Aqueous Copper Research Articles

Impact of aluminum surface area on the rate of reaction with aqueous copper (II) chloride solutions

Throughout this experiment, we investigated the change in reaction temperature over the course of 120 seconds, with 30 second benchmarks, following the introduction of either aluminum strips or granular aluminum to variable concentrations of CuCl2(aq) in order to gain insight into the role that metal surface area plays within the rate of this single replacement reaction. We prepared solutions of CuCl2 (ranging from 0.33M to 1.00M) and mixed each solution with aluminum strips and granular aluminum; we then conducted three trials for each resulting reaction. We found that, for the aluminum strips, the experiments demonstrated an expected increase in temperature, with the 0.33M mixture increasing by 5.2 degrees, 0.66M mixture increasing by 14.8 degrees, and the 1.00M mixture increasing by 36.4 degrees. However, granular aluminum did not follow this same trend, as the temperature of the 0.33M mixture increased by 9.8 degrees, the temperature for the 0.66M mixture increased by 29.3 degrees, and the temperature for the 1.00M increased by 25.6 degrees. It was demonstrated that when CuCl2 solutions were mixed with aluminum strips, the change in temperature followed a linear relationship, however when CuCl2 was mixed with granular aluminum, the 0.33M mixture created a linear trend, but the 0.66M mixture and the 1.00M mixture did not show a trend, thereby concluding that by collision theory, the greater surface area inherent to granular aluminum allowed a faster reaction rate compared to the aluminum strips.

Enhancing Fastness and Ultraviolet Protection Factor of Pelthophorum pterocarpum Natural Dye by Titania Nanoparticles Modification

The harmful effects of synthetic dyes on the environment can be mitigated through the use of natural dyes in textiles. However, textile dyeing with natural dyes has low brightness and colour resistance. TiO2 nanoparticles modified copper pod (Pelthophorum pterocarpum) dye (TMCD) was studied to enhance the fastness and ultraviolet protection factor of fabrics dyeing. This study was conducted using a cotton fabrics which processed by some mordant agents. TiO2 in various amount were dispersed in aqueous copper pod bark solution and produced a modified copper pod natural dye. Investigation of the dyed fabrics was conducted in 3 parameters viz. the colour direction, fastness values toward sunlight and ultraviolet protection factor (UPF). The results showed that the mordant agents affect the final colour palette and brightness, suggesting that TiO2 improved the colour intensity and fastness value of copper pod dye. It also enhanced the ultraviolet protection factor (UPF) of dyed fabrics by 3-8 point higher than the control groups.

Building in biologically appropriate multifunctionality in aqueous copper indium selenide-based quantum dots.

Advanced nanoplatforms equipped with different functional moieties for theranostics hold appealing promise for reshaping precision medicine. The reliable construction of an individual nanomaterial with intrinsic near-infrared (NIR) photofunction and magnetic domains is much desired but largely unexplored in a direct aqueous synthesis system. Herein, we develop an aqueous phase synthetic strategy for Mn2+ doping of ZnS shell grown on Zn-Cu-In-Se core quantum dots (ZCISe@ZnS:Mn QDs), providing the optimal NIR fluorescence quantum efficiency of up to 18.9% and meanwhile efficiently introducing paramagnetic domains. The relaxometric properties of the water-soluble Mn-doped QDs make them desirable for both the longitudinal and transverse (T1 and T2) magnetic resonance (MR) contrast enhancement due to the shell lattice-doped Mn2+ ions with slow tumbling rates and favoured spin-proton dipolar interactions with surrounding water molecules. Surprisingly, the incorporation of Mn2+ ions into the shell is found to significantly enhance the production of reactive oxygen species (ROS) by combining both the chemodynamic and photodynamic processes upon NIR light irradiation, showing great potential for efficient photo-assisted ablation of cancer cells. Furthermore, a broad-spectrum excitation range beneficial for bright NIR fluorescence imaging of breast cancer has been proven and offers high flexibility in the choice of incident light sources. Multiparametric MR imaging of the brain has also been successfully demonstrated in vivo.

