Spent lead-acid battery recycling in China - A review and sustainable analyses on mass flow of lead

Highly dispersed Ir/Fe nanoparticles anchored at nitrogen-doped activated pyrolytic carbon black as a high-performance OER catalyst for lead recovery

The use of a methanesulfonic acid (MSA) electrolytic system is recommended as a green method for hydrometallurgical recovery of metallic Pb from waste lead-acid batteries (LABs), contributing to the sustainable protection of the ecosystem. Nevertheless, the system's high energy consumption is a current issue due to the substantial overpotential of the oxygen evolution reaction (OER) and competitive anodic oxidation of Pb2+. Herein, we propose an IrFe/nitrogen-doped pyrolytic carbon black (IrFe/NCBp) composite as a novel OER catalyst for the MSA electrolytic system, which demonstrates advanced OER catalytic efficiency and selectivity for H2O oxidation. This can be ascribed to the catalyst's thoughtful design, which enhances the number and uniformity of Ir and Fe species via increasing the specific surface area and employing NCBp as a sustainable substrate. The optimized IrFe/NCBp composite exhibits superior OER performance, with a low 252 mV@10 mA cm-2 overpotential and a 62 mV dec-1 Tafel slope, and excellent durability in a 1 M MSA electrolyte for 30 h operation compared to commercial Ir/C. In contrast to carbon paper (CP) and commercial Ir/C anodes, the anodic reaction of IrFe/NCBp is primarily OER-driven (97%) in 1 M MSA and 0.2 M Pb2+ electrolyte for Pb recovery. This effectively circumvents the high potential oxidation of Pb2+ into PbO2, reducing the electrolytic voltage to 488 kWh for the recovery of 1 ton Pb metal. This work provides a green, low-carbon footprint solution for the MSA electrolytic system, thereby promoting the commercialization of the hydrometallurgical Pb recovery.

Design and simulation of a cross-regional collaborative recycling system for secondary resources: A case of lead-acid batteries

In emerging economies, a significant amount of secondary resources are recycled by the informal sector, which can seriously harm the environment. However, some previous studies of industry management policy design ignored geographical factors. This paper introduces Geographic Information Systems into an agent-based cross-regional recycling model, and employs lead-acid batteries as an example. The model quantitatively displays the evolution of recycling markets in 31 provinces in Mainland China. Results show that: (1) High subsidies can significantly increase the number of formal enterprises in the short term, but their effectiveness decreases when the proportion of government funds in subsidies is above 80% in the long run; (2) The number of illegal recycling enterprises increases by 294% in eight inland provinces (e.g., Ningxia, Xinjiang) when all funds are invested in supervision, but this number is quite small in subsidy policy scenarios; (3) In four eastern regions, including Beijing and Tianjin, the number of illegal recycling enterprises decreases by 84% if supervision is more favored than subsidy; (4) In the optimal case where spatiotemporal factors are considered in all 31 regions, illegal recycling enterprises and waste lead emissions can be reduced by 95.59% and 45.85% nationwide. Our proposed recycling model offers a detailed simulation of multiple regions and diverse stakeholders, and serves as a useful reference for targeted recovery policies. Governments in inland regions like Ningxia and Xinjiang should implement subsidy policies, while supervision policies should be implemented in developed regions like Beijing and Tianjin.

In situ detection of reactive oxygen species spontaneously generated on lead acid battery anodes: a pathway for degradation and self-discharge at open circuit

Prospects for refurbishing and recycling energy storage technologies such as lead acid batteries (LABs) prompt a better understanding of their failure mechanisms. LABs suffer from a high self-discharge rate accompanied by deleterious hard sulfation processes which dramatically decrease cyclability. Furthermore, the evolution of H2, CO, and CO2 also poses safety risks. Despite the maturity of LAB technologies, the mechanisms behind these degradation phenomena have not been well established, thus hindering attempts to extend the cycle life of LABs in a sustainable manner. Here, we investigate the effect of the oxygen reduction reaction (ORR) on the sulfation of LAB anodes under open circuit (OC). For the first time, we found that the sulfation reaction is significantly enhanced in the presence of oxygen. Interestingly, we also report the formation of reactive oxygen species (ROS) during this process, known to hamper cycle life of batteries via corrosion. Electron spin resonance (ESR) and in situ scanning electrochemical microscopy (SECM) unambiguously demonstrated the presence of OH˙ and of H2O2 as the products of spontaneous ORR on LAB anodes. High temporal resolution SECM measurements of the hydrogen evolution reaction (HER) during LAB anode corrosion displayed a stochastic nature, highlighting the value of the in situ experiment. Balancing the ORR and HER prompts self-discharge while reaction of the carbon additives with highly oxidizing ROS may explain previously reported parasitic reactions generating CO and CO2. This degradation mode implicating ROS and battery corrosion impacts the design, operation, and recycling of LABs as well as upcoming chemistries involving the ORR.

