Use Of Copper Sulfate Research Articles

The Effect of Novel Submicronic Solid Activators on Sphalerite Flotability

In this study, we examine the effect of novel submicronic activators made from copper minerals and copper-rich concentrate on sphalerite flotability. The copper minerals and copper concentrate are ground in a vibratory micromill and ultrasonically treated to obtain submicronic sphalerite activators. Histograms show that the concentration of copper particles in the activator after treatment is 92%–94%, with particle sizes of 105–115 nm. The results concerning monomineral flotation showed that sphalerite flotation is possible with the use of submicronic copper particles as an activator. At the same time, the consumption of mineral copper is much lower (by 10 times) than that of copper sulfate. The best results are achieved when submicronic particles of covellite and bornite (with a 60% concentration of particles 300–500 nm in size) were used. Sphalerite recovery amounted to 80%, which is higher than the recovery obtained with the use of copper sulfate by 2% but is 2% lower compared to the use of copper oxyhydroxide. The flotation effect of the submicronic activators on sphalerite was tested in laboratory conditions using polymetallic ore from one of Kazakhstan’s deposits. It is shown that the novel submicron activators based on bornite and copper concentrate exhibit much lower consumption rates and can replace the more expensive copper sulfate at the same Zn content (54.8%–54.9%), obtaining recovery rates of 95.69%–96.57%.

Leucoderma in Buffaloes (Bubalus bubalis) in the Amazon Biome.

Leucoderma is a condition that affects the skin and hair of animals, causing depigmentation and acromotrichia. In buffaloes, this condition results in significant economic losses for the production chain due to its impact on the leather trade. This study aimed to investigate the epidemiological and clinicopathological aspects of leucoderma in buffaloes in the Amazon biome and describe the prophylactic treatment to control the disease. The study included 40 buffaloes, 16 males and 24 females, aged between 1 and 10 years, and were of the Murrah, Jafarabadi, Mediterranean, and Murrah × Mediterranean crossbreed breeds. The animals were raised without mineral supplementation. The clinical signs observed in the animals included acromotrichia and depigmentation, with varying degrees and distribution of skin lesions. Histological examination of the epidermis showed interrupted melanin production, mild dermal fibrosis, mild perivascular mononuclear inflammatory infiltrate, and pigmentary incontinence. None of the animals had the genotype for albinism. After 120 days of mineral supplementation based on the use of copper sulfate, the clinical signs of leucoderma regressed. There was no predisposition by breed, sex, or age for the occurrence of the disease. The regression of skin lesions after proper mineral supplementation suggests that copper deficiency may be considered an important factor for the occurrence of leucoderma in buffaloes in the Amazon biome.

Protecting Apricot Orchards with Rain Shelters Reduces Twig Blight Damage Caused by Monilinia spp. and Makes It Possible to Reduce Fungicide Use

Blossom and twig blight, caused by Monilinia spp., is the main disease in apricot trees. In this study, we installed transparent rain shelters in apricot orchards to study their influence on the modification of the microclimate at the level of the tree canopy and on the reduction in moniliosis damage in twigs. Rain shelters significantly reduced the leaf wetness time measured within the foliage compared to the unsheltered trees (a reduction of between 43% and 67%). However, very few differences were observed in the daily averaged air temperature (up to 6%) and daily averaged air relative humidity (up to 1%). In the first experiment, on the apricot variety Bergarouge® (CEP Innovation, Lyon, France), moniliosis damage on twigs in the absence of phytosanitary protection was reduced by up to 62% for the trees provided with rain protection compared to the trees that did not receive rain shelters. A second experiment, involving five apricot tree varieties, made it possible to verify that fungicide protection could be reduced for the trees protected by rain covers, reducing moniliosis damage on twigs compared to full fungicide protection combined without rain protection. Finally, a third experiment comprising two apricot tree varieties has shown that in organic orchards, rain protection provides protection against moniliosis (twig blight) that is equivalent to an organic farming fungicide protection programme based on the use of copper sulphate and calcium polysulphide.

