Sodium alginate-encapsulated nano-iron oxide coupled with copper-based MOFs (Cu-BTC@Alg/Fe3O4): Versatile composites for eco-friendly and effective elimination of Rhodamine B dye in wastewater purification.

This study explores the effectiveness of Alginate-coated nano­iron oxide combined with copper-based MOFs (Cu-BTC@Alg/Fe3O4) composites for the sustainable and efficient removal of Rhodamine B (RhB) dye from wastewater through adsorption and photocatalysis. Utilizing various characterization techniques such as FTIR, XRD, SEM, and TEM, we confirmed the optimal synthesis of this composite. The composites exhibit a significant surface area of approximately 160 m2 g-1, as revealed by BET analysis, resulting in an impressive adsorption capacity of 200 mg g-1 and a removal efficiency of 97 %. Moreover, their photocatalytic activity is highly effective, producing environmentally friendly degradation byproducts, thus underlining the sustainability of Cu-BTC@Alg/Fe3O4 composites in dye removal applications. Our investigation delves into kinetics and thermodynamics, revealing a complex adsorption mechanism influenced by both chemisorption and physisorption. Notably, the adsorption kinetics indicate equilibrium attainment within 100 min across all initial concentrations, with the pseudo-second-order kinetic model fitting the data best (R2 ≈ 0.999). Furthermore, adsorption isotherm models, including Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich, elucidate the adsorption behavior, with the Temkin and Dubinin-Radushkevich models showing superior accuracy compared to the Langmuir model (R2 ≈ 0.98 and R2 ≈ 0.96, respectively). Additionally, thermodynamic analysis reveals a negative Gibbs free energy value (-6.40 kJ mol-1), indicating the spontaneity of the adsorption process, along with positive enthalpy (+24.3 kJ mol-1) and entropy (+82.06 kJ mol-1 K) values, suggesting an endothermic and disorderly process at the interface. Our comprehensive investigation provides insights into the optimal conditions for RhB adsorption onto Cu-BTC@Alg/Fe3O4 composites, highlighting their potential in wastewater treatment applications.

Application of fluidized bed homogeneous crystallization for simultaneous recovery of Fe(II) and Cu(II) as particles from wastewater.

The mixture of copper and iron often results in materials with favorable properties. The material production processes involving these metals including electroplating produce hazardous wastewater. In this study, the Fluidized Bed Homogeneous Crystallization (FBHC) process was applied to treat iron and copper-containing wastewater. The initial iron copper particles were successfully recovered from synthetic wastewater with [Fe]0:[Cu]0 of 2:1, the total metal concentration of 3 mM, at effluent pH = 7.75 ± 0.75, with the upflow velocity (U) of 1.76 m/h. The agglomerates hardening process is a crucial step for initial particle synthesis. The SEM analysis reveals the spherical particle's densified crust and porous core. The particle formation mechanism which includes the formation of the nucleus, attachment of precipitate flakes, and densification of particles was proposed after microscopic observation. The initial particles synthesized were used to initiate the treatment of synthetic wastewater at the operating condition pH = 7.75 ± 0.5, [Fe]0:[Cu]0 of 2:1, the total metal concentration of 3 mM, [CO32-]0:[M]0 = 1.2:1, and U of 28.66 m/h which results in the total metal removal of 99% and crystallization ratio of 90% and 88% for iron and copper respectively. The conditions were then applied to treat electroplating wastewater and resulted in the total metal removal of 99% for both iron and copper and a crystallization ratio of 83% and 79% for iron and copper, respectively. The treatment provided advantages in terms of treating larger amounts of sludge while eliminating the need to provide seed thus yielding a higher purity of product.

Sequential removal of phosphate and copper(II) ions using sustainable chitosan biosorbent.

Although adsorbents are good candidates for removing phosphorus and heavy metals from wastewater, the use of biosorbents for the sequential treatment of phosphorus and copper has not yet been studied. Porous chitosan (CS)-based biosorbents (CGBs) were developed to adsorb phytic acid (PA), a major form of organic phosphate. This first adsorbate (PA) further served as an additional ligand (P-type ligand) for the CGBs (N-type ligand) to form a complex with the second adsorbate (copper). After the adsorption of PA (the first adsorbate), the spent CGBs were recycled and used as a new adsorbent to adsorb Cu(II) ions (the second adsorbate), which was expected to have a dual coordination effect through P, N-ligand complexation with copper. The interactions and complexation between CS, PA and Cu(II) ions on the PA-adsorbed CGBs (PACGBs) were investigated by performing FTIR, XPS, XRD, and SEM-EDS analyses. The PACGBs exhibited fast and enhanced adsorption of Cu(II) ions, owing to the synergistic effect of the amino groups of CS (the original ligand, N-type) and the phosphate groups of PA (an additional ligand, P-type) on the adsorption of Cu(II) ions. This is the first time that sequential removal of phosphorus and heavy metals by biosorbents has been performed using biosorbents.