Environmental risk assessment near a typical spent lead-acid battery recycling factory in China

In recent years, environmental pollution and public health incidents caused by the recycling of spent lead-acid batteries (LABs) has becoming more frequent, posing potential risk to both the ecological environment and human health. Accurately assessing the environmental risk associated with the recycling of spent LABs is a prerequisite for achieving pollution control. In this study, a spent LABs recycling factory in Chongqing was investigated through on-site investigation, sample analysis. Exposure assessment and health risk assessment were also conducted. The results showed that: firstly, Pb and As concentrations exceeding the standard limit values were found in the environmental air and vegetables near the spent LABs recycling factory. Secondly, exposure assessment results showed that total average daily exposure to hazardous substances for children (3.46 × 10-2 mg/kg) is higher than for adults (4.80 × 10-2 mg/kg). The main exposure pathways for Pb, Cr, Ni, Cu, Zn, and Hg are ingestion of vegetables, while those for Cd, As, and Sb are through inhalation. Thirdly, health risk assessment results indicate that environmental exposure poses unacceptable non-carcinogenic and carcinogenic risk to both adults and children near the spent LABs recycling factory, with children facing higher risk than adults. Pb and As are the main contributors to non-carcinogenic risk, and Ni and As are the main contributors to unacceptable carcinogenic risk. In particular, As, has a greater contribution to total carcinogenic risk index through inhalation than vegetable ingestion. Overall, vegetable ingestion and inhalation are the main exposure pathways for non-carcinogenic and carcinogenic risk. Consequently, future risk assessment should focus on the impact of hazardous substances on children, as well as the health risk associated with ingestion of vegetables and inhalation. Our findings will provide basic information for proposing measures of environmental risk prevention during the recycling of spent LABs, for example, controlling of As in exhaust gas emissions.

Preparation of NH4Cl-Modified Carbon Materials via High-Temperature Calcination and Their Application in the Negative Electrode of Lead-Carbon Batteries

The performance of lead-acid batteries could be significantly increased by incorporating carbon materials into the negative electrodes. In this study, a modified carbon material developed via a simple high-temperature calcination method was employed as a negative electrode additive, and we have named it as follows: N-doped chitosan-derived carbon (NCC). The performance of this material was compared with a control battery containing activated carbon (AC). X-ray diffraction (XRD), scanning electron microscopy (SEM) and Raman spectroscopy were engaged in analyzing the crystal structure and morphology of the material. Afterwards, the electrochemical and battery performance was examined through cyclic voltammetry (CV), linear voltammetry (LSV) and constant current charge-discharge testing. Markedly, the electrode plate containing 1 wt.% NCC indicates the highest specific capacity (106.48 F g^-1) as compared to the control battery, which is 1.56 times higher than the AC electrode plate and 4.75 times higher than the blank electrode plate. The linear voltammetry shows that the hydrogen precipitation current density of the 1 wt.% NCC electrode plate is only -0.028 A cm^-2, a much higher value than that of the AC electrode plate. In addition, the simulated battery containing 1 wt.% NCC has a cycle life of 4324 cycles, which is 2.36 times longer than that of the same amount of additive AC battery (1834 cycles) and 5.34 times longer than that of the blank battery (809 cycles). In summary, NCC carbon has the advantage of extending the life of lead-acid batteries, rendering it a promising candidate for lead-acid battery additives.

Novel PbO@C composite material directly derived from spent lead-acid batteries by one-step spray pyrolysis process

A one-step spray pyrolysis process is investigated for the first time in the field of spent lead-acid batteries (LABs) recycling. The spent lead paste that derived from spent LAB is desulfurized and then leached to generate the lead acetate (Pb(Ac)₂) solution, which is then sprayed directly into a tube furnace to prepare the lead oxide (PbO) product by pyrolysis. The low-impurity lead oxide product (9 mg/kg Fe and 1 mg/kg Ba) is obtained under the optimized conditions (the temperature of 700 °C, the pumping rate of 50 L/h, and the spray rate of 0.5 mL/min). The major crystalline phases of the synthesized products are identified to be α-PbO and β-PbO. In the spray pyrolysis process, Pb(Ac)₂ droplets are sequentially transformed into various intermediate products: H₂O(g)@Pb(Ac)₂ solution, Pb(Ac)₂ crystals@PbO, and the final PbO@C product. Owning its carbon skeleton structure, the recovered PbO@C product (carbon content of 0.14%) shows better performance than the commercial ball-milled lead oxide powder in battery tests, with higher initial capacity and better cycling stability. This study could provide a strategy for the short-route recovery of spent LABs.

A STEEP based hybrid multi-criteria decision making model for the evaluation of battery recycling plant location

Purpose

Increased demand for new batteries and strict government protocols have stressed the battery industries to collect and recycle used batteries for economic and environmental benefits. This scenario has forced the battery industries to collect used batteries and establish the formal battery recycling plant (BRP) for effective recycling. The starting of BRP includes several strategic decisions, one of the most critical decisions encountered is to find the best sustainable location for BRP. Hence, this paper aims to address the complexity of the issues faced during the BRP location selection through a hybrid framework.

Design/methodology/approach

In this study, the criteria are identified under socio-cultural, technical, environmental, economic and policy and legal (STEEP) dimensions through literature review and experts' opinions. Then, the hybrid methodology integrating fuzzy decision making trial and evaluation laboratory (DEMATEL), best worst method (BWM) and technique for order preference by similarity to an ideal solution (TOPSIS) has been proposed to find the inter-relationship between criteria, the weights of criteria and the best alternative.

Findings

The identified five main criteria and 26 sub-criteria have been analyzed through fuzzy DEMATEL, and found that the policy and legal criteria have more inter-relationship with other criteria. Then from BWM results, it is found that the support from government bodies has attained the maximum weightage. Finally, the second alternative has been identified as a more suitable location for establishing BRP using TOPSIS. Further, it is found from the results that the support from government bodies, the impact of emissions, availability of basic facilities and community health are the essential criteria under STEEP dimensions for establishing BRP.

