PbSO4 Research Articles

Isolation and Identification of Lead (Pb) Solubilizing Bacteria from Automobile Waste and Its Potential for Recovery of Lead from End of Life Waste Batteries

End of life waste Lead (Pb) acid batteries are one of the largest sources of secondary lead production globally. Recycling lead by melting down used batteries is a commercial trade all over the world; but, regrettably, reprocessing lead from end of life batteries is reported for anthropogenic lead exposures causing harsh human health consequence and environmental pollution. The current research intends to isolate and identify Lead (Pb) solubilizing bacteria from automobile waste deposits from Agartala city in Tripura state of India. Scanning Electron Microscope equipped with energy-dispersive X-ray characterization of the grounded lead sample was carried out, and the micrographs demonstrated scattered structures across the matrix. The X-ray diffraction (XRD) spectrum indicates the presence of Lead Oxide (PbO), Lead dioxide (PbO2), and Lead sulfate (PbSO4) in the collected samples. A single bacterium viewing observable growth on Pb supplemented plates was isolated and its Pb recovering capability was estimated through ICP AES analysis. Molecular characterization of the bacterium was investigated using 16S rRNA sequencing along with isolated culture was taxonomically grouped as Cupriavidus sp. The genomic DNA sequences were submitted in NCBI GenBank with the accession number MG171197. In the present case of inspection, the ability of the bacterial strain to recover Pb from end life battery waste was carried out in laboratory scale on a shake flask for 20 days. The experiment conducted under optimum bioleaching parameters with initial pH 6, 5% w/v of microbial culture, 2% pulp density and 2 g/100 mL dextrose concentration at 30 °C temperature with a speed of 200 RPM resulted in 67% Pb recovery from the battery sample. This investigation emphasizes the significance of Pb recycling ability of native bacterial isolate for efficient Pb bio-recovery from end of life waste batteries.

AMORPHOUS PbSe THIN FILM PRODUCED BY CHEMICAL BATH DEPOSITION AT pH OF 5–8

Lead selenide (PbSe) thin films have been deposited on amorphous glass substrates at room temperature, using the simple chemical bath deposition technique. Lead sulfate and sodium selenosulfate were used as the source materials to obtain lead selenide films. Transmittance, absorption, optical bandgap and refractive index of the films were investigated via the UV–vis spectrum. Amorphous form was observed in the XRD pattern. The structural and optical properties of PbSe thin films produced at different pH were analyzed. SEM analysis was performed for analyzing the surface of the films. Some properties of the films were observed to vary with pH and these properties were investigated according to the change of pH, for pH values of 5–8. Optical bandgap varied with pH between 1.46[Formula: see text]eV and 1.75[Formula: see text]eV. Film thickness also changed with pH from 465[Formula: see text]nm to 1765[Formula: see text]nm.

Effect of lead sulfate on chloride ion transport properties in cementitious material

Effect of lead sulfate on chloride ion transport properties in cementitious material

Study on synthesis and application of tetrabasic lead sulfate as the positive active material additive for lead-acid batteries.

Tetrabasic lead sulfate (4BS) was used as a positive active material additive for lead-acid batteries, which affirmatively affected the performance of the battery. Herein, tetrabasic lead sulfate was synthesized from scrap lead paste that was formed through the production process of the lead-acid batteries. This solves the disposing problem of the scrap lead paste that is challenging in the production of the lead-acid batteries. Scrap lead paste was first pre-treated and the 4BS with high purity and crystalline was synthesized by sintering at the temperature of 450°C and hold time of 7 h. As demonstrated by X-ray diffraction and scanning electron microscopy test and Material Studio software calculation, the purity of synthesized 4BS is higher than 98 wt%, small particles have pillar forms and are evenly distributed. Moreover, the synthesized 4BS of 1 wt% was added to the positive lead paste and then valve-regulated lead-acid battery was made after the pasting, curing and formation processes. The effectiveness of the lead-acid batteries after adding 4BS as crystal seeds was evaluated, and the 100% charge–discharge cycle life of the new battery (523 times) was about 1.4 times higher than that of general lead-acid batteries (365 times).

