Quantitative monitoring and potential mechanism of the secondary corrosion risk of PAH-contaminated soil remediated by persulfate oxidation.

The proportion of activated persulfate (PS) oxidation technology in the remediation of domestic organic contaminated sites has increased every year, and the potential corrosion risk of site reuse caused by residual oxidants and by-products has also attracted the attention of researchers. In this work, the potential corrosion degree such as the mass reduction rate and surface crack width of standard iron flakes under different conditions, including with different PS dosages and release times, was monitored quantitatively over a long period, and the corresponding corrosion risk was quantitatively assessed. The results showed that when n (Na2S2O8):n (PAHs) increased from 5:1 to 100:1, the higher the oxidizer dosage, the more severe the corrosion weight loss and surface crack width, indicating that the oxidizer dosage was positively correlated with the potential corrosion risk. In addition, the corrosion crack width of the standard iron flake had a significant positive correlation with the reaction time and a significant negative correlation with the mass change. According to the changes in the standard iron flake, the corrosion process could be divided into three stages, in which the corrosion risk from high to low followed the order of oxidant corrosion stage > oxidant and salt corrosion stage > salt and microbial corrosion stage. Therefore, the dosage of chemicals should be controlled, the molar ratio of oxidizer to contaminant should not exceed 25:1, and a natural recovery period of at least one year should be left post remediation. During the reuse of the remediation sites in the future, the potential corrosion risks should also be calculated based on the dosage and time, to avoid redevelopment and use of the restoration site in the high corrosion risk stage.

Migration characteristics of heavy metals during simulated use of secondary products made from recycled e-waste plastic.

Recycling of plastics from e-waste can conserve resources, however, aging during the use of plastic products can cause the migration of heavy metals in additives. This study presents a methodology for evaluating the risks of heavy metals in waste plastic secondary products during long term use associated with heavy metal migration. The study processes were investigated by: (1) recycling waste plastics and producing secondary products; (2) thermal aging of secondary products; and (3) toxic leaching used to quantitatively analyse the dissolution of heavy metals. Combined with the changes in mechanical properties and microstructure, the effect of aging on the migration of heavy metals was observed. The results showed that the polymer appeared to delaminate, the adhesion of waste plastics to additives decreased, and the mechanical properties clearly decreased after the thermal aging experiment. Leaching experiments showed that the leached concentrations of Ni, Cu, Zn, Pb, and Sb in the three types waste plastic products increased over time. After 8 d of aging, the leached concentrations of Ni, Sb, and Pb exceeded the third, fourth, and third class of the groundwater quality standard, respectively. Specifically, the concentrations of Sb were 141, 289, and 21.1 times higher than the maximum permissible level. Therefore, management hierarchy and safe environmental recycling methods should be developed to reduce the risk of heavy metals in waste plastic secondary products.

Administration of losartan preserves cardiomyocyte size and prevents myocardial dysfunction in tail-suspended mice by inhibiting p47phox phosphorylation, NADPH oxidase activation and MuRF1 expression.

BACKGROUND: Spaceflight or microgravity conditions cause myocardial atrophy and dysfunction, contributing to post-flight orthostatic intolerance. However, the underlying mechanisms remain incompletely understood and preventive approaches are limited. This study investigated whether and how losartan, a blocker of angiotensin-II receptor, preserved cardiomyocyte size and prevented myocardial dysfunction during microgravity. METHOD: Adult male mice were suspended with their tails to simulate microgravity. Echocardiography was performed to assess myocardial function. Heart weight and cardiomyocyte size were measured. NADPH oxidase activation was determined by analyzing membrane translocation of its cytosolic subunits including p47phox, p67phox and Rac1. Heart tissues were also assayed for oxidative stress, p47phox phosphorylation (Ser345), MuRF1 protein levels and angiotensin-II production. RESULTS: Tail-suspension for 28 days increased angiotensin-II production in hearts, decreased cardiomyocyte size and heart weight, and induced myocardial dysfunction. Administration of losartan preserved cardiomyocyte size and heart weight, and prevented myocardial dysfunction in tail-suspended mice. These cardioprotective effects of losartan were associated with inhibition of p47phox phosphorylation (Ser345), NADPH oxidase and oxidative stress in tail-suspended mouse hearts. Additionally, the NADPH oxidase inhibitor, apocynin, also reduced oxidative stress, preserved cardiomyocyte size and heart weight, and improved myocardial function in tail-suspended mice. Furthermore, losartan but not apocynin attenuated tail-suspension-induced up-regulation of MuRF1 protein in mouse hearts. CONCLUSIONS: Administration of losartan preserves cardiomyocyte size and prevents myocardial dysfunction under microgravity by blocking p47phox phosphorylation and NADPH oxidase activation, and by inhibiting MuRF1 expression. Thus, losartan may be a useful drug to prevent microgravity-induced myocardial abnormalities.

