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A novel mechanochemically assisted persulfate activation method was proposed in this study to enhance the leaching of valuable metals from lithium-ion batteries by combining ball-milling, advanced oxidation processes and sucrose reduction. By optimizing leaching parameters including temperature, pH, milling time and solid-to-liquid ratio, high leaching efficiencies of 97.1%, 94.0%, 87.6% and 93.8% can be achieved for Li, Ni, Co and Mn respectively. In the mechanochemical process, the breakage of covalent bonds in cathode material is facilitated by free radicals generated from zero valent iron activated ammonia persulfate as well as mechanochemical activation. To further explore the role of free radicals, the mechanism of ammonia persulfate activation by zero valent iron was elucidated, and SO

A three-dimensional (3D) electrode was successfully fabricated by coating carbon felt substrate with PbO2 using an electrodeposition method. Compared with the conventional planar Ti/SnO2-Sb/PbO2 electrode, the CF/PbO2 electrode displayed superior electrocatalytic performance for the degradation of phenol, with an 11.2 times higher rate constant. The improved performance was due to its larger active surface area, enrichment of phenol on the surface due to adsorption, and enhanced mass transfer with the porous 3D structure. It also exhibited an 11.4 times higher current efficiency and a 9.1 times lower energy consumption due to the superior electrocatalytic activity and a higher oxidation potential to hinder oxygen evolution. Moreover, the generation rate of •OH from CF/PbO2 was 1.3 times higher than that of the Ti/SnO2-Sb/PbO2 electrode. The surface chemistry on the CF/PbO2 electrode during phenol degradation was explored by in situ attenuated total reflection-Fourier transform infrared (ATR-FTIR) characterization, with aromatic intermediates and carboxylic acids identified as key reaction intermediates. This composite electrode also presented excellent long-term stability and durability and negligible leaching of Pb cation, demonstrating as a promising electrode for the electrocatalytic degradation of refractory pollution in wastewater treatment.

CoO/NiO nanosheet assembled nanocages (CoO/NiO@C-NC) were prepared to improve the electrochemical performance of Li–S batteries. CoO/NiO@C-NC shows a synergistic adsorption–electrocatalysis effect to accelerate the redox of lithium polysulfides.

Field-scale trials were conducted to remove cadmium (Cd) from paddy soil by using recycled hydroxyapatite modified biochar (HBC) plus low-level CaCl

Developing efficient catalysts with low cost and environmental friendliness for peroxymonosulfate (PMS) activation attracts broad interest. In this study, TiO

Enhancements in the light response and hydrogen peroxide utilization are critical to the catalytic performance of heterogeneous Fenton-like perovskites. Here, in this research, oxygen vacancy-enriched La

The narrow acid pH range and the nonselectivity of the dominant •OH limit the Fenton systems to remediate the organic wastewater. Inspired by the role of heme in physiological processes, we employed iron porphyrin as a novel homogeneous catalyst to address this issue. Multiple active species are identified during the activation of H

Here the role of microplastic size on dissolved organic matter, leaching compounds and microbial community during anaerobic sludge digestion was evaluated. Compared to that without the addition of polyvinyl chloride (PVC), during the 30 days' incubation, the anaerobic sludge digestion by adding PVC at the size of 75 μm and the concentration of 2.4 g/g volatile solids (VS) showed a 8.5% lower cumulative methane production, while a 17.9% higher cumulative methane production was noted by adding PVC at the size of 3000 μm and the concentration of 2.4 g/g VS. A long-term fed-batch laboratory-scale fermenter test for 147 days further testified, that higher removal efficiencies of total solids, volatile solids, and total chemical oxygen demand, and higher methane production were noted by adding PVC (2.4 g/g VS, 3000 μm) into the fermenter. More interestingly, higher concentrations of proteins, polysaccharides, volatile fatty acids, and soluble microbial by-products component were noted in the liquid phase of sludge drawn from the fermenter added with PVC since the biomass therein showed higher efficiencies of solubilization, hydrolysis, acidification, and methanogenesis. Moreover, as identified from the fermenter added with PVC, dibutyl phthalate (DBP) was the most predominant leaching phthalates compound, although the biomass therein showed a 93.4% anaerobic biodegradability of DBP. The leaching of DBP drove the predominance of microbial community towards Synergistota and Methanosaeta. More irregular elliptical shallow dimples were noted on the PVC surface after 147 days' incubation, accompanied with abundances of Proteobacteria, Actinobacteriota, Chloroflexi, Methanosaeta and Methanobacterium. The results from this study showed that the size of microplastic was a crucial factor in evaluating its impact on anaerobic sludge digestion.

