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Biocyanidation is an environment-friendly technology for recovering precious metals from waste printed circuit boards (WPCBs). Although the leaching mechanism has been studied a lot, Au-release behavior still remains unknown. In this paper, density functional theory (DFT) was employed to investigate the electronic structure of the complex existing in the Au cyanidation process. Extended charge decomposition analysis (ECDA) showed that the adsorption of CN– to Au and the adsorption of O to the formed [AuCN]⁻ caused net electron transfer of 0.356 and 0.574 au, respectively. Dissociation of O from [AuCNO]⁻ had a Gibbs free energy change of −154.229 kcal/mol. Electron localization function (ELF) and localized orbital locator (LOL) confirmed that CN– covalent bonding led to a transformation of the orbit localization region of the adsorbed Au atom. It might cause electrostatic repulsion from the nondirectly contacted Au atom. This speculation was demonstrated by the Mulliken overlap population analysis, which showed that CN– bonding caused antibonding interaction. The repulsive interaction would be an important factor triggering the release of the adsorbed Au atom. This work presented a new interpretation of Au cyanidation, providing important insights into Au-release behavior. It might help construct the leaching kinetics of multimetal resources to facilitate the recovery of precious metals from waste printed circuit boards.

Polyethylene glycol terephthalate and ethylene-vinyl acetate copolymer are applied as packaging materials in solar cells. Abundant polyethylene glycol terephthalate and ethylene-vinyl acetate copol...

Highlights Small cobalt nanoparticles are carefully encapsulated into a N-doped carbon shell (Co-NC) by calcining a Prussian blue analogue precursor. The presence of cobalt nanoparticles and Co-N bonds not only promotes adsorption behavior, but also reduces the diffusion energy barrier, enabling fast diffusion kinetics of K+ ions. The good diffusion kinetics and capacitive adsorption behavior of the Co-NC material synergistically contributes to enhanced potassium storage performances. Electronic supplementary material The online version of this article (10.1007/s40820-020-00534-x) contains supplementary material, which is available to authorized users., Potassium-ion batteries (KIBs) have great potential for applications in large-scale energy storage devices. However, the larger radius of K+ leads to sluggish kinetics and inferior cycling performance, severely restricting its practical applicability. Herein, we propose a rational strategy involving a Prussian blue analogue-derived graphitized carbon anode with fast and durable potassium storage capability, which is constructed by encapsulating cobalt nanoparticles in nitrogen-doped graphitized carbon (Co-NC). Both experimental and theoretical results show that N-doping effectively promotes the uniform dispersion of cobalt nanoparticles in the carbon matrix through Co–N bonds. Moreover, the cobalt nanoparticles and strong Co–N bonds synergistically form a three-dimensional conductive network, increase the number of adsorption sites, and reduce the diffusion energy barrier, thereby facilitating the adsorption and the diffusion kinetics. These multiple effects lead to enhanced reversible capacities of 305 and 208.6 mAh g−1 after 100 and 300 cycles at 0.05 and 0.1 A g−1, respectively, demonstrating the applicability of the Co-NC anode for KIBs. Electronic supplementary material The online version of this article (10.1007/s40820-020-00534-x) contains supplementary material, which is available to authorized users.

Recycling of electronic waste (e-waste) and inevitable pollution under current technology have always been a concern of people. Generation and release of pollutants in the recycling process of e-waste are closely related to processing technology and equipment. In this paper, the pollution characteristics of different functional areas and critical processing units in formal e-waste dismantling base have been studied systematically and comprehensively. The results showed that the overall pollutants concentration in crushing workshop and cathode ray tube (CRT) monitor disposing workshop are much higher than other functional areas. Screen-cone glass separation for CRT monitor was the processing unit with the greatest exposure risk and the hazard index (HI) of Pb was 4.60. Pollutant emission factor of the main processing units was calculated and the waste printed circuit board (WPCB) crushing was the most polluted unit. Appropriate improvements in technology and equipment can effectively reduce the generation and release of pollutants. Some reasonable prospects about intelligent equipment and special technologies were proposed for e-waste disposal. All the results provided theoretical and data support for pollution control and technology upgrade of the formal e-waste dismantling base.

Waste printed circuit boards (WPCBs) are hazardous wastes but also valuable resources. Mechanical crushing is widely used to recycle WPCBs. Some pollutants are released during the crushing, but the...

