Removal Of Zinc Research Articles

Follow-Up Application of <i>Spondias Mombin</i> Modified Nano-Sorbent for Trace Metals Remediation

Environmental pollution, specifically soil contamination by trace metals, is a significant problem that has caused widespread concern around the globe due to its grave negative effects on the fragile ecosystem. Zero-valent iron nano-compound modified with <i>Spondias mombin</i> leaves extract was employed in the removal of Zinc (Zn), Chromium (Cr), Lead (Pb), and Nickel (Ni) from contaminated soil. The metal compositions in both plant and soil were evaluated using Atomic Absorption Spectrophotometer (AAS). The result showed that the pH conditions for optimum removal efficiency (%) of Zn (70.53%), Pb (98.89%), and Ni (99.99%) were in the range of 7 < pH ≤ 12 while Cr (98.67%) was in the range of 3 < pH ≤ 7. The result revealed that the adsorbent dosage for optimum removal efficiency (%) was 0.2 g for Cr (99.99%) and Pb (98.89%) while 0.8 g for Zn (57.51%), and Ni (99.99%). The optimum contact time was 15 min for Cr (99.99%) and Pb (86.38%) while 120 min for Zn (52.43%) and Ni (99.99%). The modified nano-compound showed higher removal efficiency (%) for Ni (99.99%) under the same condition. This study has revealed that the modified adsorbent can serve as an effective and efficient eco-benign matrix for soil remediation.

The role of zinc binding sites in the cation diffusion facilitator YiiP.

YiiP is a zinc/proton antiporter that couples zinc export to the proton motive force. YiiP binds zinc at three sites: site A in the transmembrane domain, site B in a cytoplasmic loop between transmembrane helices M2 and M3, and site C in the cytoplasmic, C-terminal domain (CTD). Previous Cryo-EM analysis revealed that global removal of zinc by EDTA produced a novel inward occluded state that was postulated to be an intermediate between the inward and outward facing states. In this study we introduced mutations to study binding affinities and conformational effects of each individual site. Cryo-EM analysis showed that disruption of site A produces little change, but that disruption of site B induces the inward occluded state observed previously. Double mutation at site C produced nonnative oligomers, indicating that site C is important for assembly of the native homodimer. Molecular dynamic simulations with zinc removed from site B showed increased mobility of the CTD and disordering of the M2M3 loop in agreement with the structural studies. Binding affinity was quantified by microscale thermophoresis using either citrate or NTA to buffer the concentration of free zinc. The results demonstrate nanomolar affinity at sites A and C and micromolar affinity at site B. Site A is highly sensitive to pH changes with Kd increasing from 1 nM to 302 μM as pH decreases from 7.4 to 5.6. Based on these observations, we propose a transport mechanism whereby zinc is initially recruited at site B and that transfer to site A induces conformational changes leading to transport. The pH dependence of site A is key to energy coupling by ensuring high affinity binding from the cytoplasm and then promoting release to the more acidic periplasmic milieau.

Recovery Of Zinc from Scrap Steel Using Zinc-Bromine Battery Technology.

Secondary production of steel is known to significantly decrease the CO2 emissions of steelmaking, but only 40 % of steel is produced through recycling, which is made difficult by contamination of scrap resources with nonferrous metals and nonmetal debris. These contaminants include zinc, towards which blast furnace and electric arc systems have a low tolerance (<0.02 wt %). In this work, clean and efficient recovery of zinc from the surface of steel substrates was investigated using a custom-made low-cost membrane-free non-flow zinc-bromine battery (ZBB) that enabled rapid and straightforward integration and removal of steel substrates. The electrical performance of the cell was characterized by charge-discharge profiles, and zinc removal and recovery onto electrodes was characterized by using scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). Upon discharging, the cell efficiently removed >99.9 wt % zinc from steel surfaces. On recharging the cell, zinc was re-electroplated onto a carbon foam electrode in an easily recoverable form and with high purity. The process was repeated over 30 cycles to demonstrate robustness. The work shows the importance of the cutoff voltage upon discharging: if less than 0.5 V, the cell co-extracted iron into the electrolyte solution, affecting cell durability and zinc purity. A two-stage process for recovering zinc from scrap steel is proposed, illustrating how ZBB technology could enable efficient and clean recovery of zinc from complex scrap steel resources in the steel industry.