Boron doped graphene nanosheets as negative electrode additive for high-performance lead-acid batteries and ultracapacitors

Sulfation at the negative electrode is one of the major failure modes of lead-acid batteries. To overcome the issues of sulfation, in this work we synthesize Boron doped graphene nanosheets as an efficient negative electrode additive for lead-acid batteries. 0.25 wt % Boron doped graphene nanosheets additive in negative electrode which contains around 3% of Boron doping shows impressive electrochemical performance in first discharge capacity, ∼60% increase the capacity in relation to the conventional lead-acid cell. Noticeably, 15–20% enhancement in the discharge capacity at lower C rates and almost double increase in capacity at higher C rates show Boron doped graphene nanosheets as a potential additive for lead-acid battery operating under high rate partial state of charge applications. The superior electrochemical performance is due to the p-type or hole conductivity of the Boron doped graphene lattice, which reduces lead sulfate formation and thereby enhances active material utilization, charge acceptance, and reduces hydrogen evolution. Besides, the high C-rate performance of Boron doped graphene nanosheets additive cell is due to the capacitive property of Boron-doped graphene nanosheets which delivers specific capacitance of 90 F g−1 at 2 A g−1 with >75% capacity retention at the end of 2000 cycles.

Leaching Behavior of Lead and Silver from Lead Sulfate Hazardous Residues in NaCl-CaCl2-NaClO3 Media

The leaching behavior of lead and silver from lead sulfate residues in NaCl-CaCl2-NaClO3 media was studied systematically. The results indicate that Cl− concentration, NaClO3 concentration, leaching time and temperature had significant effects on lead and silver leaching, whilst agitation speed and the liquid–solid ratio had a secondary effect on silver leaching but little effect on lead leaching. The Ca2+ concentration had an important effect on $$ {\text{SO}}_{4}^{2 - } $$ removal but little effect on lead and silver leaching. The optimum parameters for lead and silver leaching were: initial Cl− concentration: 207.5 g/L; NaClO3 concentration: 12 g/L; Ca2+ concentration: 1.3 times of stoichiometric quantity; temperature: 90 ± 2 °C; time: 1 h; liquid–solid ratio: 8:1–10:1; and agitation speed: 450 rpm. The lead and silver leaching were > 98% and 95%, respectively. The removal ratio of $$ {\text{SO}}_{4}^{2 - } $$ was > 98%. The leaching kinetics of lead follow the shrinking core model of mixed control, and the apparent activation energy was 13.4 kJ/mol.

Inhibition of galena flotation by humic acid: Identification of the adsorption site for humic acid on moderately oxidized galena surface

The influence of humic acid on the flotation of galena under different redox conditions was studied based on micro-flotation experiment. The results showed that the humic acid was an effective inhibitor for moderately oxidized galena. Adsorption tests indicated that the surface oxidation played an incredibly important role in the adsorption of humic acid on galena surface. Explorations on identifying the mechanism for the selective adsorption of humic acid on the surface of oxidized galena were carried out by Zeta potential, XPS and FT-IR analysis. The results indicated that the oxidation of galena caused significant changes in surface components, which was beneficial to the adsorption of humic acid. The elemental sulfur formed by the oxidation of galena is one of the adsorption sites for humic acid besides lead sulfate.

Dense Post-Barite-type Polymorph of PbSO4 Anglesite at High Pressures.

Synchrotron X-ray diffraction measurements on lead sulfate have been performed up to 67 GPa using He as pressure transmitting medium. Experiments reveal the existence of a reversible pressure-induced phase transition from the initial Pnma barite-type to the P212121 post-barite-type structure at pressures above 27 GPa. This phase transition involves a volume collapse of 2.4% and requires a considerable pressure overshoot (large pressure range with coexistence of phases) to overcome the large kinetic barrier of the transition. DFT calculations confirm the experimental observations and support the hypothesis that post-barite-type phase is the thermodynamically stable high-pressure structure for ABO4 ternary oxides with large A and small B atoms. The mechanism of the phase transition is described, and the compressibility and anisotropy of both polymorphs are estimated.