Increased generation of spent lithium-ion batteries (LIBs) has driven the exploration of new methods for reusing and/or recycling LiCoO₂ cathode materials. Herein, an electrochemical relithiation method was proposed to directly regenerate LiCoO₂ cathode materials using the waste LiₓCoO₂ electrode as a base. It was shown that Li⁺ was successfully inserted into the waste LiₓCoO₂ electrode, and this relithiation process became faster with either a higher Li₂SO₄ concentration or a higher cathodic current density. The XRD analysis confirmed that the peak positions of the relithiation products were consistently close to those of a standard LiCoO₂ material. The crystal structure of the relithiation products was restored with a post-annealing process. The activation energy for electrochemical relithiation (Eₐ) was estimated at 22 kJ mol–¹, and the constant of equilibrium constant k₀ was determined as 1.35 × 10–⁶ cm s–¹. The relithiation process was controlled by the charge transfer process when the Li₂SO₄ concentration was high (e.g., 1, 0.8, and 0.5M), and a lower concentration at 0.01–0.3 M led to a diffusion control pattern. The electrode made of the regenerated LiCoO₂ materials had a charge capacity of 136 mAh g–¹, close to that of the commercial LiCoO₂ electrode (140 mAh g–¹). A potential mechanism of electrochemical relithiation was proposed involving lithium defects, relithiation, and crystal regeneration.

The effects of anion charge and lattice volume (lithium–anion bond length) on lithium ion migration have been investigated by utilizing the density functional theory calculations combined with the ...

Proper design principles are essential for the efficient development of superionic conductors. However, the existing design principles are mainly proposed from the perspective of crystal structures. In this work, the face-centered cubic (fcc) anion sublattices were creatively constructed to study the effects of anion charge and lattice volume on the stability of lithium ion occupation and lithium ion migration by the density functional theory calculations. Both the large negative anion charges and large lattice volumes would increase the relative stabilities of lithium-anion tetrahedron, making lithium ions prefer to occupy the tetrahedral sites. For a tetrahedral lithium ion migration to its adjacent tetrahedral site through an octahedral transition state, the smaller the negative anion charge is, the lower the lithium ion migration barrier will be. While for an octahedral lithium ion migration to its adjacent octahedral site through a tetrahedral transition state, the more negative anion charge is, the lower the lithium ion migration barrier will be. New design principles for developing and optimizing superionic conductors with the fcc anion sublattice were proposed. Low lithium ion migration barriers would be achieved by adjusting the non-lithium elements within the same crystal structure to obtain the desired electronegativity difference between the anion element and the non-lithium cation element.

Background: Triple-negative breast cancer (TNBC) is a heterogeneous disease. TNBC lacks targeted therapies and represents a disproportional share of the breast cancer (BC) mortality rate. Histone deacetylase inhibitors (HDACIs) are emerging as promising multifunctional agents in TNBC to elicit cytotoxic actions. Recent studies have shown that cancer cells elucidate feedback activation of leukemia inhibitory factor receptor (LIFR) which in turn curtails response to HDACIs. We developed a first-in-class inhibitor of LIFR, EC359 that directly interacts with LIFR and effectively blocks LIFR downstream signaling. Here, we examined whether the novel LIFR inhibitor, EC359, has the ability to counteract negative effects of LIFR signaling to enhance HDACIs therapeutic efficacy in the treatment of TNBC. Methods: We tested multiple HDACIs currently in clinical trials including vorinostat, panobinostat, romidepsin, and givinostat using multiple TNBC models. The effect of combination therapy of HDACIs and EC359 on TNBC cell viability and invasion was examined using MTT assays and matrigel invasion assays respectively. The efficacy of combination therapy on cell survival and apoptosis was determined using clonogenic assays and Caspase 3/7 assays, respectively. Mechanistic studies were performed using Western blotting, qRT-PCR, and reporter gene assays. The efficacy of combination therapy in vivo was examined using Xenograft, patient-derived xenograft (PDX), and patient-derived explant (PDEX) models. Results: We demonstrated that the treatment of TNBC models with HDACIs increased the expression of LIFR. Immunohistochemistry analyses of breast tumors using tissue microarrays revealed significant expression of LIFR in TNBC samples. Knockdown of LIFR or treatment with a small molecule inhibitor of LIFR (EC359) significantly enhanced the efficacy of HDACIs in reducing cell viability, colony formation ability, and invasiveness as well as promoted apoptosis compared to monotherapy of HDACIs or EC359 in TNBC cell lines. Mechanistic studies, reporter gene assays and biochemical studies using multiple TNBC models exhibited activation of the LIFR signaling pathway upon HDACIs treatment but was attenuated by EC359+HDACI combination therapy. Treatment of human breast tumors utilizing PDEX assays showed that EC359 enhanced the ability of HDACIs to decrease the proliferation (Ki-67 positivity) compared to monotherapy. Furthermore, using TNBC xenografts and PDX models, we demonstrated that EC359 treatment enhanced the ability of HDACIs to reduce in vivo tumor growth compared to monotherapy. Conclusions: Our results suggest that the combination therapy of HDACIs and EC359 provides greater therapeutic efficacy than monotherapy. In addition, treatment with EC359 can overcome the feedback activation of LIFR currently observed in the treatment of TNBC with HDACIs. Citation Format: Suryavathi Viswanadhapalli, Mengxing Li, Bindu Santhamma, Uday P Pratap, Yiliao Luo, Junhao Liu, Kristin A Altwegg, Xiaonan Li, Hui Yan, Zhenming Xu, Andrew Brenner, Gangadhara R Sareddy, Rajeshwar R Tekmal, Hareesh B Nair, Klaus J Nickisch, Ratna K Vadlamudi. Targeting LIFR enhances the activity of HDAC inhibitors for the treatment of triple negative breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-11-08.