Pollution analysis of soil polycyclic aromatic hydrocarbons from informal electronic waste dismantling areas in Xinqiao, China.

Polycyclic aromatic hydrocarbons (PAHs) are considered to be persistent organic pollutants, which pose a great threat to human health and the surrounding environment. In order to explore the influence of informal electronic waste (e-waste) dismantling activities on inhabitants who live nearby, soil samples were collected from informal e-waste dismantling areas in Xinqiao, China and analysed for 16 United States Environmental Protection Agency (USEPA) priority PAHs. Results indicated that the 16 USEPA priority PAHs were found at all seven sampling locations. Sampling location 3, which was only 10 m away from a residential area, had 1053.69 µg kg-1 of PAHs and seriously exceeded the standard value specified by the Netherlands. The total percents of 4-ring and 5-ring PAHs accounted for 61.74 and 71.70%, respectively, indicating that most of the detected PAHs belonged to high-ring PAHs. The informal e-waste dismantling activities are the major sources of soil PAHs in Xinqiao. Furthermore, the concentration of seven carcinogenic PAHs was 114.76 µg kg-1 and represented a potential health risk to humans. Thereinto, benzo[a]pyrene contributed the most, accounting for more than 50% in these locations. Our results may provide a reference about the influence of informal e-waste dismantling activities on the surrounding inhabitants and suggest that e-waste dismantling activities must be conducted in a formal enterprise which is far away from residential areas.

Stocks and environmental release of mercury in backlight cold cathode fluorescence lamps.

Cold cathode fluorescent lamps (CCFLs), with mercury as their essential component, were widely used as backlight in liquid crystal display (LCD) appliances before 2008. Since 2008, the mercury-free light emitting diode started to be used as a substitute for CCFLs and the replacement finished in about 2014. Nowadays, CCFLs are obsolete products from the viewpoint of manufacture but they are important as waste. In recent years, large amounts of CCFLs are flowing to waste phase for treatment and this has become a major issue in most countries. To better understand and control the risk of CCFLs, the stock of mercury in CCFLs, its flow to waste phase and mercury emission with the life cycle of CCFLs in mainland China were estimated in this study. Results showed that there was 15.2 tons of mercury stocked in CCFLs in main LCD appliances (i.e., LCD televisions, LCD monitors, and laptop monitors) from 2003-2015. CCFLs and mercury started to flow to waste phase around the year 2007 and will likely peak in 2018 with an annual flow of 324.8 million units and 1.5 tons respectively, then will likely decline dramatically till 2030. Dismantling and production were the two main life stages of CCFLs with mercury vapor release, during which approximately 2.1 tons and 1.2 tons of mercury were released to the atmosphere respectively. The research also indicates that mercury recycling in specialized facilities was another life stage with high mercury emission risk in which the processes of shredding, separation, and residue disposal are inevitably accompanied by mercury release.

Efficient removal of copper from wastewater by using mechanically activated calcium carbonate.

