Copper Sulfate Salts Research Articles

Towards anaerobic digestate valorization to recover fertilizer nutrients: Elaboration of technology and profitability analysis

The study aimed to develop a technology for creating granular fertilizers, containing amino acids, based on food waste digestate. Pork hemoglobin (Ntot: 14.9 ± 1.5%, C: 47.2 ± 4.7%) served as an additional source of nitrogen and organic carbon. The proposed method comprises four unit processes: (1) chemical hydrolysis of raw materials with a mixture of sulfuric (VI) acid and phosphoric (V) acid, (2) neutralization with solid potassium hydroxide and correction of the composition with minerals (sulfate salts of copper, manganese, zinc and iron), (3) granulation with a mixture of biomass combustion, potato starch and peat, and (4) drying the granules. The prepared formulation meets the requirements of European Parliament Regulation 2019/1009 and is classified as PFC 1(B)(I): solid organo-mineral fertilizer (N: 4.49 ± 0.45%, C: 35.0 ± 3.50%, P2O5: 2.83 ± 0.57%, K2O: 4.78 ± 0.96%). The forms of nutrients were determined in accordance with current PN-EN standards. The effect of amino acid fertilizer on cucumber plants (Cucumis sativus, W. Legutko) was studied in 10-day germination tests under normal, salinity and drought conditions. It was noted that a low dose of the preparation under normal conditions had a stimulating effect on root development, while higher supplementation positively affected the aboveground parts of the plants. Under drought conditions, plants accumulated higher amounts of free amino acids, particularly glutamic acid, arginine, glycine, phenylalanine, serine and tryptophan. A significant portion of the study focused on the economic analysis, which included financial calculations for the production of the proposed fertilizer, an evaluation of profitability, and a sensitivity analysis.

Biosynthesis, Characterization and Antibacterial Properties of CuO Nanoparticles of Psychrotrophic Bacteria

Copper oxide nanoparticles have many applications in industry and medicine. Nevertheless, few studies have been conducted in relation to the biological production of these nanoparticles. In the present study, the ability of isolated Psychrotrophic (cold-resistant) prokaryotes from the Zagros highlands located in Lorestan province of Iran and some isolated Streptomyces strains from the Oman Sea has been evaluated in the synthesis of copper oxide nanoparticles. The maximum lethal concentration of copper salts was determined for the strains and the strains with the highest level of resistance were selected. The biosynthesis of copper oxide nanoparticles was done extracellularly by inoculating Psychrotrophic and Streptomyces strains in liquid TSB culture medium containing 0.01 M copper sulfate salt and keeping the culture medium in a shaker incubator at 20 °C at 150 rpm. The production of copper oxide nanoparticles was evaluated by changing the color of the reaction solution from light blue to dark green. From the 44 cold-resistant strains and the investigated Streptomyces strains, all strains were able to tolerate concentrations higher than 5 mM. Of these, the strain OSNP13 belonging to the genus Microbacterium liquefaciens (X77444) has been able to synthesize the highest amount of copper oxide nanoparticles. The optical absorption of the solution containing synthesized nanoparticles was determined in the range of 250-350 nm by UV-vis spectrophotometer, which had a specific peak at 288 nm. And the copper oxide nanoparticles have an average size of 63.21 nm based on DLS analysis. The crystallographic characteristics of copper oxide nanoparticles were also determined by using XRD analysis, which showed that the prepared nanoparticles had a hexagonal crystal structure with a size of 31.29 nanometers. Then, the antibacterial activity of produced nanoparticles was evaluated. The MIC values ​​of copper oxide nanoparticles for E. coli and S. aureus bacteria were calculated as 125 and 250 micrograms per milliliter, respectively. The produced copper oxide nanoparticles have shown a good antimicrobial properties and can be suitable candidates for use as antimicrobial agents.

Ultra-Responsive MEMS Sensing Chip for Differential Thermal Analysis (DTA).

