Deposition Of Lead Research Articles

Underpotential deposition of lead on quasi-spherical and faceted gold nanoparticles

The underpotential deposition of lead was studied on spherical and faceted gold nanoparticles. On 21.7nm spherical nanoparticles, a single stripping peak from Au(111) face was observed at −0.2V, whereas on 82nm faceted gold nanoparticles the peak split in to two at −0.2V and −0.18V vs Ag/AgCl (3M KCl). The roughening of the Au(111) terraces by electrochemical treatment leads to the suppression of the spike. It appears that the extent of surface crystallinity of nanoparticles causes the observed differences in the upd-stripping behaviour. The splitting of the Pb-upd stripping peak from Au(111) face can be used as an indication for the surface crystallinity of gold nanoparticles.

Electrodeposition of Pb from PbO in urea and 1-butyl-3-methylimidazolium chloride deep eutectic solutions

In this work, urea and 1-butyl-3-methylimidazolium chloride (urea-BMIC) deep eutectic solutions were used as electrolytes for electrodeposition of lead from lead oxide. The electrochemical behavior of Pb (II) ions was investigated by cyclic voltammetry, chronopotentiometry, and chronoamperometry techniques at 353–373K. Cyclic voltammograms and chronopotentiograms indicate that the reduction of Pb (II) ions to Pb is a diffusion-controlled quasi-reversible process and it proceeds via one step two-electron transfer process at −0.38V (vs. Ag). The diffusion coefficient of Pb (II) ions increases from 3.22×10−8cm2s−1 to 1.49×10−7cm2s−1 as temperature increases from 353K to 373K. The activation energy for diffusion is determined to be 83.93kJmol−1. In addition, results from chronoamperometry show that lead deposition involves in a three-dimensional instantaneous nucleation and diffusion-controlled growth. On the other hand, the electrodeposit on a Cu substrate was pure Pb as confirmed by X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS). Scanning electron microscopy (SEM) image indicated that a uniform, dense, and non-dendritic coating with grain size of 3μm in diameter was prepared by potentiostatic electrolysis at −0.4V (vs. Ag). The optimized current efficiency (96.17%) and energy consumption (0.11kWhkg−1) was obtained by potentiostatic electrolysis at −0.4V (vs. Ag) and 373K from urea-BMIC deep eutectic solutions containing 0.072moldm−3 PbO.

Next-generation ice core technology reveals true minimum natural levels of lead (Pb) in the atmosphere: Insights from the Black Death.

Contrary to widespread assumptions, next‐generation high (annual to multiannual) and ultra‐high (subannual) resolution analyses of an Alpine glacier reveal that true historical minimum natural levels of lead in the atmosphere occurred only once in the last ~2000 years. During the Black Death pandemic, demographic and economic collapse interrupted metal production and atmospheric lead dropped to undetectable levels. This finding challenges current government and industry understanding of preindustrial lead pollution and its potential implications for human health of children and adults worldwide. Available technology and geographic location have limited previous ice core investigations. We provide new high‐ (discrete, inductively coupled plasma mass spectrometry, ICP‐MS) and ultra‐high resolution (laser ablation inductively coupled plasma mass spectrometry, LA‐ICP‐MS) records of atmospheric lead deposition extracted from the high Alpine glacier Colle Gnifetti, in the Swiss‐Italian Alps. We show that contrary to the conventional wisdom, low levels at or approaching natural background occurred only in a single 4 year period in ~2000 years documented in the new ice core, during the Black Death (~1349–1353 C.E.), the most devastating pandemic in Eurasian history. Ultra‐high chronological resolution allows for the first time detailed and decisive comparison of the new glaciochemical data with historical records. Historical evidence shows that mining activity ceased upwind of the core site from ~1349 to 1353, while concurrently on the glacier lead (Pb) concentrations—dated by layer counting confirmed by radiocarbon dating—dropped to levels below detection, an order of magnitude beneath figures deemed low in earlier studies. Previous assumptions about preindustrial “natural” background lead levels in the atmosphere—and potential impacts on humans—have been misleading, with significant implications for current environmental, industrial, and public health policy, as well as for the history of human lead exposure. Trans‐disciplinary application of this new technology opens the door to new approaches to the study of the anthropogenic impact on past and present human health.