Copper removal from aqueous solution is necessary from the stances of both environmental protection and copper resource recycling. It is important to develop a new chemical precipitation method suitable for removing copper particularly at low concentration as the case of waste mine water, with regards to the various problems related to the current precipitation methods by using strong alkalis or soluble sulfides. In this research, we studied a possible chemical precipitation of copper ions at concentration around 60 mg/L or lower by cogrinding copper sulfate in water with calcium carbonate (CaCO3) using wet stirred ball milling. With the aid of ball milling, copper precipitation as a basic sulfate (posnjakite: Cu4 (SO4) (OH)6·H2O) occurred at a very high copper removal rate of 99.76%, to reduce the residual copper concentration in the solution less than 0.5 mg/L, reaching the discharge limit, even with the addition amount of CaCO3 as a stoichiometric ratio of CaCO3/Cu2+at 1:1. It is more interesting to notice that, at the same conditions, other heavy metals such as Ni, Mn, Zn and Cd do not precipitate obviously just with CaCO3 addition at CaCO3/M2+at 1:1 so that the precipitate without the impurities can be processed as good source to recover copper. This newly proposed concept can be further developed to treat wastewaters with other metals to serve both purposes of environmental purification and resource recovery in a similar way.

Effect of Worm Predation on Changes in Waste Activated Sludge Properties.

This study explored the effects of worm predation on changes in waste activated sludge properties. Results showed that the rate by which worm predation reduced mixed liquor volatile suspended solids (MLVSS) was approximately 23.7% ± 3.1%. Particle size distribution and extracellular polymeric substance (EPS) analyses indicated that the reduction of fine particles and EPS content in sludge predated by worms mainly increased dewaterability and reduced the ratio of MLVSS/mixed liquor suspended solids. Moreover, both mean particle size and protein/carbohydrate ratio increased. The results of three-dimensional excitation-emission matrix and gel filtration chromatogram analyses demonstrated the varied properties of soluble microbial products and EPS were attributed to the worms' selective predation of low molecular-weight organic matter, which facilitated the hydrolysis of macromolecular organic matter.

Lead recovery from scrap cathode ray tube funnel glass by hydrothermal sulphidisation.

This research focused on the application of the hydrothermal sulphidisation method to separate lead from scrap cathode ray tube funnel glass. Prior to hydrothermal treatment, the cathode ray tube funnel glass was pretreated by mechanical activation. Under hydrothermal conditions, hydroxyl ions (OH(-)) were generated through an ion exchange reaction between metal ions in mechanically activated funnel glass and water, to accelerate sulphur disproportionation; no additional alkaline compound was needed. Lead contained in funnel glass was converted to lead sulphide with high efficiency. Temperature had a significant effect on the sulphidisation rate of lead in funnel glass, which increased from 25% to 90% as the temperature increased from 100 °C to 300 °C. A sulphidisation rate of 100% was achieved at a duration of 8 h at 300 °C. This process of mechanical activation and hydrothermal sulphidisation is efficient and promising for the treatment of leaded glass.

Eliminating drug target interference with specific antibody or its F(ab')2 fragment in the bridging immunogenicity assay.

Background: DB-1003 is a humanized anti-IgE monoclonal antibody with higher affinity than omalizumab. In the affinity capture elution (ACE)-based bridging electrochemiluminescent immunoassay (ECLIA) for antibodies to DB-1003, monkey serum IgE caused false-positive results. Materials & methods: The target-specific antibody or its F(ab')2 fragment was used to mitigate drug target interference in an ACE-based bridging ECLIA for the detection of anti-DB-1003 antibodies. Results: The sensitivity of the developed assay was at least 100 ng/ml. When the anti-drug antibody concentration was 250 ng/ml, the assay tolerated at least 20.0 µg/ml of the monkey IgE. Conclusion: Incorporating the target-specific antibody or its F(ab')2 fragment can overcome the interference from monkey serum IgE in ACE-based bridging ECLIA for anti-DB-1003 antibody detection.

A novel process utilizing mechanochemical sulfidization to remove lead from cathode ray tube funnel glass.

