The wide use of lithium ion batteries (LIBs) has brought great numbers of discarded LIBs, which has become a common problem facing the world. In view of the deleterious effects of spent LIBs on the ...environment and the contained valuable materials that can be reused, much effort in many countries has been made to manage waste LIBs, and many technologies have been developed to recycle waste LIBs and eliminate environmental risks. As a review article, this paper introduces the situation of waste LIB management in some developed countries and in China, and reviews separation technologies of electrode components and refining technologies of LiCoO2 and graphite. Based on the analysis of these recycling technologies and the structure and components characteristics of the whole LIB, this paper presents a recycling strategy for all components from obsolete LIBs, including discharge, dismantling, and classification, separation of electrode components and refining of LiCoO2/graphite. This paper is intended to provide a valuable reference for the management, scientific research, and industrial implementation on spent LIBs recycling, to recycle all valuable components and reduce the environmental pollution, so as to realize the win–win situation of economic and environmental benefits.
Microwave (MW) technology has gained increasing interest in wastewater treatment due to its unique properties, such as fast and uniform heating, hot spots effect, and non-thermal effect. MW enhances ...the production of active radicals (e.g., OH, SO4−), which exerts a stronger integrated treatment effect in combination with advanced oxidation processes. Over the years, microwave-assisted advanced oxidation processes (MW-AOPs) have developed rapidly to degrade pollutants as innovative treatment approaches. This paper provides a detailed classification and a comprehensive review of MW-AOPs. The latest applications of MW in different advanced oxidation systems (oxidation systems, catalytic oxidation systems, and photochemical, electrochemical and sonochemical systems) are reviewed. The reaction parameters and performance of MW-AOPs in wastewater treatment are discussed, and the enhancement of pollutant degradation by MW is highlighted. In addition, the operating costs of MW-AOPs are evaluated. Some recommendations on MW-AOPs are made for future research. This review provides meaningful information on the potential development and evolution of MW-AOPs.
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•The mechanisms of MW in various AOPs are summarized.•Three types of MW-AOPs based on different oxidation systems are described.•The synergistic effect in the MW catalytic oxidation system is discussed.•The advantages of MW-assisted photochemical, electrochemical, and sonochemical AOPs are demonstrated.•The economic costs of MW-AOPs are evaluated.
Heavy metals such as Co, Li, Mn, Ni, etc. and organic compounds enrich spent lithium-ion batteries (LIBs). These batteries seriously threaten human health and the environment. Meanwhile, with the ...development of new energy vehicles, the shortage of valuable metal resources which are used as raw materials for power batteries is becoming a serious problem. Using proper methods to recycle spent LIBs can both save resources and protect the environment. Pyrometallury is a kind of recycling method that is operated under high temperature with the aim of recovering useful metals after pre-treatment and organic binder removal with the characteristic of high temperature and it is easy to operate. Hydrometallurgy is characterized by high recovery efficiency, low reaction energy consumption, and high reaction rate, and is widely used in the recycling process of spent LIBs. During biometallurgy, valuable metals in the spent LIBs are extracted by microbial metabolism or microbial acid production processes. Since the drive for green and low secondary pollution, biometallurgy as well as solvent extraction and the electrochemical method have earned more attention during recent years. This mini-review analyzes the relationship between the emergence of new energy vehicles and the recycling status of spent LIBs. Meanwhile, this paper also consists of detailed treatment and recycling methods for LIBs and provides a summary of the management regulations of current waste for LIBs. What is more, the main challenges and further prospects in terms of LIBs management in China are analyzed.
•The paper systematically introduces recycling system of WEEE management in China.•The paper introduces the new policy about WEEE management in China.•This paper analyzes the results of its ...implementation.•This paper evaluates the effectiveness to WEEE management in China.
The consumption of electrical and electronic equipment is surging, so is the generation of waste electrical and electronic equipment (WEEE). Due to the large quantity, high potential risk and valuable capacity of WEEE, many countries are taking measures to regulate the management of WEEE. The environmental pollution and human health-harming problems caused by irregular treatment of WEEE in China make the government pay more and more attention to its management. This paper reviews the development of WEEE management in China, introduces the new policy which is established for WEEE recycling and especially analyzes the effectiveness of the policy, including huge recovery, formation of new recycling system, strict supervision to related enterprises, and the stimulation to public awareness. Based on the current achievement, some recommendations are given to optimize the WEEE management in China.