The effects of experimentally supplied lead nitrate on three common Mediterranean moss species.

We assess here, through an experimental simulation using lead nitrate, the response to lead deposition of three common Mediterranean bryophyte species in the family Pottiaceae. Five concentrations of lead nitrate (from 0 to 10-3M) were sprayed for 4months on plants belonging to Tortula muralis (reported as toxitolerant), Syntrichia ruralis (medium-tolerant), and Tortula subulata (less tolerant). The three species showed a remarkably high tolerance to lead nitrate, with a low incidence of damage even at concentrations as high as 10-4M. The maximum concentration (10-3M), although resulting eventually in serious damages in the gametophyte of the three species (high mortality rates in S. ruralis and T. subulata, or a significant percentage of damaged tissue in T. muralis), did not prevent the production of sporophytes in the two species with fertile samples (T. muralis and T. subulata). Growth parameters show limited value as bioindicators of lead deposition, as they only show clear effects at very high concentrations. Besides, we identified the existence of a lead exclusion strategy mediated by mucilage using histochemical analyses and scanning electron microscopy combined with energy-dispersive X-ray spectroscopy. This mechanism can hamper the usefulness of these mosses in quantitative estimation of lead deposition.

Remobilisation of industrial lead depositions in ash during Australian wildfires

This study examined the recycling of lead (Pb) in ash from wildfires, its source and potential contribution to environmental contamination. Ash from wildfires was collected from four Australian sites following uncontrolled fires during 2012 to 2013 close to major urban populations in Sydney (New South Wales), Hobart (Tasmania) and Adelaide (South Australia). The samples were analysed for their total Pb concentration and Pb isotopic composition to determine the sources of Pb and the extent, if any, of industrial contamination and its recycling into the ecosystem. Median ash concentrations (23mg/kg) released from a wildfire close to Australia's largest city, Sydney, exceeded the median ash Pb concentrations from wildfires from the less populated locations of Hobart, Adelaide and NSW Central Coast. Lead isotopic compositions of Duffys Forest wildfire ash demonstrate that anthropogenic inputs from legacy leaded petrol depositions were the predominant source of contamination. Despite the cessation of leaded petrol use in Australia in 2002, historic petrol Pb deposits continue to be a substantial source of contamination in ash: petrol Pb contributed 35% of the Pb in the Woy Woy ash, 73% in Duffys Forest ash, 39% in Forcett ash and 5% in Cherryville ash. The remobilisation of legacy industrial Pb depositions by wildfires in ash results in it being a persistent and problematic contaminant in contemporary environmental systems because of its known toxicity.

Velocity Dynamics Effect on Partial Deposition of Lead of Heterogeneous Coarse Formation Applying Predictive Model

Velocity Dynamics Effect on Partial Deposition of Lead of Heterogeneous Coarse Formation Applying Predictive Model

Dampak Pencemaran Aktivitas Kendaraan Bermotor terhadap Kandungan Timbal (Pb) dalam Tanah dan Tanaman Padi

Increasing in volume and activity of motor vehicles cause to increasing in gasoline consumption and air pollutants such as lead (Pb). The lead in the ambient environment will be deposited to the soil and absorbed by plants. The study was conducted to assess the lead content in soil and rice plant at rice field at Lamongan that caused by motor vehicles activities. The motor vehicles activities along Lamongan boulevard were identified and assess to lead emission. The deposition of lead from ambient were observed to soil, and rice plant at the road side (north and south) for 100, 1000, and 2000 m, and analyzed befor and after rice planting. The Lead content in rice plants highest at north side of 100 m, while the lowest was found in rice plant south side with a distance of 2000 m. Lead content in the highest rice bean found in rice plant north side of 100 m, while the lowest was found in rice paddies south side of the road a distance of 2000 m.

