Article
Multidisciplinary Sciences
Navashree Nagarajan, Parthasarathy Panchatcharam
Summary: Electronic waste generation is a global concern, and the management and recycling of such waste are crucial. Printed circuit boards (PCBs), containing valuable metals, can be an important resource for recovery. This study aims to develop a simple and economical method for copper recovery from waste PCBs. The combination of citric acid, acetic acid, and hydrogen peroxide was found to increase the leaching efficiency of copper. The results suggest that these organic acids can be eco-friendly alternatives to inorganic acids for waste management.
Article
Environmental Sciences
Pushpa Gautam, Arup Kumar De, Indrajit Sinha, Chhail Kumar Behera, Kamalesh Kumar Singh
Summary: This study focuses on producing copper oxide nanoparticles from discarded printed circuit boards (PCBs) to obtain a value-added nanoproduct. The synthesized nanoparticles were confirmed to be pure monoclinic CuO of size 19.23 nm without any impurity. These nanoparticles have a high specific surface area and mesoporous structure, making them suitable for photocatalytic degradation under visible light irradiation. Utilizing e-waste from PCBs to produce nanomaterials helps reduce environmental problems.
ENVIRONMENTAL RESEARCH
(2023)
Article
Engineering, Environmental
Shun-xiang Shi, Si-qi Jiang, Chun-chen Nie, Biao Li, Hong-hao Chang, Xiang-nan Zhu
Summary: This study focused on two environmentally friendly copper leaching systems, ammonia-ammonium chloride leaching system and glycine-hydrogen peroxide leaching system, revealing the factors influencing the leaching rate of copper and proposing a simple yet effective leaching kinetics model.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2022)
Article
Green & Sustainable Science & Technology
Weifeng Liu, Xiaoli Hu, Rui Jia, Duchao Zhang, Lin Chen, Tianzu Yang
Summary: This study proposed a two-stage leaching process to remove impurity metals from copper powder of waste printed circuit boards (WPCBs) and successfully achieved the separation and recovery of valuable metal resources.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Engineering, Environmental
Alireza Esmaeili, Mahdokht Arshadi, Soheila Yaghmaei
Summary: E-waste, particularly the component of computers, is rapidly increasing due to short lifespan and high consumption rates. This research focuses on bioleaching Cu, Ni, and Al from computer printed circuit boards using Penicillium simplicissimum, optimizing parameters to achieve maximum leaching efficiency. The main leaching mechanisms were acidolysis for Al and Ni, and complexoysis for Cu. Optimal conditions of 60 g/l sucrose concentration, 16 g/l pulp density, and initial pH 6 resulted in high metal leaching efficiencies. Analysis techniques such as XRD, HPLC, SEM, and FTIR confirmed the effectiveness of bioleaching process and the presence of specific compounds in CPCBs waste powder.
RESOURCES CONSERVATION AND RECYCLING
(2022)
Article
Green & Sustainable Science & Technology
Md Tasbirul Islam, Usha Iyer-Raniga
Summary: Electronic waste is growing rapidly worldwide. Recycling is an environmentally friendly waste management strategy that recovers valuable materials. In Australia, waste printed circuit boards are mainly recycled overseas. This study uses lifecycle assessment to identify the best solution for waste PCB disposal. The results suggest that integrated material and energy recovery is the best approach for waste PCB recycling in Australia.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Engineering, Environmental
Giulia Merli, Alessandro Becci, Alessia Amato, Francesca Beolchini
Summary: The work presented in this paper focuses on using ammonium thiosulfate solution to extract gold (Au), silver (Ag), and palladium (Pd) from electronic waste. Thiosulfate is a non-toxic and highly selective alternative to cyanide for extracting precious metals. The study analyzed the interactions between sodium thiosulfate, total ammonia/ammonium, precious metal concentrations, and the particle size of waste printed circuit boards (WPCBs) to optimize precious metal mobilization. The results showed that different conditions and particle sizes affected the efficiency of metal extraction.
