Zinc Capacity Research Articles

The effect of calcium carbonate content on the zinc quantity-intensity relationship in some soils of Mosul, Irak

The quantity-intensity relationship (Q/I) was used to evaluate thermodynamic parameters of zinc in soils under different agricultural management. Ten soil samples were collected from Mosul city to study zinc distribution of calcium carbonate content in these soils. Generally, Q/I relationship of zinc may provide an index for the strength and quantity of effective zinc supply to plants in soils. The Q/I parameters of zinc were studied to quantify zinc release before and after removing carbonates in the studied soils. Results showed that the zinc activity ratio (AReZn) is related to changes with labile zinc (±ΔZn) at equilibrium and increased together with increasing zinc concentrations, intensity (I) ranged between 0.8584 and 0.9972×10-3 mol/L1/2 before removing carbonates and between 0.0909 and 2.7626×10-3 mol/L1/2 after removing carbonates. The ranges of labile Zinc (ZnL) values before and after removing carbonates were between 0.5755-0.7815 and 0.0009-0.0104 cmol/kg, respectively, while the Zinc (PBCZn) before and after removing carbonates fluctuated from 0.5839 to 0.9104 and 0.00112 to 0.00990 cmol/kg(mol/L)−1/2, respectively. That means calcium carbonate increases exchangeable zinc and zinc capacity at equilibrium conditions. The free energy (−ΔF) ranged between -1.001 and -0.979 kJ/mol before removing carbonates and between -1.319 and -0.841 kJ/mol after removing carbonates. Gapon Selectivity Coefficient (kG) ranged between 0.0193835 and 0.027453 and 0.000045 and 0.00450 (mol/L)1/2 before and after removing carbonates, respectively. Therefore, these results may be used as a reference for zinc soil fertilization, whereas thermodynamic parameters values may be used to predict soil ability to supply available zinc.

Heavy Metals Adsorption on Cellulosic Materials from Agricultural Waste

Adsorption technique has been known to be a very effective method for treatment of heavy metals polluted wastewater, with the advantages of specific affinity, simple design and being user-friendly. However, the high cost of activated carbon commonly used as the adsorbent makes it necessary to explore the use of cheap cellulosic adsorbents. In this study, the adsorptive property of sugarcane bagasse (SB) and orange mesocarp (OM) was investigated. The cellulosic adsorbents were used for the sorption of lead and zinc ions from aqueous solutions. The effects of varying adsorbent dose, varying contact time and initial metal ion concentration on adsorption process of the metals were studied. The results show that both adsorbents (though waste materials) are viable for removal of metals from wastewater. Moreover, SB had higher sorption capacity for zinc (12.95 for SB and 12.68 for OM) while OM had higher sorption capacity for lead (9.90 for OM and 9.48 for SB) at optimum dosage. The isothermal studies shows that for lead adsorption, experimental data best fitted the Langmuir isotherm for both adsorbents (R2 of 0.9574 for OM and 0.98 for SB) while the data for zinc adsorption best fitted into Freundlich isotherm with SB (R2 of 0.9565)and Langmuir isotherm for OM(R2 of 0.814).

Heavy Metals Adsorption on Cellulosic Materials from Agricultural Waste

Adsorption technique has been known to be a very effective method for treatment of heavy metals polluted wastewater, with the advantages of specific affinity, simple design and being user-friendly. However, the high cost of activated carbon commonly used as the adsorbent makes it necessary to explore the use of cheap cellulosic adsorbents. In this study, the adsorptive property of sugarcane bagasse (SB) and orange mesocarp (OM) was investigated. The cellulosic adsorbents were used for the sorption of lead and zinc ions from aqueous solutions. The effects of varying adsorbent dose, varying contact time and initial metal ion concentration on adsorption process of the metals were studied. The results show that both adsorbents (though waste materials) are viable for removal of metals from wastewater. Moreover, SB had higher sorption capacity for zinc (12.95 for SB and 12.68 for OM) while OM had higher sorption capacity for lead (9.90 for OM and 9.48 for SB) at optimum dosage. The isothermal studies shows that for lead adsorption, experimental data best fitted the Langmuir isotherm for both adsorbents (R2 of 0.9574 for OM and 0.98 for SB) while the data for zinc adsorption best fitted into Freundlich isotherm with SB (R2 of 0.9565) and Langmuir isotherm for OM (R2 of 0.814).