Quantification of human plasma metalloproteins in multiple sclerosis, ischemic stroke and healthy controls reveals an association of haptoglobin-hemoglobin complexes with age.

Advanced analytical methods play an important role in quantifying serum disease biomarkers. The problem of separating thousands of proteins can be reduced by analyzing for a 'sub-proteome', such as the 'metalloproteome', defined as all proteins that contain bound metals. We employed size exclusion chromatography (SEC) coupled to an inductively coupled plasma atomic emission spectrometer (ICP-AES) to analyze plasma from multiple sclerosis (MS) participants (n = 21), acute ischemic stroke (AIS) participants (n = 17) and healthy controls (n = 21) for Fe, Cu and Zn-metalloproteins. Using ANOVA analysis to compare the mean peak areas among the groups revealed no statistically significant differences for ceruloplasmin (p = 0.31), α2macroglobulin (p = 0.51) and transferrin (p = 0.31). However, a statistically significant difference was observed for the haptoglobin-hemoglobin (Hp-Hb) complex (p = 0.04), being driven by the difference between the control group and AIS (p = 0.012), but not with the MS group (p = 0.13), based on Dunnes test. A linear regression model for Hp-Hb complex with the groups now adjusted for age found no statistically significant differences between the groups (p = 0.95), but was suggestive for age (p = 0.057). To measure the strength of association between the Hp-Hb complex and age without possible modifications due to disease, we calculated the Spearman rank correlation in the healthy controls. The latter revealed a positive association (r = 0.39, 95% Confidence Interval = (-0.05, 0.83), which suggests that either the removal of Hp-Hb complexes from the blood circulation slows with age or that the release of Hb from red blood cells increases with age. We also observed that the Fe-peak corresponding to the Hp-Hb complex eluted ~100 s later in ~14% of all study samples, which was not correlated with age or disease diagnosis, but is consistent with the presence of the smaller Hp (1-1) isoform in 15% of the population.

Cancer Influences the Elemental Composition of the Myocardium More Strongly than Conjugated Linoleic Acids-Chemometric Approach to Cardio-Oncological Studies.

The aim of the study was to verify in a cardio-oncological model experiment if conjugated linoleic acids (CLA) fed to rats with mammary tumors affect the content of selected macro- and microelements in their myocardium. The diet of Sprague-Dawley females was supplemented either with CLA isomers or with safflower oil. In hearts of rats suffering from breast cancer, selected elements were analyzed with a quadrupole mass spectrometer with inductively coupled plasma ionization (ICP-MS). In order to better understand the data trends, cluster analysis, principal component analysis and linear discriminant analysis were applied. Mammary tumors influenced macro- and microelements content in the myocardium to a greater extent than applied diet supplementation. Significant influences of diet (p = 0.0192), mammary tumors (p = 0.0200) and interactions of both factors (p = 0.0151) were documented in terms of Fe content. CLA significantly decreased the contents of Cu and Mn (p = 0.0158 and p = 0.0265, respectively). The level of Ni was significantly higher (p = 0.0073), which was more pronounced in groups supplemented with CLA. The obtained results confirmed antioxidant properties of CLA and the relationship with Se deposition. Chemometric techniques distinctly showed that the coexisting pathological process induced differences to the greater extent than diet supplementation in the elemental content in the myocardium, which may impinge on cardiac tissue's susceptibility to injuries.

A Simple One-Step Modification of Shrimp Shell for the Efficient Adsorption and Desorption of Copper Ions.