Originality/value

In addition to the various existing sustainable criteria, this study has also considered a set of policy and legal criteria for the evaluation of locations for BRP. Further, the hybrid MCDM method has been proposed in this study for selecting the best alternative. Thus, this study has yielded more insights to the decision-makers in choosing a sustainable location for BRP.

An Experimental Investigation of the Environmental Risk of a Metallurgical Waste Deposit

The aim of this study is to investigate the environmental risk of long-term metallurgical waste disposal. The investigated site was used for the open storage of lead and zinc waste materials originating from a lead smelter and refinery. Even after remediation was performed, the soil in the close vicinity of the metallurgical waste deposit was heavily loaded with heavy metals and arsenic. The pollutants were bound in various compounds in the form of sulfides, oxides, and chlorides, as well as complex minerals, impacting the pH values of the investigated soil, such that they varied between 2.8 for sample 6 and 7.34 for sample 8. In order to assess the environmental risk, some eight soil samples were analyzed by determining the total metal concentration by acid digestion and chemical fractionation of heavy metals using the BCR sequential extraction method. Inductively coupled plasma optical emission spectrometry (ICP-OES) was used to determine six elements (As, Cd, Cu, Pb, Zn, and Ni). Total concentrations of the elements in the tested soil samples were in the range of 3870.4–52,306.18 mg/kg for As, 2.19–49.84 mg/kg for Cd, 268.03–986.66 mg/kg for Cu, 7.34–114.67 mg/kg for Ni, 1223.13–30,339.74 mg/kg for Pb, and 58.21–8212.99 mg/kg for Zn. The ratio between the mean concentrations of the tested metals was determined in this order: As > Pb > Zn > Cu > Ni > Cd. The BCR results showed that Pb (50.7%), Zn (49.2%), and Cd (34.7%) had the highest concentrations in mobile fractions in the soil compared to the other metals. The contamination factor was very high for Pb (0.09–33.54), As (0.004–195.8), and Zn (0.14–16.06). According to the calculated index of potential environmental risk, it was confirmed that the mobility of Pb and As have a great impact on the environment.

Analysis on the Optimal Recycling Path of Chinese Lead-Acid Battery under the Extended Producer Responsibility System

The pollution control problem of discarded lead-acid batteries has become increasingly prominent in China. An extended producer responsibility system must be implemented to solve the problem of recycling and utilization of waste lead batteries. Suppose the producer assumes responsibility for the entire life cycle of lead batteries. In that case, it will effectively reduce environmental pollution caused by non-compliant disposal of waste lead batteries, reduce environmental pollution, and achieve the sustainable development of lead resources. Based on the operating mechanism of the extended responsibility system for lead-acid battery producers in China, this article considers three recycling channel structures: recycling only by manufacturers (mode M), recycling by the union (mode R), and third-party recycling (mode C). This article comprehensively compares the differences between the three recycling channels. The research results show that: (1) under the EPR system, the choice of production companies is affected by the recovery rate and profit rate. (2) By comparing different recycling channel models, we found that the recovery rate of independent recycling by the manufacturer is the largest. Still, the profit rate of the manufacturer that entrusts the alliance (M) to recycle is the highest. The manufacturer can entrust to alliance or independent recycling of waste lead batteries according to the different profit rates and recovery rates. (3) From the perspective of the supply chain, independent recycling (M) by production companies or recycling (R) by the commissioned union may be the best. The choice of recycling channels for producers depends on independent recycling and commissioning alliance’ recycling costs and reuse costs.

Exploration of hydrated lithium manganese oxide with a nanoribbon structure as cathodes in aqueous lithium ion and magnesium ion batteries

Aqueous lithium/magnesium ion battery was assembled with Li0.21MnO2·H2O (LMO) as the cathode and VO2 as the anode.

Advances in the Functional Nucleic Acid Biosensors for Detection of Lead Ions

Lead ions (Pb²⁺) are destructive to the natural environment and public health, so the efficient detection of Pb²⁺ is particularly important. Although the instrumental analysis methods have high accuracy, they require high cost and precise operation, which limits their wide application. Therefore, many strategies have been extensively studied for detecting Pb²⁺ by biosensors. Functional nucleic acids have become an efficient tool in this field. This review focuses on the recent biosensors of detecting Pb²⁺ based on functional nucleic acids from 2010 to 2020, in which DNAzyme, DNA G-quadruplex and aptamer will be introduced. The biosensors are divided into three categories that colorimetric, fluorometric and electrochemical biosensors according to the different reported signals. The action mechanism and detection effect of each biosensor are explained. Finally, the present situation of nucleic acid biosensor for the detection of Pb²⁺ is summarized and the future research direction is prospected.

Novel recycling of incinerated sewage sludge ash (ISSA) and waste bentonite as ceramsite for Pb-containing wastewater treatment: Performance and mechanism

With rapid economic growth and urbanisation, the reuse and recycling of solid wastes has become a high priority for the sustainable development of modern cities. In this study, two typical solid wastes, incinerated sewage sludge ash (ISSA) and waste bentonite, were co-valorised to produce granular adsorbents through a simple and energy-saving pelletisation/sintering process. A mixture of ISSA and bentonite at a weight ratio of 3:1 was pelletised and sintered at 700 °C. The resultant ceramsite, with good mechanical strength, could effectively remove Pb(Ⅱ) from aqueous solutions. The adsorption kinetics can be described by the pseudo-first-order (PFO) model. The results indicated that the Pb(Ⅱ) adsorption process was dominated by electrostatic attraction, precipitation, and complexation. The isothermal data exhibited a good correlation with the Freundlich model, indicating that the adsorption process was non-ideal and spontaneous. The maximum adsorption capacity was approximately 21.6 ± 0.35 mg/g at 318 K. After 5 cycles of regeneration, the adsorbent maintained good adsorption performance. Moreover, the removal rate was not greatly affected by ionic strength. These findings demonstrate that the granular adsorbent prepared with ISSA and waste bentonite can be recognised as a promising adsorbent for Pb-containing wastewater treatment.