Spindle bearing fits mainly include interference fit of inner ring and clearance fit of outer ring, which directly affect the vibration characteristics of spindle rotor-bearing system. In this paper, ...the influence of spindle bearing inner and outer ring fits on bearing support stiffness is firstly studied. Considering the spindle bearing inner and outer ring fits, a dynamic model of spindle rotor-bearing system is established. Then, the analysis methods of bifurcation and time domain are used to perform simulation analysis. The influence of bearing fit on the vibration characteristics of rotor system is researched. Lastly, at different rotating speeds, bearing fits experiments are conducted on built motorized spindle test platform, which verifies the correctness of the dynamic model. The results show that the influence of bearing fit on vibration is nonlinear. The influence of clearance fit on vibration is smaller, when the clearance fit value of bearing outer ring is about 4-6 μm. The vibration characteristics of rotor are more sensitive to the clearance fit of bearing outer ring than the interference fit of bearing inner ring. The research work provides an important theoretical basis for the optimal of spindle bearing assembly.
Since the majority of valuable components in spent lithium-ion batteries, such as lithium, exists in the electrode materials, common studies focused on the treatment of the cathode materials, which ...ignored the harm of residual electrolyte. The cavitation and thermal effects produced by ultrasonic can not only be used for the separation of electrode materials, but also have a wide range of applications in the field of sewage pollutant degradation. This work used ultrasonic to treat simulated electrolyte (propylene carbonate (PC)) solution of spent lithium-ion batteries, explored the effect of ultrasonic power, the addition amount of H2O2 solution (30 wt%) and reaction temperature on the degradation of electrolyte, and analysed the ultrasonic degradation reaction from the perspective of reaction kinetics. And the synchronous experiment of cathode material separation and electrolyte degradation was conducted under the optimal conditions. The results showed that the highest degradation efficiency of PC in the electrolyte was 83.08% under the condition of ultrasonic power of 900 W, the addition of H2O2 solution (30 wt%) of 10.2 mL, reaction temperature of 120°C and reaction time of 120 minutes, and the separation efficiency was 100%. This work reduced the environmental and health risks in the cathode material separation process and was conducive to the green development of spent lithium-ion battery recycling technology.
Epithelial-to-mesenchymal transition (EMT) is a developmental process important for cell fate determination. Fibroblasts, a product of EMT, can be reset into induced pluripotent stem cells (iPSCs) ...via exogenous transcription factors but the underlying mechanism is unclear. Here we show that the generation of iPSCs from mouse fibroblasts requires a mesenchymal-to-epithelial transition (MET) orchestrated by suppressing pro-EMT signals from the culture medium and activating an epithelial program inside the cells. At the transcriptional level, Sox2/Oct4 suppress the EMT mediator Snail, c-Myc downregulates TGF-β1 and TGF-β receptor 2, and Klf4 induces epithelial genes including E-cadherin. Blocking MET impairs the reprogramming of fibroblasts whereas preventing EMT in epithelial cells cultured with serum can produce iPSCs without Klf4 and c-Myc. Our work not only establishes MET as a key cellular mechanism toward induced pluripotency, but also demonstrates iPSC generation as a cooperative process between the defined factors and the extracellular milieu.
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► Mouse fibroblast reprogramming involves a mesenchymal-to-epithelial transition ► Sox2, Oct4, and c-Myc suppress TGF-β signaling ► Klf4 activates multiple epithelial genes including E-cadherin ► E-cadherin knockdown impairs reprogramming
Gestational diabetes mellitus (GDM), a common endocrine disorder with rising prevalence in pregnancy, has been reported to be associated with alteration of gut microbiota in recent years. However, ...the role of gut microbiome in GDM physiopathology remains unclear. This pilot study aims to characterize the alteration of gut microbiota in GDM on species-level resolution and evaluate the relationship with occurrence of GDM.
