Concentrations Of Copper Sulfate Research Articles

Investigating the Toxicity of Malachite Green and Copper Sulfate in Brine Shrimp: in-vivo and Computational Study

Colour is crucial for enhancing the appetizing value and consumer acceptance of food products. The commonly used food colourants and food preservatives such as Malachite Green (MG) and Copper Sulfate (CS) can cause severe health problems. This study investigates the toxicity of these food-grade colourants through acute exposure using in vivo cytotoxicity using the brine shrimp model including 3D surface analysis (3DSA) and in-silico studies Brine shrimp were treated with various concentrations of MG and CS. The cytotoxic effect was confirmed by brine shrimp lethality assay and 3DSA. Molecular docking and Molecular Dynamic simulation were done using hAChE binding cavity. Results showed that concentrations (2.5-10µg/ml) of MG and CS significantly decreased locomotor behaviour within 1hour, while higher concentrations (10-100µg/ml) caused high mortality rates. Morphological studies revealed that there is a significant reduction (p<0.05) in shrimp length treated with MG and CS. The 3DSA indicates that there is an inappropriate surface of the shrimp morphology. Interestingly, MG-treated shrimps had shown significant inhibition of AChE in homogenates, indicating cholinergic nerve-mediated toxicity. Computational studies showed MG confined active binding with human acetylcholinesterase (hAChE), with a binding energy MMGBSA of -51.3kcal/mol. MD simulation confirmed reversible binding stability inside the hAChE pocket. It can be concluded that acute exposure to brine shrimps with MG and CS exhibited cytotoxicity as evidenced by the increase in mortality of the shrimps. This study further warrants the investigation of MG and CS residues from commonly used fruits and vegetables and their putative toxic effect using in-vivo studies.

Effects of copper sulphate stress on the morphological and biochemical characteristics of Spinacia oleracea and Avena sativa

Plants are subjected to various biotic and abiotic stresses that significantly impact their growth and productivity. To achieve balanced crop growth and yield, including for leafy vegetables, the continuous application of micronutrient is crucial. This study investigates the effects of different concentrations of copper sulphate (0, 75, 125, and 175 ppm) on the morphological and biochemical features of Spinacia oleracea and Avena sativa. Morphological parameters such as plant height, leaf area, root length, and fresh and dry weights were optimized at a concentration of 75 ppm copper sulfate. At this concentration, chlorophyll a & b levels increased significantly in Spinacia oleracea (462.9 and 249.8 \U0001d707\U0001d454/\U0001d454), and Avena sativa (404.7 and 437.63\U0001d707\U0001d454/\U0001d454). However, carotenoid content and sugar levels in Spinacia oleracea were negatively affected, while sugar content in Avena sativa increased at 125 ppm (941.6 µg/ml). Protein content increased in Spinacia oleracea (75 ppm, 180.3 µg/ml) but decreased in Avena sativa. Phenol content peaked in both plants at 75 ppm (362.2 and 244.5 µg/ml). Higher concentrations (175 ppm) of copper sulfate reduced plant productivity and health. Plants exposed to control and optimal concentrations (75 and 125 ppm) of copper sulpate exhibited the best health and growth compared to those subjected to higher concentrations. Maximum plant height, leaf area, root length, fresh and dry weights were observed at lower concentrations (75 and 125 ppm) of copper sulfate, while higher concentrations caused toxicity. Optimal copper sulfate levels enhanced chlorophyll a, chlorophyll b, total chlorophyll, protein, and phenol contents but inhibited sugar and carotenoid contents in both Spinacia oleracea and Avena sativa. Overall, increased copper sulfate treatment adversely affected the growth parameters and biochemical profiles of these plants.