Removing toxic heavy metal species from aqueous solutions is a point of concern in our society. In this paper, a promising biomass adsorbent, the modified waste shrimp shell (MS), for Cu (II) removal was successfully prepared using a facile and simple one-step modification, making it possible to achieve high-efficiency recycling of the waste NaOH solution as the modification agent. The outcome shows that with the continuous increase in pH, temperature and ion concentration, the adsorption effect of MS on Cu (II) can also be continuously improved. Adsorption isotherm and adsorption kinetics were fitted with the Langmuir isotherm model and the pseudo-second-order model, respectively, and the maximum adsorption capacity of Cu (II) as obtained from the Langmuir isotherm model fitting reached 1.04 mmol/g. The systematic desorption results indicated that the desorption rate of Cu (II) in the MS could reach 100% within 6 min, where HNO3 is used as the desorption agent. Moreover, experiments have proven that after five successive recycles of NaOH as a modifier, the adsorption capacity of MS on Cu (II) was efficient and stable, maintaining tendency in 0.83-0.85 mmol/g, which shows that waste NaOH solution can be used as a modification agent in the preparation of waste shrimp shell adsorbent, such as waste NaOH solution produced in industrial production, thereby making it possible to turn waste into renewable resources and providing a new way to recycle resources.

Production of Zinc and Copper as Nanoparticles by Green Synthesis Using Pseudomonas fluorescens.

<b>Background and Objective:</b> Nanoparticles with a little size to an enormous surface (1-100 nm) have expected clinical, mechanical and agricultural applications. This study aimed to produce nano Zinc Oxide (ZnO) and nano Copper Oxide (CuO) particles by green synthesis. <b>Materials and Methods:</b> Two strains of <i>Pseudomonas fluorescens</i> i.e., PSI and PSII, both cell culture supernatants and cell pellets from the two strains were examined separately in CuSO₄ or ZnSO₄ solutions. The supernatants from both strains produced color changes in both solutions referring to the formation of nano CuO or ZnO particles. The solutions were examined for nano-particle characteristics using UV-spectroscopy, particle size and morphology were tested using a scanning electron microscope and transmission electron microscopy. <b>Results:</b> UV-Vis absorption spectrum of solutions at a wavelength range 200-800 nm exhibits a distinct absorption peak in the region of 238-331 and at 303-366 nm for CuO or ZnO NPs, respectively. Absorption bands and the characteristic Surface Plasmon Resonance (SPR) spectra confirm the existence of CuO and ZnO NPs. SEM analysis micrographs indicated that CuO NPs were formed as spherical particles, while the exact shape of ZnO NPs could be identified as oval aggregates. <b>Conclusion:</b> Changes of color occurred in both solutions of two strains referring to the formation of nano CuO or ZnO particles.

Magnetic and electric field accelerate Phytoextraction of copper Lemna minor duckweed.

In accordance with the opinion of the World Health Organization and the World Water Council the development of effective technologies for the treatment of wastewater from heavy metals for their discharge into water bodies or reuse is an urgent task nowadays. Phytoremediation biotechnologies is the most environmentally friendly and cheapest way of the treatment of wastewater, suitable for sustainable development principals. The main disadvantage of the phytoremediation is the slow speed of the process. A method for accelerating the process of phytoremediation by the combined effect of magnetic and weak electric fields is proposed. The purpose of this study is to determine the values of the parameters of the magnetic and weak electric fields that are most suitable for extracting cuprum ions from wastewater using the higher aqua plants (Lemna minor). A corresponding technological process based on the results of the study is proposed. The results have shown that the removal of copper cations from sulfate solutions effectively occurs in the initial period of time (1-5 hours) under the influence of a magnetic field with an intensity of H = 2 kA/m. Under the combined influence of an electrical current with density j = 240 µA/cm2 and a magnetic field (H = 2 kA/m) the highest rate of copper extraction by duckweed leaves is achieved. Under these conditions, the greatest growth and development of plant leaves occurs. The paper presents the results of determining of the parameters of the electrochemical release from the eluate of the spent phytomass of duckweed. It has been determined that the release of metal occurs at E = 0.32 V. An original scheme for wastewater treatment from copper with subsequent separation of copper from the spent phytomass of duckweed is proposed. In general, the presented results are a scientific justification of wastewater treatment technologies and a contribution to resolving the crisis in the field of fresh water supply. An important contribution in the circular economy is a technology recommendation proposed for recovering copper from duckweed after wastewater treatment.

A mesoporous nanocellulose/sodium alginate/carboxymethyl-chitosan gel beads for efficient adsorption of Cu2+ and Pb2.