Preparation of phosphorus-doped boron nitride and its adsorption of heavy metals from flue gas.

Boron nitride, also known as white graphene, has attracted extensive attention in the fields of adsorption, catalysis and hydrogen storage due to its excellent chemical properties. In this study, a phosphorus-doped boron nitride (P-BN) material was successfully prepared using red phosphorus as a dopant for the preparation of porous boron nitride precursors. The phosphorus content in the P-BN was adjusted based on the addition rate of phosphorus. The specific surface area of P-BN first increased and then decreased with increasing addition rate of phosphorus. The maximum specific surface area was 837.8 m2 g−1 when the phosphorus addition rate was 0.50. The P-BN prepared in the experiments was used as an adsorbent, and its adsorption capacity for heavy metals from flue gas was investigated. In particular, P-BN presented a stronger adsorption selectivity for zinc compared with other heavy metals, and its adsorption capacity for zinc was 5–38 times higher than for other heavy metals. The maximum adsorption capacity of P-BN for zinc and copper in a single heavy metal atmosphere was 69.45 and 53.80 mg g−1, respectively.

Сорбционная очистка растворов от ионов тяжелых металлов с применением цеолита, модифицированного углеродными нанотрубками

The processes of heavy metal ions sorption – copper and zinc, with the use of natural zeolite modified by multi-walled carbon nanotubes (MWСNT) with functionalized surface of polar groups (carboxyl, carbonyl, hydroxyl) by ultrasonic action have been investigated. The most effective is the functionalization of the carbon nanotube surface by carbonyl groups (MWСNT–СООН) in the treatment of native MWСNT with a compound of concentrated sulfuric and nitric acids. Carbonyl and hydroxyl groups are also fixated on the surface of nanotubes. The processes of adsorption of zinc and copper ions from solutions on the original and modified zeolite have been studied. For the intensification of sorption processes the application of ultrasonic treatment is the most effective. In this case, the diffusion restrictions in the adsorption layer are removed, the concentration is equalized by mixing the liquid. The dependence of the degree of extraction of ions of zinc and copper from the content of MWCNT–COOH in the zeolite has been studied. At the optimum concentration of 0.1 wt. % MWCNT–COOH, the degree of extraction for zinc is 97.8 %, for copper it is 96.4 %. A further increase in the concentration of nanotubes in zeolite insignificantly increases the degree of extraction. The optimal duration of ultrasonic treatment is 100 s. Under these conditions with the use of unmodified zeolite, the degree of extraction of zinc and copper ions amounts to 72.4 and 68.3 per cent, respectively. Without the influence of ultrasound the results that are close in degree of extraction can be obtained by zeolite treatment of solutions of zinc and copper salts for 2–4 h. The adsorption isotherms at various concentrations of the zinc and copper cations in a solution have been represented, and the basic parameters of the processes have been determined. Modification of zeolite by carbon nanotubes increases the degree of extraction by 20–25 %, the sorption capacity for zinc by 3 times, for copper it increases by 3.5 times. In the case of modification with the use of ultrasonic influence the specific surface of the sorbent increases by 2.3 times. The spent zeolite can be regenerated by treatment with acids for not less than 6 cycles with reduction of extraction degree to 25 %. The scheme of obtaining and sorption purification with the use of modified zeolite by nanotubes has been suggested.

Sorption on Amberlite IRA410 Resin using Taguchi's Methodology for Design of Experiments

The present work focuses on identifying the parameters, with the most significant contribution on zinc removal as [] using the methodology developed by Taguchi. Five parameters have been taken into consideration, with the purpose of investigating their influence on the adsorption capacity of zinc by Amberlite IRA410 resin. The experimental data have been processed with “larger-the-better” signal-to-noise ratios. Analysis of variance (ANOVA) has been taken into consideration to analyze the obtained data. The parameter identified as the most significant for the considered process was the resin quantity with a contribution of 85%. The p-value (ANOVA analysis) indicated significant evidence against null hypothesis, for concentration, resin quantity, and acid concentration. Also three experiments were conducted in order to confirm the results obtained using the design of experiments methodology. The experimental value of the confirmation experiment, 56.80 mg/g, was in good agreement with the predicted result, 56.66 mg/g.