Efficient and rapid removal of EDTA-chelated Pb(II) by the Fe(III)/flue gas desulfurization gypsum (FGDG) system

This study introduces the application of the Fe(III)/flue gas desulfurization gypsum (FGDG) system to remove EDTA-chelated Pb(II). Systematic experiments were conducted to explore the possibility of removing EDTA-chelated Pb(II) and the crucial factors of the removal process, as well as to determine the underlying removal mechanism. The results showed that the removal reaction was a quick process, with the removal rate exceeding 90% after 1 min. The system removed 97.35% of EDTA-chelated Pb(II), reducing its concentration from 700 mg/L to 18.81 mg/L. EDTA-chelated Pb(II) can be most effectively removed at pH 2. This system had a high removal rate from 50 mg/L to 1000 mg/L of EDTA-chelated Pb(II), particularly at 700 mg/L when the removal rate reached 97.35%. When the molar ratio of Fe(III)/Pb(II) was greater or smaller than 1:1, an inhibitory effect on removal was observed. TOC and UV–Vis analyses indicated that ferric ions replaced lead ions, resulting in the conversion of the EDTA-chelated Pb(II) to EDTA-chelated Fe(III). Surface structure, crystalline phase and elemental distribution were analyzed to explore the transformation of substances. The results indicated that FGDG coprecipitated with free lead ions to form lead sulfate. Overall, the rapid and efficient removal performance with cost-effective characteristics makes the Fe(III)/FGDG system a potentially attractive method for the removal of EDTA-chelated Pb(II)in wastewater.

Bioaccumulation, Growth and Photosynthetic Response of a New Found in Bulgaria Invasive Species Lemna minuta and L. valdiviana to Heavy Metal Pollution

ABSTRACT: Heavy metals can meet in the surrounding environment as natural ingredients or from agricultural, industrial and chemical industries. The study was conducted in order to trace the potential of the aquatic plant L. minuta and L. valdiviana for the bioaccumulation of Cu, Cd, and Pb from contaminated water at low levels of these elements. Each of the duckweed species was treated separately with CuSO4.5H2O, CdSO4, Pb SO4 (Valerus, Bulgaria) at 0.5 and 1 mg L-1 concentrations of for 96 hours. After conducting the experiments, relative growth rate (RGR), bioconcentration factor (BCF), tolerant index (Ti) and photosynthetic pigments of two Lemna species were studied. The solution with higher metal concentration more inhibits the growth of macrophytes. The BCF of the metals on the two species were in decreasing order: Cu > Pb > Cd. Our study showed that L. minuta and L. valdiviana at a concentration of 0.5 mg L-1 copper have better affected on the photosynthetic apparatus compared to the control. Better bioaccumulation ability was established in L. minuta compared to L. valdiviana.

Anodizing Pb Electrode for Synthesis of β-PbO2 Nanoparticles: Optimization of Electrochemical Parameters

Lead dioxide (PbO2) nanoparticles are electrodeposited on lead anode, using pulsed and constant direct current (DC) in 4.8 M H2SO4 solution, to improve active surface area and promote catalytic activity of lead electrode. To increase the yield of PbO2 nanoparticles, current density, temperature and time of anodization are optimized using the response surface methodology. The optimum condition is found to be 25 mA cm−2 current density, 100°C temperature and 4-hour pulsed DC and 1-hour constant current for anodizing time. To increase the yield of nano β-PbO2 from 41.62% to 99%, porosity of the lead layer is increased and the passive layer of lead sulfate is broken. For this purpose, the lead substrate is pretreated in an electrochemical bath of sulfuric acid and perchloric acid, followed by immersing the electrode in hydrofluoric and nitric acid. Formation mechanism of β-PbO2 is also identified.

Unravelling the spatial dependency of the complex solid-state chemistry of Pb in a paint micro-sample from Rembrandt's Homer using XRD-CT.

The surface of many Old Master paintings has been affected by the appearance of whitish lead-rich deposits, which are often difficult to fully characterise, thereby hindering conservation. A paint micro-sample from Rembrandt's Homer was imaged using X-ray Diffraction Computed Tomography (XRD-CT) in order to understand the evolving solid-state Pb chemistry from the painting surface and beneath. The surface crust was identified as a complex mixture of lead sulfates. From the S : Pb ratios throughout the paint layer, we can conclude that S is from an external source in the form of SO2, and that the nature of Pb-SO4 product is dependent on the degree of diffusion/absorption of SO2 into the paint layers.