Using Moss to Assess Airborne Heavy Metal Pollution in Taizhou, China.

Bryophytes act as bioindicators and bioaccumulators of metal deposition in the environment. To understand the atmospheric deposition of heavy metals (cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), and zinc (Zn)) in Taizhou, East China, samples of moss (Haplocladium microphyllum) were collected from 60 sites selected by a systematic sampling method during the summer of 2012, and the concentrations of these heavy metals were determined by inductively coupled plasma atomic emission spectroscopy (ICP-AES). The results suggested that the concentrations of these metals varied moderately among different sites, indicating a similar contamination level for each element throughout the monitoring region. The mean values under investigation were higher than those from neighboring cities, such as Wuxi, Xuzhou, and Nanjing, and much higher than those in Europe based on a 2010 survey. Significant (p < 0.01) correlations were identified among some of the heavy metals, suggesting that these originated from identical sources. There was no statistically significant correlation between Hg and all the other elements. Spatial distribution maps of the elements over the sampled territory were created using Arc-GIS 9.0. The potential ecological risk index indicated that the air was heavily polluted by Cd and Hg, and that there was a considerable potential ecological risk from all the heavy metals studied.

Evaluating the lead affinity of graphite additives in lead-acid batteries by electrochemical deposition

The improvement of lead-acid batteries with respect to charge acceptance and cycle life in partial state of charge operations due to carbon additives in negative electrodes is state of the art. However, there is still a lack of knowledge about the mechanisms which generate these enhancements. Especially the influence of the physicochemical connection between the carbon additives and the surrounding lead skeleton has not been investigated in much detail yet, but seems to play an important role. Therefore, we developed a new method for characterizing the degree of interaction between lead and carbon additives with focus on graphite materials. By potentiostatic deposition of lead on graphite electrodes, we observe a correlation between the deposition overpotential and the number density of nucleation sites. Chronoamperometry is used to calculate the number density of nucleation sites on graphite electrodes which is in accordance with microscopic observations. We found that expanded graphite exhibits a significantly higher number of nucleation sites than synthetic graphite. Finally, a correlation between this number density of nucleation sites and the integration of the graphite particles in real lead electrodes is observed. Thus, the technique can be used to predict the integration of different graphite particles into the negative active material.

Application of screen-printed carbon electrode modified with lead in stripping analysis of Cd(II)

AbstractIn the work presented, a lead film electrode was prepared in situ on a screen-printed carbon support using a reversibly deposited mediator (Zn) and applied to the determination of Cd(II) by anodic stripping voltammetry. The electrochemical method for lead film formation is based on a co-deposition of a metal of interest (Pb), with a reversibly deposited zinc mediator, followed by oxidation of zinc, with additional deposition of lead at the appropriate potential. It serves to increase the density of lead particles, promoting lead film growth, and consequently helps to improve the electrochemical properties of the electrode. This was confirmed by microscopic and voltammetric studies. The obtained detection limit of Cd(II) is equal to 6.6 × 10−9mol L−1(−1.6 V for 180 s and then −0.95 V for 5 s). The presented procedure was successfully applied to cadmium determination in Bystrzyca River water samples.

Dandelion-enriched diet of mothers alleviates lead-induced damages in liver of newborn rats.