Green synthesis and antimicrobial activity of copper nanoparticles (Cu-NPS) by Piper longum fruit extract

Many applications of green synthesis in the field of environment and biomedicine aiming at decreasing the use of toxic chemicals through utilizing of plants which are safe. In this study, at 0.1 M concentration of copper sulfate (CuSO4.5H2O), CuNPs were prepared and identified by changing the blue color into green color (ethanolic extract) and from blue color to black color (water extract) and the spectrophotometric detection of ultraviolet and infrared spectra. X-Ray diffraction (XRD) pattern was utilized to confirm the crystal structure of CuNPs. The morphology and size of the CuNPs was measured by a high-resolution transmission electron microscope (HR-TEM). Energy dispersive X-ray (EDX) was used for identification of the elemental composition of CuNPs involving copper and oxygen. Field emission scanning electron microscopy (FESEM) was utilized to confirm the shape of prepared copper nanoparticles. In vitro antibacterial activity was tested using two methods including desk diffusion assay considering zones of inhibition and minimum inhibitory concentration (MIC) against six types of certain bacterial types (Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Staphylococcus aureus, Streptococcus pneumoniae and Enterococcus faecalis). The results showed potent inhibitory activity of copper nanoparticles (CuNPs) and water extract (Ext. 2) against all bacterial strains. KEY WORDS: Copper nanoparticles, Piper Longum, Extract, Synthesis, Antibacterial Bull. Chem. Soc. Ethiop. 2024, 38(6), 1653-1666. DOI: https://dx.doi.org/10.4314/bcse.v38i6.12

Novel method for finishing nonwoven fabrics from domestic raw materials with flame retardant and antimicrobial properties

This study aims to obtain a non-woven material with flame retardant and biocidal properties, considering the use of salicylic acid, copper sulfate, and guanidine hydrochloride in a finishing composition, based on preliminary studies. The concentrations of copper sulfate, guanidine hydrochloride, and salicylic acid were varied, respectively, within 1–5 g/L, 5–15 g/L, and 3–7 g/L. The conditions of the finishing process involved the application of the aqueous solutions, by spraying on the surface of the material, followed by drying at 120 °C for 5 min and heat treatment at 180 °C on a thermal press. In the production of nonwovens, treatment with a flame retardant and biocidal composition can be combined with emulsification of a mixture of fibers, or carried out after the formation of the canvas with subsequent heat treatment and calendering. The untreated sample of non-woven material, when tested for flammability with an ignition time of 15 s, burns completely in 40 s. For the sample treated by the proposed method, the self-burning is reduced to zero (DIN 53906). To study the biocidal activity, a microbiological essay was conducted according to ASTM E2149. It was found that the tested sample exhibits fungicidal activity against the tested strains. In addition, tests conducted on the skin-irritating effects of nonwovens treated with the proposed method have shown its safety for human health.

Studies on the quantitative analysis of an electrochemical solution via the Schlieren method

A quantitative schlieren technique has been applied to measure the change of copper sulfate concentration in an electrochemical cell during the copper electroplating process. We constructed a mathematical model that correlates the grayscale values of schlieren images with the concentration of copper sulfate and analyzed the impact of refraction, reflection, and absorption of light during its passage through the solution on the precision of a schlieren quantitative analysis. Ultimately, by examining the temporal and spatial changes in the distribution of the copper sulfate concentration, we ascertained the impacts of convection, diffusion, and electromigration on the concentration distribution. The impact of the current studies would be greatly expanded in important electrochemical practices such as renewable energy conversions and rechargeable batteries.

Pest management facing warming and chemical stresses: Multi-stress effects on the biological agent Trichogramma oleae

Global change is affecting plant-insect interactions in agroecosystems and can have dramatic consequences on yields when causing non-targeted pest outbreaks and threatening the use of pest natural enemies for biocontrol. The vineyard agroecosystem is an interesting system to study multi-stress conditions: on the one hand, agricultural intensification comes with high inputs of copper-based fungicides and, on the other hand, temperatures are rising due to climate change. We investigated interactive and bottom-up effects of both temperature increase and copper-based fungicides exposure on the important Lepidopteran vineyard pest Lobesia botrana and its natural enemy, the oophagous parasitoid Trichogramma oleae. We exposed L. botrana larvae to three increasing copper sulfate concentrations under two fluctuating thermal regimes, one current and one future. Eggs produced by L. botrana were then exposed to T. oleae. Our results showed that the survival of L. botrana, was only reduced by the highest copper sulfate concentration and improved under the warmer regime. The development time of L. botrana was strongly reduced by the warmer regime but increased with increasing copper sulfate concentrations, whereas pupal mass was reduced by both thermal regime and copper sulfate. T. oleae F1 emergence rate was reduced and their development time increased by combined effects of the warmer regime and increasing copper sulfate concentrations. Size, longevity and fecundity of T. oleae F1 decreased with high copper sulfate concentrations. These effects on the moth pest and its natural enemy are probably the result of trade-offs between the survival and the development of L. botrana facing multi-stress conditions and implicate potential consequences for future biological pest control. Our study supplies valuable data on how the interaction between pests and biological control agents is affected by multi-stress conditions.