In this study, a novel mesoporous nanocellulose/sodium alginate (SA)/carboxymethyl-chitosan (CMC) aerogel was fabricated using a simple method. The adsorption of Cu2+ and Pb2+ on the aerogel in aqueous solutions was investigated. The obtained aerogel was characterized using scanning electron microscopy, fourier-transform infrared spectroscopy, transmission microscope, atomic force microscopy and N2 adsorption-desorption. Furthermore, the fundamental Cu2+ and Pb2+c adsorption behaviours of the mesoporous aerogel, including the effect of pH, adsorption equilibrium and kinetics were investigated. The adsorption isotherms and kinetics of aerogel closely followed the Langmuir model and pseudo-second-order model, respectively, indicating that the adsorption behaviours can be classified as monolayer chemical adsorption. The aerogel exhibited high efficiency for the adsorption of Cu2+ (169.94 mg/g) and Pb2+ (472.59 mg/g). The aerogel maintained a high adsorption capacity for Cu2+ (56 mg/g) and Pb2+ (245 mg/g) after five adsorption-desorption cycles. Therefore, the as-prepared mesoporous aerogel has great potential in wastewater treatment.

Bioleaching of copper and nickel from mobile phone printed circuit board using Aspergillus fumigatus A2DS.

The recovery of metals from electronic waste was investigated by using fungal strain Aspergillus fumigatus A2DS, isolated from the mining industry wastewater. Fifty-seven percent of copper and 32% of nickel were leached (analyzed by Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-OES)) by the organism after one-step leaching at a temperature of 30 °C (shaking condition for 7 days). Maximum % of copper and nickel were obtained at a pH of 6 (58.7% Cu and 32% Ni), the temperature of 40 °C (61.8% Cu and 27.07% Ni), a pulp density of 0.5% (62% Cu and 42.37% Ni), and inoculums of 1% (58% Cu and 32.29% Ni). The XRD pattern of PCB showed 77.6% of copper containing compounds. XRD analysis of the leachate residue showed only 23.2% Euchorite (ASCu2H7O8) and 9.4% other copper containing compounds, indicating the leaching property of the fungus. HPLC analysis of the spent medium showed the presence of different acids like citric, succinic, and fumaric acid. The FTIR spectrum showed a decrease in carboxylic stretching in the leachate produced after bioleaching using spent medium. ICPOES of the leachate obtained using spent medium showed that 61% of the copper and 35% of nickel were leached out after seven days of incubation at shaking condition and 57% of copper and 32.8% of nickel at static condition confirming acidolysis property of the strain. A. fumigatus A2DS metal absorption and adsorption ability were observed using transmission electron microscopy (TEM) and scanning electron microscopy energy dispersive X-ray (SEM-EDX) respectively. The results thus indicate that bioleaching of Cu and Ni is bioleached by A. fumigatus A2DS.

Valonea Tannin: Tyrosinase Inhibition Activity, Structural Elucidation and Insights into the Inhibition Mechanism.

Valonea tannin is a natural product readily extracted from acorn shells that has been suggested to have potential skin whitening properties. This study investigated the tyrosinase inhibition activity of extracted valonea tannin and the associated structure-function activity. Nuclear magnetic resonance spectroscopy and molecular weight analysis with gel permeation chromatography revealed that valonea tannin could be characterized as a hydrolysable tannin with galloyl, hexahydroxydiphenoyl and open formed-glucose moieties and an average molecular weight of 3042 ± 15 Da. Tyrosinase inhibition assays demonstrated that valonea tannin was 334 times more effective than gallic acid and 3.4 times more effective than tannic acid, which may relate to the larger molecular size. Kinetic studies of the inhibition reactions indicated that valonea tannin provided tyrosinase inhibition through mixed competitive-uncompetitive way. Stern-Volmer fitted fluorescence quenching analysis, isothermal titration calorimetry analysis and in silico molecule docking showed valonea tannin non-selectively bound to the surface of tyrosinase via hydrogen bonds and hydrophobic interactions. Inductively coupled plasma-optical emission spectroscopy and free radical scavenging assays indicated the valonea tannin had copper ion chelating and antioxidant ability, which may also contribute to inhibition activity. These results demonstrated the structure-function activity of valonea tannin as a highly effective natural tyrosinase inhibitor that may have commercial application in dermatological medicines or cosmetic products.

Fractionation of Heavy Metals in Multi-Contaminated Soil Treated with Biochar Using the Sequential Extraction Procedure.