Lithium ion batteries have been undergoing rapid development in the global market due to their superior performance. However, the soaring number of lithium ion batteries in the market presents serious disposal challenges at the end of life. Moreover, continuous mining processes are harmful to the environment. From the viewpoint of cleaner production and green chemistry, the efficient recovery and reutilization of spent lithium ion batteries are necessary. In this perspective, the overall process of lithium ion battery recycling, especially the recent advances of hydrometallurgical methods, are summarized, focusing on the leaching, separation, and purification processes. The proper disposal of the waste discharged during the recycling process is proposed, highlighting the mitigation of secondary pollution. In addition, the environmental impact of recycling processes is summarized and thoroughly evaluated by recent life cycle assessment studies, revealing the key role of recycling strategic metal elements toward sustainability in an anthropogenic cycle. Finally, the current challenges in this area are pointed out and perspectives on sustainable approaches, cleaner production, and life cycle assessment are proposed.

The rural teacher development policy plays a key role in cultivating high-quality and sufficient rural teachers in China. This study aims to apply a bibliometric analysis to explore the rural teacher development policy in China’s current education system. The advanced retrieval function of Web of Science (WoS) is used for the literature data, the core collection of Web of Science is selected for the database, and the time span of literature retrieval is consistent with the selected literature. We apply Citespace to analyze the spatial dimension, research paradigm and research method, research theme, research hotspots and co-occurrence of keywords, the evolution process of research hotspots and content of rural teacher development policy in China. It is found that with the deepening of the reform and development of rural elementary education, scholars not only pay attention to the exploration of the deep mechanism of rural teacher policy, but also to data-oriented diversified empirical research.

Hemin has attracted considerable interest as an efficient catalyst recently, however, its direct application is inefficient due to severe molecular aggregation. Immobilizing hemin on various supports is a feasible approach to address this issue. In this work, a CNTs-hemin catalyst was prepared by loading hemin onto multiwalled carbon nanotubes (CNTs) through ball milling. Compared with hemin, CNTs-hemin demonstrates remarkably enhanced performance in the peroxymonosulfate system, with a 650-fold improvement of apparent rate constant, reaching 97.8% degradation of sulfathiazole in 5 min. High-valent iron-oxo porphyrin cation ((Porp)

Owing to the development of urbanization, the amount of sewage sludge generated through biological activated sludge process has increased dramatically. Anaerobic fermentation of sludge is recognized as an expedient and efficient treatment process, widely applied for biogas generation, resource recovery, and volatile fatty acid production. Volatile fatty acids are one of the most widely used carbon sources and have great use in biological nutrient removals. Volatile fatty acids production in anaerobic sludge fermentation is affected by sludge properties, metabolic pathways, and operating parameters. This paper aims to present an overview of the recent advancement in volatile fatty acids production from waste activated sludge. Standalone and hybrid pretreatment methods prior to the sludge fermentation were introduced and assessed based on VFAs accumulation rate and system performance. In addition, different metabolic steps involved in anaerobic fermentation (i.e. hydrolysis, acidification, and methanogenesis) were deeply evaluated. More importantly, the effects of humic substances were evaluated, among which, the electron transfer, the enzyme activity of microbial species, and the interaction between exogenous electron transporters and humic substances were illustrated. Furthermore, the influence of nitrogen and phosphorus ingredients in sludge fermentation and volatile fatty acids production was introduced. It was found that the additives and pretreatment of waste activated sludge are energetically preferred for the hydrolysis improvement and accelerating the volatile fatty acids accumulation. It was concluded that different structures of humic substances may have different effect on the fermentation process and volatile fatty acids production. The synergistic addition of hydrolytic enzymes assisted to reverse the negative effect of humic acids in some cases, and mitigated the adverse effect of humic substances on the inhibition of bacterial growth. The composition and properties of waste activated sludge may limit its biodegradability and hamper the volatile fatty acids production.

Extracellular polymeric substance (EPS) is recognized as a critical component that determines sludge dewaterability. In this study, a layer by layer degradation of EPS was confirmed for the first t...