Feasible Time for Extraction of Lead from Spent Paste by Pyrometallurgical Process

This paper focuses on determining the feasible time for production of lead from spent paste (SP) by pyrometallurgical process through the rotary furnace. The extraction process faces several problems due to difficulties to control reaction media conditions. The experiments had been done on rotary furnace which exists in a secondary lead smelter in Baghdad - Khan Dhary. The SP mainly consists of lead sulfate and lead oxides. The experiments are implemented at high temperatures (1300°C) for reduction and desulfurization. 20 experiments were designed to determine the feasible smelting cycle time. The weight of slag, matte, and lead bullion was determined in each experiment as well as the percent of lead in each phase. These data were analyzed and graphically represented. The reaction’s rate profile can be detailed in the following manner: (1) High rate during the first 90 smelting min. Low rate from 90 to 120 min. Very low rate after 120 min. (2) The feasible extraction time is between 120 and 130 min with average lead percent in slag not >8%. (3) The slag with lead percent higher than 5% is returned to the furnace whereas the lower one is extracted by the blast furnace.

Tracking flows of secondary vehicle batteries in China

With the increasing demand for lead acid batteries, there were a great number of spent lead acid batteries generated. They have the dual characteristics of resource and harm, making the recovery an important subject. In this paper, a novel approach to recover lead oxide from spent lead acid batteries by desulfurization and crystallization in sodium hydroxide solution after sulfation was proposed. During sulfation process, 85% sulfuric acid (17.786 g sulfuric acid per 2 g negative pastes) was the best for negative lead pastes, and the content of lead sulfate was up to 91.34%. For positive lead pastes, the optimal conditions were 85% sulfuric acid (17.786 g sulfuric acid per 2 g positive pastes) at 65 °C, and the content of lead sulfate was 95.69%. In the process of desulfurization and crystallization, the optimal parameters for the recovery ratio of lead oxide were 90 mg/L of solid-liquid ratio, 42 mL of mother liquor retention, and 8.24 mol/L of sodium hydroxide concentration. The recovery ratio and purity of lead oxide were 95.72% and 95.31% under the optimal conditions. Compared to pyrometallurgy and traditional hydrometallurgy, this novel approach greatly shortens the process flow. It reduces the energy consumption and secondary pollution, having great potential for industrial application.

Thermodynamic analysis of the bottom-blown direct reduction of lead sulfate with carbon

The thermodynamic analysis of bottom-blown direct reduction of lead sulfate with carbon was studied in this investigation, and the industrial verification test was carried out. The thermodynamic analysis results indicated that lead sulfate was easily decomposed into lead sulfide at $$P_{{{\text{SO}}_{2} }}$$ values above 10−3 atm and $$P_{{{\text{O}}_{2} }}$$ values below 10−12 atm. The lead sulfide could be converted into lead oxide or metallic lead in the decomposition of lead sulfate by the addition of Fe, FeS and CaO. The phase diagrams for the C–CaO–PbSO4 and C–Fe–PbSO4 systems were constructed at 1273–1573 K, indicating that the addition of coal, limestone and scrap iron during reduction could cause the slag chemical composition variation, which consequently changed the Pb-liq + CaS and Pb-liq + FeS zones area. The industrial verification test demonstrated that the average addition of limestone, scrap iron and coal in the direct reduction of lead paste was approximately 2.8%, 5.4% and 11.5%, respectively. The direct recovery rate of lead bullion was about 61%, and the total recovery rate of lead could reach 99%. The average content of lead, zinc and sulfur in the reduced slag was 2.42%, 1.55% and 0.51%, respectively.

Investigation of effect of sulfate ion on xanthate consumption in galena flotation based on thermodynamic diagrams

Flotation is a common process in sulfide ore beneficiation. Due to the restrictions and lack of access to high-quality water sources for industrial purposes, recycled water plays an important role in the flotation processes. Due to the existence of various organic and inorganic substances in the process, water influences the flotation performance. In this work, the effect of accumulation of sulfate ion in processed water on galena flotation was investigated. Flotation experiments using processed water without sulfate ion led to a concentrate containing 40.7% of lead and a maximum recovery of 58.9%. The presence of higher sulfate ion levels (2000 M) in processed water caused a significant decrease in the grade and recovery of the lead concentrate. With 2000 mg/L of sulfate ion, the grade and recovery of lead decreased from 40.7 to 24.3% and from 58.9 to 32.1 %, respectively. Thermodynamic calculations showed that when the sulfate ion concentration was increased from 300 to 2000 ppm, it was more likely that lead sulfate (solid) was formed. With increase in the xanthate ion concentration from 10-6 to 10-4 M, could be substituted by . On the basis of the results obtained, it was concluded that in order to reduce the negative effects of sulfate ion accumulation in water and increase the efficiency of the galena flotation process, higher dosages of xanthates should be added to the system.