UNLABELLED: A novelprocess ofmechanochemical sulfidization for the treatment of cathode ray tube (CRT)funnel glass has been investigated by co-grinding with the element sulfur The ground samples were characterized by means of a set of analytical methods, including scanning electron microscopy (SEM), x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and thermogravimetric analysis (TG). The analytical results showed that during the co-grinding of the CRTfunnel glass with sulfur, the Si-O-Pb bond in glass and S-S bond broke and recombined into lead sulfide (PbS). The sulfidizing reaction proceeded with an increase in grinding time and the amount of the added sulfur. The sulfidizing rate increased rapidly from 16.6%for the JO-min ground sample to 96.7% for the 120-min ground sample. Using this process, current mineralprocessing technology, such as flotation separation, might be used to recover PbS. The proposed technology could also be used to treat other leaded glass and even other lead-containing wastes. IMPLICATIONS: In this research, a mechanochemical sulfidization method was proposed to recover lead from waste cathode ray tube (CRT) funnel glass. CRT funnel glass was co-ground with sulfur in N2 atmosphere by mechanical milling. After milling, lead in CRT funnel glass was transferred into lead sulfide (PbS). Using this process, current nfiineral processing technology, such as flotation separation, might be used to recover PbS from the ground sample. The process can be applied to treat other leaded glass or lead-containing wastes.

Lead recovery from cathode ray tube funnel glass with mechanical activation.

UNLABELLED: In the disposal of electronic waste, cathode ray tube (CRT) funnel glass remains an urgent environmental problem because of its high lead content. This research developed mechanical activation as a pretreatment process, and it proved to be an effective method for extracting lead from CRT funnel glass. The effects of mechanical activation on the structural changes of CRT funnel glass were investigated using X-ray diffraction (XRD), particle size analysis, specific surface area (SSA), and a scanning electron microscope (SEM). Nitric acid leaching behaviors of the activated CRT funnel glass were studied by varying several parameters: leaching time, liquid-to-solid ratio, acid concentration, and heating temperature, as well as various conditions of activation. The lead recovery rate was observed to increase rapidly, particularly with increases in activation time and leaching temperature, but to vary relatively less under other experimental parameters. Under the optimal leaching conditions, the lead recovery rate for funnel glass activated for 2 hr at the rotational speed of 500 rpm (by ball mill) reached 92.5%, compared with 1.2% from the unactivated sample. IMPLICATIONS: CRT funnel glass containing lead has become a serious environmental problem facing the whole world. In order to dispose of CRT funnel glass, some technologies have been developed. However, these technologies are associated with higher operation and maintenance costs. In this study, mechanical activation was introduced to change the physicochemical properties of CRT funnel glass, which can transform the glass into an easily dissolved one. Under atmospheric pressure leaching conditions, good recovery rate for lead can be achieved and the residue has wide uses. The process can be applied to treat other leaded glass or lead-containing wastes.

Thermal separation of plastic components from waste crystalline silicon solar cells: Thermogravimetric characteristics and thermokinetics.