ACT001 has been shown to exhibit excellent antitumor and anti-fibrosis activities. However, the role of ACT001 in acute lung injury (ALI) and the underlying mechanism remains largely unclear. The present study aimed to investigate the protective effects of ACT001 on ALI and explore the potential mechanisms. Herein, we firstly established the ALI mouse model induced by intratracheal instillation of lipopolysaccharide (LPS). ACT001 treatment significantly alleviated histopathological changes of lung tissues with lower infiltration of pulmonary M1 macrophages in ALI mice. Then, we performed in vitro experiment and found that ACT001 treatment effectively inhibited the M1 phenotype of RAW264.7 and THP-1.. Next, we performed pull-down and mass spectrometry analysis to screen the interacting proteins of ACT001, identifying IKKβ and STAT1 as the critical target proteins of ACT001. And ACT001 treatment significantly suppressed the NF-κB and STAT1 pathways, thereby inhibiting the M1 polarization against inflammation in vivo and in vitro. Finally, we used IMD 0354 (IMD) and Fludarabine (Flud) to specifically block the activity of IKKβ and STAT1, and stimulated macrophages through IKKβ and STAT1 overexpression. Our data clearly showed that ACT001-induced decrease of the M1 polarization was blocked by IMD and Flud treatment, and reversed by IKKβ and STAT1 overexpression in RAW264.7 cells. In conclusion, we discovered that ACT001 significantly alleviates inflammation and limits M1 phenotype of pulmonary macrophages via suppressing NF-κB and STAT1 signaling pathways, providing new insights for the development of drugs to treat ALI/ARDS.

Power overshoot that presents in the power curves of microbial fuel cells (MFCs) is one of the main reasons for the deterioration of MFC performance over the high current region. In this research, the mechanisms of power overshoot were investigated with single-chamber MFCs integrated with carbon cloth anode and Fe/N-doped carbon cathodes possessing varied capacitance properties. It was revealed that insufficient anodic current produced at high potential is responsible for power overshoot generation, which could be eliminated with higher capacitive cathode (7.79 F) compared with the one with lower capacitive cathode (3.74 F). This elimination can be ascribed to the improvement of MFC capacitance induced by cathode capacitance, which was proved by MFC charge-discharge test. However, cathode capacitance can only increase the MFC capacitance to a limited extent, as power overshoot can still occur when applying long stabilization time for polarization test.

Cathode oxygen reduction reaction (ORR) performance is crucial for power generation of microbial fuel cells (MFCs). The current study provides a novel strategy to prepare Fe/N-doped carbon (Fe/N/C) catalyst for MFCs cathode through high temperature pyrolyzing of biomass capsuling melamine resin polymer. The obtained Fe/N/C can effectively enhance activity, selectivity and stability toward 4 e– ORR in pH neutral solution. Single chamber MFC with Fe/N/C air cathode produces maximum power density of 1166 mW m−2, which is 140% higher than AC cathode. The improved performance of Fe/N/C can be attributed to the involvement of nitrogen and iron species. The excellent stability can be attributed to the preferential structure of the catalyst. The moderate porosity of the catalyst facilitates mass transfer of oxygen and protons and prevents water flooding of triple-phase boundary where ORR occurs. The biomass particles encapsulated in the catalyst act as skeletons, which prevents catalyst collapse and agglomeration.

Arsenic-alkali residue (AAR) from antimony production can pose significant health and environmental hazards due to the risk of arsenic (As) leaching. In this study, geopolymer composite synthesized from fly ash (FA) was investigated for efficient stabilization of high-arsenic-containing AAR (As

This study investigated the effects of electrical signaling disruption induced by adding tetraethylammonium (TEA, a potassium channel blocker) on the formation of mixed-cultured electroactive biofilms, especially the relative abundance of Geobacter over time. Results showed that TEA addition decelerated the biofilm formation, but selectively enriched Geobacter over time (45.8% on Day 32, 67.7% on Day 60 and 78.1% on Day 90), thus resulting in higher final extracellular electron transfer (EET) efficiency. Redundancy analysis (RDA) confirmed that TEA and operation time were significant factors for the selective enrichment of Geobacter. Moreover, increase in cellular processes and signal processing by PICRUSt analysis indicated adaptive responses of electrogenic biofilms to electrical signaling disruption. Furthermore, qRT-PCR indicated the compensatory roles of key cytochromes and pilA in electrochemical communication, which induced Geobacter enrichment. This work provided a broader understanding of electroactive biofilm regulation and potential applications for electricity generation and biosensor in the future.

This study compared effects of three different valent iron (Fe0, Fe(II) and Fe(III)) on enhanced anaerobic sludge digestion, focusing on the changes of oxidation reduction potential (ORP), dissolved organic nitrogen (DON), and microbial community. Under the same iron dose in range of 0–160 mg/L after an incubation period of 30 days (d), the maximum methane production rate of sludge samples dosed with respective Fe0, Fe(II) and Fe(III) at the same concentration showed indiscernible differences at each iron dose, regardless of the different iron valence. Moreover, their behavior in changes of ORP, DON and microbial community was different: (1) the addition of Fe0 made the ORP of sludge more negative, and the addition of Fe(II) and Fe(III) made the ORP of sludge less negative. However, whether being more or less negative, the changes of ORP may show unobservable effects on methane yield when it ranged from −278.71 to −379.80 mV; (2) the degradation of dissolved organic nitrogen, particularly proteins, was less efficient in sludge samples dosed with Fe0 compared with those dosed with Fe(II) and Fe(III) after an incubation period of 30 d. At the same dose of 160 mg/L iron, more cysteine was noted in sludge samples dosed with Fe(II) (30.74 mg/L) and Fe(III) (27.92 mg/L) compared with that dosed with Fe0 (21.75 mg/L); (3) Fe0 particularly promoted the enrichment of Geobacter, and it was 6 times higher than those in sludge samples dosed with Fe(II) and Fe(III) at the same dose of 160 mg/L iron.