Potential larvicidal bioefficacy of copper sulfide-based hybrid nanoemulsions of eucalyptus oil against Aedes aegypti (Linnaeus).

Nanotechnology, an emerging field, has acquired considerable attention for the control of vectors. The present study aimed to synthesize, characterize copper sulfide- and eucalyptus oil-based hybrid nanoemulsions and investigate their larvicidal potential against Aedes aegypti by studying larvicidal bioassay, morphological aberrations, histopathological alterations, biochemical analysis and evaluation of risk assessment in non-target organisms. Hybrid nanoemulsions were prepared by mixing aqueous copper sulfide nanoparticles (CuSNPs) with non-polar eucalyptus oil in five ratios (1:1, 1:2, 1:3, 1:4 and 1:5) by sonication, screened and characterized using Transmission electron microscopy (TEM). Larvicidal activity was recorded and toxicity values were calculated by log-probit method. Morphological, histological and biochemical changes were examined in Aedes aegypti larvae after treatment. Nanohybrids were also tested under simulated conditions and against non-target organism. The nanohybrid ratio of 1:5 was found to be stable after thermodynamic stability tests. TEM studies revealed average size of 90±7.90 nm with globular shape. LC50 and LC90 toxicity values of prepared CuSNPs were calculated out to be 5.00 and 5.81ppm after 24 hours treatment. Effective concentration of prepared nanohybrid (6.5ppm) tested under simulated conditions showed maximum larvicidal mortality after 48 hours of exposure. No toxicity towards the Mesocyclops spp. was observed after treatment of these nanohybrids even up to 21 days. Copper sulfide based hybrid nanoemulsions were found to show efficient larvicidal property which can be used for the formulation of ecofriendly bio-larvicide against Aedes aegypti.

Efficient copper removal using low-cost H3PO4 impregnated red-gram biochar-MnO2 nanocomposites

Copper metal removal from wastewater is an essential step to detoxify wastewater before release into human contact. To serve the same purpose, H3PO4 impregnated and KMnO4 functionalised, red-gram seed coat biochar is synthesized, for efficient and economic biosorption of aqueous copper ions. Response Surface Methodology (RSM) is employed to achieve a high optimal adsorption capacity of 493.34 mg/g, using a low adsorbent dosage of 0.6 g/L in only 90 min. Pre- and post-adsorption characterization of the adsorbent was done using XRD & XPS spectroscopy, FE-SEM, TGA and BET analysis to study its microstructure and mechanism of adsorption. A high mesoporous surface area of 207 m2/g and the negatively charged moieties on the surface help in complexation of the ions by reduced monolayer chemisorption. Cyclic regeneration of the adsorbent was studied to assess the adsorption efficiency, which retained a value as high as 70 % after 3 adsorption-desorption cycles.

Efficacy of Biological Copper Oxide Nanoparticles on Controlling Damping-Off Disease and Growth Dynamics of Sugar Beet (Beta vulgaris L.) Plants

One of the most prevalent diseases affecting sugar beet crops globally is damping-off disease, which is caused by fungi or soil-borne bacteria. The objective of the current study was to assess the antimicrobial activity of various concentrations of CuO-NPs against Fusarium oxysporum, Macrophomina phaseolina, and Pectobacterium carotovorum in a lab setting and how they influenced vegetative growth, physiological traits, antioxidant enzymes, disease incidence percentage, and mineral nutrients of sugar beet plants in a greenhouse experiment. Sugar beet (Beta vulgaris cv. Oscar poly) seeds were soaked in different concentrations (50, 100, and 150 µg L−1) of the tested NPs for two hours pre-sowing. According to in vitro studies, as compared to aqueous copper sulphate and control, CuO-NPs at 25, 35, and 100 µg mL−1 had the greatest inhibitory effect (100%) on the mycelial growth of M. phaseolina, F. oxysporum, and P. carotovorum, respectively. Results from the greenhouse experiment showed that the 150 µg mL−1 concentration produced the greatest reduction in disease incidence %, with efficacy values of 24.53, 13.25, and 23.59% for F. oxysporum, M. phaseolina, and P. carotovorum, respectively. In addition, as compared to untreated control plants, the same concentration of CuO-NPs significantly (p ≤ 0.05) increased the vegetative development, physiological characteristics, antioxidant enzymes, and mineral nutrients of sugar beet plants. Therefore, the antimicrobial activity demonstrated by the biosynthesized CuO NPs indicates that they can resist plant pathogenic microorganisms of sugar beet plants.