Ultra-responsive single-crystal silicon MEMS thermopiles for differential thermal analysis (DTA) are developed. Facilitated by a unique "microholes interetch and sealing (MIS)" technique, pairs of suspended thermopiles are batch fabricated in a differential form, with high-density (54 pairs) n-type/p-type single-crystal silicon thermocouples integrated within each thermopile (sample area ~0.045 mm2). The fabricated MEMS thermopile sensors exhibit outstanding power responsivity of 99.5 V/W and temperature responsivity of 27.8 mV/°C, which are more than 4 times higher than those reported for material thermal analysis. The high-responsivity MEMS DTA chips allow us to accurately measure the indium melting point at different heating rates of ~1-100 °C/s. We also perform DTA measurement of the dehydration process of CuSO4·5H2O and the crystals show three stages of losing water of crystallization before becoming anhydrous copper sulfate salt. Our high-performance, cost-effective MEMS sensing chips hold promise for rapid and accurate DTA characterization for a wide range of applications.

Investigation of the Effect of Mixed Anion and Mixed Metal on Heavy Metal Removal from Contaminated Aqueous Solutions

Aims: To investigate the effect of variation of metals (Cu vs Zn) and anions (nitrate vs sulfate) in heavy metal remediation by charcoal and coffee waste from contaminated water.
 Study Design: Aqueous solution of single and mixed nitrate and sulfate salts of copper and zinc were respectively treated with charcoal and coffee waste for 12 hr and the residual metal concentration and percent metal removal were determined.
 Place and Duration of Study: The experiments were conducted in the Chemistry Department at Dillard University between January 2021 and November 2021
 Methodology: Coffee waste (2 grams) and charcoal (2 grams) were respectively mixed with 40 ml of 500 parts per million (ppm) of each of the following combination of metal solutions: Cu(NO3)2; CuSO4; Zn(NO3)2; ZnSO4; Cu(NO3)2 and Zn(NO3)2; CuSO4 and ZnSO4; Zn(NO3)2 and ZnSO4; Cu(NO3)2 and CuSO4; Cu(NO3)2 and ZnSO4; Zn(NO3)2 and CuSO4. Each solution was agitated for 12 hours at room temperature. The mixtures were centrifuged at 3000 rpm for 10 minutes and residual copper and zinc were analyzed. The results showed that copper was preferentially adsorbed by coffee waste compared to zinc in all binary metal (copper-zinc) solutions. Copper removal by coffee waste from CuSO4 and CuSO4-ZnSO4 were 43.9% and 65.5% respectively. Zinc removal from ZnSO4 and CuSO4-ZnSO4 by coffee waste was 34.79% and 20.3% respectively. Conversely, the zinc removal from mixed copper-zinc salt solutions, CuSO4-ZnSO4 and Cu(NO3)2-Zn(NO3)2 were 70.5% and 79.9% respectively.
 Conclusion: Metal type can affect the extent of metal removal from mixed metal solutions. In this research, the copper was 21% more effectively removed from the mixed metal solutions than from a single metal-single anion solutions. In addition, zinc removal was11-14% suppressed in binary metal salt solutions compared to its removal from single-metal-single anion salt solutions. The anion type does not influence metal removed from single metal-single anion salt solutions. However, in the mixed metal-mixed anion systems, more metals were removed when the anion is a nitrate than when it is a sulfate, especially with coffee waste as adsorbent. 9.4% more zinc was removed from CuSO4-Zn(NO3)2,79.9%) than from ZnSO4-Cu(NO3)2, 70.5%). Thus, both metal and anion type affect extent of metal removal from mixed metal mixed anion.

The influence of the cultivar and foliar treatment with micronutrient preparations on the yield, economics and energy efficiency of grain production of spring soft wheat (Triticum aestivum L.)