Novel Highly Efficient Green and Reusable Cu(II)/Chitosan-Based Catalysts for the Sonogashira, Buchwald, Aldol, and Dipolar Cycloaddition Reactions

In this study, new Cu(II)/chitosan-based systems were designed via (i) the treatment of chitosan with sodium sulfate (1a) or sodium acetate (1b); (ii) the coating of 1a or 2a with a sodium hyaluronate layer (2a and 2b, correspondingly); (iii) the treatment of a cholesterol–chitosan conjugate with sodium sulfate (3a) or sodium acetate (3b); and (iv) the succination of 1a and 1b to afford 4a and 4b or the succination of 2a and 2b to yield 5a and 5b. The catalytic properties of the elaborated systems in various organic transformations were evaluated. The use of copper sulfate as the source of Cu2+ ions results in the formation of nanoparticles, while the use of copper acetate leads to the generation of conventional coarse-grained powder. Cholesterol-containing systems have proven to be highly efficient catalysts for the cross-coupling reactions of different types (e.g., Sonogashira, Buchwald–Hartwig, and Chan–Lam types); succinated systems coated with a layer of hyaluronic acid are promising catalysts for the aldol reaction; systems containing inorganic copper(II) salt nanoparticles are capable of catalyzing the nitrile-oxide-to-nitrile 1,3-dipolar cycloaddition. The elaborated catalytic systems efficiently catalyze the aforementioned reactions in the greenest solvent available, i.e., water, and the processes could be conducted in air. The studied catalytic reactions proceed selectively, and the isolation of the product does not require column chromatography. The product is separated from the catalyst by simple filtration or centrifugation.

ПОЛУЧЕНИЕ ЖИДКОГО ТОПЛИВА ИЗ КОРОДРЕВЕСНЫХ ОТХОДОВ ДЛИТЕЛЬНОГО СРОКА ХРАНЕНИЯ МЕТОДОМ ГИДРОТЕРМАЛЬНОГО ОЖИЖЕНИЯ

The pulp and paper industry leads to the formation of a significant amount of bark and wood waste (BWW), which is not processed in Russia, but is placed in bark dumps, which leads to a negative impact on environmental objects, incl. on the planet's climate. This article presents an assessment of the resource potential of long-term storage bark and wood waste based on the results of physicochemical and thermal analysis. It was found that during long-term storage BWW undergoes degradation rather weakly, while the proportion of carbon in the composition of BWW remains practically unchanged (at the level of 48.4%). It has been proven that the initial BWW are characterized by high humidity (60.8% to 74.9%), low calorific value (14.56 MJ/kg per d.m.) and moderate ash content (9.8% d.m.a.). For wet biomass, hydrothermal liquefaction can be considered the most suitable conversion method, which makes it possible to obtain liquid fuels without pre-drying, since. Water in this process acts as a solvent and a source of radicals. The average yield of biofuel during hydrothermal conversion of BWW is 10%, while the use of Iron ammonium alum as catalysts provided an increase in oil yield by more than 2 times to 28.4%, the use of copper sulfate led to an increase in yield up to 16.1%. The obtained bio-oil was characterized by a high degree of saturation (atomic ratio H/C was 1.3), but the oxygen content was also high (at the level of 22% wt.). The content of sulfur and nitrogen was minimal (0.6 and 0.2%, respectively). The composition of fuels was dominated by oxygen-containing aromatic compounds of the phenol group (62%), cyclic esters (19.8%); as well as fatty acids, which account for 12.9%.