TOXICOLOGICAL ASSESSMENT OF COPPER SULPHATE ON CHANNA ORIENTALIS AND HETEROPNEUSTES FOSSILIS: LC50 VALUES AND MORTALITY ANALYSIS

The adverse effects of heavy metals, particularly copper sulphate, released from industrial effluents on aquatic life are well-documented. In this study, we determined the LC50 values of copper sulphate for two freshwater air-breathing fish species, Channa orientalis (Bloch) and Heteropneustes fossilis (Bloch). The LC50 values for Channa orientalis were determined to be 33 ppm at 24 hours, 32 ppm at 48 hours, 21 ppm at 72 hours, and 7.5 ppm at 96 hours. For Heteropneustes fossilis, the corresponding LC50 values were 15 ppm at 24 hours, 13 ppm at 48 hours, 9.5 ppm at 72 hours, and 5 ppm at 96 hours. We observed a significant increase in mucus secretion at higher concentrations of copper sulphate as compared to lower concentrations. The potential mechanisms of fish mortality under these conditions are also discussed in detail

Improvement of sulforaphane production in hairy root cultures of broccoli (Brassica oleracea L. var. italica) by eliciting Myrosinase gene expression and its effect on breast cancer cells

Plant-derived hairy root cultures have the potential to be a significant biotechnological tool for producing valuable secondary metabolite compounds. This study deals with the production of broccoli’s hairy root cultures via the mediation of Agrobacterium rhizogenes and investigates the effects of different concentrations of copper sulfate (CuSO4) and zinc sulfate (ZnSO4) as two elicitors on the production of sulforaphane in broccoli's hairy root. The expression of the Myrosinase (MY) gene, associated with sulforaphane production, was quantified using real-time PCR. Moreover, the cytotoxic effect of different treatments of sulforaphane on the breast cancer cell line, MDA-MB-231, was estimated and the transcription levels of apoptosis-associated genes were also determined. The highest amount of sulforaphane was produced at 4 µM CuSO4 after 16 h and 16 µM ZnSO4 after 8 h of elicitation. Overexpression of the MY gene was found to be associated with increased production of sulforaphane. All sulforaphane treatments induced a dose-dependent reduction in the viability of cancer cells. The sulforaphane extracted from broccoli's hairy roots treated with CuSO4 exerted a higher cytotoxic effect on the MDA-MB-231 breast cancer cell line than the sulforaphane extracted from broccoli's hairy root treated with ZnSO4. All treatments of sulforaphane up-regulated the Apoptosis Regulator (Bax) gene, Proapoptotic Bcl2 Associated X, Caspase-3, Caspase-8, and Caspase-9, while down-regulating the B-cell lymphoma 2 (Bcl-2) gene (antiapoptotic) transcription. The overall results showed an antiapoptotic effect of sulforaphane extract derived from broccoli's hairy roots on MDAMB-231 breast cancer cells, thereby establishing the potential anticancer activity of the sulforaphane produced in broccoli's hairy root cultures.

Study on the Genotoxic Effect of Copper Sulphate in the Spotted Snakehead Fish Channa Punctatus (Bloch, 1793)

The genotoxic effects of a herbicide containing CuSO4 were assessed using the micronucleus assay in Channa punctatus. The study involved intraperitoneal administration of three different doses (1.0, 3.0, and 5.0 mg/kg body weight) and exposure to varying concentrations of copper sulphate (15, 25, and 35 ppm) in laboratory aquaria. Peripheral blood smears stained with 15 to 20% Giemsa (pH=7.0) were examined. Apart from micronuclei, the herbicide induced other nuclear and cytoplasmic abnormalities. The findings suggest a direct impact of increasing CuSO4 concentration on the biological samples of Channa punctatus. This fish species is commonly found in freshwater habitats like ponds, ditches, wetlands, and rice fields, especially in Odisha, India. India is crucial for maintaining aquatic biodiversity. The study highlights the potential detrimental effects of improper use of CuSO4 containing pesticides in agriculture on Channa punctatus and emphasizes the need for careful management of such chemicals to protect aquatic ecosystems.