Design and simulation of a secondary resource recycling system: A case study of lead-acid batteries

The recycling of secondary resources is complicated as consumers, recyclers and governments are all involved in this process. In developing countries, compared to legal recyclers, illegal recyclers not only have cost advantages but also create serious pollution. Inappropriate management policies may cause disorder in the recycling market or inefficient fiscal management. This paper takes China's lead-acid batteries (LABs) from 2000 to 2015 as an example to construct a model of a secondary resource recovery system based on heterogeneous groups and analyzes the environmental and economic impacts of used LAB recycling. By simulating the implementation of different tax cuts, subsidies and regulatory policies by the government in each year, we observe the overall environmental impact of the recycling industry. This study finds that when the total amount of government expenditures is limited, the optimal policy combination emphasizes tax reduction and subsidy policies during the growth period of the recycling industry and uses more funds for supervision in the mature period. Under the balance of fiscal revenues and expenditures, the optimal policy combination can reduce the number of illegal recycling companies and waste lead emissions from the recycling market by 97.9% and 45.8%, respectively. Compared to research conducted using mathematical models and system dynamics models, this result is more in line with the actual situation, and the content is more intuitive. The government needs to adopt different policy combinations in different periods according to the state of the recycling market so that the recycling of secondary resources can achieve the optimal effect.

Naturally growing grimmiaceae family mosses as passive biomonitors of heavy metals pollution in urban-industrial atmospheres from the Bilbao Metropolitan area

In analytical chemistry, biomonitoring is known as the methodology, which consider the use of living organisms to monitor and assess the impact of different contaminants in a known area. This type of monitoring is a relatively inexpensive method and easy to implement, being a viable alternative to be developed in sites where there is no infrastructure/instruments for a convenctional air quality monitoring. These organisms, having the capability to monitor the pollution, are also known as passive biomonitors (PBs), since they are able to identify possible contamination sources without the need of any additional tool. In this work, a multianalytical methodology was applied to verify the usefulness of naturally growing Grimmia genus mosses as PBs of atmospheric heavy metals pollution. Once mosses were identified according to their morphology and taxonomy, thei ability to accumulate particulate matter (PM) was determined by SEM. EDS coupled to SEM also allowed to identify the main metallic particles deposited and finally, an acid digestion of the mosses and a subsequent ICP-MS study define more precisely the levels of metals accumulated on each collected moss. The study was focused on six sampling locations from the Bilbao Metropolitan area (Biscay, Basque Country, north of Spain). The experimental evidences obtained allowed to propose naturally growing Grimmia genus as PB of atmospheric heavy metals pollution and to identify the anthropogenic sources that contribute to the emission of the airborne particulate matter rich in metals, evaluating in this sense the atmospheric heavy metals pollution of the selected locations.

Comparative analysis of internal and external characteristics of lead-acid battery and lithium-ion battery systems based on composite flow analysis

Due to human's diversified requirements and the constraints of external environmental factors, lead-acid batteries and lithium-ion batteries coexist and compete with each other now. However, the difference of internal and external characteristics between the two battery systems is unknown. Based on the analysis of the internal flows and its impact on the external environment, this research established a framework for the relationship between the battery system and the external systems. The internal and external evaluation index system was developed. The external influence results of the two systems in China mainland at 2016 show that when the amount of social service provided by lead-acid battery system (LABS) was 1.6 times more than that of lithium-ion battery system (LIBS), the consumed lead ore was 52 times more than the lithium ore; the total energy consumption of the systems was 23.12 million tce, and that of the LABS accounted for about 63%; waste lead emissions was 2.7 million tons, and the waste lithium emissions was 40,900 tons lithium carbonate equivalent (LCE); the total economic outcomes were 220.23 billion yuan, and the proportion of that in LABS was about 44.4%. The recycle rates of LABS and LIBS were 0.368 and 0, respectively; the energy density of the LIB was 4.4 times of that in LAB; the "price" of the lithium in lithium ore and LIB were about 12 times and 3 times of that in LAB. The management suggestions on sustainable development were put forward from the aspects of waste recycling, product structure in the application field and product performance. What's more, future plan was discussed for the sustainable development.

Multi-Criteria Evaluation of Best Available Treatment Technology for Waste Lead-Acid Battery: The Case of China

Improper waste lead-acid battery (LAB) disposal not only damages the environment, but also leads to potential safety hazards. Given that waste best available treatment technology (BATT) plays a major role in environmental protection, pertinent research has largely focused on evaluating typical recycling technologies and recommending the BATT for waste LABs. First the evaluation indicators were selected based on the analysis of main factors affecting the pollution control of waste LAB treatment. The relative weights of each indicator were determined via the Delphi-attribute hierarchy model (AHM) in the second step. To determine the BATT, the attributive mathematics theory was adopted to calculate the attribute measure of single and multiple indices. Then, five recycling technologies commonly used in the secondary lead industry were estimated using the proposed evaluation system, and the feasibility of the recommended BATT was preliminarily verified. The results indicated that mixed smelting technology (MST), pre-desulfurization and multi-chamber smelting technology (PD-MCST), and direct smelting technology (DST) were found to perform well and were therefore deemed optimal for waste LAB disposal at this stage. The validation study showed that the DST can meet the requirements of pollution control, which is consistent with the evaluation results.

