Zinc Sulfate Solution Research Articles

Asynchronous Fuzzy Cognitive Networks Modeling and Control for Goethite Iron Precipitation Process

Goethite iron precipitation process is a key step in direct leaching process of zinc, whose aim is to remove ferrous ions from zinc sulphate solution. The process consists of several cascade reactors, and each of them contains complex chemical reactions featured by strong nonlinearity and large time delay. Therefore, it is hard to build up an accurate mathematical model to describe the dynamic changes in the process. In this paper, by studying the mechanism of these reactions and combining historical data and expert experience, the modeling method called asynchronous fuzzy cognitive networks (AFCN) is proposed to solve the various time delay problem. Moreover, the corresponding AFCN model for goethite iron precipitation process is established. To control the process according to fuzzy rules, the nonlinear Hebbian learning algorithm (NHL) terminal constraints is firstly adopted for weights learning. Then the model parameters of equilibrium intervals corresponding to different operating conditions can be calculated. Finally, the matrix meeting the expected value and the weight value of steady states is stored into fuzzy rules as prior knowledge. The simulation shows that the AFCN model for goethite iron precipitation process could precisely describe the dynamic changes in the system, and verifies the superiority of control method based on fuzzy rules.

Hydrometallurgical recovery of zinc from industrial hot dipping top ash

Abstract Top ash from hot-dip galvanizing plant was investigated as a source of secondary zinc to be returned to galvanizing bath. The waste material contained 63% Zn as metallic, oxide and hydroxychloride phases. It was leached in H2SO4 solutions (20% and 25%) at various bath loadings (100−300 g/L). Leaching behaviors of zinc, manganese, iron and chloride ions were investigated. A few strategies of iron elimination from leaching liquors were examined. Flocculant addition was harmful for subsequent filtration of iron precipitates due to increased viscosity of solution, while a combination of zinc oxide and calcium carbonate for rising pH resulted in the formation of dense suspension unenforceable to separate from zinc sulphate solution. Zinc electrowinning was carried out at different pH (from −0.5 to 2.8) using a range of current densities (3−10 A/dm2). Optimal conditions for pure metal recovery were: leaching in 20% H2SO4 solution at zinc ash content 100−150 g/L, Fe2O3·xH2O precipitation using H2O2 and CaCO3, zinc electrowinning at pH of 0.1−1.0 at 3−6 A/dm2. Correlations between pH and free H2SO4 concentration in electrolyte solutions were also discussed. pH−acid concentration dependence for zinc electrolyte was between experimental and calculated curves for pure H2SO4 solutions, while the curve was shifted towards lower pH if ferric ions were in the solution.

Maranta arundinacea root assisted zinc oxide nanoparticles and its characterisation using TEM and UV-vis spectroscopy

Arrow root is a tropical root crop cultivated for its starchy rhizomes that have carbohydrate contents. Zinc oxide nanoparticles have emerged a promising potential in biomedicine, especially in the fields of anticancer, wound healing, free radical scavenging and antimicrobial including antibacterial, antifungal and antiviral research fields, which might be worried with their potent ability to trigger extra reactive oxygen species (ROS) production, launch zinc ions, and induce mobile apoptosis. 1 gram of Arrow root powder extract was mixed with 100 mL of water and filtered for nanoparticles synthesis. The zinc sulphate was used as a precursor for the zinc oxide nanoparticles synthesis and 30 mM was used. 50 mL of freshly prepared root extract and zinc sulphate solution was added together for the synthesis of Zinc oxide nanoparticles, which was then dried and characterisedcharacterized using transmission electron microscope (TEM) and during reaction it was characterized using UVvis spectroscopy method. A spherical shaped nanoparticle with plant extract in the background was observed. The peak at 300 nm confirm the nanoparticles synthesis using root extract. Based on our results we confirmed the capability of arrow root for the zinc oxide nanoparticles synthesis and it will be used for the various biomedical application in future.