FRONTIERS OF ENVIRONMENTAL SCIENCE & ENGINEERING
(2023)
Article
Engineering, Environmental
Ya Liu, Qingming Song, Lingen Zhang, Zhenming Xu
Summary: In this study, a simple, efficient and green approach for metals separation from Ni-Cu-Ag-Pd-Bi-Sn multi-metal system of e-waste was proposed combining mild leaching and stepwise potential-controlled electrodeposition. The leaching process was analyzed, showing the existence of Ag-Pd continuous solid solution in the alloy lowering the oxidation potential of Pd facilitating its leaching. The results indicated high purity property of Ag-Pd and Cu-Bi alloy after extraction. This process can achieve cleaner and efficient extraction of metals from multi-metal system in e-waste.
JOURNAL OF HAZARDOUS MATERIALS
(2021)
Article
Engineering, Chemical
Qiwen Xia, Hui Zhang, Kejia Liu, Jian Li, Xuxia Zhang, Yangyang Xie, Tao Qi
Summary: A clean approach was proposed to recycle copper from waste printed circuit boards using leaching, purification, and electrolysis. Ceric ammonium nitrate (CAN) was used as the leaching agent, and the leaching process followed the mixed control model with an apparent activation energy of 47.56 kJ/mol. The purified solution was used for electrolysis to produce high purity copper at the cathode and regenerate CAN.
SEPARATION AND PURIFICATION TECHNOLOGY
(2023)
Article
Engineering, Environmental
Taiyu Huang, Jie Zhu, Xiongfei Huang, Jujun Ruan, Zhenming Xu
Summary: This study investigates the distribution of precious metals in waste printed circuit boards and evaluates the economic value of recycling. Gold, silver, and palladium were detected in different parts of the boards, with gold being widely distributed and silver concentrated on the pins of electronic components. The economic value of recyclable precious metals in 1 ton of waste printed circuit boards reaches up to $2292.94, with gold contributing the most. This study highlights the economic benefits and provides guidance for the recovery of precious metals from waste printed circuit boards.
Article
Geochemistry & Geophysics
Guadalupe Martinez-Ballesteros, Jesus Leobardo Valenzuela-Garcia, Agustin Gomez-Alvarez, Martin Antonio Encinas-Romero, Flerida Adriana Mejia-Zamudio, Aaron de Jesus Rosas-Durazo
Summary: Printed circuit boards (PCBs) are valuable for metal recycling as they contain high concentrations of Cu, Zn, Ni, and Fe. In this study, optimal conditions for leaching Cu, Zn, and Ni from PCBs were determined to be 2 M sulfuric acid, 0.55 MPa oxygen pressure, and a temperature of 90 degrees C, resulting in recovery rates of greater than 90% for Zn and 98% for Cu and Ni. SEM-EDS analyses confirmed the presence of Cu, Ni, and Zn in the PCBs. These findings highlight the potential of using PCBs as a secondary resource for the recovery of copper, nickel, and zinc.
Article
Engineering, Environmental
Huan Li, Elsayed Oraby, Jacques Eksteen
Summary: The research shows that using cyanide-starved glycine solution can effectively extract precious metals from waste printed circuit boards, reducing cyanide usage significantly while maintaining good selectivity and allowing reagent recycling. Under optimized conditions, 90.1% Au, 89.4% Ag, and 70.1% Pd were extracted, along with 81.0% Cu and 15.0% Zn.
Article
Green & Sustainable Science & Technology
Weifang Chen, Yanjun Chen, Yongkai Shu, Yinan He, Jinbo Wei
Summary: The non-metallic fraction of waste printed circuit board (WPCB) was found to be valuable after metal recovery, rich in organic polymer and inorganic materials which could serve as a source of chemicals and fuel. Through pyrolysis under different conditions, solid, liquid, and gaseous products were collected and characterized, showing that the products contained phenol, alkylated phenols, CO2, CH4, and H2. Pyrolysis pathways of WPCB disintegration were proposed based on the compositions of the products.
JOURNAL OF CLEANER PRODUCTION
(2021)
Article
Engineering, Chemical
Nieves Iglesias-Gonzalez, Pablo Ramirez, Juan Lorenzo-Tallafigo, Aurora Romero-Garcia, Alfonso Mazuelos, Rafael Romero, Francisco Carranza
Summary: This study focuses on the recovery of copper from waste printed circuit boards (PCBs) using biogenic ferric sulfate at a high solid to liquid ratio. PCB parts were packed in a column and biogenic ferric was recirculated. By connecting the PCB column to a flooded packed-bed (FPB) bioreactor, the spent ferric ions were regenerated and the copper dissolution rate was greatly increased. The proposed system is simple, inexpensive, low energy consumption, eco-friendly, and effective for copper recovery from PCBs.