From the environmental safety and resource recovery viewpoint, a novel method of recycling gallium arsenide (GaAs) from scrapped GaAs-based integrated circuits (ICs) was proposed in this study. A h...

Lithium metal, as an ideal anode material for rechargeable and high energy density batteries, suffers from the inherent limitation of sensitivity to dendrite growth and a humid atmosphere. Here, a bifunctional composite interphase is designed to settle these issues. The interphase which is generated on the surface of Li foil through electroless plating with a solution of aluminum fluoride can guide uniform Li plating/stripping behaviors with reduced overpotential and simultaneously improve moisture resistance. Owing to the unique features, the assembled cells with the protected anode and a LiFePO4 cathode exhibit long cycle life (>300 cycles) with an extraordinary capacity retention (>95%). Further, even if the protected anodes are exposed to humid air (25% relative humidity) for over 24 h, the cells still achieve outstanding performance, comparable to that without exposure. This work thus provides a promising approach towards dendrite-free and air-stable lithium metal batteries.

Spent lithium ion battery (LIB) recovery is becoming quite urgent for environmental protection and social needs due to the rapid progress in LIB industries. However, recycling technologies cannot keep up with the exaltation of the LIB market. Technological improvement of processing spent batteries is necessary for industrial application. In this paper, spent LIB recovery processes are classified into three steps for discussion: gathering electrode materials, separating metal elements, and recycling separated metals. Detailed discussion and analysis are conducted in every step to provide beneficial advice for environmental protection and technology improvement of spent LIB recovery. Besides, the practical industrial recycling processes are introduced according to their advantages and disadvantages. And some recommendations are provided for existing problems. Based on current recycling technologies, the challenges for spent LIB recovery are summarized and discussed from technological and environmental perspectives. Furthermore, great effort should be made to promote the development of spent LIB recovery in future research as follows: (1) gathering high-purity electrode materials by mechanical pretreatment; (2) green metals leaching from electrode materials; (3) targeted extraction of metals from electrode materials.

Li-ion batteries (LIBs), the widely used energy storage devices, have been intensively studied to further increase their energy density and working life. To this end, lithium metal is the most promising high-capacity anode material, but the unstable electrochemical performance and dendrites formation inhibit its development. Based on DFT calculation, the adsorption energy analysis shows that the preferential and uniform Li deposition may occur on Li–Ag surface comparing to bare carbon surface. Therefore, we adopt thermal evaporation to silver the carbon surface to change the electrodeposition behavior of lithium metal. Li metal preferentially deposits on the Ag surface with flat appearance, restraining the formation of Li dendrites. The lithium metal/carbon composite anodes are subsequently prepared by electrodepositing Li metal on the bare or the modified carbon substrates, and three types of cell configurations, namely, Ag (B), bare CP and Ag (F), are compared in terms of electrochemical performance. The results show that the Ag (B) cell can effectively prolong the short-circuit time, enhance the electrochemical stability in the Coulombic efficiency, and better retain the specific capacity in full-cell tests due to the suppression of “dead Li”. This research provides a basic guidance for the electrochemical preparation of lithium metal/carbon composite anodes.