Morphohistopathological alteration in the gills and central nervous system in Cyprinus carpio exposed to lethal concentration of copper sulfate

Copper Sulfate (CuSO4) is the most used in aquaculture as chemotherapeutic bath against bacterial, fungal and parasitic diseases but it is very toxic for fish so the goal of this study was to determine the lethal concentration of CuSO4 and evaluate it is toxicity in the gill and central nervous system (brain and spinal cord) in Cyprinus carpio. Fish exposed to 0, 2.5, 5 and 10 mg/L for 24 hours, each concentration with three replication each have six fish. The mortality rate was 100% at concentration 10 mg/L, which represented lethal concentration, while medium lethal concentration (LC50) was determined by Trevan method and it is 5mg/L. The fish with LC100 concentration exhibit abnormal respiration with gasping swimming, nervous sings with up down and stay at basin then die at 2-3 hours. The histopathological examination of the gills revealed circulatory disturbances, cellularity reaction, progressive and regressive alteration, this microscopic alteration was evaluated as semi-quantities analysis and there was variable significant (P≤0.05) in the pathological alteration and gill indexes between two treatments. In the brain and spinal cord, the lesions are represented by vasogenic edema, infiltration of inflammatory cells with atrophy in the neuronal body cells and hemorrhage. It is concluded from this study that the use of copper sulfate is within limited concentrations because increasing its concentration leads to fish toxicity, and it was observed that the gill tissue is more sensitive to toxicity than the central nervous system

Study on amyloodiniosis outbreak in captive-bred percula clownfish (Amphiprion percula) and improved control regimens.

The amyloodiniosis outbreak was documented with high mortality of percula clownfish (Amphiprion percula) and subsequently, various therapeutics were evaluated to control the infection. The affected fish exhibited symptoms such as discoloration of the skin and jerky movement with severe respiratory stress. Microscopic examination of the gill and body surface of the infested moribund fish showed the presence of brown coloured spherical shaped trophonts with the size range of 150-300µM. Copper sulphate (10ppm) and hydroxychloroquine phosphate (10ppm) treatment with 14days of continuous bath showed 76 ± 5.3 and 66 ± 4.3% survival rates. However, formalin (10ppm) and malachite green (10ppm) treated groups showed a survival of 41 ± 1.7 and 32.7 ± 1.2% respectively. The present results suggest that, use of copper sulphate to treat amyloodiniosis in clownfish will relatively more effective than other treatment options. The findings will be helpful to mitigate amyloodiniosis in marine finfish aquaculture, particularly marine ornamentals.

CHANGES IN BLOOD INDICATORS IN CASE OF USE OF BIS[BIS(3,5-DIMETHYLPYRAZOL-1-YL)ACETATO]COPPER(II) COMPLEX AFTER BURN INJURIES

Burn injuries cause profound changes in hematological parameters. The degree of severity of such changes and the speed of development of disturbances depend on the quantitative parameters of the injuries (area and degree of damage). One of the most urgent modern healthcare problems is the search and development of new effective approaches and medications for healing burn injuries. Radioprotectors differ by their effectiveness and duration of their protective action. For the purpose of promotion of tissue regeneration after burn injuries, medications with anti-inflammatory, analgesic and pro-regenerative properties are used. In this regard, copper-based complexes are of particular interest. The biogenic role of copper includes its participation in the processes of hematopoiesis. Copper also plays an important role in neutralizing the toxins of microorganisms, in prolongation of the action of antibacterial medications, as well as in reducing inflammatory reactions. The use of copper sulfate promotes the acceleration of skin regeneration in burn wounds, and Cu complexes show low toxicity. The aim of the study is to identify a possible positive effect of the bis[bis(3,5-dimethylpyrazol-1-yl)acetato]copper(II) complex, Cu[HC(COO)(pzMe2)2]2, in case of burns. As a result of hematological and cytogenetic studies, it was found that Cu[HC(COO)(pzMe2)2]2 has the ability to prevent or reduce the pathological processes in case of deep burns. The findings were also confirmed by survival assessments (100%).