Zinc removal from synthetic waters using magnetite/graphene oxide composites

AbstractThe removal of heavy metals from wastewater has become a global challenge, which demands the continuous study of efficient and low‐cost treatment alternatives such as adsorption. In this research, the removal of zinc was evaluated using batch adsorption processes with nonconventional materials such as graphene oxide (GO), magnetite (MG), and their composites (GO:MG), formulated with three weight ratios (2:1, 1:1, and 1:2). Graphene was synthesized by the modified Marcano method, using pencil lead graphite as a precursor. MG and the composites were synthesized by chemical coprecipitation of ferrous sulfate and ferric chloride. The materials were characterized by Raman and Fourier transform infrared spectroscopies, scanning electron microscopy, X‐ray diffraction, and the Brunauer–Emmett–Teller method to determine the functional groups, microstructural and morphological characteristics, and specific surface area. Batch adsorption tests were carried out to optimize the adsorbent dose and contact time with zinc solutions of 10 ppm. Zinc adsorption reached equilibrium at 2 h, with an optimal dose between 0.25 and 1.0 g/L. The maximum zinc removal efficiencies/adsorption capacities were 98.6%/165.6, 83.4%/47.6, 83.5%/21.9, 72.8%/19.9, and 82.2%/9.25 mg/g using GO, 2GO:1MG, 1GO:1MG, 1GO:2MG, and MG, respectively. Furthermore, the analysis of the isotherm and adsorption kinetics models determined that the adsorption processes using MG and the composites fit the Sips and pseudo‐second‐order models.

Removal of Zinc from Concentrated Galvanic Wastewater by Sodium Trithiocarbonate: Process Optimization and Toxicity Assessment

In the present research, the removal of zinc from concentrated galvanic wastewater (pH 3.1, conductivity 20.31 mS/cm, salinity, 10.16 g/L, Chemical Oxygen Demand (COD) 2900 mg O2/L, Total Organic Carbon (TOC) 985 mg/L, zinc (Zn) 1534 mg/L and ethylenediaminetetraacetic acid (EDTA) 70 mg/L) by combination of lime (Ca(OH)2) and sodium trithiocarbonate (Na2CS3) as precipitation agents is studied. Central Composite Design (CCD) and response surface methodology (RSM) were applied for modelling and optimizing the designed wastewater treatment process. Analysis of Variance (ANOVA) and the experimental verification of the model confirmed the consistency of the experimental and estimated data calculated from the model (R2 = 0.9173, R2adj. = 0.8622). The use of Ca(OH)2 and Na2CS3 in the optimal condition calculated from the model (pH = 10.75 ± 0.10, V Na2CS3 dose 0.043 mL/L and time = 5 min) resulted in a decrease in the concentration of Zn in treated wastewater by 99.99%. Other physicochemical parameters of wastewater also improved. Simultaneously, the application of Ca(OH)2 and Na2CS3 reduced the inhibition of activated sludge dehydrogenase from total inhibition (for raw wastewater) to -70% (for treated wastewater). Under the same conditions the phytotoxicity tests revealed that the seed germination index for the raw and treated wastewater increased from 10% to 50% and from 90% to 100% for white mustard (Sinapis alba) and garden cress (Lepidium sativum L.), respectively. The parameters of root and shoot growth showed a statistically significant improvement. Treated wastewater (1:10) showed a stimulating effect (shoot growth) compared to the control sample (GI = -116.7 and -57.9 for S. alba and L. sativum L., respectively). Thus, the use of Na2CS3 is a viable option for the treatment of concentrated galvanic wastewater containing zinc.

Removal of Zinc (II) ions from industrial wastewater by adsorption on to activated carbon produced from pine cone

Recently heavy metal pollution is consider among the most essential environmental issues. Due to their impact, the removing of heavy metals from the environment is a high demanding concern. Heavy metals adsorption is a new technology for wastewater treatment that contain different selected heavy metals types. This study aim to adopted adsorbents with low cost application, in this technique a pine cones used as plant wastes adsorbents in Industrial wastewater treatment by implemented batch technique adsorbent dosage and adsorbate initial concentration). The plant waste sample of (pine cone) was used to test its efficiency which that provide the optimum performance in removing heavy metals and other pollutants (Turbidity, TSS and TDS). Activated carbon produced from Pine cones Turkish Pine (ACPC) was adopted as an adsorbent for the Zinc ions removal from wastewater with industrial pollutants. Surface analysis was preform to measure the pore size distribution and specific surface area of the activated carbon produced from pine cone. Optimal parameters, pH, equilibrium time, adsorbent dosage, temperature and mix speed were investigated. Using Langmuir, Freundlech and Elvich isotherm models, equilibrium data were evaluated. Langmuir isotherm model provided the highest fit to the equilibrium data.