Effect of zinc powder size on cobalt removal from zinc sulphate solutions

Effect of zinc powder size on cobalt removal from zinc sulphate solutions

Pretreatment with zinc protects Kupffer cells following administration of microbial products

BackgroundSystemic inflammation and severe fibrosis can reduce serum zinc levels, while zinc supplementation is reported to improve the prognosis of patients with chronic liver disease (CLD). ObjectivesWe aimed to investigate the clinical application of serum zinc in patients with CLD and the anti-infective mechanism of zinc supplementation. MethodsBased on the serum zinc level, 149 CLD patients were divided into 3 groups and their clinical parameters were compared. In in-vitro experiments, microbial isolates derived from patients were used to stimulate human liver non-parenchymal cells, and the zinc sulfate solution was added in certain experiments. The effect of zinc was compared by LDH and thromboxane A2 levels in the cell supernatant. ResultCompared with other groups, patients with low serum zinc levels had significantly higher C-reactive protein (CRP), total bilirubin, INR, creatinine, and MELD scores, while albumin and GOT levels were reduced. Only CRP and albumin were significantly correlated with serum zinc in both low and normal-zinc groups. Bacterial isolates significantly increased LDH levels in Kupffer cells (KCs) and stellate cells but had no effect on sinusoidal endothelial cells, whereas zinc pretreatment protected KCs but not stellate cells. Thromboxane A2 secreted by KCs can also be induced by bacterial stimulation, accompanied by increased gene expression of Myd88, MAPK and NF-kB, while zinc pretreatment can attenuate that. ConclusionSerum zinc levels can be used to estimate infection and liver fibrosis in CLD patients. As a new antibacterial weapon, zinc supplementation acts on KCs through Myd88-MAPK related pathways.

Study to enhance cementation of impurities from zinc leach liquor by modifying the shape and size of zinc dust

Cementation is a prominent purification technique used for removal of copper, cadmium, cobalt, and nickel from impure zinc sulphate solution obtained after leaching of zinc ore. Zinc dust is primarily used for this purpose still the extent of purification is limited. The present study represents the encouraging result in context to utilization of zinc dust for better purification by altering its dosage, size and morphology. The investigations showed that 300% excess zinc dust dosage than stoichiometric results in enhanced cement formation. The study also revealed that fine size and ball milling of zinc dust favors cementation. Zinc dust of −300 mesh (BSS) after 2 h ball milling highly purifies the impure solution within 2 h contact time. The yield of the impurities removal after the optimized cementation is 100, 99.99, 100 and 15% for Cu, Cd, Ni and Co respectively. The kinetics of cementation has been also studied and revealed that the reaction is in mixed controlled mechanism for copper and cadmium cementation. At the same time, for nickel, it is considered to be chemically controlled. The activation energy for the cementation of copper, cadmium and nickel were 38.19, 30.87 and 68.15 kJ /mol, respectively. The estimated activation energies were found within the range which corroborates with the mixed and reaction model and ensures industrial feasibility of the proposed process.

A Highly Selective Complexometric Determination of Mercury(II) using L-Tyrosine as a Masking agent

Determination of mercury in the existence of various other metal ions, a transparent speedy and accurate complexometric method is described, depending on the selective masking ability of L-Tyrosine towards Hg (II). Along with other associated metal ions, Hg (II) present in a given sample solution is first complexed with an surplus of EDTA and the leftover EDTA is titrated with Zinc sulfate solution in the presence of xylenol orange as an indicator at pH 5.0-6.0.A known excess of 0.02M L-Tyrosine solution is then added to discharge the EDTA from Hg (II)-EDTA complex and then it is mixed well. The displaced EDTA is again titrated with a Zinc sulfate solution. The method goes well in the range 4-80 mg of mercury (II) with the relative error ±0.4 and standard deviation ≤0.05 mg. The issue of the existence of various metal ions on the exactitude of the results has been studied. And the method can be applied for the determination of Mercury in alloys, in its synthetic mixtures of ions and its complexes.

