 290&ndash;360 cm&ndash;1 Raman spectrum in the compounds obtained by extraction from the aqueous solutions of copper and nickel chlorides. The flotation tests carried out using a sample of finely disseminated refractory copper-nickel ore from the Pechenga ore field have showed that feeding Tecflote S12 into the main flotation cycle, combined with xanthate and aeroflot, allows improving the yield of the finished concentrate and ensures lower nickel losses with tailings.

Synthesis and application of environment friendly membranes of chitosan and chitosan-PTA for removal of copper (II) from wastewater

ABSTRACT The development of environmental consciousness and practices is critically needed. Membranes have outperformed methods such as distillation and extraction in prominence. Technological development is essential for improving wastewater treatment methods. Renewable resources can be regarded as ideal materials for membrane production. It is critical to choose ecologically acceptable materials that are easy to use and have a high separation efficiency. This paper reports the preparation of adsorptive membranes of environmentally friendly chitosan and heteropolyacids. Membranes were prepared by a simple solvent evaporation technique and the effect of dodecatungstophosphoric acid on the composite membrane structure of chitosan were explored. The solution casting method was employed to prepare the membranes. The membrane films were characterised in terms of elemental composition, morphology, and structure using various analytical techniques like SEM-EDX, FTIR-ATR, TGA-DSC, and Universal Testing Machine. An aqueous solution of copper (C 0 = 100–2000 ppm) was adsorbed using these membranes. The effect of heteropolyacid on adsorption was studied. Adsorption above 90% was achieved and the adsorption followed pseudo 2nd order isotherm with R 2 > 0.99. The heteropolyacid acts as a dynamic ion exchanger in the process. The membranes were made from natural, non-toxic, cheap, and easily available materials and have a lot of potential.

Polymer-metal complex based on copper(II) acetate and polyvinyl alcohol: thermodynamic and catalytic properties

In this work we obtained a polymer-metal complex by mixing aqueous solution of copper(II) acetate with PVA at a certain ratio, pH of the solution and temperature. The composition of the complex compound was determined by potentiometric and conductometric titration. The possibility of a complex formation was proved by calculating thermodynamic characteristics. The stability constant of the polymer-metal complex was calculated on the basis of the modified Bjerrum’s method. The metal-polymer complex was synthesized in the ratio 1:2. IR spectroscopy and scanning electron microscopy (SEM) confirmed the coordination of polymeric PVA ligand to copper and allowed evaluating the morphology and features of the complex surface. The catalytic activity of the synthesized compound was evaluated in the oxidation reaction of elemental phosphorus (P4) by oxygen in aqueous-organic media under mild conditions. Quantitative analysis of phosphoric acid was made by photocolorimetric method. We found that the oxidation process of P4 in the presence of the complex Cu(PVA)2(OAc)2 in aqueous-organic media is characterized with the maximum absorption rate, in comparison with Cu(OAc)2·H2O oxidation process with P4, and yields up to 97% of the products. The process of oxidation of yellow phosphorus by oxygen in the presence of the copper(II)-PVA complex proceeds through key reactions of two-electron reduction of the catalyst P4 with the formation of intermediate phosphorus-containing products P3+ and the stages of catalyst regeneration by oxygen. Twenty-electron oxidation of P4 to the phosphorus-containing P5+ products involves 10 two-electron redox reactions and a number of complexation or hydrolysis stages.

Thermodynamic analysis of electroosmosis regulated peristaltic motion of Fe3O4–Cu/H2O hybrid nanofluid

This study aims to investigate the thermodynamic analysis for electroosmotic flow of [Formula: see text]–[Formula: see text] hybrid nanofluid in the presence of peristaltic propulsion. Hybrid nanofluid is an aqueous solution of copper and iron oxide nanoparticles. Effects of electric field, Ohmic heating, magnetic field, viscous dissipation, heat sink/source and mixed convection are also considered. The Debye–Hückel and lubrication approach has been adopted to perform mathematical modeling. The resulting differential equations are numerically solved by employing the Shooting method. Analysis has been presented for irreversibility rate and heat transfer for the flow of hybrid nanoliquid. Results reveal that the addition of nanoparticles reduces the temperature and entropy generation of hybrid nanoliquid. Heat transfer rate enhances by improving Joule heating and electroosmotic parameters. An increase in Helmholtz–Smoluchowski velocity and Hartmann number decrease the velocity of fluid. Thermal performance of hybrid nanofluid ([Formula: see text]–[Formula: see text]) is more noticeable in comparison with conventional mono nanofluid ([Formula: see text]–[Formula: see text]) and base fluid ([Formula: see text]).

Aging of microplastics and their role as vector for copper in aqueous solution

Microplastics (MPs), considered to be potential vectors for the transfer of heavy metals, undergo aging in the environment. However, the aging mechanisms of MPs and their interactions with heavy metals in aquatic environments still require additional studies. This study investigated the aging of micro-sized polyethylene terephthalate (mPET) and polyamide (mPA) in simulated seawater and changes in their physical and chemical properties, as well as the adsorption of copper by virgin and aged MPs. The effect of pH on adsorption behavior of MPs on copper was also elucidated. The results showed that the aging process of MPs was characterized by some wrinkles along with rough and fractured surface textures, as well as the changes in functional groups such as hydroxyl groups (–OH), aromatic carbon–carbon double bond (CC), and carbon hydrogen bond (C-H). These changes further influence the aromaticity of the aged MPs and their affinity to pollutants. The aged MPs have higher sorption abilities as compared with that of virgin MPs (e.g., aged mPA > aged mPET > virgin mPA > virgin mPET) and the maximum adsorption capacity of mPA and mPET was achieved at pH 10. This study would contribute to understand the interactions among aged MPs, copper, and environmental factors, which can serve as a baseline for further studies on the toxicity of MPs in combination with heavy metals in the environment.