Thermal treatment is a mainstream technique to separate plastic components from waste crystalline silicon (c-Si) photovoltaic (PV) modules. In this study, the thermogravimetric analysis (TGA) was conducted for a better understanding of the characteristics of plastic components mainly poly(ethylene-co-vinyl) acetate (EVA) binder and polyfluoroethylene composite membrane (TPT) backsheet in waste c-Si PV panels through thermal treatment at four different heating rates (5-20°C·min-1) under nitrogen and air conditions, respectively. The thermal process of the EVA binder whether in a nitrogen or air atmosphere could be divided into two phases, which were 300-400°C and 400-515°C in nitrogen with the total weight loss reached 99.64%; the two phases in the air were 270-405°C and 405-570°C with the total weight loss was 99.68%. The thermal weight loss of TPT in nitrogen has only one phase occured between 380°C and 520°C, and the weight loss rate is about 83%. There are two weight loss phases in the air atmosphere, which the first phase starts from 265°C to 485°C and the second phase ends at 635°C with a final weight loss reaching 97%. Furthermore, the Kissinger-Akahira-Sunose (KAS) method was chosen to calculate the pyrolysis kinetic parameters. The activation energy for EVA in nitrogen (261.16 kJ·mol-1) was higher than in air (209.04 kJ·mol-1), also the TPT in nitrogen (188.28 kJ·mol-1) higher than in air (172.21 kJ·mol-1). That indicated that the thermal decomposition of EVA binder was accelerated at first phase in nitrogen, but there is little difference in air atmosphere. Moreover, the activation energy of PVF of the TPT backsheet in the first phase was lower than that in the second phase. This study provides the fundamental basis to develop efficient thermal separation for the plastic components EVA and TPT in waste PV panels.Implications: This study mainly aims to explore the thermal separation of plastic components of waste c-Si panels for heating treatment, so that developing an accurate heat treatment approach that is efficient to implement for the separation of secondary raw material i.e., glass and silicon wafer from end-of-life PV panels. Therefore, this research findings have significant implications for providing the basic data support for waste PV panels management recycling standards, specifications, or policy documents.

Association between single nucleotide polymorphisms in exon 3 of the alpha-A-crystallin gene and susceptibility to age-related cataract.

BACKGROUND: The mutations in the αA-crystallin (CRYAA) gene may contribute to the development of age-related cataract (ARC). In this study, we searched for single nucleotide polymorphisms (SNP) in exons of CRYAA and investigated the associations between the identified SNPs and the subtypes of ARC. MATERIALS AND METHODS: Peripheral venous blood was collected for the extraction of genomic DNA. Three exons of CRYAA were sequenced to detect SNPs. The frequency distributions of alleles and genotypes were compared between the ARC and control groups. RESULTS: There were 618 patients with various subtypes of ARC (nuclear cataract [NC], cortical cataract [CC], posterior subcapsular cataract [PSC]). The control group comprised 236 patients. The incidence of early-onset cataract was significantly greater in PSC patients (P = .002 for NC; P = .036 for CC). One SNP was detected in exon 3 of CRYAA (rs76740365 G>A). When the distribution of rs76740365 was compared among the ARC subtypes, only the difference between the PSC group and the control group was statistically significant (allele frequency: P = .000057, OR 2.945; genotype distribution frequency: P = .000458). The heterozygote genotype (GA) carried a significantly greater risk than the homozygous wild-type genotype (GG) by 1.742 times for all types of cataracts and 2.369 times for the PSC subtype. CONCLUSIONS: The SNP rs76740365 G>A in exon 3 of the CRYAA gene is associated with greater susceptibility of ARC, particularly the PSC subtype. Individuals carrying the SNP rs76740365 G>A may be more likely to develop PSC at a younger age than other subtypes.

Lead recovery from waste CRT funnel glass by mechanochemical reaction with reductive Al powder.

The safe disposal of waste cathode ray tubes (CRTs) has always been a serious problem due to the stable microstructure of toxic lead (Pb) located in glass. Thousands of researches have been trying to explore environmental and efficient ways to dispose of waste CRTs. To recycle lead from waste CRT funnel glass effectively, a mechanochemical reduction method has been developed in this research. Aluminum was used as a reductant, and the hydrochloric acid solution was used in the leaching process to separate lead from the solution. After mechanochemical ball milling with aluminum, lead ion in CRT funnel glass was transferred into nano-sized element lead. Lead recovery from CRT funnel glass increased significantly as compared to non-activated leaded glass. Approximately 40 % of lead was leached after mechanical activation without aluminum, while over 96 % of lead in the CRT funnel glass could be recovered after mechanochemical reduction with aluminum. Lead chloride (PbCl2) can be recycled from the leaching solution after cooling crystallization. Nano-sized Pb formation and the structural changes of leaded CRT funnel glass by mechanochemical reduction process contributed to obvious improvement in lead recovery. This research provided a high-efficiency and feasible approach for recovering lead in form of PbCl2 crystal from leaded glass.