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.

A novel high-performance liquid chromatography with diode array detector method for the simultaneous quantification of the enzyme-reactivating oximes obidoxime, pralidoxime, and HI-6 in human plasma.

Oximes such as pralidoxime (2-PAM), obidoxime (Obi), and HI-6 are the only currently available therapeutic agents to reactivate inhibited acetylcholinesterase (AChE) in case of intoxications with organophosphorus (OP) compounds. However, each oxime has characteristic agent-dependent reactivating efficacy, and therefore the combined administration of complementary oximes might be a promising approach to improve therapy. Accordingly, a new high-performance liquid chromatography method with diode-array detection (HPLC-DAD) was developed and validated allowing for simultaneous or single quantification of 2-PAM, Obi, and HI-6 in human plasma. Plasma was precipitated using 5% w/v aqueous zinc sulfate solution and subsequently acetonitrile yielding high recoveries of 94.2%-101.0%. An Atlantis T3 column (150 × 2.1mm I.D., 3 μm) was used for chromatographic separation with a total run time of 15 min. Quantification was possible without interferences within a linear range from 0.12 to 120 μg/mL for all oximes. Excellent intra-day (accuracy 91.7%-98.6%, precision 0.5%-4.4%) and inter-day characteristics (accuracy 89.4%-97.4%, precision 0.4%-2.2%) as well as good ruggedness were found. Oximes in processed samples were stable for at least 12 h in the autosampler at 15°C as well as in human plasma for at least four freeze-thaw cycles. Finally, the method was applied to plasma samples of a clinical case of pesticide poisoning.

Comprehensive recycling of zinc and iron from smelting waste containing zinc ferrite by oriented transformation with SO2

The comprehensive recycling of zinc and iron from smelting waste containing zinc ferrite (SWCZF) remains a challenge. A study is to be the first proposed that hazardous SWCZF is directionally converted with SO2 for simultaneous recycling of zinc and iron. In the first step, zinc and iron phases in SWCZF were transformed into zinc sulfate and ferric oxide via oriented transformation with SO2. The decomposition rate of zinc ferrite and the yield of zinc sulfate were 94% and 95%, respectively. In the second step, zinc and iron in SWCZF were directionally enriched to obtain zinc sulfate solution and iron concentrate via water leaching-magnetic separation. The leaching rate of zinc from water leaching was 93.2% and the iron recovery from magnetic separation was 83.8%. The zinc sulfate solution can be directly returned to the traditional hydrometallurgical process to produce electrolytic zinc or be used to produce zinc sulfate with no generation of iron residues. The iron concentrate can be used as a raw material for iron making. Meanwhile, a clean slag was produced and can be safe for storage or potentially used as construction materials. Therefore, the deep reclamation, reducing quantity and harmlessness of SWCZF were realized via this cleaner technical route.

Intralesional zinc sulfate 2% vs intralesional vitamin D in plantar warts: A clinicodermoscopic study.

Verrucae are benign proliferations seen in skin due to infection with papillomaviruses. There are different treatment strategies for warts but all of these treatments are painful, time consuming, expensive, and recurrence is common. To evaluate and compare the efficacy of intralesional 2% zinc sulfate solution vs vitamin D3 in the treatment of plantar warts, as well as reporting the side effects. This three-armed randomized clinical trial included 105 patients presented with plantar warts divided into three groups, 35 patients per group. The first group received intralesional 2% zinc sulfate, the second group received intralesional 2% vitamin D3, and the third group received normal saline. Four sessions were done, one every 2 weeks. At the end of the study, patients showing complete response were more in zinc group (71.4%), vitamin D3 group (62.9%) compared to saline group (40%). Most of the patients in zinc group showed severe pain during injection (48.6%), most of the patients in vitamin D3 group showed mild pain (80%), while most of the patients in saline group showed no pain (57.1%). Both intralesional 2% zinc sulfate and vitamin D3 are effective in treatment of plantar warts, with zinc sulfate being more effective.