Optimization studies on laccase activity of Proteus mirabilis isolated from treatment sludge of textile industry factories : Optimization of laccase activity of Proteus mirabilis.

Laccase is an exothermic enzyme with copper in its structure and has an important role in biodegradation by providing oxidation of phenolic compounds and aromatic amines and decomposing lignin. The aim of this study is to reach maximum laccase enzyme activity with minimum cost and energy through optimization studies of Proteusmirabilis isolated from treatment sludge of a textile factory. In order to increase the laccase enzyme activities of the isolates, medium and culture conditions were optimized with the study of carbon (Glucose, Fructose, Sodium Acetate, Carboxymethylcellulose, Xylose) and nitrogen sources (Potassium nitrate, Yeast Extract, Peptone From Soybean, Bacteriological Peptone), incubation time, pH, temperature and Copper(II) sulfate concentration then according to the results obtained. Response Surface Method (RSM) was performed on six different variables with three level. According to the data obtained from the RSM, the maximum laccase enzyme activity is reached at pH 7.77, temperature 30.03oC, 0.5g/L CuSO4, 0.5g/L fructose and 0.082g/L yeast extract conditions. After all, the laccase activity increased 2.7 times. As a result, laccase activity of P. mirabilis can be increased by optimization studies. The information obtained as a result of the literature studies is that the laccase enzymes produced in laboratory and industrial scale are costly and their amounts are low. This study is important in terms of obtaining more laccase activity from P.mirabilis with less cost and energy.

A mathematical model of the copper plating process in restoration of road transport equipment parts

Introduction. The use of restored parts of motor vehicles makes it possible to reduce the financial costs of repairing equipment. The cost of the restored parts should not exceed 50% of the cost of the new part. Increasing the productivity (deposition rate) of an electrolytic copper coating during the restoration of parts of motor vehicles requires taking into account the technological and economic aspects of the restoration process. The study of the factors (deposition conditions) that most affect the deposition process of the copper coating, the analysis of the experimental results and its statistical processing made it possible to optimize the technology of restoration of copper parts to create the most appropriate deposition modes with maximum productivity, thus reducing the cost of restoration of parts of motor vehicles. The purpose of the research is to develop a mathematical model of the effect of deposition conditions (electrolyte temperature, cathode current density) and electrolyte composition (concentration of copper sulfate and sulfuric acid) on the performance of the deposition process of copper coating, for further development of the most productive technology for restoring collectors of electric motors of motor vehicles.Materials and methods. The studies on equipment that allows obtaining the necessary data with the required accuracy were carried out. Mathematical processing using modern statistical data processing tools that excluded possible errors, providing to obtain the dependence of factors with the necessary accuracy was carried out.Results. In the course of studies of copper sulfate electrolytes to obtain an electrolytic copper coating, with the further development of technology for the restoration of automotive parts, it became necessary to determine the effect of deposition conditions – “factors” (cathode current density, electrolyte temperature, copper sulfate concentration, sulfuric acid concentration) on the deposition rate – “response”. It was found that the factor “cathode current density” and the combination of factors “cathode current density” and “sulfuric acid concentration” are the most significant. The deposition conditions in order to obtain the most productive technology for restoring collectors of electric motors of motor vehicles by depositing a copper coating have been optimized. According to the obtained model, the optimal values of the deposition conditions for obtaining the maximum deposition rate are the electrolyte temperature of 35...40 ° C, the cathode current density of more than 5 A/Dm2, the concentration of copper sulfate 200...250 g/l, the concentration of sulfuric acid 40...70 g/l.