Assessment of the Mitigative Capacity of Dietary Zinc on PCB126 Hepatotoxicity and the Contribution of Zinc to Toxicity.

Hepatic levels of the essential micronutrient, zinc, are diminished by several hepatotoxicants, and the dietary supplementation of zinc has proven protective in those cases. 3,3',4,4',5-Pentachlorobiphenyl (PCB126), a liver toxicant, alters hepatic nutrient homeostasis and lowers hepatic zinc levels. The current study was designed to determine the mitigative potential of dietary zinc in the toxicity associated with PCB126 and the role of zinc in that toxicity. Male Sprague-Dawley rats were divided into three dietary groups and fed diets deficient in zinc (7 ppm Zn), adequate in zinc (30 ppm Zn), and supplemented in zinc (300 ppm). The animals were maintained for 3 weeks on these diets, then given a single IP injection of vehicle or 1 or 5 μmol/kg PCB126. After 2 weeks, the animals were euthanized. Dietary zinc increased the level of ROS, the activity of CuZnSOD, and the expression of metallothionein but decreased the levels of hepatic manganese. PCB126 exposed rats exhibited classic signs of exposure, including hepatomegaly, increased hepatic lipids, increased ROS and CYP induction. Liver histology suggests some mild ameliorative properties of both zinc deficiency and zinc supplementation. Other metrics of toxicity (relative liver and thymus weights, hepatic lipids, and hepatic ROS) did not support this trend. Interestingly, the zinc supplemented high dose PCB126 group had mildly improved histology and less efficacious induction of investigated genes than did the low dose PCB126 group. Overall, decreases in zinc caused by PCB126 likely contribute little to the ongoing toxicity, and the mitigative/preventive capacity of zinc against PCB126 exposure seems limited.

Selective Separation and Recovery of Zinc and Lead from Galvanizing Industrial Effluents by Anion Exchange

The recovery of zinc and its separation from iron, hydrochloric acid, and minor elements in the galvanizing pickling baths were studied by anion exchange. The breakthrough curves demonstrated that the resins, Lewatit MonoPlus MP 500 and AMBERLYST A21, exhibit a greater capacity for zinc than for cadmium, copper, and lead. The results indicated the feasibility of operating the ion exchange process to treat a real effluent. During the loading, lead started eluting until its complete removal from the resin. Like this, a two-step removal solution is proposed, using two columns with Lewatit MonoPlus MP 500, for separating zinc and lead.

Research on a Zinc Flow Cell Prototype

With the purpose of development of zinc flow cells/batteries, a fundamental study on the cell plate stress distribution, power generation performance and the changes of the internal material before and after the test was carried out in a single zinc flow cell system. The results show that locations between the main channels and the reaction zone area are prone to leakage, the cell power performance is mainly influenced by ohmic losses, the total generating capacity depends on the zinc quantity in the cells and the quantity of electrolyte in the circulatory system, the zinc granule surface becomes more microporous when it comes to the power stage, and the catalytic layer repeated wetting and drying may be the important reason to influence the cycle life. This research is basis for development of higher power and larger capacity zinc flow cell systems.

Accumulation and mobility of zinc in soil amended with different levels of pig-manure compost

Applying manure compost not only results in zinc accumulation in the soil but also causes an increase in zinc mobility and enhances zinc leaching. In this study, the physical and chemical characteristics of zinc, zinc profiles, and zinc balance were investigated to characterise the fate of zinc in fields where the quality and amount of pig manure compost applied have been known for 13 years. Moreover, we determined zinc fractionation in both 0.1 mol L−1HCl-soluble (mobile) and -insoluble (immobile) fractions. Adsorption of zinc in the soil was enhanced with increasing total carbon content following the application of pig manure compost. The 159.6 mg ha−1 year−1manure applied plot (triplicate) exceeded the Japanese regulatory level after only 6 years of applying pig manure compost, whereas the 53.2 mg ha−1 year−1 manure applied plot (standard) reached the regulatory level after 13 years. The zinc loads in the plots were 17.0 and 5.6 kg ha−1 year−1, respectively. However, 5.9 % and 17.2 % of the zinc loaded in the standard and the triplicate pig manure compost applied plots, respectively, were estimated to be lost from the plough layer. Based on the vertical distribution of mobile and immobile zinc content, a higher rate of applied manure compost caused an increase in the mobile zinc fraction to a depth of 40 cm. Although the adsorption capacity of zinc was enhanced following the application of pig manure compost, a greater amount of mobile zinc could move downward through the manure amended soil than through non manure-amended soil.