Synthesis and photocatalytic performance of ZnO with flower-like structure from zinc oxide ore

Employing zinc sulfate solution obtained from zinc oxide ore as raw material, sodium hydroxide as precipitant and PEG20000 as dispersant, ultrafine ZnO powders with different morphologies were successfully synthesized through hydrothermal method. The influences of the dosage of PEG20000 solution, molar ratio of OH−/Zn2+, reaction temperature, reaction time and Zn2+ concentration on the structures and morphologies of the ZnO powders were discussed in detail. The reaction conditions of synthesizing ZnO powders with flower-like structure were obtained as below: dosage of PEG20000 with 10% mass fraction 5 mL, molar ratio of OH− to Zn2+ 5, reaction temperature 150 °C, reaction time 8 h at Zn2+ concentration 1 mol L−1. The growth mechanism of ZnO particles with different morphologies was proposed. The ZnO powder with flower-like structure are composed of multiple micro-rods with hexagon morphology and has good photocatalytic degradation ability to degrade RhB. 20 mL RhB solution with 15 mg L−1 could be completely degraded over flower-like ZnO powder 300 mg within 3 h.

Effect of Pyridine on Zinc Electrolysis Parameters at Different Current Densities

The effect of pyridine on the parameters of electrolysis in acidic and neutral solutions of zinc sulfate was studied in a wide range of potentials and current densities. The effect of pyridine additives on the parameters of cationic discharge from the zinc sulfate electrolytes, including sulfuric acid, was analyzed. The zinc-to-sulfuric acid mass ratio in one of the three electrolytes corresponded to the composition of the commercial solutions utilized for zinc electrolysis. It was shown that an increase in the electrolyte acid content and cathode potential results in higher cation discharge rate, while an addition of pyridine causes it to decrease. The obtained experimental data evidence the preferential effect of pyridine on hydrogen cation discharge in zinc-containing electrolyte solution. It was noted that an increase in overvoltage accelerates quicker in the solution containing pyridine additives at a current density (j) in excess of 300 A/m2 , while without such additives it actually slows down. This is associated with the ability of pyridine additive to protonate and absorb a significant amount of hydrogen causing a stronger inhibition of hydrogen discharge compared to zinc in the areas with high current density. It was shown that within certain regions of the voltammetric curves with the current density exceeding 300 A/m2 , the exchange current (iex ) increases by about nine times at elevated cathode potentials and increased pyridine concentrations to 0.3 mg/liter. However, when the pyridine concentration increases to 0.6 mg/liter, the exchange current, same as the rate of ionic discharge, decreases, which is consistent with the Butler-Volmer equation for a cathodic process at high overvoltage values associated with increased current densities. The calculations of the transfer coefficients made it possible to conclude that at current densities of 600 A/m2 and higher, the transfer coefficient approaches zero, and the process of cationic discharge from acidic electrolytes with the addition of pyridine proceeds in an activationless mode. The results of the conducted study have led to the following important conclusion in terms of practical use of zinc electrolysis: in order to exclude the negative effect of pyridine, the process should be conducted below the current densities of 300–350 A/m2.