MINERALS ENGINEERING
(2022)
Article
Engineering, Chemical
Sonalben B. Prajapati, Alok Gautam, Shina Gautam, Zhitong Yao, Fiseha Tesfaye, Xiaoshu Lu
Summary: In this study, the thermal decomposition characteristics of waste-printed circuit boards (PCB) and cotton stalk (CS) were investigated using a thermogravimetric analyzer. The results showed that CS, as an additive, can improve the quality of bio-oil and fix bromines in the char. The FWO method was found to be more efficient in describing the degradation mechanism of solid-state reactions.
Article
Computer Science, Interdisciplinary Applications
Sathish Paulraj Gundupalli, Rishabh Shukla, Rohit Gupta, Subrata Hait, Atul Thakur
Summary: This paper discusses the importance of using robots for automated waste sorting in waste management and proposes a genetic algorithm-based method for generating optimal PAP sequence plans to optimize sorting time. Through numerical simulations and physical experiments, the algorithm's effectiveness was validated, showing a speedup of up to 4.28%, indicating that this method can significantly improve sorting performance in an MRF.
JOURNAL OF COMPUTING AND INFORMATION SCIENCE IN ENGINEERING
(2021)
Review
Environmental Sciences
Neha Parashar, Subrata Hait
Summary: During the COVID-19 pandemic, plastics have shown their dual role as both protectors of public health and pollutants of the environment, depending on proper management and responsible use.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Review
Environmental Sciences
Bhavini Saawarn, Byomkesh Mahanty, Subrata Hait, Sahid Hussain
Summary: This review consolidates the most recent data on different aspects of PFAS, such as their occurrence and prominent sources. Significant variation in PFAS concentrations globally has been observed, and conventional treatment techniques are inadequate in remediating PFAS. Innovative treatment approaches, such as a novel treatment train approach and nanofiltration combined with electrochemical degradation, have shown effectiveness in PFAS removal.
ENVIRONMENTAL RESEARCH
(2022)
Article
Green & Sustainable Science & Technology
Neha Parashar, Subrata Hait
Summary: This study evaluated the presence of microplastics (MPs) in sewage and sludge in a hybrid growth, secondary treatment-based sewage treatment plant (STP) system. Results showed the existence of MPs in both sewage and sludge, with fragments and fibers being the predominant forms. The overall removal efficacy of the studied STP was estimated to be around 80%.
JOURNAL OF CLEANER PRODUCTION
(2022)
Review
Environmental Sciences
Amber Trivedi, Anusha Vishwakarma, Bhavini Saawarn, Byomkesh Mahanty, Subrata Hait
Summary: The rapid increase in e-waste and its improper handling have negative impacts on both humans and the environment. Waste printed circuit boards (WPCBs), which contain toxic and precious metals, require efficient metal recovery for environmental protection and economic growth. Fungal biotechnology has emerged as a viable eco-friendly approach for metal extraction from WPCBs. Fungi have shown promising efficiency in metal extraction and can work in a wide pH range. However, research on fungal bioleaching for metal recovery from WPCBs is still limited.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2022)
Article
Environmental Sciences
Amber Trivedi, Subrata Hait
Summary: Recycling printed circuit boards (PCBs) in the e-waste stream is crucial for ecological protection and metal recovery. In this study, an optimization and predictive modeling approach was used to efficiently extract metals from discarded cellphone PCBs through enzymatic bioleaching. The results showed that the maximum metal extraction efficiency was achieved under the optimized conditions, and the artificial neural network (ANN) model provided more accurate predictions compared to the support vector machine (SVM) model.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2023)
Review
Environmental Sciences
Neha Parashar, Subrata Hait
Summary: This study provides a critical review of recent advances in the sampling, detection, occurrence, fate, and removal of microplastics in wastewater treatment plants (WWTPs). It highlights the variability in microplastics removal efficiency among different treatment stages and discusses the effectiveness of advanced treatment methods such as membrane bioreactors and coagulation/flocculation. The review also examines the physical and chemical characteristics of microplastics, associated toxicity, and factors affecting removal efficiency.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2023)
Article
Engineering, Environmental
Neha Parashar, Subrata Hait
Summary: This study for the first time examines and compares the abundance, characteristics, transport, and source analysis of atmospheric microplastics (MPs) in the urban and peri-urban areas of Patna city, Bihar, India. The results show higher concentrations of MPs in the urban area compared to the peri-urban area, with polyethylene terephthalate and polypropylene being the most abundant polymers. Meteorological parameters and backward trajectory analysis suggest vehicular emissions, construction activities, and waste mismanagement as potential sources of atmospheric MPs. This study highlights the importance of further research in understanding the fate, movement, and potential health hazards associated with atmospheric MPs.