Historical evolution of lead-acid battery system and its relationship with external environment based on the composite flow

The quantitative demand for composite flow of lead-acid battery (LAB) system varies with the requirement from human and affects the external environment. A framework with four stages [production of primary lead (PPL), fabrication and manufacturing (F&M), use and waste management and recycling (WMR)] and the external dynamic evaluating system was developed. The historical evolution characteristics of the system in the Chinese mainland from 1990 to 2016 was investigated. For material aspect, the consumption of secondary lead increased faster. All lead ore was consumed in PPL and reduced by the average rate 1.2%. The total lead emissions declined before they increased, that in F&M reduced the most with the average rate 29%; the share of scrap lead in waste LAB was vital, 63%-75%. For energy aspect, the energy consumption in WMR grew faster. And the external performance of energy flow grew, that in PPL reduced the fastest with the average rate 31%, and the share of that in use was approximately 80%. For value aspect, the value of lead in LABs increased faster. The influence from the value flow grew negatively. The index of WMR increased the positively and fastest by average rate 85%, and its proportion of use was largest, about 313%. The evolution of the key internal factors was analyzed, which have a great influence on the system. The overall change of large recycling rate, intermediate recycling rate and lead emissions rate of WMR grew. The lead emissions rates of F&M and PPL increased before decreasing. The reasons influencing the variation, such as policies and technologies, were analyzed.

Lead recovery from spent lead acid battery paste by hydrometallurgical conversion and thermal degradation

Spent lead paste is the main component in lead-acid batteries reaching end of life. It contains about 55% lead sulphate and 35% lead dioxide, as well as minor amounts of lead oxide. It is necessary to recycle spent lead paste with minimal pollution and low energy consumption instead of the conventional smelting method. In this study, a novel approach involving hydrometallurgical desulphurisation and thermal degradation is developed to recover lead as PbO products from spent lead acid batteries. First, the desulphurisation effects and phase compositions of products with different transforming agents were compared, and the optimum conditions using (NH₄)₂CO₃ as a transforming agent were determined. And then, the thermal degradation processes of both precursors lead carbonate and lead dioxide were investigated to prepare α-PbO, Pb₃O₄, and β-PbO products in argon and air atmospheres, respectively. Both the desulphurisation precursors and the calcination products were characterised by thermogravimetry and differential scanning calorimetry, X-ray diffraction, and scanning electron microscopy. The results showed that the lead oxide products were prepared, including α-PbO at 450°C in argon, Pb₃O₄ and β-PbO at 480°C and 620°C in air, respectively.

Microwave-absorbing properties of cathode material during reduction roasting for spent lithium-ion battery recycling

As a hazardous material to the environment and human health, spent lithium-ion batteries need to be recycled in a reasonable way. To explore the effect of microwave heating on spent lithium-ion batteries (LIBs) recycling, the microwave-absorbing properties of a spent cathode powder (LiNi_xCo_yMn_zO₂) were studied by measuring its dielectric properties from 25-900 °C at 2450 MHz under different conditions (temperature, carbon dose and apparent density). X-ray diffraction and thermogravimetric analysis (TGA) were used to study decomposition and reduction reactions in the heating process. The results indicated that the cathode material has good microwave-absorbing properties over the entire temperature range (25-900 °C), especially when mixed with carbon. As the reduction reactions proceed, the dielectric properties of the material increase rapidly from 600 °C, which means that microwave heating can promote a carbothermal reduction reaction. The effect of the carbon dose on the dielectric properties indicates that the carbothermal reduction reaction can fully occur when the carbon dose reaches 18%. Furthermore, the best microwave-absorbing performance can be achieved when the apparent density of the material is 1.41 g/cm³. These studies have established a basis for research towards the direct recovery of lithium from LIBs by microwave reduction roasting.

Simultaneous Removal of Residual Sulfate and Heavy Metals from Spent Electrolyte of Lead-Acid Battery after Precipitation and Carbonation

Spent electrolyte from lead-acid battery contains high concentrations of sulfate acid and heavy metals; therefore without proper handling, they might cause severe environmental pollution. A relatively high concentration of sulfate ions (approximately 3000 mg/L) and heavy metals still exists in the effluent even after precipitation with slaked lime and carbonation process, which need to be further processed to lower both the concentrations of sulfate and heavy metals for direct discharge. A process that involves the reduction of sulfate to sulfide with sulfate-reducing bacteria and precipitation of the excessive sulfide with Fe(OH)2 was adopted to dispose of the effluent after precipitation and carbonation for direct discharge. Thermodynamic calculations were adopted to narrow down the optimum experimental range and understand the precipitation mechanism. In the whole process, no new impurities nor ions were introduced and 99.2% of sulfate, 99.9% of sulfide, 99.1% of Ca and more than 94.6% of Pb and 99.8% of Cd were removed and the obtained effluent was safe to discharge.