Spring soft wheat is an important food crop, which requires good mineral nutrition, including microelements. The present investigation was conducted during 2019 at the Mordovian Research Institute of Agriculture, Branch of the Federal State Budgetary Scientific Institution Federal Agrarian Scientific Center of the North-East (Russia). Earlier, on leached chernozems of the Republic of Mordovia, conflicting data had been obtained on the effectiveness of complex micronutrient preparations in grain crops. There are interesting reasons for the low effectiveness of individual drugs, given their large market share and the presence of positive reviews from some scientists. The work is devoted to the study of productivity and economic and energy efficiency of spring wheat cultivation on leached chernozem, depending on the variety and separate and joint use of micronutrient preparations of manganese, copper, molybdenum, and Ultramag combi. The novelty of the study is that concerning the conditions of the Republic of Mordovia, the most effective combination of microelements when combined as a fertilizerstimulating agent in foliar feeding was substantiated. The varietal response to the preparations used has been studied. Paired and triple mixtures of trace elements of manganese, copper, and molybdenum were studied in comparison with the complex fertilizer Ultramag combi. We used sulfate salts of copper and manganese, as well as ammonium molybdate, chelated with Na2EDTA in a molar ratio of 1:1. It was found that the best productivity parameters were formed in the Yoldyz spring wheat variety. An optimal combination of microelements has been established that has a positive effect on the efficiency of spring wheat seed grain production. The best parameters of yield and production efficiency of spring wheat varieties Tulaykovskaya 10 and Tulaykovskaya 108 were formed with the foliar treatment of crops with a paired mixture of copper and molybdenum against a background of nitrogen, and the best parameters of Yoldyz variety were formed after treatment with manganese and copper, as well as manganese and molybdenum against a background of nitrogen. Foliar treatment with a multicomponent preparation Ultramag combi, as well as with separately applied nitrogen in the amide form, was less effective.

A Novel Treatment of Antibiotic Effluent pollution From Abattoirs In Mosul City

Beta-lactam substances released into the environment by continuous using via human, animal and plant protection from bacterial infection. These of antibiotic presence has considered very dangerous problem of the public health in general throughout many side effects. Also, the prevalence of antibiotics into the wastewater abattoirs leads to environmental hazard as results of remains into the surrounding and difficulty disposal. In this study, the research have focused on how to elimination of antibiotic from wastewater abattoirs (animal slaughtered sources), in particular, subunits of wastewater stations have not ability to trapping these kinds of substances. Chemical pathways have used to interact directly with Beta-lactam group and convey to the chemical complex and easy to completely removal from wastewater discharged by using Copper sulfate salts. Our results found that using four molecules of CuSo4 for one molecule of Beta-lactam, in order to complete removal process and possibility reusing it at the same time almost 300% percentage. Also, for increase the reaction process, it is recommended to use optimal a temperature between 40-60 ° C. Overall, we need strict laws to limit the spread of antibiotic contamination in the nature as a results of harmful and side effects on all creatures.

Effect of modified biochar on the availability of some heavy metals speciation and investigation of contaminated calcareous soil

The aim of this study was to investigate the speciation of copper (Cu), lead (Pb), and cadmium (Cd) in a modified biochar amended soil in a long-term pot experiment. The efficiency of amendments was evaluated using the extraction of the sequence. Here, rice husk biochar was modified using three levels of cadmium nitrate salt (0, 40 and 80 mg kg−1 soil), copper sulfate salt (0, 50 and 200 mg kg−1 soil) and lead nitrate salt (0, 300 and 600 mg kg−1 soil). In addition, two levels (0 and 4 wt%) rice husk biochar was modified with Fe3O4, NaOH, and H2SO4 and applied each at three replicates. In order to study soil fractionation 5 months after incubation, chemical forms of cadmium, copper, and lead were determined by the fractionation method, a mobility factor and sequential extraction procedure were applied for appraising the effectiveness of the amendments. Based on the results, biochar modified with NaOH is the most effective and thus reduces lead release in solution and increases in residual form. The modified biochar decreases cadmium concentration and leads to increased copper concentration in the corn plant. Modified rice husk biochar decreased translocation factor, the least translocation factor was observed in NaOH-modified biochar.