The Value of Copper Sulphate in Umbilical Granuloma a Prospective Study

Background: Umbilical granuloma is one of the commonest presentations in the pediatric surgery outdoor. Persistent drainage or moisture involving the umbilicus is chief complaint. If umbilical granuloma remains untreated, it could ooze and present with persisting irritation for several months. The main concern has been over avoidance of surgery in infants with umbilical granuloma. Different protocols have been proposed from time to time. Objective: To evaluate the therapeutic effect of copper sulphate on umbilical granuloma in infants. Materials and Methods: This prospective study was conducted on 25 infants with umbilical granuloma. In all patients Copper sulphate applied once over the Umbilical granuloma for 5 minutes. A sterile gauze and adhesive bandage were applied after cleaning of copper sulphate application. Treatments were administered in outpatient settings, and the patients were followed up at 1 week, and 2 weeks interval to record the outcome. Result: All 25 cases responded well to this approach with complete resolution of lesions. No major complication or recurrence was noted in follow-up. Conclusion: The use of copper sulphate in treating umbilical granuloma is simple, cost-effective, curative, and safe.

Micropropagation of Philodendron selloum: Influence of copper sulfate on endophytic bacterial contamination, antioxidant enzyme activity, electrolyte leakage, and plant survival

Endophytic microorganisms is a major constrain to the establishment and growth of tissue culture plants. We report the use of copper sulfate (CuSO4.5H2O) to eliminate the endophytic bacteria in Philodendron selloum in vitro cultures. Contaminated shoots were cultured onto Murashige and Skoog (MS) medium containing 5 mg/L BA and supplemented with different concentrations of copper sulfate at 0, 35, 70 and 140 mg/L for 6 weeks. Copper sulfate at 70 mg/L completely eliminated the endogenous bacteria without decline in plant growth. However, 35 mg/L copper sulfate was optimal for maximum shoot multiplication (25), survival percentage (100%) and growth of plants. Antioxidant enzymes activity of catalase, peroxidases, and polyphenol oxidase were increased because of copper sulfate treatments. Conversely, electrolyte leakage was decreased at low copper sulfate (≤70 mg/L). Randomly amplified polymorphic DNA (RAPD) analysis revealed that plantlets exposed to different levels of copper sulfate were not genetically different from control plants.

Effect of novel teat dips on milk biochemical parameters in dairy cattle

The study was conducted on bovine mastitis with an objective to prevent its occurrence. The attempt was envisaged through use of copper sulphate and zinc sulphate, used as post milking teat dips and were selected after evaluating their antimicrobial potential against major mastitis causing bacteria in vitro using agar well diffusion method. Different concentrations of these compounds in distilled water were prepared (10%, 7.5%, 5% and 2.5%). Invitro cytotoxicity studies were also carried out using these concentrations. The invitro antimicrobial and cytotoxicity studies revealed 2.5% solution of copper sulphate and zinc sulphate to be most effective in terms of preventing bacterial growth and being safe. For the prophylactic study 40 healthy cows, maintained under similar management and found negative for mastitis through CMT, pH, EC, SCC and culture of milk samples were included in the study. Cows were randomly divided into 4 groups, viz., group I, group II, group III and group IV with ten cows in each. Group I, served as control, in which no teat dip was used. In group II animals conventional teat dip (0.5% Povidone Iodine) was used. In group III and group IV Copper Sulphate (2.5% aqueous solution) and Zinc Sulphate (2.5% aqueous solution) teat dips were used respectively. Post-milking teat dipping was done twice a day for a period of two months. Milk samples were collected aseptically from all the quarters on Day 0, 15, 30, 45 and 60 to see the effect of post-milking teat dipping with copper sulphate and zinc sulphate on biochemical properties of milk (Fat, SNF, Protein and lactose)and compare them with povidone iodine and control groups. The biochemical properties of milk did not change using copper sulphate and zinc sulphateas post milking teat dips. It is concluded that the use of 2.5% each of copper sulphate and zinc sulphate solutions as post-milking teat dips can prove beneficial in prophylaxis of bovine mastitis.