Heavy metals (HMs) toxicity represents a global problem depending on the soil environment's geochemical forms. Biochar addition safely reduces HMs mobile forms, thus, reducing their toxicity to plants. While several studies have shown that biochar could significantly stabilize HMs in contaminated soils, the study of the relationship of soil properties to potential mechanisms still needs further clarification; hence the importance of assessing a naturally contaminated soil amended, in this case with Paulownia biochar (PB) and Bamboo biochar (BB) to fractionate Pb, Cd, Zn, and Cu using short sequential fractionation plans. The relationship of soil pH and organic matter and its effect on the redistribution of these metals were estimated. The results indicated that the acid-soluble metals decreased while the fraction bound to organic matter increased compared to untreated pots. The increase in the organic matter metal-bound was mostly at the expense of the decrease in the acid extractable and Fe/Mn bound ones. The highest application of PB increased the organically bound fraction of Pb, Cd, Zn, and Cu (62, 61, 34, and 61%, respectively), while the BB increased them (61, 49, 42, and 22%, respectively) over the control. Meanwhile, Fe/Mn oxides bound represents the large portion associated with zinc and copper. Concerning soil organic matter (SOM) and soil pH, as potential tools to reduce the risk of the target metals, a significant positive correlation was observed with acid-soluble extractable metal, while a negative correlation was obtained with organic matter-bound metal. The principal component analysis (PCA) shows that the total variance represents 89.7% for the TCPL-extractable and HMs forms and their relation to pH and SOM, which confirms the positive effect of the pH and SOM under PB and BB treatments on reducing the risk of the studied metals. The mobility and bioavailability of these metals and their geochemical forms widely varied according to pH, soil organic matter, biochar types, and application rates. As an environmentally friendly and economical material, biochar emphasizes its importance as a tool that makes the soil more suitable for safe cultivation in the short term and its long-term sustainability. This study proves that it reduces the mobility of HMs, their environmental risks and contributes to food safety. It also confirms that performing more controlled experiments, such as a pot, is a disciplined and effective way to assess the suitability of different types of biochar as soil modifications to restore HMs contaminated soil via controlling the mobilization of these minerals.

From Laboratory towards Industrial Operation: Biomarkers for Acidophilic Metabolic Activity in Bioleaching Systems.

In the actual mining scenario, copper bioleaching, mainly raw mined material known as run-of-mine (ROM) copper bioleaching, is the best alternative for the treatment of marginal resources that are not currently considered part of the profitable reserves because of the cost associated with leading technologies in copper extraction. It is foreseen that bioleaching will play a complementary role in either concentration-as it does in Minera Escondida Ltd. (MEL)-or chloride main leaching plants. In that way, it will be possible to maximize mines with installed solvent-extraction and electrowinning capacities that have not been operative since the depletion of their oxide ores. One of the main obstacles for widening bioleaching technology applications is the lack of knowledge about the key events and the attributes of the technology's critical events at the industrial level and mainly in ROM copper bioleaching industrial operations. It is relevant to assess the bed environment where the bacteria-mineral interaction occurs to learn about the limiting factors determining the leaching rate. Thus, due to inability to accurately determine in-situ key variables, their indirect assessment was evaluated by quantifying microbial metabolic-associated responses. Several candidate marker genes were selected to represent the predominant components of the microbial community inhabiting the industrial heap and the metabolisms involved in microbial responses to changes in the heap environment that affect the process performance. The microbial community's predominant components were Acidithiobacillus ferrooxidans, At. thiooxidans, Leptospirillum ferriphilum, and Sulfobacillus sp. Oxygen reduction, CO2 and N2 fixation/uptake, iron and sulfur oxidation, and response to osmotic stress were the metabolisms selected regarding research results previously reported in the system. After that, qPCR primers for each candidate gene were designed and validated. The expression profile of the selected genes vs. environmental key variables in pure cultures, column-leaching tests, and the industrial bioleaching heap was defined. We presented the results obtained from the industrial validation of the marker genes selected for assessing CO2 and N2 availability, osmotic stress response, as well as ferrous iron and sulfur oxidation activity in the bioleaching heap process of MEL. We demonstrated that molecular markers are useful for assessing limiting factors like nutrients and air supply, and the impact of the quality of recycled solutions. We also learned about the attributes of variables like CO2, ammonium, and sulfate levels that affect the industrial ROM-scale operation.