Environmental information in recovery of waste plastic in a certificated factory in industrial park in Eastern China is provided in this paper. The process involves raw material storage, washing, closed crushing, closed regeneration, product storage, and waste storage. Particulate matters, heavy metals, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyis (PCBs), and polybrominated diphenyl ethers (PBDEs) emitted from the production process are analyzed. A total of 25 atmospheric samples, 6 soil samples, and 2 water samples are sampled in and around the factory. The following conclusions could be concluded: (1) the concentrations of Cu and Pb are significantly higher than that of Ni, Cr and Cd in total suspended particulate matters; (2) PHE, DghiP, NAP and FLA are the main PAHs components in the air; PHE, FLA, DghiP, NAP, and PYR are the main congeners of PAHs in both washing wastewater and surface water; PHE, NAP, FLA, and CHR are the major congeners in the soil samples; (3) PCB-18, PCB-17 and PCB-31,28 are the main congeners in the air samples; PCB-70 and PCB-110 are the main congeners in soil samples; PCB-49 and PCB-52 are the main congeners in both surface water and washing wastewater; (4) DBDPE and BDE-209 are the main congeners for the all air, water and soil samples. Washing process and crushing process are identified as the main sources of all the above pollutants releases, and management strategies are provided to reduce the pollutants emission and the environmental hazardous caused by the waste plastic recovery process.

Histone deacetylase inhibitors (HDACi) are identified as novel therapeutic agents, however, recent clinical studies suggested that they are marginally effective in treating triple negative breast cancer (TNBC). Here, we show that first-in-class Leukemia Inhibitory Factor Receptor (LIFRα) inhibitor EC359 could enhance the therapeutic efficacy of HDACi against TNBC. We observed that both targeted knockdown of LIFR with CRISPR or treatment with EC359 enhanced the potency of four different HDACi in reducing cell viability, cell survival, and enhanced apoptosis compared to monotherapy in TNBC cells. RNA-seq studies demonstrated oncogenic/survival signaling pathways activated by HDACi were attenuated by the EC359 + HDACi therapy. Importantly, combination therapy potently inhibited the growth of TNBC patient derived explants, cell derived xenografts and patient-derived xenografts in vivo. Collectively, our results suggest that targeted inhibition of LIFR can enhance the therapeutic efficacy of HDACi in TNBC., Li, Viswanadhapalli et al utilized multiple in vitro, ex vivo and in vivo models of TNBC to investigate LIFR inhibition. The authors reported that HDAC inhibition in TNBC cells led to an increase of LIFR expression and over activation of the downstream signaling elements (e.g., STAT3, mTOR, AKT), enhancing the aggressive potential of TNBC cells, and an LIFR inhibitor, EC359, synergistically enhanced the efficacy of HADC inhibitors in suppressing TNBC in vitro and in vivo.

Tribo-Electrostatic Separation (TES) is suitable for recycling plastic from waste to avoid losing its virgin value. The separation model, which comprised of computing the electric field and the analysis of forces on the particles, was utilized to write a program by MATLAB language. The particle trajectory model based on TES is established. The model includes electric field computation and part of an analysis of forces on the particles. The electrode parameters and material parameters can be changed in the model. A photographic system including a high-speed camera (1000fps) was used to capture the plastic particle trajectories and to verify the model. Both waste PVC and waste PP particles were captured. The results computed by the model have a good agreement with the experimental results. The model can find suitable parameters for separating different waste plastics and help explore TES applications.

The zinc finger antiviral protein (ZAP) is known to restrict viral replication by binding to the CpG rich regions of viral RNA, and subsequently inducing viral RNA degradation. This enzyme has recently been shown to be capable of restricting SARS-CoV-2. These data have led to the hypothesis that the low abundance of CpG in the SARS-CoV-2 genome is due to an evolutionary pressure exerted by the host ZAP. To investigate this hypothesis, we performed a detailed analysis of many coronavirus sequences and ZAP RNA binding preference data. Our analyses showed neither evidence for an evolutionary pressure acting specifically on CpG dinucleotides, nor a link between the activity of ZAP and the low CpG abundance of the SARS-CoV-2 genome.