Lead (Pb) is a highly toxic metal present in the environment. It causes disturbances of several functions, including hematologic, renal, reproductive and nervous ones. Preventive or curative use of medicinal plants against these disorders may be a promising and safe therapeutic strategy. This study evaluated the hepatic toxic effects of prenatal exposure to lead in rats and the possible protective effect of dandelion (Taraxacum officinale) added to the diet. Female rats were given a normal diet (control) or a diet enriched with dandelion (treated). In addition, lead acetate was administered to half of the rats through drinking water from the 5th day of gestation until the 14th day postpartum. Lead toxicity was evaluated in their offspring by measuring body and liver weights, plasma biochemical parameters, liver damage, as well as protein content and activities of antioxidant enzymes in the liver tissues. Lead poisoning of mothers caused lead deposition in blood and stomach of their pups as well as hepatic tissue damages. Moreover, significant decreases in liver weight and protein content were found. Lead treatment caused oxidative stress and marked changes in the activity of antioxidant enzymes. However, no damages or biochemical changes were observed in puppies from the rats co-treated with lead and dandelion. These results indicate that supplementation of pregnant and lactating rats with dandelion protects their offspring against lead poisoning, likely through reduction of oxidative stress and liver damages.

Urban Lead: Modeling Its Distribution and Effects on Children

We model the transportation of lead from the atmosphere and from the surface of the soil simultaneously at the macroscale and mesoscale to study its health effects on children in Jersey City, NJ. We conceptualize Jersey City as an open system where lead is continuously emitted from a local smelting plant and a local power plant, deposited onto the surface soil of playgrounds, and ingested by children. The model is constructed using the diffusion-advection partial differential equation in three spatial dimensions and one temporal dimension with an initial condition and boundary conditions. The model is solved using the Crank-Nicolson numerical method at the macroscale to determine the deposition of lead from the smelting plant and the local power plant and at the mesoscale to refine the amount of lead deposition for the areas considered. We then determine the health consequences for the average child using the bioaccessibility of lead from soil to children, the bioavailability of ingested lead to the circulatory system, and the biological half-life of lead isotopes in the blood. The health effects on children from lead are directly proportional to the blood lead concentration.

A 150-year isotopic record of lead deposition in Yancheng coastal wetland, China

Radioactive markers are useful in dating lead (Pb) deposition patterns from industrialization in sedimentary archives. As a well-known natural reserve in the world, Yancheng coastal wetland in Jiangsu Province is one of areas most sensitive to global sea level change and is located in the most developed and polluted region of China. Two cores were collected in Yancheng wetland in October 2013 and dated using 210Pb and 137Cs radiometric techniques. Sediments in both cores were sectioned into depth bands and examined systematically for dry bulk density, water content, magnetic susceptibility and grain-size. Multiple elements including Pb were also measured using inductively coupled plasma systems. Unsupported 210Pb activities decreased with depth in both of the two cores, and 210Pb chronologies were established (covering 150 years) using the constant rate of supply (CRS) model. The measured Pb contents ranged from 14.97 mg/kg to 29.40 mg/kg with average values of 17.17–22.79 mg/kg, and the Pb fluxes ranged from 41.70 mg/(m2·yr) to 172.70 mg/(m2·yr) with averages of 95.59–123.41 mg/(m2·yr). Temporal variations of Pb flux, enrichment factors and Pb isotopes show a gradual and continuous increase over time and clearly reflect increased emissions from anthropogenic activities in the region. The Pb isotopic compositions show that most of Pb deposition in Yancheng wetland is input from natural sources by water flows and has the same levels of Pb as in the surface sediment of the Yangtze River and the Pacific mineral aerosol. We also stress the anthropogenic Pb contribution in Yangcheng wetland sediment and the reason of our Pb isotopes not showing anthropogenic signature is likely the instability of anthropogenic Pb in high Fe/Mn oxide conditions. Therefore, more attention should be paid to current local pollution problems, and society should take action to seek a balance between economic development and environmental protection.