Activated carbon impregnated with copper to remove l-cysteine in an aqueous medium

In this work, the surface of commercial activated carbon was modified with the copper sulfate salt by impregnation method, aiming at the removal of reduced sulfur compounds from aqueous media. The materials were characterized by X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy with energy dispersion spectroscopy, and using nitrogen gas as adsorbent, the apparent specific surface areas were determined. In addition, the semiquantitative analysis to explore the surface area was performed using methylene blue a ‘molecular probe.’ For the adsorption, was used l-cysteine as the model adsorbate. After the impregnation of activated carbon, the presence of copper in the forms of copper oxide and metallic copper was confirmed. The mapping of functional groups demonstrated the carbonaceous characteristic of the material. The photomicrographs showed crystals on the surface of the activated carbon impregnated with copper and revealed a copper atomic content of 16.8% w/w. However, the impregnation caused a reduction in the apparent specific surface, probably due to the clogging of the pores with the impregnation salt. On the other hand, the results of adsorption tests showed an increase in l-cysteine removal with impregnation, ranging from 76 to 93%. The results suggest that the adsorbent impregnated with copper is considered promising for the removal of compounds with reduced sulfur.

Decoration of N-functionalized graphene nanoflakes with copper-based nanoparticles for high selectivity CO2 electroreduction towards formate

The present electrocatalyst consists of copper and copper sulfide nanoparticles dispersed on graphene nanoflakes (GNFs), a stack of 5–20 highly crystalline graphene layers having typical side lengths of 100 by 100 nm. Plasma-based functionalization is used for adding covalently bonded nitrogen sites on the surface of the GNFs to a level of up to 2 at%. The catalyst nanoparticles are synthesized through wet chemistry, where graphene and a copper sulfate salt are mixed in a solvent and dried prior to pyrolysis under inert atmosphere at 700 °C. The amount of copper added to the carbon support is well controlled through this method, and is comprised between 20 and 50 wt%. Tests made towards the electrocatalytic reduction of carbon dioxide show these catalysts generate a faradaic efficiency of up to 42.5% toward liquid products at −0.6 V vs RHE, with a high selectivity for formate. The performance of the catalysts is mostly driven by the amount of the copper sulfide phase rather than the metallic copper content, and competes with similar catalysts found in the literature for a fraction of the metal content.

Effects of reaction temperatures and reactant concentrations on the antimicrobial characteristics of copper precipitates synthesized using L-ascorbic acid as reducing agent

Abstract Copper-based precipitates were synthesized using a straightforward wet chemical reduction method with copper sulfate salts as precursor and L-ascorbic acid as reducing agent. Scanning electron micrographs of the precipitates reveal particle-like structures with edges. The percent age yield was observed to increase with the reaction temperature and the reductant-to-precursor concentration ratio. Comparison of samples prepared at different times showed that the bulk of the precipitates was formed during the first 24 hours. New yield added to the bulk decreased over time. Here, the ascorbic acid served as a capping agent, which impeded the oxidation. This capping was not visible in the electron micrographs but may be inferred from the infrared spectra. Faster capping reduced the amount of oxides in the precipitates. This was seen in samples prepared at a higher temperature and with a lower reductant-to-precursor concentration ratio. Antimicrobial testing under dynamic contact conditions showed that the copper-based precipitates were more effective against Staphylococcus aureus (a gram-positive bacteria) than Escherichia coli (a gram-negative bacteria). Copper-based precipitates collected after the first 24 hours were more potent than those collected after eight days. Furthermore, samples prepared at room temperature and lower reductant-to-precursor concentration ratios were found to be more effective in reducing the number of S. aureus after one hour of contact. The synthesized copper-based precipitates was observed to reduce the population of S. aureus (CFU/mL) by up to 98% after one hour of contact.

Antibacterial effect of copper sulfate against multi-drug resistant nosocomial pathogens isolated from clinical samples.

Background and Objective:With the emergence of antibiotic resistance and the hospital acquired infection, the interest for antimicrobial agents has recently increased again in public health. Copper is recommended as a supplementary method of increasing biological safety in the hospital environment. The objective of this study was to determine the antibacterial activity of copper sulfate salts on strains of bacterial pathogens isolated from different clinical pictures in different health establishment in Algeria.Methods:A total of 25 different bacterial isolates (16 Enterobacteriaceae, 5 Staphylococci, and 4 Pseudomonas) were tested for susceptibility to copper sulfate using minimum inhibitory concentration (MIC-Cu) and minimum bactericidal concentrations (MBC-Cu) determinations. All isolates were also tested for susceptibility to six antibiotics.Results:Antibiotic susceptibility studies revealed that 100% of isolates were resistant to one or more antibiotics. Fifty two percent of isolates were very susceptible to copper sulfate, with MICs ranging from 100 to 200 µg/ml. MBC-Cu = 1600 μg/ml showed the best bactericidal effect against the great majority of studied bacteria (52%). A good bactericidal activities of copper sulfate were recorded against Proteus vulgaris and Staphylococcus aureus (MBC/MIC=1). The Gram-negative bacteria isolates which were copper resistant also showed a high resistance to chloramphenicol (r=0.78) and Trimethoprime (r=0.61). Furthermore, the strains that were no-susceptible to three different antimicrobial classes (Escherichia coli, Staphylococcus saprophyticus) were not resistant to copper sulfate.Conclusion:Copper sulfate salts has significant antibacterial activity against multi-drug resistant nosocomial pathogens.