While CIGS solar cell has been experiencing an expanded photovoltaic market and increasing research interest in cell design, its treatment after obsoletion remains an upcoming issue. The heavy metals involved, such as Cd, can threat the environment, while strategic resources, such as rare metals In and Ga, offer a great recycling oppotunity. However, due to its multimetal feature, traditional recycling methodology shows poor separation-extraction efficiency and additional environmental burdens with intense reagent consumption and waste generation. Here, we report a sequential electrodeposition method for pure metal recycling from this Cu-In-Cd-Ga quaternary system in a more environmentally friendly and efficient manner. Stability constant-corrected redox potential supplemented with metal electroreduction tests predicts well the potential window for sequential electrodeposition. Cu and In electrodeposition shows 100% separation with high Coulombic efficiency (>80%), whereas Ga electrodeposition presents slower kinetics and performs better at a pH of 2.5. Environmental impact assessment indicates that the proposed recycling route allows remarkable reduction of global warming and toxicity impacts compared with metal production from virgin mining and reference processes. We further unveiled the applicability of the electrodeposition technique in the context of anthropogenic mineral recycling, emphasizing resource sustainability and cleaner production.

As a kind of typical veterinary drug, fluoroquinolone antibiotics (FQs) are widely used in the field of livestock and poultry breeding, but these FQs escape to surrounding soil through various pathways, polluting soil through long-term accumulation. Current study proposed a clean technology named thermal desorption to deal with FQs contaminated soils. It was observed that time, temperature and soil particle size were the critical factors in FQs thermal desorption. Results of the study showed that higher temperature was more effective in the removal of FQs, while removal of FQs attached with finer particles was more difficult compared to coarse particles. Fine soil particles (0.6-0.85 mm) were decontaminated up 99.4% when treated with 400 °C for 60min. Thermal desorption of FQs from contaminated soil was governed by first-order kinetics. Based on the detection of exhaust gas components, a possible thermal desorption mechanism was proposed. Study suggested that thermal desorption was a clean and effective remediation method to treat FQs-contaminated soils without generating any further waste.

The service life of glass is limited, leading to a large amount of waste glass generated. The waste glass recycling base, as an essential municipal supporting facility of a sustainable city, has a significant impact on the surrounding ecological environment. This study conducted a comprehensive investigation and analysis of the potential pollutants in a large waste glass terminal recycling base. It was found that the waste glass treatment process may produce various pollutants such as particulate matter, heavy metals and so on, which might cause pollution to surrounding areas. Microplastics (MPs) of particulate matter, which were widely distribute in the study area, had high abundance and interact with heavy metals. Its release is related with different treatment processes. MPs were found in all sampling sites, a total of 59 polymer types were identified. The relationship between MPs and process characteristics is mainly reflected on the polymer types. The crushing and screening process are more likely to produce Acrylic, while the label-eliminate process is more likely to produce PMMA. It was estimated that the annual load of MPs in the waste glass recycling site is about 3.211 tons.

Recovering valuable materials from spent lithium-ion batteries is an important task because of the asymmetry in resource distribution, supply, and demand around the world. A lithium-ion battery is a combination system of various elements and their oxides. Current recovering technologies focus on the separation of valuable metal elements. They can inescapably bring secondary contamination and cost to the environment due to the addition of leachants and precipitants. To recover valuable materials, in situ recombination of elements in spent lithium-ion batteries can be a more economical and environment-friendly solution. Herein, we developed a technology based on in situ aluminothermic reduction and interstitial solid solution transformation to recover high-value γ-LiAlO