ALGICIDAL AND BACTERICIDAL PROPERTIES OF COPPER-CONTAINING GLASSY PHOSPHATE COMPOSITIONS

The paper presents the results of studies of the algicidal and bactericidal properties of copper-containing glassy phosphate composition (MSFC). It has been established that the presence of MSFC in aqueous solutions inhibits the processes of bacterial reproduction, water bloom in them due to the fact that the protective phosphate film formed not only on the surface of heating elements, but also on the surface of the water microflora does not lose its continuity due to the partial hydrolysis of the readily soluble sodium components of the composition, and prevents the access of oxygen to the microflora of water and aqueous solutions and copper cations lead to the suppression of the vital activity of biological pollutants. MSFC can be recommended for the treatment of water for any purpose related to water use.

Novel laboratory extraction method using magnetically micro bubble stream

Innovative, sensitive and accurate method for liquid-liquid extraction using bubble phenomenon. is presented in this work. A working system was designed, consisting of two basic parts: the pump air to generate the bubbles and the pump device, to pump or withdraw the organic layer from the liquid-liquid system key variables study was performed in the system containg Dithizone (0.001 M) in CHCl₃ solvent and aqueous copper (II) chloride (1000 ppm) solution to find out the extent of their impact on the extraction performance obtained in this way. The effect of copper concentration in the initial sample, shake time, size of bubbles flowrate were studied, fixing the optimal conditions: for a sample of (10 mL) aqueous solution of Cu (II) chloride, the optimum copper (II) concentration in the analyzed sample is (0.0001M) , the size of bubbles 2.6 L\min, the shaking time is (15 min), and the pump flowrate is ( 50sec/mL). In these optimum conditions, the extraction degree was (91.1 %). The results of the innovative bubbles extraction method were compared with previous studies, and found they were more efficient than the classical methods of extraction using funnel separation and multiple extraction.

Magnetic reed biochar materials as adsorbents for aqueous copper and phenol removal.

Organics and heavy metals are common pollutants in many wastewaters and water bodies. Adsorption processes by magnetic materials can rapidly remove these pollutants from water and effectively recycle adsorbent. In this study, magnetic analyzer, X-ray diffraction, Flourier transform infrared spectroscopy, and granulometry were used to characterize the synthesized magnetic reed biochar materials (ZnFe2O4/biochar). Influences of adsorption time, pH, temperature, initial solution concentration, and adsorption equilibrium concentration on adsorption performances were investigated for Cu2+ and phenol adsorption by ZnFe2O4/biochar. Adsorption kinetic and isotherm models were used to describe the adsorption processes. Adsorption of phenol and Cu2+ by ZnFe2O4/biochar reached saturation within 45min and increased slightly with the increase of temperature from 15 to 45°C. Adsorption of Cu2+ increased with the increase of pH, while the adsorption of phenol peaked at pH = 6. The adsorption processes fit the pseudo-second order kinetics model, and both conformed to the Langmuir model. The fitting results show that the maximum single-component adsorption capacity of phenol and Cu2+ by ZnFe2O4/biochar is 63.29 and 12.20mg/g, and the maximum bi-component adsorption capacity reaches 40.16 and 9.48mg/g, respectively. All the findings demonstrate that ZnFe2O4/biochar has good adsorption performance for phenol and Cu2+.