Preparation of Al-magadiite material, copper ions exchange and effect of counter-ions: antibacterial and antifungal applications

In this work, the Al-magadiite is synthesized by the hydrothermal method. It is then used to prepare three copper exchanged materials using copper nitrate, copper chloride, and copper sulfate salts. The materials obtained were characterized and applied as antibacterial and antifungal agents against pathogen strains. The characterization methods showed the presence of four coordinated aluminum atoms in the magadiite framework. The presence of aluminum leads to the total exchange of interlayer sodium cations. Otherwise, the copper exchange rate is influenced by the nature of the counter-ion used. Indeed, the exchanged rate increased in the sense of copper nitrate > copper chloride > copper sulfate. The chemical analysis shows that the ion exchange of Al-magadiite with copper salts is accompanied with dehydration of Cu-exchanged materials. This result was confirmed by XRD diffraction, chemical analysis, and FTIR spectroscopy. This dehydration depends on the nature of the counter ion increase also in the sense of copper nitrate > copper chloride > copper sulfate. Tested as antibacterial and antifungal materials against pathogens strains, all the copper exchanged materials exhibited a good antibacterial activity against Gram-positive bacteria which increased with increasing the copper content of a sample. The best activity was observed in the exchanged sample prepared from copper nitrate. However, a low or no activity is observed against Gram-negative bacteria.

Adsorption desalination-cooling system employing copper sulfate driven by low grade heat sources

In this study benefits of employing copper sulfate salt hydrate with water vapor as a new adsorption pair in thermally driven adsorption desalination-cooling systems (ADCSs) have been investigated. Adsorption characteristics (isotherm and kinetic) of copper sulfate/water vapor pair have been presented in this study within temperature range of 25–55 °C. Sun-Chakraborty (S-C) and Dubinin-Astakhov (D-A) models have been used for fitting isotherms results, while linear driving force (LDF) model has been used for the kinetics results. Experimental adsorption capacity of water vapor onto copper sulfate is found to be around 0.51 kg/kg at 25 °C. Activation energy (Ea) and the pre-exponential coefficient (Dso) are estimated to be 25.053 kJ/mol and 1.89 × 10−7 m2/s respectively. A theoretical model for an ADCS has been investigated employing copper sulfate as adsorbent material. The proposed system can produce specific daily water production about 8.2 m3 per ton of copper sulfate, 227 W/kg of copper sulfate specific cooling power and 0.57 coefficient of performance. The performance of the modeled system indicates that the proposed system can be driven efficiently by renewable energy such as solar energy.

The Influence of Dyeing on the Adsorption of Silver and Copper Particles as Antibacterial Agents on to Cotton Fabrics

ABSTRACTIn this paper, the effect of dyeing on the adsorption of silver and copper particles on cotton fabrics was investigated. Vat, direct, and reactive dyes are among the major class of dyes used for cotton fabrics dyeing. In this study, in the first phase, the dyeing of cotton fabrics with direct blue 151, reactive blue 187, and vat blue 6 was performed and in the second phase, the dyed fabrics were immersed and exhausted into a silver and copper solution. The silver and copper solutions were prepared via silver nitrate and copper sulfate salts. The scanning Electron Microscope was applied for morphological study and the elemental analysis was studied by the energy dispersive X-ray. The reflection factor of dyed samples before and after immersion in silver and copper solutions was monitored by using reflectance spectrophotometer analyses. By dyeing cotton with mentioned dyes and usual methods, adsorption of metal on the cotton samples increases. The obtained data show that vat-dyed samples can absorb more silver and copper particles in compare with other dyes. This study may offer an easy way to absorb more amounts of metallic salts as antibacterial agents.