Pyrolysis is a potential technique in the application of decomposing organics from waste printed circuit boards (WPCBs), which has advantage of resource recovery, high efficiency and easy operation. In order to support and promote pyrolysis technology, it is necessary to carry out harmless disposal and comprehensive utilization of pyrolysis products. Considering the compositions, pyrolysis products can be used as carbon source. In this work, pyrolysis products, waste zeolites (WZs) and residual heat were used to prepare magnetic zeolites coated with carbon fibers (MZCCFs). The results showed that the mass ratio of Fe@WZs and NMs with 2.0, diameter of Fe@WZs with 0.15–0.30 mm, reaction temperature with 750 °C and reaction time with 20 min were optimum parameters to fabricated MZCCFs. Besides, SEM, XRD, FT-IR and Raman spectra suggested that carbon fiber was successfully formed when the temperature raised to 750 °C. And the interplanar spacing, thickness of microcrystal and crystallite size of carbon fiber were 0.3767 nm, 1.67 nm and 3.64 nm, respectively, indicating that MZCCFs have ordered graphite structure. Moreover, MZCCFs exhibited excellent thermostability and large specific surface area, which can be employed as demulsifier and have good demulsification, excellent corrosion resistance and recyclability for emulsified oil removing. In conclusion, an environmental-friendly method for recycling pyrolysis products of WPCBs was proposed, which provide novel idea for complex organic disposing.

Based on density functional theory calculations of iodide-type compounds Li3MI6 (M = Sc, Y, and La), Li3LaI6 with stable octahedral Li occupation is theoretically found to meet the requirements of ...

This paper focuses on current progress of supercritical fluid (SCF) technology for e-waste treatment through reviewing characteristics and challenges of existing technologies. With the high-speed development of science and technology, electronic and electric equipment continually upgrades and updates, which bring a series of problems on dealing with the e-waste. The most serious problem is that the harmless disposal of halogen flame retardants and refractory polymers in e-waste is difficult. In recent years, the recycling technologies for e-waste has entered a new stage through tireless efforts of the researchers. Compared with the common recycling technologies like pyrolysis and acid leaching, SCF technologies have great advantages in the field of environment, without air or water pollution risks. Supercritical fluids such as supercritical water and supercritical carbon dioxide are sustainable green solvents as well as highly promising reaction mediums. The principles, operation procedures and optimized parameters of SCF treatment are discussed and summarized in this paper. Furthermore, SCF technologies applied in the field of e-waste recycling have also achieved satisfactory results. Significant progress has been made in the detoxification of e-waste and removal of refractory polymers by SCF technologies. The dechlorination efficiency and debromination efficiency has been reported to be over 90%. The base metals, the precious metals, and other inorganic materials were all reported to be recovered from e-waste by SCF technologies with a recovery rate of more than 93%. Common challenges in SCF process like corrosion and salt precipitation also came up with some propose solutions. Hence, the application of SCF technology in e-waste treatment demonstrates green reaction and resource recovery with significant economy and environment perspectives.

Recycling resources from millions of tons of e-wastes are a global challenge. E-wastes is complex and contains both toxic organics and valuable metals. Therefore, the technologies for e-wastes recycling are totally different from those used for mineral separation. Current technologies for e-wastes tend to focus on recycling materials with high economic value and ignore components that cannot be recycled or have low reuse value. As a result, some secondary pollution problems inevitably occur due to the recycling process. Based on these problems, we summarize the universal characteristics of e-wastes and explore new approaches to achieve complete resource recycling of e-wastes with minimum secondary waste generation. A concept of element recycling is proposed to achieve complete resource recycling of e-wastes in the study. We can use the properties of the elements in different types of e-wastes to achieve e-wastes recycling, i.e., recycle of elements in e-wastes. Under the guidance of element recycling, various e-wastes types have common connections. If element recycling in e-wastes is realized, all components in e-wastes can be fully recycled without/with minimal production of secondary waste. The two case studies are discussed to clarify the concept and principle of element recycling. This study explores the recycling of e-wastes from a new perspective-element recycling in e-wastes. The concept of element recycling is significant for resource recycling from e-wastes.

Waste penicillin bottles, a main component of medical wastes, have greatly produced in the world. Because of containing residual medicines and different microorganism, this kind of medical wastes is considered as hazardous waste. The unidentified microorganism inside waste penicillin bottles makes it difficult to dispose and manage. To our knowledge, there was little published information about the suitable recovery technology of waste penicillin bottles. In this study, the microorganisms in penicillin bottles were identified by the methods of gram staining and gene sequencing. Two gram-positive bacteria in the penicillin bottles were found, one was gram-negative bacterium, the other was fungus. The results of the analysis of gene sequencing and phylogenetic trees of the four bacterial showed three injurious microorganisms (Cladosporium australiense, Staphylococcus haemolyticu, and Vagococcus carniphilus) were presented in waste penicillin bottles. We also developed a novel process to recover nano glass from waste penicillin bottles. It included the processes of shearing, screen, and ball-milling. When the ball-milling time was greater than 36 h, most of the glass particles had the size ranged in 200–400 nm, 400–600 nm, and 600–800 nm, even reached the size of 0–200 nm. Ball-milling of the glass of waste penicillin bottles will bring a certain economic benefits by selling this nano glass. Additionally, we also found the transient temperature on glass particles during ball-milling process could reach 476 °C, which was enough to kill the injurious microorganisms. Therefore, ball-milling can reduce the cost of sterilization of medical wastes. This study provided a new and safe technology of recovering nano glass from penicillin bottles of medical wastes.