Separation and Removal of Cobalt and Zinc from Chloride Solution by Indion BSR—A Chelating Resin

Ion‐exchange removal of zinc and cobalt from aqueous solutions on Indion BSR, an indigenous chelating resin, was studied in detail. The percentage removal of zinc and cobalt was examined by varying experimental conditions, viz., dosage of adsorbent, pH of the solution and contact time, metal concentration in aqueous feed, and temperature. It was found that more than 95% removal of both the metals was achieved under optimum conditions. The loading capacity for zinc and cobalt under optimized conditions was found to be 4.27 g Zn/100 g resin and 6.15 g Co/100 g resin with a feed concentration of 2 g/L each. Effect of various salts like sulfate, carbonate and chloride of sodium, and ammonium were also studied. Separation of both these metals from a binary mixture was also studied. Under optimized condition this resin was found to have more affinity for Zn than Co, indicating the feasibility of zinc separation from cobalt. The studies showed that this chelating resin could be used efficiently for the removal and separation of cobalt and zinc from chloride solutions.

Zinc-metallothionein levels are correlated with enhanced glucocorticoid responsiveness in mouse cells exposed to ZnCl(2), HgCl(2), and heat shock.

Metallothioneins (MTs) are the major low molecular weight, zinc-binding proteins in mammalian cells. It has been hypothesized that they play a role in the function of zinc-dependent signal transduction proteins and transcription factors. We investigated the capacity of zinc and other metal ions and conditions to increase both Zn-associated MT levels and the receptiveness of cells to transcriptional activation mediated by the zinc-dependent glucocorticoid receptor (GR). We studied, in a GR-responsive mouse mammary-tumor cell line, the ability of dexamethasone (DEX) to stimulate transcription of a chloramphenicol acetyltransferase (CAT) gene controlled by a mouse mammary-tumor virus promoter. In cells pretreated with 20 to 100 microM ZnCl(2), DEX-induced CAT activity correlated with zinc-induced MT levels. However, 0.05 to 0.5 microM CdCl(2) had no effect on CAT activity, despite an increase in Cd-associated MT. Copper-associated MT was detected in cells treated with 20 microM CuCl(2,) but there was no change in the level of Zn-MT, nor was CAT activity altered in cells exposed to 5 to 20 microM CuCl(2). These results may reflect a functional difference between zinc-associated MT, and MT associated with other metals. Significantly more CAT activity was observed in both heat-shocked cells and in cells exposed to 40 or 50 nM HgCl(2). Although absolute amounts of MT were unchanged by these two treatments, a higher percentage of total cellular zinc was associated with the MT protein fractions after treatment. Changes in GR levels could not account for variations in CAT activity. These data indicate that hormonal signalling can be altered by exposure to metal salts and heat shock, and the effect is correlated with the level of Zn-MT.

Development and Testing of a Partial Exfiltration Trench for In Situ Treatment of Highway Drainage

Urban roadway drainage often contains high concentrations of anthropogenic metal elements, solids, and organic compounds. Metal elements and solids accumulate on the pavement surface between precipitation events and are transported to surficial soils, receiving waters, and ground-water by pavement drainage. A report is provided on the design and performance of a bench-scale and prototype in situ control strategy, called a partial exfiltration trench (PET). The PET serves as a modification to the current practice of pavement underdrainage, providing a water quality function, in addition to water quantity control. The water quality modification functions by immobilizing infiltrated metal elements within the PET. The PET utilizes sand modified with an oxide coating (OCS). Bench-scale PET simulations were utilized to evaluate PET feasibility and breakthrough capacity. Results indicate OCS capacity for zinc, cadmium, lead, and copper was significantly improved as the pH increased from 6.5 to 8.0. Based on characteristic metal loadings from urban Cincinnati pavement drainage, bench-scale PET performance indicates that the design life of a PET may exceed 15 years in a humid climate. Performance of a prototype PET installed along an urban Cincinnati highway indicates metal element mass removal efficiency is generally greater than 80 percent after nearly 1 year of pavement drainage loadings.