Application of a deep eutectic mixture and ionic liquid as carriers in polymer adsorptive membranes for removal of copper(II) and zinc(II) ions from computer scrap leachates

Application of a deep eutectic mixture and ionic liquid as carriers in polymer adsorptive membranes for removal of copper(II) and zinc(II) ions from computer scrap leachates

Potassium Hydroxide Activated Peanut Shell as an Effective Adsorbent for the Removal of Zinc, Lead and Cadmium from Wastewater

Potassium Hydroxide Activated Peanut Shell as an Effective Adsorbent for the Removal of Zinc, Lead and Cadmium from Wastewater

Silver N-heterocyclic carbene complexes are potent uncompetitive inhibitors of the papain-like protease with antiviral activity against SARS-CoV-2.

The ongoing SARS-CoV-2 pandemic has caused a high demand for novel innovative antiviral drug candidates. Despite promising results, metal complexes have been relatively unexplored as antiviral agents in general and in particular against SARS-CoV-2. Here we report on silver NHC complexes with chloride or iodide counter ligands that are potent inhibitors of the SARS-CoV-2 papain-like protease (PLpro) but inactive against 3C-like protease (3CLpro) as another SARS-CoV-2 protease. Mechanistic studies on a selected complex confirmed zinc removal from a zinc binding domain of PLpro as relevant factor of their activity. In addition, enzyme kinetic experiments revealed that the complex is an uncompetitive inhibitor and with this rare type of inhibition it offers great pharmacological advantages in terms selectivity. The silver NHC complexes with iodide ligands showed very low or absent host cell toxicity and triggered strong effects on viral replication in cells infected with SARS-CoV-2, making them promising future antiviral drug candidates.

Features of the Phytoremediation by Agricultural Crops of Heavy Metal Contaminated Soils

The novelty of the present research consisted in the study of the features of heavy metals accumulation in the phytomass of agricultural plants under the conditions of complex heavy metals contamination of podzolized chernozem (ashy soil) in the Ryazan region (Russia). Results of the vegetation experiments conducted on four crops—oats, black beans, buckwheat, and soybeans—were analyzed, which made it possible to assess the ability of these plants to accumulate heavy metals in their phytomass depending on the level of the heavy metals contamination of the soil. Results of the study showed that the removal of copper, zinc, and lead by beans was noticeably higher than that by oats, buckwheat and soy, due to their greater tolerance and ability to form a large phytomass, which must be taken into consideration when choosing phytoremediation for soil decontamination. This made it possible to evaluate the possibility of using the analyzed plants for the biological purification of polluted soil. The results are also planned to be used in the digitalization of agricultural production.

DETERMINATION OF CONDITIONS FOR MAXIMUM DEZINCIFICATION OF A MIXTURE OF FERROUS MATERIALS IN THE SINTERING PROCESS BASED ON NUMERICAL CALCULATIONS USING THE FactSage THERMOCHEMICAL PROGRAM

Multi-million tons of sludge produced as a result of wet dedusting of blast furnace and converter gases have been deposited in landfills across the country. These materials are also created on an ongoing basis. Due to the high iron content, their potential as a ferrous raw material is significant. Unfortunately, in addition to components which are desirable from the point of view of metallurgical processes such as Fe, C and CO, they also contain many harmful elements such as Zn, Pb, Na and K. The article describes the sources and form of Zn found in post-production waste of steelworks and the methods of removing zinc from ferrous waste materials. The optimal conditions for zinc removal during the sintering process of galvanised ferrous materials were identified using thermochemical calculations carried out with the FactSage computer program.

Cadmium Depth Separation Method in Polymetallic Sulfate Solution: Flow-Electric Field Enhanced Cementation Combined with M5640 Extraction

An efficient and controllable process for separating copper and cadmium was required to be developed due to the high cost of the long separation process of copper cadmium slag generated from the zinc smelting process. Therefore, a new process for the application and deep separation of copper and cadmium was developed by combining the Circulating Flow Electric (CFE) cadmium cement method and the 2-hydroxy-5-nonyl formaldehyde oxime (M5640) copper extract method. The process firstly removed copper ions utilizing M5640 and obtained a primary purification solution, followed by CFE method to extract cadmium in depth. The effects of extractant volume fraction, pH, Oil phase/Aqueous phase (O/A) ratio and reaction time on the removal of copper ions were investigated. The results showed that the removal of copper was above 97%, while the removal of zinc and cadmium was below 1.6%, respectively, proved that the selectivity of M5640 for copper was significantly higher than that for metals such as cadmium and zinc. The characterization results indicate that the oxygen on the hydroxyl group and the nitrogen on the oxime group co-ligated with the copper ions and subsequently formed chelated extracts. That was the mechanism of the copper ion purification by M5640. Furthermore, the extraction of high purity cadmium was carried out in the extraction residual liquid. A novel method of cadmium removal enhanced by coupling an electric field with a circulating flow field was developed and applied to the cement cadmium from sulfate solutions. The optimal process conditions of the method were explored, which were further fitted into statistical equations and optimized by response surface analysis. Since the fitted theoretical results were close to the experimental results, the optimization was considered as effective. The optimized experimental parameters were 6.23 mL/s of flow rate, 48.14 mA/cm2 of current density, 2.25 of pH, and 0.93 of anode/cathode area ratio, respectively. Next, the extraction electrical efficiency, purity and its weight distribution in the cell of cadmium sponge under different flow fields were calculated and measured. The results were analyzed to prove the existence of an optimal interval for the distribution of cadmium under high-speed flow field.