Integrated circuits (ICs) are widely used in all the electrical and electronic equipment, and the recycling technology of ICs has been poorly developed. This study proposes a promising process to d...

To separate mixed plastic wastes into pure components can hugely elevate their reusable value and reduce the environmental risks. This study proposes a compound process to handle mixed plastics wastes. The study used mixed plastic granules of polypropylene (PP), acrylonitrile butadiene styrene (ABS), poly vinyl chloride (PVC), and polystyrene (PS) as the feeding material. Vibrating and cyclone tribo-chargers were used to find charge performance of different granules. In vibrating tribo-charger the biggest gap of charge/mass ratio (CMR) between different granules was 3.63 nC/g, when the wall material was ABS. In cyclone tribo-charger, this value was 8.37 nC/g. Then two modes of compound separation were proposed to separate mixture. In mode-1, only one kind of material was separated from mixed granules each time. In mode-2, the mixed granules were separated to two groups. The separation results showed that the average separation efficiency (Es) of mode-1 was 72.44%, the average Es of mode-2 was 65.18%. The mixed plastic particles can be potentially separated by changing their triboelectric series as long as their CMR have significant differences.

Heating processes for the removal of electronic components from waste printed circuit boards (WPCBs) is an important step in the chain of electronic waste recycling, and toxic fumes are generated during the de-soldering process, causing environmental pollution and posing health risks for the workers. This study is aimed to characterize emission and deposition fluxes of respirable particulate matter (PM), and assess exposure of workers to particle-bound polybrominated diphenyl ethers (PBDEs). An electrical low-pressure impactor was used to measure the real-time PM concentrations inside and outside the hood during the WPCBs de-soldering process. The results show that PM mass concentration inside the hood (204 mg/m3) was significantly higher than outside the hood (9.4 mg/m3), representing 95.4% PM removal by the hood. According to the International Commission on Radiological Protection model, the total deposition fluxes of PM in head airways region, tracheobronchial region, and alveolar region were determined as 1930, 74.0, and 123 μg/h, respectively. The deposition flux for coarse particles (2.5-10 μm) in the head airways was the largest (1830 μg/h), accounting for 86.1% of total PM deposited in respiratory system. The ∑8PBDEs concentration in PM10 inside the WPCBs de-soldering workshop was 20,300 pg/m3, and the ∑8PBDEs inhalation exposure for the worker was 1.46 ng/kg/day. This study improves understanding of PM emission mechanisms and provides fundamental data for health assessments during WPCBs de-soldering process.

The demand for gold in the field of national storage, jewelry, and electronics has never been higher. However, gold extraction is not always welcomed by local residents because of the resulting environmental contamination. For more than a century, cyanide and aqua reiga were dominantly used for gold mining because of their low costs, high efficiencies, and easy operations. In this article, an improved chlorination process, a traditional cyanidation process, and a traditional aqua regia process were quantitatively analyzed and compared from the perspective of environmental impact. The Biwer-Heinzle method is employed. The results showed that the improved chlorination process had the lowest environmental hazard. The values of General Environmental Indices computed for the Inputs and Outputs were quite small, closing to the minimum values of 0 and 1, respectively, depending on the calculation approach used, via arithmetic average or via multiplication. The results also revealed that the aqua regia process ha...