High copper levels induce premature senescence in 3T3-L1 preadipocytes

Copper (Cu) dyshomeostasis has been linked to obesity and related morbidities and also to aging. Cu levels are higher in older or obese individuals, and adipose tissue (AT) Cu levels correlate with body mass index. Aging and obesity induce similar AT functional and structural changes, including an accumulation of senescent cells. To study the effect of Cu-mediated stress-induced premature senescent (Cu-SIPS) on preadipocytes, 3T3-L1 cell line was exposed to a subcytotoxic concentration of copper sulfate. After Cu treatment, preadipocytes acquired typical senescence characteristics including diminished cell proliferation, cell and nuclei enlargement and increased lysosomal mass (higher Lamp2 expression and a slight increased number of cells positive for β-galactosidase associated with senescence (SA-β-Gal)). Cell cycle arrest was due to upregulation of p16Ink4aInk4a and p21Waf1/Cip1. Accordingly, protein levels of the proliferation marker KI67 were reduced. Cu-SIPS relates with oxidative stress and, in this context, an increase of SOD1 and HO-1 expression was detected in Cu-treated cells. The mRNA expression of senescence-associated secretory phenotype factors, such as Mmp3, Il-6 and Tnf-α, increased in Cu-SIPS 3T3-L1 cells but no effect was observed on the expression of heterochromatin-associated protein 1(HP1).Although the downregulation of Lamin B1 expression is considered a hallmark of senescence, Cu-SIPS cells presented higher levels of Lamin B1. The dysregulation of nuclear lamina was accompanied by an increase of nuclear blebbing, but not of micronuclei number.To conclude, a Cu-SIPS model in 3T3-L1 preadipocytes is here described, which may be an asset to the study of AT dysregulation observed in obesity and aging.

Accumulation and Potential Remediation of Copper in Golf Course Putting Greens

The objective of this study was to determine the potential accumulation of copper (Cu) within a USGA golf green profile and analyze potential remediation techniques of soils containing toxic Cu concentrations. Accumulation study utilized: copper phthalocyanine pigment (Par), copper hydroxide (Junction DF), varying concentrations of copper sulfate (CuSO4) within irrigation, and combinations of each. Products were applied over 13 weeks at Clemson University horticulture greenhouses with samples taken at thatch depth, 0-5.1 cm below thatch, and 5.1-10.2 cm below thatch at conclusion of study. Average Cu concentrations in thatch layer was 634.7 kg Cu ha-1, with 0 - 5.1 cm and 5.1 - 10.2 cm depth concentrations of 11.26 and 6.84 kg Cu ha-1, respectively. Remediation studies exposed 5 mg Cecil sandy loam to 15 ml 1000 ppm of CuSo4-Cu followed by 4 sequential 20 ml filtration cycles of 1 N ammonium sulfate, 1 N calcium nitrate, 1 N gypsum, or water. Single filtration of ammonium sulfate removed similar or greater amount of Cu than cumulative impact of 4 filtrations of any other products with 2064 mg Cu kg-1. Studies suggest that the management or removal of thatch may alleviate toxic accumulation of copper, however the use of ammonium sulfate in irrigation water may provide additional remediation options to turfgrass managers.

Influence of Copper Sulphate on Anther Culture for Haploid Production in African Marigold (Tagetes erecta L.)

The present study was carried out to improve the yield of androgenesis in marigold, for which copper sulfate was tested during the pretreatment of anther culture at various concentrations. The best results were obtained when copper sulfate was added at 15 µM and 20 µM. With the addition of copper sulphate at 20 µM, the percent of responding anthers increased from 81.6 to 92.2 %. While. percent caulogenesis increased from 66.8 to 78.4 % with copper sulphate concentration of 15 µM. With the same concentration of copper sulphate (15 µM), the number of shoot buds per anther increased from 7.4 to 9.6 and the number of regenerants per anther increased from 5.8 to 8.6. The positive influence of copper sulphate may be due to an increase in the microspore survival during anther culture.

Green synthesis of CuO nanoparticles using Jasmin sambac extract: Conditions optimization and photocatalytic degradation of Methylene Blue dye

This investigation utilized an eco-friendly method to produce copper oxide nanoparticles (CuO NPs) through the utilization of Jasminium sambac leaf extract. Optimization of pH, temperature, reaction time, and copper sulfate concentration were performed. Characterization via UV–Vis, SEM, XRD, FTIR, and EDX techniques revealed a peak at 243 nm in UV–Vis, and an FTIR band at 590 cm−1 confirmed Cu(II) ion reduction to CuO NPs. pH, temperature, reaction time, and copper sulfate concentration were identified as crucial synthesis parameters. EDX analysis indicated a composition of 75.94% copper and 24.06% oxygen. CuO NPs were dispersive, monoclinic, crystalline, and pure, with an average particle size of 13.4 nm. Photocatalytic experiments achieved 97% Methylene Blue dye degradation in 210 min, highlighting the efficacy of the green synthesis method for CuO NPs with significant photocatalytic activity in wastewater remediation.