Application of sulphate and magnesium enriched waste rapeseed cake biochar for recovery of Cu(II) and Zn(II) from industrial wastewater generated in sulphuric acid plants

The development of an efficient and green adsorbent is of great significance for copper(II) and zinc(II) removal and recovery from industrial wastewater. In this study, for the first time, waste rapeseed cake is used as a biosource to synthesize MgO-SO3 enriched biochar. The newly developed adsorbent was produced in a one-step process by pyrolysis at 973.15 K for 2 h, under anoxic conditions. Porous structure, specific surface area, and composition of biochar were studied. Furthermore, sorption properties of the obtained biochar in relation to copper(II), zinc(II), and arsenic(III) ions were also studied. The impact of parameters such as: sorption time, temperature, adsorbate concentration, sorbent mass, and solution pH on the efficiency of the adsorption process of the studied cations was examined. Rapeseed cake biochar exhibits good Cu(II) adsorption capacity (90.4 mg g−1) with a short equilibrium time (4 h), which indicates the competitiveness to similar adsorbents. The adsorption of Cu(II) on the biochar was more consistent with the pseudo-second-order kinetic models and Langmuir model. The Freundlich and pseudo-second-order kinetic models best fitted the removal of Zn(II) by modified biochar. The mechanism of Cu(II) and Zn(II) adsorption was also postulated. Experimental data collected have shown that the presence of arsenic(III) at higher concentrations adversely affects the sorption efficiency of Cu(II) and Zn(II) ions. Thus, this study shows that the sorbent can be successfully used for the separation of Cu(II) and Zn(II) from technological wastewaters. A flowsheet for the proposed process is presented.

Schoenoplectus californicus as Potential Remover of Metal Elements from Mine Effluents: A Laboratory Assessment

AbstractAcid mine drainage (AMD) is one of the most significant environmental challenges facing the mining industry worldwide. For this reason, many methods for AMD treatment are developed, being wetlands a good option for metal elements removal from these mining effluents. The efficiency of Peruvian native plants such as Schoenoplectus californicus (S. californicus) to remove metal elements in effluents through artificial wetlands is studied. Batch removal tests are carried out with different effluents containing copper, zinc, lead, and iron. For iron‐metal binary effluents, copper, zinc, and lead are removed by 82%, 75%, and 88%; while in the effluent containing all metals, the removal rate is 90% and 92% for copper and lead, respectively. According to the preliminary results, it is concluded that iron interferes more in the removal of zinc and lead than in copper from binary effluents. The use of S. californicus turns out to be an efficient, attractive, and economical alternative for the treatment of effluents contaminated with copper, zinc, lead, and iron.

The Chemically Modified Leaves of Pteris vittata as Efficient Adsorbent for Zinc (II) Removal from Aqueous Solution

High concentrations of zinc along with other metals are released by steel mills, and this has a number of negative effects on organism health; most notably, neurological symptoms have been recorded with a high risk of brain atrophy. In the current study, Zn (II) was eliminated from steel mill effluent, utilizing chemically processed Pteris vittata plant leaves as a biosorbent. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), and energy dispersive X-ray spectroscopy (EDX) were applied to characterize the chemically modified Pteris vittata leaves, from now onward abbreviated as CMPVL. In order to identify the ideal parameter, batch studies were conducted varying a single parameter affecting the biosorption process at a time, including variations in temperature (293–323 K), initial metal concentration (20–300 mg/L), and adsorbent doses (0.01–0.12 g), pH (2–8), as well as contact time (10–140 min). To describe the isothermal experimental results, a number of models were used including Freundlich, Langmuir, Temkin, Jovanovich, and Harkins–Jura. Among these models, the Langmuir model provided a significant fit to the isotherm data with an R2 of 0.9738. The kinetics data were fitted to the pseudo first order, pseudo second order, power function, Natarajan–Khalaf, and intraparticle diffusion models. The highest R2 (0.9976) value was recorded for the pseudo second order model. Using the Langmuir isotherm, the highest uptake ability (84.74 mg/g) of Zn was recorded. The thermodynamic investigation, carried out at various temperatures, led to the conclusion that the biosorption process was exothermic and spontaneous in nature. The CMPVL, thus, has the potential to function well as an alternative to existing carbon-based adsorbents in the effective elimination of zinc from aquatic environments.