Titanium dioxide-reduced graphene oxide hybrid as negative electrode additive for high performance lead-acid batteries

Abstract Sulfation at the negative electrode is one of the major failure modes of lead-acid batteries. To overcome the issues of sulfation, we herein report solvothermal synthesis of titanium dioxide- reduced graphene oxide hybrid as negative electrode additive in lead acid cell. The presence of titanium dioxide-reduced graphene oxide hybrid additive (0.5 wt. %) provides high interfacial stability, slows down hard sulfation, high active material utilization by occupying pores on the negative plate. 0.5 wt. % of titanium dioxide-reduced graphene oxide hybrid (3:1 wt. ratio) additive to the negative active mass delivers 85% increase in capacity during the first formation cycle, and thereby increases the formation efficiency from 3 cycles to 1 cycle; >20% and ∼200% increase in capacity at low discharge rates of C/20 and high rates of discharge (2C), respectively as compare to conventional lead acid cell. Besides, 3:1 wt. ratio titanium dioxide-reduced graphene oxide hybrid additive cells show ∼200% increase in high rate partial state of charge cycle life in relation to conventional cell. Titanium dioxide-reduced graphene oxide hybrid additives to the negative active mass provides increase in conductivity, controls the crystallization of lead sulphate growth, acts as a capacitor, decreases the hydrogen evolution and hence enhances the electrochemical performance.

Role of pH on the adsorption of xanthate and dithiophosphinate onto galena

ABSTRACTIn the concentrators of a Mexican mining company has been observed that the pH of the flotation has a significant effect on the galena recovery: the increase of pH from 7.5 to 9.5 in the Pb/Cu flotation circuit, resulted in a decrease of about 10% of lead recovery. In the present investigation, experimental models and techniques were developed to study the effect of pH on xanthate and di-isobutyl dithiophosphinate adsorption onto galena. The results obtained by UV / Vis spectroscopy showed that once galena surface has been slightly oxidised by the dissolved oxygen of the aqueous suspension, adsorption of both surfactants increases significantly, being adversely affected by the increase of pH from 5.5 to 9.5. Microflotation measurements performed for both surfactants support these findings. Thermodynamic simulation of the system suggests that the observed behaviour is due to the nature of the solid species formed on the galena surface at the particular pH: lead sulfate (PbSO4) under neutral and slightly acid conditions, and the basic sulfate (2PbO·PbSO4) under neutral and slightly alkaline conditions, as well as to their respective solubility. Infrared spectrometry confirmed the occurrence of sulfate onto galena particles, with a higher concentration for the acid pre-conditioning compared to the alkaline pre-conditioning.

Understanding the functions of carbon in the negative active-mass of the lead–acid battery: A review of progress

Abstract The addition of supplementary carbon to lead–acid batteries that are intended for use in emerging automotive duties can provide improvement in two aspects of performance. (i) In both hybrid electric and battery electric vehicles that are designed to preserve energy through the operation of regenerative-braking, conventional lead–acid batteries exhibit a rapid decline in the efficiency of the recuperative charging (which can involve rates up to 30C1) and fail quickly as a result of an accumulation of lead sulfate on the negative plate. It has been widely reported that supplementary carbon — either intimately mixed with the negative active-material or included as a separate component attached to the plate — can enhance charge-acceptance. (ii) Full-hybrid electric and battery electric vehicles employ high-voltage batteries composed of large numbers of cells connected in series. Consequently, when conventional lead–acid batteries are used in such configurations, the continuous cycling encountered in normal driving will almost certainly lead to divergence in the states-of-charge of the unit cells and thereby demand periodic equalization charges. In this application, it has been demonstrated that lead–acid batteries with supplementary carbon incorporated into the negative plate are rendered immune to the divergence problem and therefore operate without the need for an equalization charge. The inclusion of supplementary carbon does, however, promote hydrogen evolution and failure due to the loss of water from the electrolyte solution. Current research efforts are directed towards methods by which this disadvantage can be mitigated without losing the benefits that the addition of carbon provides. This review covers the extensive research that has been conducted to understand the mechanism by which the additional carbon operates, the additional studies that have sought to identify the best types and optimum amounts of carbon that should be used, together with the most effective manner for their deployment.