An analysis based on 16S rRNA microarray was performed on fecal samples obtained from 30 women with GDM and 28 healthy pregnant women.
We found 54 and 141 differentially abundant taxa between GDM and control group at the genus and the species level respectively. Among GDM patients, Peptostreptococcus anaerobius was inversely correlated with fasting glucose while certain species (e.g., Aureimonas altamirensis, Kosakonia cowanii) were positively correlated with fasting glucose.
This study suggests that there are large amounts of differentially abundant taxa between GDM and control group at the genus and the species level. Some of these taxa were correlated with blood glucose level and might be used as biomarkers for diagnoses and therapeutic targets for probiotics or synbiotics.
Previous studies have indicated that diarrhea with kidney-yang deficiency syndrome leads to a disorder of small intestine contents and mucosal microbiota. However, the relationship of TMA-lyase ...(CutC) activity and TMAO with diarrhea with kidney-yang deficiency syndrome remains unexplored. Therefore, this study explores the relationship between cecal microbiota and choline TMA-lyase (CutC) activity, as well as the correlation between trimethylamine oxide (TMAO), inflammatory index, and CutC activity.
Twenty SPF-grade male KM mice were randomly divided into the normal group (CN) and the diarrhea model group (CD). Diarrhea mouse models were established by adenine combined with
administration. CutC activity, TMAO, interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) levels were detected, and the cecal content microbiota was sequenced.
After 14 days, diarrhea occurred in the CD group. Compared with the CN group, there was no significant change in the activity of CutC in the small intestine of the CD group, while the activity of CutC in the cecum was significantly increased, and the levels of TMAO, IL-6, and TNF-α showed a significant increase. The Chao1 index, Observed_species index, Shannon index, and Simpson index all exhibited a decreasing trend. The main changes at the bacterial genus level were
,
,
,
,
, and
. The results of LEfSe analysis, random forest analysis and ROC curve analysis revealed
,
,
,
,
,
,
,
,
,
, and
as characteristic bacteria in the CD group. Correlation analysis showed a significant negative correlation between cecal CutC activity and
, and a significant positive correlation with
and
. The level of TMAO was significantly positively correlated with CutC activity and IL-6.
Diarrhea with kidney-yang deficiency syndrome significantly affects the physiological status, digestive enzyme activity, CutC activity, TMAO levels, and inflammatory response in mice. Additionally, there are changes in the composition and function of cecal microbiota, indicating an important impact of diarrhea with kidney-yang deficiency syndrome on the host intestinal microbiota balance. The occurrence of diarrhea with kidney-yang deficiency syndrome may be associated with dysbiosis of intestinal microbiota, increased CutC activity, elevated TMAO levels, and heightened inflammatory factor levels.
► The past, current and future status of CRT dismantling technologies are presented. ► The CRT glass recycling situation and obstacles in China are discussed. ► We provide a broad review of the ...research progress in recycling techniques for CRT cullet.
It is estimated that approximately 6000,000 scrap TVs and 10,000,000 personal computers are generated each year in China. Cathode ray tubes (CRTs) from these machines consist of 85% glass (65% panel, 30% funnel and 5% neck glass). The leaded glass (funnel-24%, neck-30%) may seriously pollute the environment if it is not properly disposed of. In this paper, the past, current and future status of CRT dismantling technologies as well as the CRT glass recycling situation in China are presented and discussed. Recycling technology for waste CRTs in China is still immature. While the conventional CRT dismantling technologies have disadvantages from both economic and environmental viewpoints, some of the new and emerging treatments such as automatic optical sorting facilities that have been applied in developed countries offer advantages, and therefore should be transferred to China in the next few years to solve the CRT pre-processing problem. Meanwhile, because the demand for CRT glass closed-loop recycling is extremely limited, the authorities should take effective measures to improve CRT glass recycling rates and to facilitate a match to local conditions. Moreover, we also provide a broad review of the research developments in recycling techniques for CRT cullet. The challenge for the future is to transfer these environmentally friendly and energy-saving technologies into practice.
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