CEVİZ KABUĞUNUN DOĞAL BİYOSORBENT OLARAK ÇİNKO GİDERİMİNDE KULLANILMASININ ARAŞTIRILMASI

Heavy metal contamination is a primary concern worldwide and it is discharged from the industrial wastewater to a large amount of heavy metal receiving environments. In recent years, the effective use of agricultural by-products is definitely a major challenge in waste management. The fact that agricultural residues are more easily obtained and cheaper than commercial adsorbents makes it attractive. In this study, removal of zinc from industrial wastewater using natural and thermally modified (biochar) walnut shells as biosorbent was investigated. It was tried to remove zinc in aqueous solutions with different concentrations by using walnut shells at different rates. The effects of initial concentration, contact time, adsorbent dosage. In addition, adsorption isotherms and kinetics were also studied. With the modified form of the walnut shell, up to 98% zinc removal efficiency was obtained. Also, adsorption was observed to be consistent with pseudo-second kinetics and Freundlich isotherm. The results showed that the modified walnut shell in zinc removal was a potential adsorbent. The adsorption of zinc, onto walnut shells was found to fit Freundlich isotherm. The results obtained in the tests with wastewater showed the potential use of walnut shells for the removal of zinc.

Mesoporous activated TiO2/based biochar synthesized from fish scales as a proficient adsorbent for deracination of heavy metals from industrial efflux

As heavy metals are very noxious for health also known as one of the most poisonous classes of water contaminants. Typically, metal pollutants are non-biodegradable and impervious towards oxidants, heat, and light. Thus, it is a precisely demanding task to eliminate them from water to reduce water pollution. In current studies, the process of adsorption was employed for deracination of Zn and Fe with modified surface of natural material as an adsorbent. TiO 2 NPs were synthesized by using leaf extract of Putranjiva roxburghii and its nanocomposites were made with the fish scale biomass. Prime conditions for proficient removal of zinc were recognized at pH = 4 and for iron at pH = 6 having an initial concentration 100 mg/L, adsorbent dose rate of 0.1 g and contact time 120 minutes. Thermodynamic study revealed that process was spontaneous, and exothermic, resulted in increase in entropy with rise in temperature. Adsorption process has been certified with different isotherm and kinetic models, where the experimental data was brought into being good agreement with pseudo second order ( R 2 = 0.986) and Freundlich isotherm ( R 2 = 0.993) as compared with other models. For characterization of synthesized adsorbents scanning electron microscopy, UV–visible spectroscopy and Fourier-transform Infrared spectroscopy, X-ray diffraction, and energy-dispersive X-ray were used. Average particle size of the adsorbent used ranged from 1 to 5 µm.

Use of propionic acid additions to enhance zinc removal from mine drainage in short residence time, flow-through sulfate-reducing bioreactors

The effectiveness of liquid carbon additions to enhance zinc removal in laboratory-scale short hydraulic residence time (19 h) compost bioreactors receiving synthetic mine water with a high influent zinc concentration (45 mg/L) was investigated. Effective removal of such elevated zinc concentrations could not be sustained by sulfate reduction and/or other attenuation processes without carbon supplementation. Propionic acid addition resulted in improved and sustained performance by promoting the activities of sulfate reducing bacteria, leading to efficient zinc removal (mean 99%) via bacterial sulfate reduction. In contrast, cessation of propionic acid addition led to carbon limitation and the growth of sulfur oxidising bacteria, compromising zinc removal by bacterial sulfate reduction. These research findings demonstrate the potential for modest liquid carbon additions to compost-based passive treatment systems to engineer microbial responses which enhance rates of zinc attenuation in a short hydraulic residence time, enabling remediation of highly polluting mine drainage at sites with limited land availability.

Removal of zinc (Zn2+) through biopolymer-enhanced ultrafiltration

Removal of zinc (Zn2+) through biopolymer-enhanced ultrafiltration

Anchoring carboxylated pineapple peel cellulose and EDTA onto magnetic (3-aminopropyl)triethoxysilane to effective removal of copper(II) and zinc(II) from polluted water

Anchoring carboxylated pineapple peel cellulose and EDTA onto magnetic (3-aminopropyl)triethoxysilane to effective removal of copper(II) and zinc(II) from polluted water