BIO- AND CHEMICAL CONTROL OF RUST DISEASE AND ITS EFFECT ON SPEARMINT YIELD UNDER SANDY SOIL CONDITIONS

A field experiment was carried out at Ismailia Agricultural Research Station, Ismailia Governorate, Egypt, during the two successive seasons of 2017 and 2018 to study the impact of beneficial microorganisms Trichoderma harzianum (fungi), Streptomyces griseus (bacteria) and two common chemical fungicides (copper sulphate and difenoconazole) to controlling spearmint rust disease. The vegetative growth, chemical constituents, essential oil production and its components in spearmint (Mentha viridis L.) plants were evaluated. The obtained results concluded that the use of copper sulfate as a chemical fungicide and the two bioagents [Streptomyces griseus and Trichoderma harzianum] reduced the incidence and percentage of rust disease severity in compared to untreated plants (control). Similarly, the level of vegetative growth, essential oil percentage and yield and the percentage of minerals and total carbohydrates in herb as well as carvone content in essential oil were noticeably more in compared to the chemical fungicide (difenoconazole) and untreated plants (control). Thus, reduce theusing of chemical fungicides means reducing environmental risks.

Durability of Reinforced Concrete Beams under Simultaneous Flexural Load in Corrosive Environment

The deterioration of concrete over time is the result of various mechanical, physical, chemical and biological processes, with the corrosion of reinforcement being the most serious problem of durability of reinforced concrete structures. Over the last 50 years, a tremendous effort has been spent by the international scientific community with laboratory research and experimental field studies in order to increase the resistance of concrete over corrosion. This paper presents an experimental study of the corrosion behaviour of reinforced concrete beams with simultaneous sustained flexural loading. For this purpose, 40 reinforced concrete beams of 5 different compositions were constructed and exposed in simulated harmful environmental conditions in 3 different stress ratios for a total period of 42 months. Their behavior against corrosion was determined via regular measurements of the electrical resistance of concrete (according to ASTM G57) and the corrosion potential of the steel-reinforced bars with the use of copper sulphate (CSE) as reference electrode (according to ASTM C876). A theoretical calculation of the corrosion rate was conducted based on the electrochemical measurements of the beams. The results indicate that the corrosion potential of steel decreased in time and more rapidly after the initiation of the corrosion process; the electrical resistance firstly increased, remained stable for a short period and then decreased with the corrosion development, as expected. An inversely proportional relationship of the water/cement ratio of a composition with its corrosion behaviour as well as an analogous relationship between the cement content of a composition and its corrosion behaviour was observed. Also, the corrosion rate of steel is increased gradually with increasing load.

PHYTOTOXIC ACTIVITY REDUCTION ASSESSMENT OF COPPER IONS THROUGH THE ONION APICAL MERISTEM

This paper investigates the protective properties of the aqueous extract of silkworm pupae (CABG) in terms of the toxic effect of copper ions on morphometrically parameters in Allium-test. Methods: It is established that the joint use of aqueous extract of silkworm pupae and copper sulphate at a concentration of 100 µm growth inhibition of roots is not happening and even stimulated by the application of aqueous extract of silkworm pupae at a concentration of 1 ml/10 ml. Stimulation of root growth is also observed with the combined use of 1000 µm copper sulfate and aqueous extract of silkworm pupae in a concentration of 10 ml/100 ml of the solution with respect to the use of copper sulfate only. A significant decrease in the parameter ‘length of sprouts' in 1.3-6.0 times with respect to the control was observed when using copper ions in concentrations of 100-1000 microns, while at a metal concentration of 10 microns no negative effect on the development of sprouts was established. The emergence of lateral roots in 20-50% of cases observed only in the use of aqueous extract of silkworm pupae. Thus, in the study of morphometric parameters of seedlings of onion (the relative growth of roots, length of shoots, their weight) set the modifier of the protective effect of aqueous extract of silkworm pupae when used together with copper sulfate in concentrations of 10 and 100 µm. At a concentration of 10 ml of aqueous extract of silkworm pupae/100 ml solution protective function in relation to ions of copper are more severe.