JOURNAL OF HAZARDOUS MATERIALS
(2023)
Article
Engineering, Environmental
Mukesh Kumar Singh, Subrata Hait, Atul Thakur
Summary: This study presents a novel approach using hyperspectral imaging in the near-infrared range to classify different polymers in complex plastic waste streams. The method utilizes entropy and contrast stretching for image segmentation and achieves classification using a two-layer feedforward network.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2023)
Article
Engineering, Environmental
Amber Trivedi, Subrata Hait
Summary: The feasibility of the bio-Fenton process using free glucose oxidase along with the influences of initial Fe2+ concentration and mixing speed on enzymatic metal bioleaching from waste printed circuit boards (WPCBs) of mobile phones was evaluated. Results showed efficient extraction of various metals and reduced human and environmental toxicity impacts through enzyme-catalyzed oxidation during the bio-Fenton process.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2021)
Article
Engineering, Environmental
Vikash Kumar, Ruchira Rudra, Subrata Hait
Summary: The novel interpenetrating polymeric network (IPN) ion-exchange membrane demonstrated excellent performance in single-chamber microbial fuel cells (MFCs), exhibiting efficient ion conduction and improved water uptake characteristics. Optimal concentrations of A2S acid and crosslinker DVB enhanced the membrane's chemical oxygen demand removal rate and maximum power density.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2021)
Article
Engineering, Environmental
Nipoon Gupta, Amber Trivedi, Subrata Hait
Summary: The study reveals that technological advancement, rather than regulations, has a significant impact on the metal content and toxicological impacts of end-of-life mobile phones. Metal content in LCDs has tripled from basic phones (2000-2004) to smartphones (2011-2016). Some end-of-life mobile phones were found to have hazard potential due to high concentrations of Pb in TCLP leachates. Cr, Pb, and Cu were identified as posing the most significant human carcinogenic, non-carcinogenic, and ecotoxicity risks, respectively.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2021)
Proceedings Paper
Biotechnology & Applied Microbiology
Shailendra Kumar Singh, Subrata Hait
RECENT DEVELOPMENTS IN WASTE MANAGEMENT
(2020)
Article
Engineering, Environmental
Anshu Priya, Subrata Hait
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2020)
Review
Engineering, Environmental
Bhavini Saawarn, Subrata Hait
Summary: The COVID-19 pandemic has raised concerns about the presence of SARS-CoV-2 in human excreta and wastewater, impacting wastewater treatment. Research aims to understand the fate of SARS-CoV-2 in the urban water cycle and its inactivation during treatment to prevent outbreaks. Further study of WBE technique is needed for reliable information, and the inactivation of SARS-CoV-2 in WWTPs depends on operational parameters and requires assessment of the risk of viral dissemination by treated effluent in the urban water cycle.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2021)
Article
Engineering, Environmental
Xingxing Hu, Lingjie Liu, Yanmeng Bi, Lu Li, Chunsheng Qiu, Jingjie Yu, Shaopo Wang
Summary: In this study, the impact of exogenous folate on the start-up process of single-stage partial nitritation-anammox (SPNA) was evaluated using two lab-scale reactors. The results showed that folate addition can enhance nitrogen removal rate, extracellular polymeric substances production, hydrazine oxidase and dehydrogenase activity, as well as the relative abundance of Candidatus Brocadia.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2024)
Article
Engineering, Environmental
Shaocang He, Tingting Shen, Jing Sun, Haoqi Pan, Chenxu Sun, Tianpeng Li, Runyao Li, Enshan Zhang
Summary: A novel process of acid leaching neutralization was developed for the preparation of inorganic polymeric composite ferric aluminum silicate coagulant (CFAS) using solid waste coal gasification coarse slag (CGCS). The optimized preparation process was determined through single-factor experiment and the performance of CFAS was evaluated for domestic sewage treatment. The results showed that CFAS exhibited excellent coagulation ability and achieved significant removal efficiency for turbidity, ammonia nitrogen, and chemical oxygen demand.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2024)