(Digital Presentation) Electrolyte Optimisation for Copper Deposition and Dissolution in Redox Flow Batteries

Aqueous copper redox flow batteries (CuRFB) based systems offer an alternative, more sustainable, redox flow battery to those based on vanadium for stationary renewable energy storage. Copper is an abundant material (~20 million tonnes/ year), that can be easily recycled and is significantly lower cost (6.5 € kg -1), by comparison with vanadium technology (20 € kg-1)[i]. CuRFBs can also be operated without perfluorinated membranes required in the vanadium redox flow batteries (VRFB). The CuRFB system takes advantage of the three stable oxidation states of copper Cu(0)-Cu(I)–Cu(II) in which the cuprous species are oxidised to cupric species in the positive half-cell and electrochemically deposited as copper on the negative electrode. The electrolyte system investigated in this work is based on chloride salts which are soluble up to 2.5 M[ii] ,[iii] . This concentration level enables high current densities to be achieved assisting with high power delivery. The present study was focussed on the electrolyte optimisation including the use of ammonium salts as an alternative to calcium salts to provide a higher conductivity chloride based electrolyte with lower overpotential and better reversibility of the copper deposition and dissolution reaction. Other smaller (mM level) quantity bismuth based chemical additives were also found to improve the coulombic efficiency of the copper deposition and dissolution reaction in extended cycling. [i] E. Sánchez-Díez, E. Ventosa, M. Guarnieri, A. Trovò, C. Flox, R. Marcilla, F. Soavi, P. Mazur, E. Aranzabe, R. Ferret, Redox flow batteries: Status and perspective towards sustainable stationary energy storage, Journal of Power Sources, 481, (2021), 228804, [ii] G. Lacarbonara, L. Faggiano, S. Porcu, P.C. Ricci, S. Rapino, D.P. Casey, J.F. Rohan, C. Arbizzani Copper chloro-complexes concentrated solutions: an electrochemical study, Batteries, 7 (2021) 83 [iii] L. Faggiano, G. Lacarbonara, W.D. Badenhorst, L. Murtomäki, L. Sanz, C. Arbizzani, Short thermal treatment of carbon felts for copper-based redox flow batteries, Journal of Power Sources, 520, (2022), 230846 Figure 1

Potency of copper(II) complexes towards drug-sensitive and -resistant Plasmodium falciparum: Structure-activity relationship, ROS-generation and proteasome inhibition

The use of copper in medicine has a long history and copper-containing compounds have multiple applications, such as in treating heart disease, arthritis, cancer, parasitic as well as other inflammatory diseases. Here, we investigate structural factors, structure-activity relationship and two mechanisms of action of a series of copper(II) complexes with 1,10-phenanthroline (phen) and/or amino acid ligands towards Plasmodium falciparum (Pf) 3D7 and artemisinin-resistant Pf5202. To achieve this, the following set of copper(II) complexes, viz. [Cu(phen)Cl2] 1, [Cu(phen)2Cl]Cl·2H2O 2, [Cu(phen)(gly)Cl]·2H2O 3, [Cu(phen)(edda)]·5H2O 4, cis-[Cu(gly)2(H2O)] 5 and [Cu(edda)] 6, (gly = glycine; edda = ethylenediamine-N,N’-diacetic acid) were selected, synthesized and characterized by FTIR, elemental analysis, UV-Visible spectroscopy, molar conductivity measurement and magnetic moment. Herein, we report comparison of aqueous copper(II) species, CuCl2 and ligands in inhibiting proteolytic sites of 20S proteasome, generation of reactive oxygen species, hemolysis and antimalarial property. Factors affecting their antimalarial potency are different from those affecting proteasome inhibition and ROS production. Complexes 1 – 4, with IC50 values of about 3 µM towards Pf3D7, were more effective against artemisinin-resistant strain Pf5202 than chloroquine and artemisinin. Evidence of apoptosis of malaria parasite in red blood cells is also presented.