This study investigated a novel sodium iron chlorophyllin-H

The utilization of recycled biochar combined with chemical leaching is an appropriate method to remove cadmium (Cd) from paddy soil. Some Cd-rich soil clay particulates (particulate Cd) are reported to be removed via biochar adsorption and the potential impact of biochar on soil properties need further study. The removal efficiencies and mechanisms of Cd from soil by using floatable hydroxyapatite modified biochar (HBC) combined with CaCl

A microbial fuel cell-photocatalysis system with a novel photocatalytic air-cathode (MFC-PhotoCat) was proposed for synergistic degradation of 2,4,6-trichlorophenol (TCP) with simultaneous electricity generation. Stable electricity generation of 350 mV was achieved during 130 days of operation. Besides, 50 mg L−1 TCP was completely degraded within 72 h, and the rate constant of 0.050 h−1 was 1.8-fold higher than MFC with air-cathode without N-TiO2 photocatalyst. Degradation pathway was proposed based on the intermediates detected and density functional theory (DFT) calculation, with two open-chain intermediates (2-chloro-4-keto-2-hexenedioic acid and hexanoic acid) detected. Furthermore, hierarchical cluster and PCoA revealed significant shifts of microbial community structures, with enriched exoelectrogen (55.2% of Geobacter) and TCP-degrading microbe (7.1% of Thauera) on the cathode biofilm as well as 61.8% of Pseudomonas in the culture solution. This study provides a promising strategy for synergic degradation of recalcitrant contaminants by intimate-coupling of MFC and photocatalysis.

Biological wastewater treatment generates a large quantity of sewage sludge that requires proper treatments. In this study, the biochar pyrolyzed by sludge conditioned with Fenton's reagent and lime (referred to as Fenton-lime system) was first used as an efficient silicon fertilizer for rice cultivation. When the pyrolysis temperature was 750 °C, the dissolved silicon and available silicon contents in biochar derived from sludge conditioned with Fenton-lime system were much higher than those in raw sludge derived biochar without conditioning (3.49 vs. 0.72, 77.25 vs. 2.33 mg/g dry solid, respectively). The enhanced available silicon content was attributed to the newly formed calcium aluminosilicate from the reactions between the added lime and silicon-rich phases in sludge. The rice cultivated with biochar derived from Fenton-lime conditioned sludge showed improved biomass of stem and root by 76.85% and 36.11%, respectively, compared to blank group without the addition of Si source. Heavy metals and the reactive oxygen species (ROS) accumulation in rice were not observed after a culture period of 30 days in the application of sludge-derived biochar as silicon fertilizer. This study provides a promising approach for sewage sludge recycling as an efficient silicon fertilizer in silicon-deficiency land.

Many studies have investigated the effects of different pretreatments on the performance of anaerobic digestion of sludge. However, the detailed changes of dissolved organic nitrogen, particularly the release behavior of proteins and the byproducts of protein hydrolysis-amino acids, are rarely known during anaerobic digestion of sludge by different pretreatments. Here we quantified the changes of three types of proteins and 17 types of amino acids in sludge samples solubilized by ultrasonic, thermal, and acid/alkaline pretreatments and their transformation during anaerobic digestion of sludge. Tryptophan protein, aromatic protein I, aromatic protein II, and cysteine were identified as the key dissolved organic nitrogen responsible for methane production during anaerobic digestion of sludge, regardless of the different pretreatment methods. Different from the depletion of other amino acids, cysteine was resistant to degradation after an incubation period of 30 days in all sludge samples. Meanwhile, the “cysteine and methionine metabolism (K00270)” was absent in all sludge samples by identifying 6755 Kyoto Encyclopedia of Genes and Genomes assignments of genes hits. Cysteine contributed to the generation of methane and the degradation of acetic, propionic, and n-butyric acids through decreasing oxidation-reduction potential and enhancing biomass activity. This study provided an alternative strategy to enhance anaerobic digestion of sludge through in situ production of cysteine.