Article
Engineering, Environmental
Kinga Szatmari, Sandor Nemeth, Alex Kummer
Summary: In this article, a resilience-based reinforcement learning approach is proposed to address the potential thermal runaway issue in batch reactors. By calculating the resilience metric for reactors and utilizing Deep Q-learning to decide when to intervene in the system, resilient-based mitigation systems can be effectively developed.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2024)
Article
Engineering, Environmental
Bingyou Jiang, Qi Yao, Mingqing Su, Jingjing Li, Kunlun Lu, Dawei Ding, Han Hong
Summary: This study investigates the inhibitory characteristics and mechanisms of ABC powder on coal powder explosion. The addition of ABC powder significantly decreases the maximum explosion pressure and can completely suppress coal dust explosions. The study also reveals the thermal decomposition characteristics and reaction kinetics of the mixed system.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2024)
Article
Engineering, Environmental
Kubilay Bayramoglu, Mustafa Nuran
Summary: This study examines the feasibility of using pyrolytic oil from waste tires as fuel in diesel engines, and evaluates its energy, exergy, and sustainability. The results indicate that pyrolytic oil has potential as a renewable fuel source with relatively high thermal efficiency.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2024)
Article
Engineering, Environmental
Xinru Duan, Yejia Lv, Jiaxing Hong, Jianzhong Wu, Jia Zhang, Yang Yue, Guangren Qian
Summary: This study successfully prepared a tube reactor with optimized catalyst formula, which showed good performance in removing dioxins and other pollutants in the experiments.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2024)
Article
Engineering, Environmental
Jiaoyang Du, Xueming Dang, Xiaorong Gan, Xin Cui, Huimin Zhao
Summary: In this study, a photocatalyst-enzyme hybrid system was constructed, which solved the issue of enzyme inactivation caused by high concentration of H2O2 through photocatalytic in-situ H2O2 production, and improved the stability and catalytic efficiency of the enzyme. The effectiveness of the system in treating phenolic EDCs was confirmed through experiments.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2024)
Article
Engineering, Environmental
Fu-Rong Xiu, Longsheng Zhan, Yingying Qi, Xinyue Lei, Jiali Wang, Haipeng Zhou, Wenting Shao
Summary: This study developed a synergetic and high-efficiency treatment of waste tantalum capacitors (WTCs) and polyvinyl chloride (PVC) using subcritical water process. The treatment significantly reduced the temperature and reaction time for metal tantalum recovery from WTCs, and improved the dechlorination efficiency of PVC. The optimized conditions resulted in 100% resin conversion efficiency of WTCs and 97.39% dechlorination efficiency of PVC. The interaction between decomposition products of WTCs and PVC produced a high level of benzoic acid.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2024)
Article
Engineering, Environmental
Bingda Li, Jiaming Song, Yuting Li, Chaoying Meng, Shuxian Wang, Linghao Zong, Honggang Ye, Yishuai Jing, Feng Teng, Peng Hu, Haibo Fan, Guangde Chen, Xin Zhao
Summary: CdPS3 nanosheets, especially those exfoliated by sodium cholate, have shown highly efficient photocatalytic degradation performance. The strong dark adsorption and dye-sensitized photocatalytic properties of CdPS3 nanosheets contribute to high degradation efficiencies of various pollutants.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2024)
Article
Engineering, Environmental
Dongxu Ouyang, Yimei Pang, Bo Liu, Zhirong Wang
Summary: This study investigates the thermal runaway features of lithium-ion cells under tunnel conditions, considering different states of charge and tunnel ceilings. The results show that the tunnel visibility is affected by the smoke generated during thermal runaway, and the shape of the tunnel ceiling influences the temperature rise differently.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2024)