Supergiant porphyry copper deposits are failed large eruptions

AbstractPorphyry copper deposits, the principal source of copper and molybdenum, form at convergent margins. Copper is precipitated from fluids associated with cooling magmas that have formed in the mantle and evolved at mid- to lower crustal levels, before rising toward the surface where they saturate and exsolve an aqueous fluid and copper. Despite advances in the understanding of their formation, there are still underexplored aspects of the genesis of porphyry copper deposits. Here we examine the role played by magma injection rates into the upper crust on the formation of porphyry copper deposits with different copper endowments. Mass balance calculations suggest that supergiant porphyry copper deposits (>10 million tonnes copper) require magma volumes (up to >2500 km3) and magma injection rates (>0.001 km3 year−1) typical of large volcanic eruptions from rift, hot spot, and subduction-related settings. Because large volcanic eruptions would destroy magmatic-hydrothermal systems or prevent their formation, the largest porphyry copper deposits can be considered as failed large eruptions and this may be one of the causes of their rarity.

High resolution optical investigation of laser intensity and solution temperature effects on thermocavitation

This paper studies cavitation induced by focusing a continuous wave laser in a highly absorbing aqueous copper nitrate solution. The Spatial Transmittance Modulation method was used to detect the cavitation bubbles and verified by high-speed shadowgraphy. The influence of intensity, solution temperature, and absorption coefficient on the cavitation dynamics was investigated by observing the bubble diameters, bubble lifetimes, cavitation times, and cavitation frequencies. The intensity was varied by changing the optical power between 1.2 W and 4.7 W and shifting the laser focal point from 4.5 mm outside to 3.5 mm inside of the cavitating solution by 1 mm increments. Additionally, six solution temperatures between 22 °C to 74 °C were tested, and three concentrations of copper nitrate (10.7, 6.35 and 3.49 g copper nitrate per 10 mL of water) were used to change the solution’s absorption coefficient. The results reveal that on average, larger intensities result in shorter cavitation times, higher frequencies, and higher percentages of small bubbles. Increasing the copper nitrate concentration has a similar effect on the cavitation events. With higher solution temperature, the time to initiate cavitation decreases, and higher percentage of larger bubbles appear due to a decrease of surface tension. However, the solution temperature does not change the cavitation randomness significantly. The findings of this investigation may allow for effective control of thermocavitation dynamics where current laser cavitation applications require managed outcomes.

Surfactant-Modulated a Highly Sensitive Fluorescent Probe of Fully Conjugated Covalent Organic Nanosheets for Detecting Copper Ions in Aqueous Solution.

Efficient detection of aqueous copper ions is of high significance for environmental and human health, since copper is involved in potent redox activity in physiological and pathological processes. Covalent organic frameworks (COFs) have shown advantages in efficient capturing and detecting of copper ions due to their large surface area, robust chemical stability, and high sensitivity, but most of them are hydrophobic, leading to the limitation in sensing copper ions in aqueous media. Herein, the design and synthesis of an sp2 -carbon conjugated COF (sp2 -TPE-COF) are reported with surfactant-assisted water dispersion for detecting traces of copper ions based on the photo-induced electron transfer (PET) mechanism. Importantly, the olefin-linked conjugated backbone of sp2 -TPE-COF works as a signal amplified transducer for metal ion sensing. Notably, it is found that a surfactant-assisted strategy can greatly enhance COF's dispersion in aqueous solution and finely modulate their sensitivity with a significantly improved KSV to 15.15 × 104 m-1 in SDBS (sodium dodecyl benzene sulfonate) solution, the value of which is larger than that of a majority of COF/MOF based sensors for copper ions. This research demonstrates the promise of surfactant modulated fully π-conjugated COFs for sensing applications.

Understanding the Role of Copper Vacancies in Photoelectrochemical CO2 Reduction on Cuprous Oxide.