Copper sulfate-embedded and copper oxide-embedded filter paper and their antimicrobial properties

In this study, copper sulfate was successfully embedded in filter paper through soaking and copper oxide was successfully embedded in filter paper via in situ technique using the copper sulfate-embedded paper as the starting material. Using color analysis, the filter paper soaked with copper sulfate solution was observed to change color from white to blue, indicating the presence of embedded copper sulfate salts. Furthermore, upon soaking this filter paper with sodium hydroxide solution, the color changed from blue to brown, indicating the presence of copper oxide. X-ray diffraction (XRD) spectroscopy confirms the observed results of the color analysis. Scanning electron microscopy (SEM) and electron dispersive x-ray (EDX) spectroscopy were used to determine the surface morphology and elemental composition of the samples, respectively. The antimicrobial property of the filter paper with copper-based particles was tested against Gram-negative bacterium (Escherichia coli) and Gram-positive bacterium (Staphylococcus aureus), and two species of fungi (Candida albicans and Aspergillus niger) using disc diffusion method. The reactivity of the copper sulfate-embedded filter paper against E. coli was found to be severe, whereas that against S. aureus was moderate. The reactivity of the samples against the two fungi was mild, having a relatively small zone of inhibition. For the copper oxide-embedded paper, the reactivity of the paper to both bacteria was moderate, whereas it shows no reactivity to C. albicans and only a mild reactivity to A. niger. After 60 min of contact with Escherichia coli, both the copper sulfate-embedded and copper oxide-embedded filter papers reduced the amount of colony forming unit to more than 99.9%.

Effect of feeding chelate complexes of trace elements on the average daily balance of Cu, Zn and Mn in the organism of cows during the period of lacta-tion

The questions are considered about the effect of feeding of trace elements of different types and concentrations in premixes on the average daily balance of copper (Cu), zinc (Zn), manganese (Mn) in the organism of cows of Ukrainian black mottled dairy breed of the two months after calving. For the experiment, 40 cows were selected and formed four groups: one control and three experimental. The cows in the control group fed a premix of sulfate salts of copper, zinc and manganese in doses that are 100% covered their lack in a forage. Experimental animals from I, II and III groups were fed premixes with chelate complexes of Cu, Zn and Mn, which offset the deficiency of trace elements in the feed ration for 100, 50 and 25% (calculated on pure element), respectively. The diet was counted on a cow with an average live weight of 550 kg, with a daily milk yield of 20 kg 4% fat and balanced on the basis of the main nutrients in accordance with the norms. Іn the feeds, excrements, urine and milk of cows, the content of trace elements copper, zinc and manganese was determined by the standardized atomic absorption method on the spectrophotometer AAS-30 («SaglZeiss», Germany). Found a higher percentage of trace elements deposition in the body cows of feeding of chelates of copper, zinc, and manganese in the concentrations that cover their deficit in the diet in the 100% and 50% in the experimental I and II groups: Cu – 7.3% (P < 0.05) and 1.4%, Zn by 12.2% and 15.0% (P < 0.001), Mn by 13.2% (P < 0.01) and 9.0% (P < 0.05), respectively, in comparison with their sulfate salts in a 100 % dose. Based on the results of the balance study, the use in the feeding of cows during lactation of chelates of trace elements in concentrations intermediate to different experimental groups was proposed, namely – below normal their input in the form of sulfate salts on 25% for copper, 50% – zinc, and 65% – for manganese (calculated on pure element).

Embedding of copper sulfate and copper oxide on multipurpose paper

Copper sulfate salts were embedded on multipurpose paper using simple soaking technique while copper oxide particles were embedded using in-situ technique. In simple soaking technique, the papers were simply soaked in copper sulfate solution in order for the copper salts to be incorporated in the paper. In the in-situ technique, the copper sulfate-embedded papers were soaked in sodium hydroxide solution for reactions to occur that will lead to the formation of copper oxide. Copper sulfate-embedded papers have blue green color while copper oxide-embedded papers have brown color. The copper sulfate-embedded paper shows excellent antimicrobial property against Staphylococcus aureus. Meanwhile, the copper oxide-embedded paper shows small zone of inhibition against Escherichia coli and Staphylococcus aureus.