Preparation of Expanded Chitin Foams and their Use in the Removal of Aqueous Copper.

Chitin is an underexploited, naturally abundant, mechanically robust, and chemically resistant biopolymer. These qualities are desirable in an adsorbent, but chitin lacks the necessary specific surface area, and its modification involves specialized techniques and equipment. Herein is described a novel chemical procedure for expanding chitin flakes, derived from shrimp shell waste, into foams with higher surface area. The process relies on the evolution of H2 gas from the reaction of water with NaH trapped in a chitin gel. The preparation method requires no specialized equipment. Powder X-ray diffraction and N2-physisorption indicate that the crystallite size decreases from 6.6 nm to 4.4 nm and the specific surface area increases from 12.6 ± 2.1 m2/g to 73.9 ± 0.2 m2/g. However, infrared spectroscopy and thermogravimetric analysis indicate that the process does not change the chemical identity of the chitin. The specific Cu adsorption capacity of the expanded chitin increases in proportion to specific surface area from 13.8 ± 2.9 mg/g to 73.1 ± 2.0 mg/g. However, the Cu adsorption capacity as a surface density remains relatively constant at an average of 10.1 ± 0.8 atom/nm2, which again suggests no change in the chemical identity of the chitin. This method offers the means to transform chitin into a higher surface area material without sacrificing its desirable properties. Although the chitin foam is described here as an adsorbent, it can be envisioned as a catalyst support, thermal insulator, and structural material.

Removal of Cu(II) Contamination from Aqueous Solution by Ethylenediamine@ß-Zeolite Composite.

The low cost ß-zeolite and ethylenediamine modified ß-zeolite (EDA@ß-zeolite) were prepared by self-assembly method and used for Cu(II) removal from contaminated aqueous solution. Removal ability of ß-zeolite toward Cu(II) was greatly improved after ethylenediamine (EDA) modification, the removal performance was greatly affected by environmental conditions. XPS results illustrated that the amide group played important role in the removal process by forming complexes with Cu(II). The EDA@ß-zeolite showed desirable recycling ability. The finding herein suggested that the proposed composite is a promising and suitable candidate for the removal of Cu(II) from contaminated natural wastewater and aquifer.

Synthesis of sodium lignosulfonate-guar gum composite hydrogel for the removal of Cu2+ and Co2.

As an emerging pollutant treatment material, hydrogel is known for its good adsorption capacity and environmental friendliness. In this study, a composite material of acrylic acid as the polymerization monomer grafted sodium lignosulfonate and guar gum was prepared, which provided a channel for adsorbing metal ions with its abundant active functional groups and porous structure. The optimized synthesized product was applied to the removal of Cu2+ and Co2+ in a one-component system and a multi-component system, and the maximum ion adsorption capacities obtained were determined to be 709 mg g-1 of Cu2+, 601 mg g-1 of Co2+, respectively. The adsorption kinetics and isotherms were well fitted by the pseudo second-order kinetic model and the Langmuir isotherm, showing that the adsorption of Cu2+ and Co2+ by the adsorbent belongs to the chemisorption on monolayer. XPS results confirmed the successful adsorption of Cu2+ and Co2+ by GG/SLS. Surface complexation was proposed to be the main mechanism for GG/SLS adsorbent to remove heavy metal ions. In addition, the use of recycling research showed that the adsorbent has good chemical stability. These results provided valuable information for designing highly efficient adsorbents that can be used as a high-quality wastewater treatment material.

Unexpected Trends in Copper Removal from Aß Peptide: When Less Ligand Is Better and Zn Helps.

Cu, Zn, and amyloid-ß (Aß) peptides play an important role in the etiology of Alzheimer's disease (AD). Their interaction indeed modifies the self-assembly propensity of the peptide that is at the origin of the deposition of insoluble peptide aggregates in the amyloid plaque, a hallmark found in AD brains. Another even more important fallout of the Cu binding to Aß peptide is the formation of reactive oxygen species (ROS) that contributes to the overall oxidative stress detected in the disease and is due to the redox ability of the Cu ions. Many therapeutic approaches are currently developed to aid fighting against AD, one of them targeting the redox-active Cu ions. Along this research line, we report in the present article the use of a phenanthroline-based peptide-like ligand (L), which is able to withdraw Cu from Aß and redox-silence it in a very stable 4N Cu(II) binding site even in the presence of Zn(II). In addition and in contrast to what is usually observed, the presence of excess of L lessens the searched effect of ROS production prevention, but it is counterbalanced by the co-presence of Zn(II). To explain such unprecedented trends, we proposed a mechanism that involves the redox reaction between Cu(II)L and Cu(I)L2. We thus illustrated (i) how speciation and redox chemistry can weaken the effect of a ligand that would have appeared perfectly suitable if only tested in a 1:1 ratio and on CuAß and (ii) how Zn overcomes the undesired lessening of ROS arrest due to excess of ligand. In brief, we have shown how working in biologically relevant conditions is important for the understanding of all of the reactions at play and this must be taken into consideration for the further rational design of ligands aiming to become drug candidates.