Investigating Industrial Effluent Impact on Municipal Wastewater Treatment Plant in Vaal, South Africa

Industrial effluents with high concentrations of toxic heavy metals are of great concern because of their persistence and non-degradability. However, poor operation and maintenance of wastewater treatment infrastructure is a great concern in South Africa. In this study, physico-chemical parameters and heavy metals (HMs) concentration of wastewater from five different industries, Leeuwkuil wastewater treatment plant (WWTP) inflow and effluent, and Vaal River water samples were monitored between January and September 2017, to investigate the correlation between heavy metal pollution and the location of industries and ascertain the effectiveness of the municipal WWTP. Physico-chemical variables such as pH, biological oxygen demand (BOD), dissolved oxygen (DO), chemical oxygen demand (COD), total dissolved solids (TDS) and electrical conductivity (EC) exhibited both temporal and spatial variations with the values significantly higher in the industrial samples. Inductively coupled plasma optical emission spectrometry (ICP-OES) results also showed that aluminium (Al), copper (Cu), lead (Pb) and zinc (Zn) were significantly higher in industrial effluents (p < 0.05), with only Zn and Al exhibiting significant seasonal variability. Statistical correlation analysis revealed a poor correlation between physicochemical parameters and the HMs compositional quality of wastewater. However, toxic HMs (Zn, Cu and Pb) concentrations in treated wastewater from WWTP were above the permissible limits. Although the WWTP was effective in maintaining most of the wastewater parameters within South African Green drop Standards, the higher Cu, Zn, Pb and COD in its final effluent is a concern in terms of Vaal river health and biological diversity. Therefore, we recommend continuous monitoring and maintenance of the WWTPs infrastructure in the study area.

Ni-Doped magnesium manganese oxide as a cathode and its application in aqueous magnesium-ion batteries with high rate performance

Aqueous magnesium-ion batteries feature good safety and high energy density and represent promising energy storage systems.

Quantitative analysis of the material, energy and value flows of a lead-acid battery system and its external performance

The comprehensive optimization of lead-acid battery system (LABS) can promote the relationship between the development of human-socio-economic system and environment. Based on the lead anthropogenic cycle, LABS is divided into four stages: production of primary lead (PPL), fabrication and manufacture (F&M), use and waste management and recycling (WM&R). According to the relationship between LABS and external environment, a framework is developed for the coupling of composite flow (material flow, energy flow and value flow). The quantitative relations between external performance indicators (lead ore consumption, scrap lead emissions, energy consumption and increase in value) and the internal factors are established, and key factors that affect external performance and their impact level are identified. The results of Chinese LABS in 2014 indicate that the external performance of the material flow reduced as the decrease of the emission rates of PPL (γ₁), F&M (γ₂) and WM&R (γ₄) and the increase of the large recycling rate (α_τ) and production ratio. The impact level of the former three was 1.5-2.2 times higher than those of the latter two. γ₂, γ₄ and α_τ had the higher impact level on energy consumption in descending order. The impact level of the emission rates was 2.0-3.0 times higher than that of the recycling rate. γ₄, α_τ, γ₁, γ₂, in descending order, were the four higher factors that affected the increase in value, and the impact levels of the farmer two were 1.5-2.0 times higher than those of the latter two. Moreover, γ₄ and γ₂ were the factors that influenced the whole external environment greater. The decreasing order of influence degree of the above factors on the external performance indicators was increase in value, energy consumption and the external performance indicators of material flow. The impact from coupling coefficients between energy, value and material on external performance is less than the above factors.

An eco-friendly closed loop supply chain network with multi-facility allocated centralized depots for bidirectional flow in a battery manufacturing industry

Purpose

Due to the economic benefits and environmental awareness, most of the battery manufacturing industries in India are interested to redesign their existing supply chain network or to incorporate the effective closed loop supply chain network (CLSCN). The purpose of this paper is to develop CLSCN model with eco-friendly distribution network and also enhance recycling to utilize recycled lead for new battery production. The existing CLSCN model of a battery manufacturing industry considered for case study is customized for attaining economic benefit and environmental safety. Hence, single objective, multi-echelon, multi-period and multi-product CLSCN model with centralized depots (CD) is developed in this work to maximize the profit and reduce the emission of CO2 in transportation.

Design/methodology/approach

The proposed CD has the facility to store new batteries (NB), scrap batteries (SB) and lead ingot. The objective of the proposed research work is to identify potential location of CD using K-means clustering algorithm, to allocate facilities with CD using multi-facility allocation (MFA) algorithm and to minimize overall travel distance by allowing bidirectional flow of materials and products between facilities. The proposed eco-friendly CLSCN-CD model is solved using GAMS 23.5 for optimal solutions.

Findings

The performance of the proposed model is validated by comparing with existing model. The evaluation reveals that the proposed model is better than the existing model. The sensitivity analysis is demonstrated with different rate of return of SB, different proportion of recycled lead and different type of vehicles, which will help the management to take appropriate decision in the context of cost savings.

Originality/value

This research work has proposed single objective, multi echelon, multi period and multi product CLSCN-CD model in the battery manufacturing industry to maximize the profit and reduce the CO2 emission in transportation, by enhancing the bidirectional flow of materials/products between facilities of entire model.

Cleaner Recycling of Spent Lead-Acid Battery Paste and Co-Treatment of Pyrite Cinder via a Reductive Sulfur-Fixing Method for Valuable Metal Recovery and Sulfur Conservation

This study proposes a cleaner lead-acid battery (LAB) paste and pyrite cinder (PyC) recycling method without excessive generation of SO2. PyCs were employed as sulfur-fixing reagents to conserve sulfur as condensed sulfides, which prevented SO2 emissions. In this work, the phase transformation mechanisms in a PbSO4-Na2CO3-Fe3O4-C reaction system were studied in detail. Furthermore, the co-treatment of spent LAB and PyCs was conducted to determine the optimal recycling conditions and to detect the influences of different processing parameters on lead recovery and sulfur fixation. In addition, a bench-scale experiment was carried out to confirm the feasibility and reliability of this novel process. The results reveal that the products were separated into three distinct layers: slag, ferrous matte, and crude lead. 98.3% of lead and 99% of silver in the feed materials were directly enriched in crude lead. Crude lead with purity of more than 98 wt.% (weight percent) was obtained by a one-step extraction. Lead contents in the produced matte and slag were below 2.7 wt.% and 0.6 wt.%, respectively. At the same time, 99.2% total sulfur was fixed and recovered.