Treatment of industry wastewater using thermo-chemical combined processes with copper salt up to recyclable limit

Abstract Sugarcane is valuable crop of India and has a major role in foreign exchange. The aim of research work is to investigate the reduction of chemical oxygen demand and color from sugarcane industry effluent by thermolysis and coagulation method. The complete study was done in batch mode to determine the effect of operating parameters. The result shows maximum 73% of chemical oxygen demand and 76% color removal with copper oxide catalyst at 5 kg/m 3 massloading, 85 °C reacting temperature, 9 h treatment time and pH 8. Combined study showed 97.6% chemical oxygen demand and 99.9% color removal at pH 6.5 and mass loading 8 mM with copper sulfate salt. The settling and filtration was found to be good at 65 °C and 75 °C with copper oxide treated sugar industry wastewater.

Differential precipitation of copper and nickel from acidic polymetallic aqueous solutions

During the pyrometallurgical treatment of copper concentrates several wastes (gaseous, solid and liquid) are generated. Wastewaters produced in a primary copper smelter are acidic polymetallic solutions characterized by intermediate to high sulphuric acid concentration. Additionally, they usually contain large quantities of valuable metals, such as Cu and Ni, as well as impurities, such as Pb, Zn, Fe, As, Sb, Bi, etc. Therefore, recovery of valuable metals from acidic polymetallic aqueous solutions is of great importance for every plant. This paper is dealing with the recovery of copper and nickel from the acidic polymetallic solutions generated in the copper smelter at Bor, Serbia. The process of differential precipitation of metals through neutralization with caustic soda was selected as the treatment alternative that combines simplicity, efficiency and reliability with low capital and maintenance costs. The concept was based on the development of a simple and efficient process that could be more attractive for industries located in countries suffering from economic recession. Theoretical analysis and experimental results showed that copper and nickel can be differentially removed from the acidic polymetallic solutions at pH=7 and pH=10, respectively, mainly contaminated by arsenic, which occurs at high concentrations in acidic polymetallic solutions. Both metals were precipitated as hydroxides, although a small portion of copper was removed also as copper sulfate salt. The resulted precipitates are rich in copper and nickel and can be recycled in copper, as well as in nickel smelters.

Determination of Hg from Cu concentrates by X-ray fluorescence through preconcentration on polyurethane foam

A methodology was developed for the separation and determination of microamounts of mercury from copper concentrate samples by wavelength dispersive X-ray fluorescence (WDXRF) after solid-phase extraction of mercury from iodide medium using polyurethane foam (PUF). The best sorption conditions for the Hg–KI–PUF system were settled using X-ray fluorescence technique after collection of ground PUF on a filter paper by vacuum filtration and direct measurement of the intensity signal of the sorbed mercury on PUF. The main parameters of sorption such as iodide concentration, pH, shaking time and sample dilution effect were studied. The system shows rapid kinetic sorption and maximum X-ray intensity signal was achieved after shaking for 2 min a 0.01 mol l −1 iodide solution containing microamounts of mercury in the pH range from 1.0 to 9.0. Effective sorption up to a volume of 0.9 l allows preconcentration of mercury. A linear fit up to 50 μg mercury was obtained by the plot of the initial mercury mass in the bulk solution (0.5 l) vs. its respective XRF intensity signal measurement on ground PUF after the sorption process. The calibration sensitivity, quantification and detection limits found were 9.09 CPS μg −1, 9.0 and 2.7 μg, respectively. The sorption of many elements was also evaluated under the best conditions. High concentrations of Cu(II) and Fe(III) interfere seriously. Mercury-selective separation could be achieved using citrate or EDTA as masking agent; no interference due to copper matrix samples was observed in citrate medium. This methodology was evaluated by recovery for mercury determination in copper concentrate ore samples supplied by a mining industry and copper sulfate salts; the results were between 98% and 106%.