3D porous tubular network-structured chitosan-based beads with multifunctional groups: Highly efficient and selective removal of Cu2.

Herein, an effective adsorbent, 3D porous tubular network-structured citric acid-chitosan/Fe/polyethyleneimine beads (CCFPB) with multifunctional active groups and strong selectivity, was prepared for the selective removal of Cu2+ from simulated wastewater. Compared with pure chitosan beads (CB), the adsorption capacity of CCFPB for Cu2+ was increased by 127 mg g-1 (238%), and the adsorption equilibrium time was shortened by 480 min. The CCFPB showed porous surface and a novel 3D porous tubular network structure in interior, which were benefit to the diffusion of Cu2+ from surface to interior of the CCFPB and the shortening of adsorption equilibrium time. The common coexisting ions in the simulated wastewater had almost no effect on the adsorption of Cu2+ by CCFPB, and the adsorption was fast and reached equilibrium within 10 h. The adsorption process followed pseudo-second-order kinetics and the Langmuir isotherm model (qm = 240.9 mg g-1 for Cu2+). The adsorption mechanism of CCFPB for Cu2+ was mainly the synergistic interaction with amino, carboxyl, and hydroxyl groups. This strategy shows great potential for developing a variety of novel, highly active, and reusable immobilized functional beads materials for effective separation of Cu2+ from multi-ion wastewater.

Preparation of a new magnetic ion-imprinted polymer and optimization using Box-Behnken design for selective removal and determination of Cu(II) in food and wastewater samples.

A new magnetic Cu(II) IIP (Fe3O4@IIP-IDC) is synthesized by polymerization of Imidazole-4,5-dicarboxylic acid functionalized Allyl chloride, and significant improvement of its performance has been compared. SPE parameters were optimized using Box-Behnken design to achieve the twin objectives of quantitative determination and removal of Cu(II). FLPSO kinetic model and BS isotherm model fits well with the capacity of 175 mg g-1. Analytical figures of merit includes a linearity range of 10-5,000 µg L-1 (R2 = 0.9986), preconcentration factor of 50 after eluting with 5 mL of 1 M HNO3, LOD of 1.03 µg L-1 and LOQ of 4.5 µg L-1. Accuracy was assessed by analysis of SRM (Standard Reference Material) and recovery experiments after spiking in food samples (Tea, coffee, chocolate, spinach, infant milk substitute) and battery wastewater. Ease of use, reusability (15 cycles), rapid adsorption and high selectivity makes it a promising candidate for efficient and selective removal and trace determination.

Copper and lead ion removal from wastewater using fava d'anta fodder (Dimorphandra gardneriana Tulasne).

The contamination of bodies of water by potentially hazardous elements has in recent decades become an environmental problem that poses serious risks to humans, fauna, flora and microbiota, compromising the quality of life of the present ecosystem. Therefore, effluents must be properly treated in a legally acceptable manner before their disposal in the environment. With this in mind, adsorption presents itself as an inexpensive efficient technique for the removal of potentially hazardous elements from effluents with excellent adsorption capacities when natural adsorbents are used. In this study, fava d'anta fodder was used in its crude and alkalinized form to remove Cu(II) and Pb(II) ions. Equilibrium studies were carried out using adsorption isotherms in batch systems with mono- and multi-elementary systems containing the two ions. The Langmuir and Freundlich models were applied to the isotherm studies, with the ions being better suited to the Langmuir model, with maximum adsorption capacities of 24.45 mg g-1 and 68.49 mg g-1 (crude form) and 11.12 mg g-1 and 35.34 mg g-1 (alkalinized form) in the mono-elementary system for Cu(II) and Pb(II) ions, respectively.