Market-Based Instruments for Managing Hazardous Chemicals: A Review of the Literature and Future Research Agenda

We take stock of the lessons learned from using market-based instruments in chemicals management and discuss the potential for increased use of risk-based taxation in the management of pesticides and other hazardous chemicals. Many chemical substances cause significant diffuse emissions when emitted over wide areas at individually low concentrations. These emissions are typically very difficult and costly to control. The targeted chemical may exist in many products as well as in a wide variety of end uses. However, the current regulatory instruments used are primarily bans or quantitative restrictions, which are applied to individual chemicals and for very specific uses. Policy makers in the area of chemicals management have focused almost solely on chemicals with a very steep marginal damage cost curve, leading to low use of price regulations. The growing concerns about cumulative effects and combination effects from low dose exposure from multiple chemicals can motivate a broader use of market-based instruments in chemicals management.

Evaluation of hybrid neutralization/biosorption process for zinc ions removal from automotive battery effluent by dolomite and fish scales

This work focused in the evaluation of Oreochromis niloticus fish scales (FS) as biosorbent material in the removal of Zn from a synthetic effluent based on automotive battery industry effluent and, further, a hybrid neutralization/biosorption process, aiming at a high-quality treated effluent, by a cooperative use of dolomite and FS. For this, a physicochemical and morphological characterization (i.e. SEM-EDX, FTIR, XRD, and TXRF) was performed, which helped to clarify a great heterogeneity of active sites (phosphate, carbonate, amide, and hydroxyl) on the biosorbent; also the inorganic constituents (apatites) leaching from the FS was identified. Biosorption results pointed out to a pH-dependent process due to changes in the functional group's anionic character (i.e. electrostatic interactions), where an initial pH = 3 favored the Zn uptake. Kinetic and equilibrium studies confirmed the heterogeneous surface and cooperative sorption, wherein experimental data were described by Generalized Elovich kinetic model and the favorable isotherm profile by Langmuir-Freundlich isotherm ( qmax  = 15.38 mg g^-1 and 1/n>1 ). Speciation diagram of Zn species along with the leached species demonstrated that, for the studied pH range, the biosorption was the most likely phenomena rather than precipitation. Finally, the hybrid neutralization/biosorption process showed great potential since both the Zn concentration levels and the pH reached the legislation standards (C_Zn = 4 mg L^-1; pH = 5). Hence, based on the characterization and biosorption results, a comprehensive evaluation of the involved mechanisms in such complex system helped to verify the prospective of FS biosorbent for the Zn treatment from solution, in both individual and hybrid processes.

Sustainable Treatment for Sulfate and Lead Removal from Battery Wastewater

In this study, we present a low-cost and simple method to treat spent lead–acid battery wastewater using quicklime and slaked lime. The sulfate and lead were successfully removed using the precipitation method. The structure of quicklime, slaked lime, and resultant residues were measured by X-ray diffraction. The obtained results show that the sulfate removal efficiencies were more than 97% for both quicklime and slaked lime and the lead removal efficiencies were 49% for quicklime and 53% for slaked lime in a non-carbonation process. After the carbonation step, the sulfate removal efficiencies were slightly decreased but the lead removal efficiencies were 68.4% for quicklime and 69.3% for slaked lime which were significantly increased compared with the non-carbonation process. This result suggested that quicklime, slaked lime, and carbon dioxide can be a potential candidate for the removal of sulfate and lead from industrial wastewater treatment.

Thermodynamic Simulations for Determining the Recycling Path of a Spent Lead-Acid Battery Electrolyte Sample with Ca(OH)2

By utilizing thermodynamic calculations, the possible removal path of spent lead-acid battery electrolytes was modeled. The process was divided into precipitation and carbonation processes. In the carbonation process, two scenarios were discussed, namely carbonation with and without pre-filtration of the precipitates resulted from the precipitation process. The results showed that in the precipitation process, the theoretical limit for the chemical removal of SO42− was 99.15%, while in the following carbonation process without filtration, only 69.61% of SO42− was removed due to the fact that CO2 reacts with Ca2+ ion in the solution, and thus leads to the production of CaCO3 and SO42− ions in the solution. In the carbonation process without filtration, with the increase of CO2 in the solution the removal ratio of SO42− further decreases. Thermodynamic simulation was effective in predicting the theoretical removal limits and helps in understanding and optimizing the removal process.

Comprehensive characterization on Ga (In)-bearing dust generated from semiconductor industry for effective recovery of critical metals

Gallium (indium)-bearing dust generated from semiconductor industry is an important secondary resource for critical metal recycling. However, the diverse and distinct physicochemical natures of such waste material have made its recycling less effective, e.g. low extraction rate and complex treatment procedures. This research is devoted to gaining in-depth knowledge of the physical and chemical properties of such waste, including the chemical composition, physical phases, particle size distribution and chemical-thermal properties with a series of technologies. As a consequence, the occurrence and distribution of GaN and metallic indium phases are found to be crucial to efficient metal recycling. The thermal-chemical behavior shows that continuous oxidation occurred in the air atmosphere, indicating that heat-treatment followed by acid leaching is feasible to improve their recycling efficiencies. This process is able to leach 80.35% of gallium and 95.78% of indium with one-step operation. Furthermore, different treatment strategies for the waste material are preliminarily evaluated and discussed for the aim of metal recovery. The results show that gallium can be selectively recycled with recycling rate of 89.59% using alkaline leaching. With this research, the understanding on the recyclability of different metals and possibilities of selective recovery can be improved. It provides guidelines during the stage of decision-making for critical metal recycling in order to achieve efficient resource circulation.