Controlling the electronic and photoexcited properties of cuprous oxide (Cu2O) through slight modifications of the synthesis method can impact a wide range of emerging technologies. Herein, we consider copper vacancies in Cu2O as a prototype of a p-type oxide semiconductor for studying the impact of crystal and electronic structure on carbon dioxide photoreduction. Oriented films of copper vacancy modulated Cu2O consisting of nano twin structures are electrodeposited by changing the potential in an aqueous alkaline copper(II)-lactate solution. The copper vacancies introduce tail states inside the band gap, improving the hole concentration and facilitating the charge separation and transfer in the Cu2O photocathode. This study gives an in-depth view of how a cation-deficient structure regulates and promotes photoelectrochemical activity toward CO2 reduction.

Enabling fast-charging selenium-based aqueous batteries via conversion reaction with copper ions

Selenium (Se) is an appealing alternative cathode material for secondary battery systems that recently attracted research interests in the electrochemical energy storage field due to its high theoretical specific capacity and good electronic conductivity. However, despite the relevant capacity contents reported in the literature, Se-based cathodes generally show poor rate capability behavior. To circumvent this issue, we propose a series of selenium@carbon (Se@C) composite positive electrode active materials capable of delivering a four-electron redox reaction when placed in contact with an aqueous copper-ion electrolyte solution (i.e., 0.5 M CuSO4) and copper or zinc foils as negative electrodes. The lab-scale Zn | |Se@C cell delivers a discharge voltage of about 1.2 V at 0.5 A g−1 and an initial discharge capacity of 1263 mAh gSe−1. Interestingly, when a specific charging current of 6 A g−1 is applied, the Zn | |Se@C cell delivers a stable discharge capacity of around 900 mAh gSe−1 independently from the discharge rate. Via physicochemical characterizations and first-principle calculations, we demonstrate that battery performance is strongly associated with the reversible structural changes occurring at the Se-based cathode.

Adsorption of Copper Ions onto Poly(1,8‐diaminonaphthalene)/Graphene Film for Voltammetric Determination of Pyridoxine

AbstractIn this work, pyridoxine (vitamin B6) was determined by the square wave voltammetry at copper‐poly(1,8‐diaminonaphthalene)/graphene modified glassy carbon electrode. The composite electrodes were fabricated with two steps. First, poly(1,8‐diaminonaphthalene) is electrodeposited onto graphene/glassy carbon electrodes with a potential cycling technique. Then, copper ions are adsorbed onto the poly(1,8‐diaminonaphthalene)/graphene modified glassy carbon electrode due to the immersion of the polymeric modified electrode in an aqueous copper (II) solution. The characterizations of synthesized materials have shown the role of graphene in facilitating the electron transfer and the remarkably electrocatalytic ability of copper for pyridoxine oxidation on the electrode surface. In 0.1 M phosphate buffer solution (pH 7.4), the peak current of square wave voltammograms of pyridoxine increased linearly with their concentration in the ranges between 0.58 and 24.51 μM with the limit of detection of 0.3 μM. The proposed electrodes showed excellent reproducibility and stability.

Effect of an aqueous copper gel electrolyte with cobalt metal organic framework based additive on performance of aqueous-dye-sensitized solar cells