Studies on mathematical modeling of the leaching process in order to efficiently recover lead from the sulfate/oxide lead paste

Increasing global lead consumption has been mainly supported by the acid battery manufacturing industry. As the lead demand will continue to grow, to provide the necessary lead will require an efficient approach to recycling lead acid batteries. In this paper was performed a mathematical modeling of the process parameters for lead recovery from spent lead-acid batteries. The results of the mathematical modeling compare well with the experimental data. The experimental method applied consists in the solubilisation of the sulfate/oxide paste with sodium hydroxide solutions followed by electrolytic processing for lead recovery. The parameters taken into considerations were NaOH molarity (4M, 6M and 8M), solid/liquid ratio - S/L (1/10, 1/30 and 1/50) and temperature (40°C, 60°C and 80°C). The optimal conditions resulted by mathematical modeling of the electrolytic process of lead deposition from alkaline solutions have been established by using a second-order orthogonal program, in order to obtain a maximum efficiency of current without exceeding an imposed energy specific consumption. The optimum value for the leaching recovery efficiency, obtained through mathematical modeling, was 89.647%, with an error of δy=3.623 which leads to a maximum recovery efficiency of 86.024%. The optimum values for each variable that ensure the lead extraction efficiency equal to 89.647% are the following: 3M - NaOH, 1/35 - S/L, 70°C - temperature.

The impact of a high magnitude flood on metal pollution in a shallow subtropical estuarine embayment

Drought-breaking floods pose a risk to coastal water quality as sediments, nutrients, and pollutants stored within catchments during periods of low flow are mobilized and delivered to coastal waters within a short period of time. Here we use subtidal surface sediment surveys and sediment cores to explore the effects of the 2011 Brisbane River flood on trace metals zinc (Zn), lead (Pb), copper (Cu), nickel (Ni), chromium (Cr), manganese (Mn), and phosphorus (P) deposition in Moreton Bay, a shallow subtropical bay in eastern Australia. Concentrations of Zn, Cu, and Pb in sediments in central Moreton Bay derived from the 2011 flood were the highest yet observed in the Bay. We suggest flushing of metal rich sediments which had accumulated on the Brisbane River floodplain and in its estuary during the preceding 10 to 40years of low flows to be the primary source of this increase. This highlights the importance of intermittent high magnitude floods in tidally influenced rivers in controlling metal transport to coastal waters in subtropical regions.

Fast fabrication of superhydrophobic surfaces on Ti–6Al–4V substrates by deposition of lead

In this paper, superhydrophobic Pb surfaces on Ti–6Al–4V substrates were fabricated based on immersion method in just 30–60 s followed by subsequent low surface energy materials modification. Hierarchical micro- and nanoscale structures were generated on titanium alloy substrates when immersed in Pb(CH3COO)2 solution. Then, the as-immersed specimens were chemically modified via fluoroalkylsilane (FAS) so as to reduce the surface energy. The as-prepared superhydrophobic Pb-coated titanium alloy surfaces, including morphologies, chemical compositions, and wettability were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), Fourier transform infrared spectrophotometry (FTIR) and contact angle measurements. The results showed that the Pb coatings on Ti–6Al–4V substrates displayed good superhydrophobicity with water contact angle of 165.5° ± 2.4° and sliding angle of 4.6° ± 2.1°. Additionally, variations in micro-morphologies, surface roughness, static and dynamic water contact angles of FAS-modified Pb-coated titanium alloy surfaces with immersion time were also investigated, and the prepared superhydrophobic surfaces exhibited long-term stability in air, good self-cleaning and anti-corrosion properties.

Lead Polluted Hotspot: Environmental Implication of Unplanned Industrial Development

Abstract In Rayer Bazaar, different industries like tannery, plastic, textile, battery recycling industry etc. are increasing rapidly without considering the environmental issues and deterioration. Since chromium (Cr) pollution of this area has been widely investigated due to the presence of tannery industries, this study was focused on examining other environmental factors. Field visits and analytical results of semi-quantitative and quantitative analysis as well as three dimensional excitation emission matrix spectroscopy (3DEEM) of water, soil and vegetative tissues indicated that, the area is highly polluted in term of different environmental parameters and metal content. The extremely high lead (Pb) content of the soil (1171.7 mg/kg in summer, 2157.1 mg/kg in winter) and blackish materials of vegetative tissues (6585.6 mg/kg in summer, 1974.1 mg/kg in winter) indicates excessive lead deposition of this area that makes it a lead polluted hotspot. One of the possible sources of the extremely high lead concentration is adjacent battery recycling industry and/or other industries surrounding this area. So it is urgent to take necessary steps to find out immediate options for possible mitigation.