Study on The Ability of H2O2 and The Effective Concentration of CuSO4 in Degrading Cyanide

PT. Aneka Tambang conducts gold processing using NaCN reagents, then from the gold processing process produces waste containing cyanide which can cause damage to the environment. One method used to reduce cyanide concentrations is the Degussa method. The Degussa method is a method to degrade free cyanide in waste by using H2O2 and Cu2+ ions as a catalyst source so that it becomes a harmless cyanide compound (cyanate ion). The purpose of the study was to determine the ability of hydrogen peroxide and determine the effective concentration of copper sulfate in degrading cyanide in the Degussa process and determine the level of stability of hydrogen peroxide oxidizers in the open air. Sample testing was carried out by varying the H2O2 retrieval time, variations in H2O2 dilution factor and copper sulfate concentration variations, then the sample was stirred with a jartes stirrer for 15 minutes. Cyanide is determined by spectrophotometer, the absorbance obtained is fed into the linear regression equation so that the final free cyanide concentration is obtained. From the experiment, it can be concluded that the concentration of cyanide degradation is effectively obtained when hydrogen peroxide and copper sulfate that have been mixed in the mixing tank are right out of use.

Influence of remediation by electrokinetic on the chemical and geotechnical properties of clayey soil contaminated by copper sulfate

The enhanced electrokinetic (EK) technique is an innovative approach and increasingly used in remediation of the fine-grained texture soils contaminated with different types of contaminant. In this study, the EK is enhanced by adding an intermediate compartment and using purging solutions at the electrode’s compartments. The natural clayey soil samples were obtained from Al-Ahadab oil field and artificially contaminated with two ratios of copper sulfate (66666.67 and 26666.67 mg/kg). The feasibility of using EK technique was evaluated by the efficiency of extracting copper from soil and the magnitude of recovery in the geotechnical properties of soil. The duration of remediation was continued for about 240-250 hours depending either on the continuity of electroosmosis flow or reach a constant rate of electrical current. The removal efficiency of copper from contaminated soil samples was ranged from 98.4% to 99.6%. The EK remediation technique proved a marginal impact on the specific gravity and Atterberg’s limits, but it has a significant effect on the shear strength parameters and compressibility of soil. Furthermore, the EK technique can be considered an efficient method for removing the low and high concentrations of copper sulfate from clayey soil of low permeability.

Effect of Copper Sulfate Induction on Phyllanthus tenellus Roxb. Total Phenolic and Flavonoid Content

Aims: Plants need an appropriate amount of nutrients such as copper for growth and development. However, excess of copper may interrupt plant development and cause stress that led to biochemical compounds being synthesized. The influence of a high copper sulfate concentration on phenolic and flavonoid content in Phyllanthus tenellus plants was investigated.&#x0D; Place and Duration of Study: The experiment was conducted in a government compound at MARDI Serdang, Selangor, Malaysia (2° 59' 31.7292'' N 101° 41' 56.706'' E), from April 2021 to Jun 2021.&#x0D; Methodology: The experiment was conducted using a vertical column planting system under a side-netted rain shelter. The plants were subjected to 0.5 M copper sulfate sprayed after 60 days of planting and harvested 0.5, 1.5, 3, 6, 12 and 24 h after sprayed for further analysis. Total phenolic content was calculated as mg gallic acid equivalent and total flavonoid content was measured as quercetin equivalent.&#x0D; Results: Highest total phenolic and flavonoid content was detected after 0.5 hours of copper sulfate application and started to decrease towards 24 hours after sprayed. Treated samples showed a 1.18-fold increase in total phenolic content and 1.4-fold increase in total flavonoid content compared to control untreated samples after 0.5 hours of sprayed. Control samples showed stability in both total phenolic and flavonoid content throughout the harvesting periods. Phenolic is the major secondary metabolites in Phyllanthus tenellus plants.&#x0D; Conclusion: Data revealed that the application of 0.5 M copper sulfate is able to enhance total phenolic and flavonoid content in Phyllanthus tenellus plants. The study suggested that the optimum harvesting time is 0.5 hours after copper sulfate application.