Improved protein determination assays obtained after substitution of copper sulfate by copper oxide nanoparticles

Copper oxide nanoparticles (nano CuO) provide Cu2+ ions which can be easily harnessed for protein determination as an alternative to the use of copper sulfate (CuSO4). In the present work, nano CuO of size <25 nm were substituted for CuSO4 in two of the well-known protein assays viz. Lowry method and bicinchoninic acid (BCA) method. Use of nano CuO in the Lowry's assay had no effect on the assay time (30 min) but significantly lowered the limit of detection (LOD) from 0.01 to 0.001 μg/ml, while the BCA method when performed using nano CuO resulted in notable reduction of not only the assay time from 30 to 20 min but also the LOD from 0.1 to 0.001 μg/ml. Nano CuO based protein determination in the human serum and urd bean seeds extract produced reliable, reproducible and consistent results. Nano CuO also alleviated the inhibition of both the methods by common interfering substances such as ammonium sulfate, glucose, EDTA, SDS, Triton X-100, dithiothreitol and 2-mercaptoethanol. Hence, successful modification and improvement of Lowry and BCA methods by substitution of CuSO4 with nano CuO for protein determination has been demonstrated.

Metals in superficial sediments of a cascade multisystem reservoir: contamination and potential ecological risk

Cascade multisystem reservoirs are extremely complex ecosystems that require studies to improve understanding of their dynamics and functioning, including the effects of contamination with metals. In this work, superficial sediments were collected during two sampling campaigns (in the dry and rainy seasons) at 19 sites along a cascade multisystem reservoir in Sao Paulo, Brazil, formed by five reservoirs. The sediments were evaluated considering the following parameters: pseudo-total metals (Cu, Cd, Cr, Ni, Pb, Zn, Mn, Fe, and Al); bioavailable metal (Cu); organic matter; total phosphorus; total nitrogen; and grain size. In the last reservoir of this system, the enrichment factors indicated enrichment of Cu, Pb, Zn, and Mn. Despite this increased metals content, the pollution load index indicated an absence of pollution (PLI < 1), and the ecological risk was low (RI < 150). According to sediment quality guideline criteria, toxicity was unlikely to occur. Principal component analysis (PCA) and one-way ANOVA indicated heterogeneity among the reservoirs (P < 0.01) and between the sampling periods. The PCA results confirmed higher levels of nutrients in the upstream reservoirs, suggesting that nutrients were precipitated in the first reservoirs of the system. On the other hand, metal levels were higher in the downstream reservoirs. The main source of metal contamination in the region was the use of copper sulfate as an algicide. This included contamination by Pb and Zn, due to impurities in the copper sulfate employed. High Mn levels were associated with wastewater discharges and erosion. In addition to helping to improve understanding of the dynamics of metals in cascade multisystem reservoirs, this work could serve as a useful tool for the management of reservoirs with contaminated sediments.

Dynamics and Control Methods of Cyanotoxins in Aquatic Ecosystem

Cyanotoxins in aquatic ecosystems have been investigated by many researchers worldwide. Cyanotoxins can be classified according to toxicity as neurotoxins (anatoxin-a, anatoxin-a(s), saxitoxins) or hepatotoxins (microcystins, nodularin, cylindrospermopsin). Microcystins are generally present within cyanobacterial cells and are released by damage to the cell membrane. Cyanotoxins have been reported to cause adverse effects and to accumulate in aquatic organisms in lakes, rivers and oceans. Possible pathways of microcystins in Lake Suwa, Japan, have been investigated from five perspectives: production, adsorption, physiochemical decomposition, bioaccumulation and biodegradation. In this study, temporal variability in microcystins in Lake Suwa were investigated over 25 years (1991~2015). In nature, microcystins are removed by biodegradation of microorganisms and/or feeding of predators. However, during water treatment, the use of copper sulfate to remove algal cells causes extraction of a mess of microcystins. Cyanotoxins are removed by physical, chemical and biological methods, and the reduction of nutrients inflow is a basic method to prevent cyanobacterial bloom formation. However, this method is not effective for eutrophic lakes because nutrients are already present. The presence of a cyanotoxins can be a potential threat and therefore must be considered during water treatment. A complete understanding of the mechanism of cyanotoxins degradation in the ecosystem requires more intensive study, including a quantitative enumeration of cyanotoxin degrading microbes. This should be done in conjunction with an investigation of the microbial ecological mechanism of cyanobacteria degradation.