A simple mono-dentate ligand substitution approach was studied to design three new potential tunable heteroleptic copper redox mediators with general formula [Cu (bnbip) (X)]1+/2+ where, bnbip is a tridentate ligand, (2,6-bis(1-(naphthalen-2-ylmethyl)-1H-benzo[d]imidazol-2-yl)pyridine), X = 4-tert-butylpyridine (tbp), 4-chloropyridine (cp) and 5-methoxy-1-(pyridin-4-yl)-1H-indole (mpi). Herein, copper mediator bearing bulky high donor ligand (mpi) reached best redox potential of 0.72 V vs NHE, which directly improves Voc and Jsc of the dye-sensitized solar cells (DSSC) devices because of its lower reorganization energy and driving force. A series of six aqueous gel electrolytes were prepared as G-1, G-2, G-3 (without additive) and G-4, G-5, G-6 (with Co-MOF additive) to analyze the role of three different heteroleptic copper redox couples and Co-MOF in aqueous gelrite polymer electrolytes. Impressively, electrolytes G-4, G-5 and G-6 affords higher PCE of 2.03, 2.12 and 3.42% under 1sun condition than electrolytes without additives, which proves the role of Co-MOF as an additive to reduce recombination process. This control in recombination occurred due to high interaction of repeating carboxylate donor groups of additive with TiO2 surface and Cu2+ ion of redox pair. The electrolyte material G-6 consists of Cu+1/+2[(bnbip)(mpi)] redox mediator, Co-MOF additive and aqueous geltrite polymer host obtained higher Jsc and PCE which were sustained via many aspects, such as high conductivity, larger charge, higher chemical capacitance, longer electron lifetime, a shift in the quasi-Fermi level of TiO2, lower recombination of electrons and fast dye regeneration.

Evaluation of Some Biological and Chemical Elements in Controlling Some Soil-borne Fungi and Stimulating Plant Growth

This study was conducted to evaluate the efficacy of the biocontrol fungi Chaetomium cupreum, Trichoderma viride, and Saccharomyces cerevisiae and some chemical nutrients that stimulate plant growth, such as calcium nitrate, ammonium phosphate, aqueous magnesium sulfate, copper and boron in controlling some common soil-borne pathogenic fungi and evaluating their role in stimulating plant growth. All the bioagents showed significant antagonistic efficiency In vitro against the pathogenic fungi Drechslera Halodes, Fusarium oxysporum, Fusarium solani, Macrophomina phaseolina, Pythium aphanidermatum and Rhizoctonia solani. Under greenhouse conditions, BC treatment composed of biological and chemical elements, achieved the highest germination rate for tomato, cucumber and cowpea seeds inoculated with the pathogenic fungi, and reached 95.83-100.00% compared to 36.67- 47.50% for the control treatment. BC treatment also excelled in reducing disease incidence and severity, as the disease rate reached 0% compared to 95.83-99.17 % for the inoculated control treatment, and without significant difference with the non-inoculated (healthy) control. In addition, the BC treatment produced 0 % disease severity rate as compared to 82.58-85.83% for the inoculated control, and without significant difference with non-inoculated control. Furthermore, the BC treatment was superior to the rest of the treatments in increasing dry weight of all the plant species tested. Keywords: Chaetomium cupreum, Trichoderma viride, Saccharomyces cerevisia, Soil-borne fungi, biological control.

The interference of copper, iron and aluminum with hydrogen peroxide and its effects on reductive leaching of LiNi1/3Mn1/3Co1/3O2

Copper and iron are known to be effective alternative reducing agents to H2O2 in Li-ion battery leaching. The aim of this work is to study the effect of added H2O2 on its overconsumption to the side reactions such as oxidation of copper, iron, and aluminum in leaching of NMC 111 active material. The interactions between the reducing agents separately were first investigated (T = 30 °C, [H2SO4] = 2 M, t = 120 min). Elemental copper was found to be a less efficient reducing agent (78%) compared to aluminum (100%) in terms of Fe3+ reduced to Fe2+. Nevertheless, copper exhibited much higher rate of iron reduction than aluminum. Additionally, aqueous copper ions were found to cement on aluminum surface and redissolve in the presence of iron, thus acting as the metallic reducing agent. In contrast, in the presence of H2O2 ferrous iron and copper were rapidly oxidized resulting in the consumption of all reducing agents. These effects were confirmed also during the leaching of NMC (T = 30 °C, [H2SO4] = 1.5 M, t = 120 min), which demonstrated that the leaching efficiency markedly decreased (∼63%) in the presence of H2O2 and Cu when compared to H2O2 alone (∼78%). Furthermore, results from NMC leaching showed that when copper-iron reductant or H2O2 were added separately, a much higher leaching efficiency was achieved (∼66% and ∼78%, respectively) in contrast to being added together (∼58%).