Chickens bred extensively as sentinels from soil contamination by Toxocara

Environmental contamination by Toxocara spp eggs can be verified by parasitological techniques, which are mostly laborious, have low sensitivity, and may require repeated tests to establish the contamination status of a certain area. Given the significance of this parasite as an agent of infections in humans, that may cause blindness, especially in children, broilers chickens created extensively were evaluated as possible markers of parasite environmental contamination, through the detection of anti-Toxocara serum antibodies. Eighteen 15-day-old Label Rouge broilers were released on a farm with a history of dogs with Toxocara infection. At 0, 15 and 30 days after the release birds blood samples were taken, as well as soil samples. At the end of the experiment the birds were slaughtered, and the gastrointestinal tract was collected for coprological exams. The presence of anti-Toxocara antibodies resulted in increased reactivity indexes with time, and at 15 days five of the birds were positive and at 30 days, seven birds showed seroconversion. Examination of the soil samples by the centrifugation-flotation method in hyper saturated zinc sulfate solution revealed contamination by embryonated or infertile eggs of Toxocara at all times of collection, as well as the presence of Ascaridia eggs at 15 days after release of birds. Examination of bird's stool samples at the end of the experiment demonstrated 100% infection by Ascaridia galli, however there was no correlation between the counts of this parasite and the ELISA reactivity indices for anti-Toxocara antibodies. The results obtained allow us to infer the possibility of using anti-Toxocara spp-specific antibodies determination in birds raised extensively, which could then serve as sentinels of environmental contamination by this parasite.

Simultaneous Removal of Nickel and Cadmium During the Cold Purification of Zinc Sulfate Solution

One of the most important steps in the zinc processing industries is the removal of impurities. In this step, cobalt, nickel and cadmium are removed from the leach solution by hot and cold purification, respectively. In this research, the effective parameters on cold purification reactor of Dandi zinc smelting plant (Zanjan—Iran) such as temperature, consumption of zinc dust, residence time, copper sulfate additive, pH of solution, zinc dust particle size and mixing speed are studied. Results demonstrated that optimum concentration of zinc dust to remove impurities properly is 2 g/L, which is less than the factory’s consumption by up to 30%. It was also found that the copper sulfate had no effect on the removal process of nickel and cadmium, and hence exclusion of this additive can cause cost-effectiveness in the process. Optimum amounts of residence time, temperature, pH and mixing speed are 75 min, 80 °C, 4.5 and 400 rpm, respectively. It was demonstrated that the smaller particle size has more effect on the removal of nickel and cadmium. The maximum efficiency was observed at < 45 µm. More ever, the high density of zinc ions had a deterrent effect on the efficiency of nickel and cadmium removal.

A historical review of the techniques of recovery of parasites for their detection in human stools.

Since the early 20th century, the detection of intestinal parasites has improved with the development of several techniques for parasitic structures recovery and identification, which differ in sensitivity, specificity, practicality, cost, and infrastructure demand. This study aims to review, in chronological order, the stool examination techniques and discuss their advantages, limitations, and perspectives, and to provide professionals and specialists in this field with data that lays a foundation for critical analysis on the use of such procedures. The concentration procedures that constitute the main techniques applied in routine research and in parasitological kits are a) spontaneous sedimentation; b) centrifugation-sedimentation with formalin-ethyl acetate; and c) flotation with zinc sulfate solution. While selecting a technique, one should consider the purpose of its application and the technical-operational, biological, and physicochemical factors inherent in the procedures used in stool processing, which may restrict its use. These intrinsic limitations may have undergone procedural changes driven by scientific and technological development and by development of alternative methods, which now contribute to the improvement of diagnostic accuracy.

Speed of Sound and Apparent Molal Volume Approach to Study the Ion-Solvent Interactions in Pharmaceutically Important Liquid Systems

Presence of zinc ion and lactose in different pharmaceutical compositions have been inspired to investigate the ion-solvation and related interactions among the components in solution media. This study has been carried out by the measurements of ultrasonic velocity, viscosity and density for the binary solutions of zinc sulphate (ZnSO4) in lactose-water mixed solvent systems at 303.15, 308.15, 313.15 K temperature and at atmospheric pressure. Different thermo-acoustic parameters such as isentropic compressibility, apparent molal volume, solvation number, free volume, internal pressure etc., have been evaluated from the measured values. All these parameters have been analyzed in the light of molecular interactions from their variations against concentration as well as temperature. Presence of ion-solvation and structure promoting nature of solute are the major findings in the present investigation. Besides, it also reveals that the ion-solvation decreases as the temperature increases.