Evaluation the toxic effect of copper ions on the condition indices of benthic diatom Actinocyclus subtilis (W.Gregory) Ralfs 1861 in the experiment

Introduction. Pollution of marine coastal areas lead to the relevance of environmental monitoring including application of biotesting methods based on- the cultures of unicellular algae. Microalgae have different species-specific resistance to pollutants that expands application of different species as bioindicators of marine pollution.&#x0D; The aim of the study was to determine the threshold concentration of copper ions (Cu2+) for the survival and increase in the cells number of benthic diatom Actinocyclus subtilis (W.Gregory) Ralfs 1861 (Bacillariophyta) under the wide range of toxicant concentrations during 10-day toxicological experiments.&#x0D; Material and methods. The response of strain culture of the benthic diatom A. subtilis to various concentrations of copper sulfate (ranged from 16 to 1024 μg/l in terms of Cu2+ ions) was studied. In accordance with the previously developed protocol, the following indices were evaluated: alterations in the absolute number and proportion (%) of alive cells in the test-culture, as well as the specific growth rate in the number of A. subtilis cells at different concentrations of toxicant. Counting of alive and dead cells was carried out by micrographs taken for 12–15 random viewing fields under Nikon Eclipse inverted light microscope.&#x0D; Results. It was found that in the control and at concentration of copper ions 16 μg/l, the increase in the absolute number of cells in culture is described by sigmoid response curve. At the control еhe exponential growth phase occurs on days 5–7 and at concentration of 16 µg/l on days 3–5 of the experiment. The threshold concentration of copper ions (32 μg/l) which is critical for the survival of A. subtilis was determined, which is 3–7 times lower than threshold level for other benthic diatom species. At concentration of 32 µg/l, the phases of acceleration and exponential growth on the abundance curve are absent. The proportion of living cells in the culture decreases to 80% of the control level on day 3 and to 39% by day 10. At Cu2+ concentrations of 64 µg/l and above, sharp inhibition and death of culture is observed as early as 1–3 days. A positive specific growth rate of A. subtilis culture was revealed in the period of 1–5 days at copper concentration of 16 and &#x0D; 32 µg/l, and at concentration of 64 µg/l and higher the culture dies off. Negative values of the specific growth rate for all concentrations of the toxicant within the period of 5–10 days were obtained.&#x0D; Limitations. By the results of 10-day experiments the effect of 8 concentrations of copper sulfate on the culture of marine benthic diatom A. subtilis was studied. Three replicates in each concentration and exposure time were measured (1350 measurements in total), which is sufficient sampling for statistically reliable determination of the threshold values of copper ion toxicity for given test object.&#x0D; Conclusion. Considering the results obtained, the benthic diatom A. subtilis is highly sensitive to copper ions impact and can be recommended as new test-object for toxicology, as well as for application in monitoring of marine water areas subject to technogenic pollution.

Investigation of Ni-Cu-B and Ni-Cu-Sn-B coatings developed by electroless method

Due to their remarkable mechanical properties and tribological behaviour which is equivalent the hard chrome coating, electroless Nickel–Boron coatings have been employed in a variety of industries. With the advent of emerging and challenging applications, there has been a need to develop newer variants of the novel Ni-B binary variant. The present work therefore investigates Ni-B-Cu coatings in a quest to achieve higher wear and corrosion resistance. A stabilizer free bath and tin chloride stabilized bath was formulated for the same to remove the harmful lead nitrate from the coating formulation. The concentration of copper sulphate was varied from 0.3 to 0.7 g/L in both the bath formulations. Based on the mass gain of the specimens, coatings obtained from 0.6 g/L copper sulphate was further investigated. The surface morphology of as-plated samples was observed which shows nodular structure and the growth was different compared to lead stabilized baths. The constant load and progressive scratch test were done to evaluate scratch hardness and coating failure respectively.