Use of Copper Sulfate to Control Egg Saprolegniasis at a Commercial Sunshine Bass Hatchery

AbstractAn obstacle to the larval production of sunshine bass (female White Bass Morone chrysops × male Striped Bass M. saxatilis) is fungal growth on the eggs caused by the water mold, Saprolegnia spp. Copper sulfate (CuSO4) is commonly used for fungus control in troughs at catfish hatcheries, but the effectiveness in other fish‐egg hatching systems is unknown. Because sunshine bass eggs begin hatching after 48 h, CuSO4 treatments (0, 10, 20, and 40 mg/L) began the afternoon of spawning with a 10‐min, aerated, static bath and were repeated the morning and afternoon of day 2; eggs were not treated after hatching began. An in vitro assay was developed for this treatment regimen that indicated maximum fungal inhibition was achieved with 20 mg/L CuSO4. In the effectiveness experiment in McDonald hatching jars (n = 3), fungus was severe in the untreated controls (27.7% survival), but very little fungus was present in treatments receiving 10 mg/L CuSO4 (31.4% survival) or higher. The control was not significantly different from the 10‐mg/L treatment. The highest survival was at 40 mg/L CuSO4 (50.5% survival); however, the survival from the 20‐mg/L CuSO4 treatment (45.8%) was not significantly different from that in the 40‐mg/L treatment and thus allows for a greater margin of safety. Fungus samples were identified as Saprolegnia ferax through genetic sequencing. Toxicity experiments on sunshine bass larvae indicated the 24‐ and 48‐h LC50 values were 5.4 and 3.9 mg/L CuSO4, respectively; the no observed effect concentrations were 0.5 and 0.25 mg/L CuSO4, respectively. This study confirms that CuSO4 can be an economical and valuable resource in hatchery management for the control of saprolegniasis on sunshine bass eggs in McDonald jars.

남조류에서 발생하는 독소의 문제점과 대책

Cyanobacteria frequently dominate the freshwater phytoplankton community in eutrophic waters. Cyanotoxins can be classified according to toxicity as neurotoxin (Anatoxin-a, Anatoxin-a(s), Saxitoxins) or hepatotoxin (microcystins, nodularin, cylindrospermopsin). Microcystins are present within cyanobacterial cells generally, and they are extracted by the damage of cell membrane. It has been reported that cyanotoxins caused adverse effects and they are acculmulated in aquatic oganisms of lake, river and ocean. In natural, microcystins are removed by biodegradation of microorganisms and/or feeding of predators. However, in process of water treatment, the use of copper sulfate to remove algal cells caused extraction of a mess of microcystins. Microcysitns are removed by physical, chemical and biological methods according to reports. The reduction of nutrients (N and P) inflow is basic method of prevention of cyanobacteria bloom formation. However, it is less effective than investigation because nutrients already present in the eutrophic lake. In natural lake, cyanobacteria bloom are not formed because macrophytes invade from coastal lake by eutrophication. Therefore, a coastal lake has to recover to prevent of cyanobacteria bloom formation.

Ecological dyeing of silk fabric with lac dye by using padding techniques

This research focuses on silk fabrics exhibiting different colour values and fastness properties. The samples were prepared by dyeing with lac as a natural colourant. Two padding techniques were used in the process, namely, the pad-batch and pad-dry techniques, under different conditions. Aluminium potassium sulphate, ferrous sulphate, copper sulphate and stannous chloride were used as mordants. The effects of differing dye concentrations added to the silk fabrics using a pre- and post-mordant method were studied and recorded. The colour fastness to washing, light, rubbing, water and perspiration of the dyed samples was performed according to the present ISO standard. Silk fabric dyed without mordant showed a pink shade, while those samples mordanted with stannous chloride and aluminium potassium sulphate displayed noticeably brighter red coloured shades. With the additional use of copper sulphate, the colour shade produced was violet, while darker grey shades were obtained by adding ferrous sulphate mordant. The test results regarding fastness properties ranged from fair to very good, while wash fastness ranged from very poor to poor.