Innovated application of mechanical activation to separate lead from scrap cathode ray tube funnel glass.

The disposal of scrap cathode ray tube (CRT) funnel glass has become a global environmental problem due to the rapid shrinkage of new CRT monitor demand, which greatly reduces the reuse for remanufacturing. To detoxificate CRT funnel glass by lead recovery with traditional metallurgical methods, mechanical activation by ball milling was introduced to pretreat the funnel glass. As a result, substantial physicochemical changes have been observed after mechanical activation including chemical breakage and defects formation in glass inner structure. These changes contribute to the easy dissolution of the activated sample in solution. High yield of 92.5% of lead from activated CRT funnel glass by diluted nitric acid leaching and successful formation of lead sulfide by sulfur sulfidization in water have also been achieved. All the results indicate that the application of mechanical activation on recovering lead from CRT funnel glass is efficient and promising, which is also probably appropriate to detoxificate any other kind of leaded glass.

Ion exchange to immobilize Cd(II) at neutral pH into silicate matrix prepared by co-grinding kaolinite with calcium compounds.

A novel silicate-based composite material was simply prepared by co-milling kaolinite and calcium compounds to endow the well studied clay minerals with active calcium for efficient removal of heavy metals. Batch experiments were carried out to investigate the main affecting factors such as raw material ratio, ball milling time, contact time, etc.. Even at a neutral solution pH, the silicate adsorbent exhibited excellent performance for the adsorption of Cd(II), reaching equilibrium in 30 min with a removal efficiency over 95%, and allowed a direct discharge of the treated solution without the need of acidic neutralization as usually used in the alkaline precipitation. A set of analytical methods including SEM/EDS and 29Si MAS NMR etc. were used to analyze the adsorption mechanism of Cd(II), revealing that the adsorption process was mainly dominated by ion exchange to accommodate Cd ions inside silicate matrix, accompanied with partial hydroxide precipitation, rather than normally reported surface adsorption on pristine minerals. Furthermore, the as-prepared adsorption material exhibited similar excellent immobilization capacity for multiple heavy metals including Cu(II), Zn(II), Ni(II), Cd(II) and Mn(II). These findings provide a novel concept for the activation of the widely available cheap silicate minerals by the same widely available cheap calcium compounds and high contribution may be expected on its potentials to the environmental purification of heavy metal pollution in water and soil.

Composition changes, releases, and potential exposure risk of PBDEs from typical E-waste plastics.

Since Stockholm Convention listed polybrominated diphenyl ethers (PBDEs) as persistent organic pollutants and banned their addition, alternative halogen flame retardants (AHFRs) have been substituted for PBDEs. This study systematically investigates the change trends of PBDEs and AHFRs from typical e-waste plastics and dust, as well as clarifying human exposure risks of PBDEs in formal and informal e-waste recycling enterprises, repair store and residential building. The results show that the PBDEs levels in five typical types of e-waste vary in the range of 1.08 × 10-3-30.8 µg/g, meeting the requirements of RoHS regulation. Compared with the residential buildings (1.49-1.68 µg/g), PBDEs in the dust from the formal and informal e-waste recycling enterprises are much higher, ranging from 4.70 to 536 µg/g. BDE-209 is the main congener in most e-waste plastic and dust samples. Meanwhile, AHFRs have become the important composition (3.5-61.5%) in e-waste plastics, while its contribution is lower in dust, implying the higher enrichment efficiency of PBDEs. For PBDEs exposure, the dust intake risk of PBDEs is much higher than skin contact for the workers, and the highest hazard quotient (HQ) value (1.40 × 10-1) and cancer risk (CR) value (1.21 × 10-7) both imply safe exposure levels.

Electronically modulated nickel boron by CeOx doping as a highly efficient electrocatalyst towards overall water splitting.