Identification of management strategies and generation factors for spent lead acid battery recovery plant wastes in Turkey

The recovery of spent or waste lead acid batteries is important both for the management of lead input to the environment and to meet the lead demand of the market in a more energy and cost effective manner than primary production. As an important producer of lead acid batteries for the Middle Eastern and Eastern European market, Turkey seems to meet 22%-52% of its total lead demand by waste lead acid battery recovery. In this study, the wastes from Turkish waste lead acid battery recovery plants are identified and management strategies that are both technically sufficient and economically feasible for each of these wastes are complied. Furthermore, ranges of the amount of each waste generated per mass of final lead produced in these plants are estimated. Some of the most significantly generated wastes are lead containing dusts, wash water treatment sludges and slags from smelting furnaces with generation rates between 5-250, 1-150 and 5-100 kg t^-1 of product lead, respectively. Many of these can be fed back to the recovery process inside the plants except a subset of slags that are called 'final slag' and have low (5%-6%) lead content. Final slags can either be recovered for the production of cement, road-filling materials or abrasives proven that they are in a non-leachable, stable state or should be stored at hazardous waste landfills. For improved environmental performance, newly emerging techniques that eliminate the generation of such slags are also discussed and suggested.

Cleaner Extraction of Lead from Complex Lead-Containing Wastes by Reductive Sulfur-Fixing Smelting with Low SO2 Emission

A novel and cleaner process for lead and silver recycling from multiple lead-containing wastes, e.g., lead ash, lead sludge, lead slag, and ferric sludge, by reductive sulfur-fixing smelting was proposed. In this process, coke and iron-containing wastes were employed as reductive agent and sulfur-fixing agent, respectively. A Na2CO3-Na2SO4 mixture was added as flux. The feasibility of this process was detected from thermodynamic and experimental perspectives. The influence of Fe/SiO2 and CaO/SiO2, composition of the molten salt, coke addition, smelting temperature, and smelting time on direct Pb recovery and sulfur-fixation efficiency were investigated. The optimal process conditions were determined as follows: WCoke = 15% WPb wastes, W Na 2 CO 3 / W Na 2 SO 4 = 0.7/0.3, Fe/SiO2 = 1.10, CaO/SiO2 = 0.30, smelting temperature 1200 °C, and smelting time 2 h, where W represents weight. Under these optimum conditions, 92.4% Pb and 98.8% Ag were directly recovered in crude lead bullion in one step treatment, and total 98.6% sulfur was fixed. The generation and emissions of SO2 can be avoided. The main phases in ferrous matte obtained were FeS, NaFeS2, Fe2Zn3S5, and a little entrained Pb. The slag was a FeO-SiO2-CaO-Na2O quaternary melt.

Recovery of valuable metals from LiNi0.5Co0.2Mn0.3O2 cathode materials of spent Li-ion batteries using mild mixed acid as leachant

A novel hydrometallurgical process for recycling LiNi_0.5Co_0.2Mn_0.3O₂ cathode materials harvested from spent Li-ion batteries (LIBs) is established in this work. The cathode material LiNi_0.5Co_0.2Mn_0.3O₂ is dissolved in a mixed acid containing phosphoric acid (leaching agent) and citric acid (leaching agent and reductant). Using 0.2 M phosphoric acid and 0.4 M citric acid with a solid to liquid (S/L) ratio of 20 g/L at 90 °C for 30 min, the proposed method results in a leaching efficiency of ca. 100% for Li, 93.38% for Ni, 91.63% for Co, and 92.00% for Mn, respectively. Kinetics of the leaching process is well described by the Avrami equation. It is found that the leaching process is controlled by surface chemical reactions, and the apparent activation energies (kJ/mol) are 45.83 for Li, 83.01 for Ni, 81.38 for Co and 92.35 for Mn, respectively. With aids of various advanced characterizations methods, including UV-Vis, FT-IR and TOC, we find that there are a great deal of citrates and a small amount of dihydrogen phosphates in the mixed acid leachate. This leaching method enjoys advantages of low acid consumption, short leaching time and no need to add extra reductant.

Forecasting model to assess the potential of secondary lead production from lead acid battery scrap

Lead acid battery (LAB) scrap management is an important issue both environmentally and economically. The recovery of lead from battery scrap leads to a reduction in negative impacts of lead mining, as well as making the battery production cycle environmentally friendly. This work aims to propose a forecasting model for lead generation from LAB scrap based on time series modeling that uses data regarding after-market of batteries and new batteries produced for new cars. In order to illustrate the applicability of the new proposal, the model was applied to the Brazilian case. The main results show that at least 1% of LAB scrap from light vehicles have unknown or improper destinations; the efficiency of the recycling process in Brazil is still low, resulting in lead losses close to 4.5%; the lack of a sectorial agreement between the official battery market and the government concerning the reverse logistics of LAB scrap leads to a lack of precise data on the amount of LAB scrap generated and its final destination. Moreover, the economic importance of lead recycling and logistics of the secondary market are also discussed, with a focus on the dangers of illegal recycling.