The recovery of waste acrylonitrile-butadiene-styrene (ABS), polystyrene (PS) and polypropylene (PP) from waste white goods was inefficient due to their similar chemical and physical property. In this work, an environmental friendly equipment based on on-line dynamic recognition for recycling the waste white goods plastic stream (i.e. ABS, PS and PP mixture) was established. It included the recognition process utilizing the near infrared (NIR) range 1050 nm-1350 nm and separation process using the air ejection. In particular, NIR spectrum of waste plastic stream were acquired on-line and analyzed dynamically with the self-designed software. Results showed that although ABS, PS and PP share very similar chemical and physical property, it is possible to separate them with a high accuracy up to 99%. Meanwhile, the optimized operating parameters of the separation process were studied to guide the further industrial recycling process. The study revealed the potentiality of NIR technique as mechanical methods in recycling of plastics from the waste white goods.

Ta3N5 is a very promising visible-light-driven photocatalyst for water splitting and organic degradation. However, the low photocatalytic activity and poor photostability limit its application. To enhance the photocatalytic performance of Ta3N5, we prepared core-shell Ta3N5@polyaniline (PANI) by a chemisorption process. The effect of PANI content on the microstructure, optical, photoelectrochemical property and the photocatalytic activity of the samples were studied. The results showed that after the adsorption process, PANI was successfully coated on Ta3N5 with intimate contact and could significantly enhance the photocatalytic performance. The PANI shell thickness dramatically affected the photocatalytic activity. The Ta3N5@PANI 2 (PANI shell thickness: 0.9 nm) possessed the highest visible light photocatalytic H2 production rate of 72.6 μmol g−1 h−1 and RhB degradation rate of 0.041 min−1, which were 3.2 and 16.6 times higher than those of Ta3N5. The Ta3N5@PANI exhibited excellent photostability and reusability. The superior photocatalytic performance of the Ta3N5@PANI was attributed to the synergic effect, including the intense interfacial interaction, enhanced visible light absorption, efficient charge separation and corrosive holes transfer from Ta3N5 to PANI. Furthermore, DFT calculations were applied to explore the interfacial interaction between PANI and Ta3N5. This study suggests that PANI modification can improve the photocatalytic application of Ta3N5 for H2 production and RhB degradation.

In the past, the pretreatment and indium extracting were conducted in independent disposal system to recycle indium from waste liquid crystal display (LCD), which make the recycling process inefficient and costly. In this study, an efficient and environmental friendly indium recycling process was proposed by an in-situ reaction process. The carbon residue generated in the pretreatment stage (organic removing stage) was used as the reductant to extract indium in the same reaction system. Comparison results indicated that the reaction effects of pyrolytic carbon were much better than coke since the structure of pyrolytic carbon is porous which would make the reactants contact better, and promote the reaction efficiency. Futhermore, results showed that the pyrolytic carbon was sufficient for the indium reduction without adding extra reductant, and indium conversion rate can reach 99.08% under the condition of 935 °C, 5 Pa, 2.5 wt%, 30 min,0.3 mm. In this study, the organic pollutants were removed, while the indium also could be recycled in a closed-loop system. To sum up, this study could simplify the process route of waste LCD recycling, and provide fundamental basis as well as practical experience for recycling waste LCD environmentally and efficiently.

Waste multilayer ceramic capacitors (MLCCs), widely existing in discarded appliances, are a valuable resource containing Ti, Nb, Ag, Pd, etc. Based on the principles of waste utilization, low-cost preparation and environmental protection, we in situ prepared a Nb–Pb codoped and Pd loaded TiO2 photocatalyst from waste MLCCs by a simple chlorination–leaching process. The particle sizes of Nb–Pb codoped TiO2 and Pd loading were 50–80 and less than 5 nm, respectively. The visible light absorption of the recycled TiO2 was enhanced and the bandgap was about 2.8 eV. The simulated sunlight photocatalytic H2 production rate and RhB degradation rate of the recycled sample could reach 185.04 μmol g−1 h−1 and 0.078 min−1, respectively, which were 4.4 and 5 times higher than those of commercial TiO2. The recycled sample exhibited excellent photostability and reusability. The highly efficient photocatalytic performance was attributed to the Nb–Pb codoping and Pd loading, which enhanced the visible light absorption and efficient charge separation. Moreover, DFT calculations suggested that the Nb–Pb codoping introduced the impurity levels into the bandgap, which decreased the photon energy required for electron transition and thus enhanced the visible light absorption. The Pd loading received the excited electrons and improved the charge separation. This study provides a novel and sustainable process to convert e-waste into a highly efficient photocatalyst, delivering environmental benefits.