Evaluation of Serum Zinc-Binding Capacity during Childbirth, in Newborn Infants and during the Menstrual Cycle

This is a study of the value of total serum zinc, serum zinc per g of protein, serum zinc-binding capacity and serum zinc-binding capacity per g of protein in 102 pregnant women during childbirth and in the cord blood of their newborn infants. A control group is established by analyzing these parameters in 10 healthy non-pregnant women on the first day of menstruation and on the day of ovulation during two consecutive menstrual cycles. The total serum zinc and serum zinc per g of protein values found were significantly higher in cord blood than in maternal blood, and the binding capacity of zinc and of zinc per g protein were significantly higher in maternal blood. There is a negative correlation between total zinc and binding capacity and total zinc and binding capacity per g protein both in maternal and in cord blood. In the control group, the values of total zinc and zinc per g protein vary from one menstrual cycle to the next and between the different phases of each cycle. Zinc-binding capacity per g protein during ovulation is significantly lower than during menstruation. These results allow us to conclude that the rise of zinc-binding capacity and zinc-binding capacity per g protein in maternal blood during childbirth, and during menstruation in the control group, can be due to the effect of progesterone. The fact that zinc-binding capacity and zinc-binding capacity per g of protein are higher in maternal blood than in cord blood would confirm the existence of mechanisms which tend to increase binding of zinc in the fetus.

Effect of metal ion concentration on its distribution in sludges

Abstract Adsorption isotherms of different types of sludges from the same treatment plant were obtained by loading them upto thousand fold excess of copper and zinc separately. The sudden increase in the bound metal at higher concentration is probably due to the precipitation of basic carbonates which is reflected in the speciation profile. In general sludges were found to have higher affinity for copper than zinc. However, activated sludge exhibited greater capacity for zinc.

A study of rechargeable zinc electrodes for alkaline cells requiring anodic limitation

A well known technology exists for the preparation of anodes for rechargeable alkaline cells in which the zinc capacity is far in excess of the cathodic capacity, as in AgOZn or NiZn cells. However, in rechargeable alkaline zinc—air cells and zinc—manganese dioxide cells the zinc limits the discharge. Especially for the manganese dioxide cathode it is necessary to limit the discharge to a definite fraction (1/3) of its available capacity to obtain a good cycle life. This study of alkaline zinc powder electrodes evaluates parameters such as cell geometry, electrolyte additives, and current collectors (see Table 1) and shows that it is a considerable achievement to obtain 50 – 100 cycles reliably under anode limiting conditions. It is this fact which has prevented the technology of alkaline MnO 2—zinc cells from producing rechargeable batteries of consumer quality up to the present time.

The binding of zinc to the plasma of winter flounder (Pseudopleuronectes americanus): affinity and specificity.

The binding affinity of winter flounder plasma proteins for zinc was determined by equilibrium dialysis. The relationship between the percentage of zinc bound and the total zinc present in the system produced a curved line. A Rosenthal type plot indicated that there was more than one binding system for zinc present. The association constant computed from the first slope, 107–108, compared with that of mammalian serum albumin. It required twice the normal total plasma zinc concentration to saturate the higher affinity binding system.All of the plasma zinc could be removed by dialyzing with 10−2M histidine.The specificity of the plasma proteins for binding zinc was studied by introducing the following cations: Cu2+, Cd2+, Ca2+, Mg2+, Co2+, Mn2+, Hg2+, Fe2+, Cr2+, and Ni2+. Only Cu2+ competed significantly with the binding of zinc to the plasma. This competitive effect was diminished in the presence of Tris buffer.Studies in the presence of EDTA indicated that the EDTA had a greater effect on the zinc binding than would be predicted from its theoretical binding capacity for zinc.

Effects of mechanical and heat treatments on the thermal capacity of zinc

Effects of mechanical and heat treatments on the thermal capacity of zinc