Endoparasites in dogs and cats diagnosed at the Veterinary Teaching Hospital (VTH) of the University of Prince Edward Island between 2000 and 2017. A large-scale retrospective study

Although many studies on the frequency of endoparasites in dogs and cats in Canada have been reported, seasonal and/or annual patterns are often not evaluated. The frequency and risk factors of endoparasite infections from fecal samples of cats and dogs submitted to the Veterinary Teaching Hospital of the Atlantic Veterinary College, University of Prince Edward Island-Canada were determined, using univariable and multivariable logistic regression analyses. Investigated predictors of endoparasitism available in the 2000–2017 database included sex, age, geographic origin and seasonality. A total of 15,016 dogs and 2,391 cats were evaluated for endoparasite status using specific diagnostic tests: direct smear, Baermann, and/or 33 % zinc sulfate solution in a standardized centrifugal flotation method. Overall, twelve and eight parasite genera were detected in dogs and cats, respectively. The overall proportional infection was 14.6 %, and the cat population showed a higher frequency of positivity to parasites compared to the dog population (P < 0.001). The most frequent genera recovered in the whole population (dogs and cats), were Giardia duodenalis (5.2 %), Cystoisospora spp. (3.3 %) and Toxocara spp. (3.2 %). Endoparasitism levels were diagnosed more in feces submitted from young, female intact dogs from PEI compared to the baselines of mature, sterilized male dogs from other provinces, respectively, and diagnoses occurred more often in autumn months than in winter months. There was no significant diagnostic trend across the years for the individual parasites models. The frequency of detected potentially zoonotic parasites in this study highlights the veterinary public health and One Health context of parasitic infections in pets. Although the presented results are not from a random sample and therefore frequency results should be interpreted with caution, the model relationship results may still be relevant. In addition, results are of value to estimate parasite impact and to assist researchers, veterinarians and pet-owners with suitable information to control parasites.

Pure and Cu-Doped ZnO Nanoparticles: Hydrothermal Synthesis, Structural, and Optical Properties

Pure and Cu-doped zinc oxide (Zn1 –xCuxO with x = 0.00, 0.05, 0.10, and 0.15) nanoparticles were prepared via hydrothermal synthesis using a solution of zinc sulfate (ZnSO4) as precursor, p-phenylenediamine as structure-directing agent in the presence of different amounts of CuSO4 and NaOH. XRD, Raman, UV–Vis, and PL techniques were used to characterize the as-synthesized samples. The XRD analysis reveals that the average particle size of pure ZnO is 13.50 nm. It decreased to 12.11 nm for the Cu-doped sample Zn0.95Cu0.05O, then to 11.00 nm when x = 0.15 (Zn0.85Cu0.15O). The optical band gap of pure and Cu-doped ZnO nanoparticles was calculated from UV–Vis spectra. It turned out to have decreased from 3.18 to 3.11 eV as the amount of Cu increases up from x = 0 to 0.15. The photoluminescence study shows that the introduction of Cu into pure ZnO causes a decrease in surface defects, such as oxygen vacancy and zinc vacancy.

Dynamic Optimization for Copper Removal Process With Continuous Production Constraints

The copper removal process (CRP) aims to reduce the copper ion concentration in zinc sulphate solution to a specific range by zinc addition. The satisfaction of production constraints and minimization of zinc consumption are vital but difficult to achieve. In this article, the dynamic optimization for CRP is conducted for optimal zinc control trajectory design considering constraints at least cost. First, a dynamic optimization problem with both state and control constraints is constructed for CRP. Then, a constrained dynamic optimization method is proposed, where a wavelet-based control parameterization method and a smooth penalty method are adopted. Specially, a hybrid optimization strategy is proposed to achieve a robust and efficient optimization performance. Numerical experiments are provided to illustrate the effectiveness of the proposed method. Results show that the proposed method can produce not only the optimal control trajectory with a qualified outlet ion concentration but also the less zinc consumption.