Nano Structured Rgo - TiO2 Composite As Negative Electrode Additive for High Performance Lead Acid Batteries

Lead acid batteries (LAB) continues to be the major energy storage system for variety of applications such as stationary, uninterruptible power supplies, telecommunications, automotive and even in hybrid and electric vehicles. Besides, LABs are of low cost, >98 % recycling, safety, high abundance of the materials. In spite of being randomly optimized its various aspects in the past, lead acid battery researchers are still facing major challenges of sulfation at the both positive and negative plates. Besides, positive electrode grid corrosion, longer curing as well as formation time of the positive plate and also its low energy density because of high atomic weight of lead (Pb) limits its application [1]. Besides, the major issue of negative plate operating under partial-state-of-charge (PSoC) conditions are sulfation and low charge acceptance. PSoC can quickly diminish the overall life of a battery, which results in frequent, costly battery replacements. So the current research in LAB is directed to achieve high energy density, long-cycle life and to reduce sulfation [2-3]. Different forms of carbon (such as graphene, graphite, carbon nanotubes etc.) additives to the negative active mass (NAM) was used to decrease the lead sulfate formation, increase the conductivity of negative active material by forming conductive network with lead sulfate crystals. Beside carbon acts as a capacitor. This capacitive property of carbon is useful in charge-discharge operations conditions at high rate to provide high voltage [4-5]. In this work we present reduced graphene oxide (rGO) - TiO2 as an ideal additive for advanced LABs operating under HRPSoC conditions. Nano structured TiO2 grown (decorated) on reduced graphene oxide (rGO-TiO2) has been successfully synthesized from the solvothermal method. Optimized 0.5 wt. % of rGO-TiO2 employed as NAM additive to enhance the initial discharge capacity, decreases the hard sulfation, improves the charge acceptance and more utilization of the NAM. Addition of 0.5 wt. % of rGO - TiO2 to the NAM in composition of rGO: TiO2 is 1:10 and 1:3 (Hereafter rGO-TiO2-1:10, 1:3) delivers > 67% and 85 % increase in capacity during the first formation cycle compared to conventional lead-acid cell (LAC). The rGO - TiO2 additive based cells are formed in one cycle whereas conventional electrode takes about 3 cycles to achieve the full capacity. 0.5 wt. % of rGO - TiO2 additive LAC delivers 20% more capacity compared to the conventional cell at all C-rates (C/20 to 2C). Presence of rGO in the negative plate to increases the charge acceptance of the cell. Cycling study was performed on 2V/2.1 Ah conventional and 0.5 wt. % of rGO, TiO2, and rGO-TiO2 (1:100, 1:10, 1:3) additive cell at 1C rate shows an increase in capacity of about 40% was observed with rGO - TiO2 additive based cells as compared to conventional cells. This could be due to the reversibility of PbSO4 to lead. As cycling progresses at the 1C rate, conventional cell has poor capacity retention due to the formation of PbSO4 at the negative plate and does not convert into the active material (Pb). It leads to the early evolution of hydrogen at the negative plate and rapidly decreases the capacity. Significant amount of RGO in the active material shows the capacitive phenomenon. During high rate charging, charging occurs at electrical double layer of the surface of the rGO. Besides addition of rGO - TiO2 in NAM could limit the sulfation of negative plates, due to the high porosity of RGO which could acts as an electrolyte reservoirs in the interior of the negative plates. This helps the active sites for the migration of PbSO4 to Pb during charge and inhibition of PbSO4 during cycling. Beside, TiO2 Nano particles occupies the pores of the active mass and also supplies electrolyte to the bulk. The combination of both rGO and TiO2 in the active mass helps to improve more active material utilization of NAM during 1C rate cycling. HRPSoC cycling increases to 22630 cycles for rGO-TiO2 additive cell compared to the 7614 cycles of conventional LAC. Acknowledgements: Financial support for this project work from Clean Energy Research Initiative (CERI) under Department of Science and Technology (DST), Govt. of India (Project Code: DST/TM/CERI/C141) gratefully acknowledged.