Exploiting economic, efficient and durable non-noble metal electrocatalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is promising, but still faces enormous challenges. Herein, the strategy of doping a metal boride with a rare earth metal oxide has been explored to develop a highly efficient bifunctional electrocatalyst. The novel electrocatalyst CeOx-NiB consists of CeOx-doped NiB supported on nickel foam, and was fabricated by a one-step mild electroless plating reaction. Remarkably, the CeOx-NiB@NF electrode delivers a current density of 10 mA cm-2 at overpotentials of only 19 mV and 274 mV for the HER and OER, respectively. Two-electrode electrolyzers with the CeOx-NiB@NF electrode require only 1.424 V to deliver 10 mA cm-2 for overall water splitting in 1.0 M KOH, outperforming the Pt-C/NF∥IrO2/NF electrolyzer. Meanwhile, the electrode also has good stability (can work for 100 hours at 10 mA cm-2) and industrial-grade current density. This work provides a new idea for the development of efficient and durable non-precious metal catalysts.

Microwave-assisted chemical recovery of glass fiber and epoxy resin from non-metallic components in waste printed circuit boards.

An efficient, microwave-assisted chemical recovery approach for epoxy resin and glass fiber from non-metallic components (NMC) in waste printed circuit boards (WPCBs) for resource reutilization was developed in this research. HNO3 was selected as the chemical reagent because epoxy resin has low corrosion resistance to HNO3. The influence of reaction parameters such as reaction time, temperature, concentration of HNO3, liquid-solid ratio, and power of the microwave synthesizer on the separation efficiency of NMC (epoxy resin and glass fiber) and the reaction mechanism were investigated. The physical and chemical properties of NMC, reaction solvent, and decomposed products were analyzed using energy dispersive X-ray Spectroscopy (SEM-EDX) and Fourier transform infrared spectroscopy (FT-IR). The results showed that up to 88.42% of epoxy resin and glass fiber ((5 g) 10 mL/g) could be separated under the action of 300 W microwave power at 95 ℃ for 12 h and a HNO3 concentration of 7 mol/L. During the reaction, C-N bonds formed by the crosslinking agent and the three-dimensional network structure of the thermosetting epoxy resin were destroyed. The carbon chain structure and chemical properties of epoxy resin did not change significantly and the functional groups of ethyl acetate maintained the chemical structure before and after the reaction. This uncomplicated and efficient inorganic acid chemical microwave-assisted process holds promise for use as a feasible recovery technology for epoxy resin and glass fibers in NMC. The proposed process is particularly appealing because of its high selectivity, considerable economic advantages, and environmental benefits.

Choline-based deep eutectic solvent combined with EDTA-2Na as novel soil washing agent for lead removal in contaminated soil.

Lead-contaminated soil was cleaned through ethylene-diamine-teraacetic acid disodium salt (EDTA-2Na) combined with diluted deep eutectic solvent (DES) which was prepared by mixing choline chloride with ethylene glycol. The influences of leaching temperature, leaching time, liquid-solid (L/S) ratio, concentration of EDTA-2Na, water-DES ratio, and the molar ratio of choline chloride-ethylene glycol (Ch-E) on the leaching rate of lead were investigated. The mineral phases of the soil and DES before and after washing were analyzed using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). The changes to the DESs before and after dissolving lead nitrate (Pb(NO3)2) were analyzed by high resolution mass spectrometry (HRMS) and nuclear magnetic resonance (NMR). Hydrogen bonds and EDTA-2Na in the Ch-M system resulted in the conversion of Pb(NO3)2 to other complex ions such as [Pb·Ch-E]- and [Pb·EDTA-2Na]- and other complex ions due to the dissolution of the washing agent. The results showed that the soil mineral phase did not change significantly and up to 95.79% of Pb could be washed under temperature, time, L/S ratio, EDTA-2Na concentration, DES/water ratio, Ch-E molar ratio, and stirring speed conditions of 40 °C, 2 h, 6, 0.02 M, 2, 0.75 and 300 rpm, respectively. The hydrogen bonds and EDTA-2Na may play a key role in the remediation of lead-contaminated soil by a washing agent. This research describes a rapid, efficient, and environmentally friendly method for remediation of lead-contaminated soil.