Nucleation and electrolytic deposition of lead on model carbon electrodes

There is a general consensus in the lead acid battery industry for the use of carbon additives as a functional component in the negative paste to boost the battery performance with regards to charge acceptance and cycle life especially for upcoming automotive and energy storage applications. Several mechanisms are discussed in the scientific literature and the affinity of the carbon surfaces to lead species seems to play a key role. With a set of experiments on model carbon electrodes we gave evidence to the fact that some carbon materials promote spontaneous nucleation of lead crystals. We propose a mechanism such that the carbon, as soon as in a lead containing environment, immobilizes some lead on its surface. Such immobilized lead acts as nucleation seed for the deposition of lead when a current is passed through the material. It is therefore possible to differentiate and select the carbon materials based on their ability to form nucleation seeds.

Lead isotope ratios in six lake sediment cores from Japan Archipelago: Historical record of trans-boundary pollution sources

Sediment cores from six lakes situated from north to south on the Japanese Archipelago were collected during 2009–2010 to investigate the hypothesis that deposition of lead (Pb) was coming from East Asia (including China, South Korea and eastern part of Russia). Accumulation rates and ages of the lake sediment were estimated by the 210Pb constant rate of supply model and 137Cs inputs to reconstruct the historical trends of Pb accumulation. Cores from four lakes located in the north and central Japan, showed clear evidence of Pb pollution with a change in the 206Pb/207Pb and 208Pb/207Pb ratios in the recent sediment as compared to the deeper sediment. Among the six studied lakes, significant inputs of anthropogenic lead emissions were observed at Lake Mikazuki (north Hokkaido in north Japan), Lake Chokai (north of Honshu), and Lake Mikuriga (central part of Honshu). Pb isotopic comparison of collected core sediment and previously reported data for wet precipitation and aerosols from different Asian regions indicate that, before 1900, Pb accumulated in these three lakes was not affected by trans-boundary sources. Lake Mikazuki started to receive Pb emissions from Russia in early 1900s, and during the last two decades, this lake has been affected by trans-boundary Pb pollution from northern China. Lake Chokai has received Pb pollutant from northern China since early 1900s until 2009, whereas for the Lake Mikuriga the major Pb contaminant was transported from southern China during the past 100years. The results of our study demonstrate that Japan Archipelago has received trans-boundary Pb emissions from different parts of East Asian region depending on location, and the major source region has changed historically.

Tracing changes in atmospheric sources of lead contamination using lead isotopic compositions in Australian red wine

Air quality data detailing changes to atmospheric composition from Australia's leaded petrol consumption is spatially and temporally limited. In order to address this data gap, wine was investigated as a potential proxy for atmospheric lead conditions. Wine spanning sixty years was collected from two wine regions proximal to the South Australian capital city, Adelaide, and analysed for lead concentration and lead and strontium isotopic composition for source apportionment. Maximum wine lead concentrations (328 μg/L) occur prior to the lead-in-air monitoring in South Australia in the later 1970s. Wine lead concentrations mirror available lead-in-air measurements and show a declining trend reflecting parallel reductions in leaded petrol emissions. Lead from petrol dominated the lead in wine (206Pb/207Pb: 1.086; 208Pb/207Pb: 2.360) until the introduction of unleaded petrol, which resulted in a shift in the wine lead isotopic composition closer to vineyard soil (206Pb/207Pb: 1.137; 208Pb/207Pb: 2.421). Current mining activities or vinification processes appear to have no impact with recent wine samples containing less than 4 μg/L of lead. This study demonstrates wine can be used to chronicle changes in environmental lead emissions and is an effective proxy for atmospherically sourced depositions of lead in the absence of air quality data.