JOURNAL OF HAZARDOUS MATERIALS

Fabrication of MOF-on-MOF composites by surfactant-assisted growth strategy for SPME of polycyclic aromatic hydrocarbons
Xu L, Chen J and Zhang J
Polycyclic aromatic hydrocarbons (PAHs) are a class of persistent organic pollutants with strong carcinogenicity and mutagenicity, which cause great harm to the environment and food. Herein, a composite (NH-MIL-88@PCN-224) was prepared through a guest PCN-224 in situ grown on the host NH-MIL-88 by a surfactant-assisted growth strategy, and successfully applied for solid-phase microextraction (SPME) of PAHs from milk samples. The prepared SPME coatings exhibited high extraction and adsorption capacity for PAHs due to their porous structure, ultra-large specific surface area, strong π-π stacking, hydrophobic interactions and size-matching effects. The SPME-GC-FID method based on NH-MIL-88@PCN-224 coated fibers has the significant advantages of wide linear range (1-200 ng mL), low detection limit (0.003-0.020 ng mL), high recoveries (92.15-106.64 %) and good reproducibility. This work overcomes the lattice-matching limitation by adopting a surfactant-assisted growth strategy, which offers a new direction for the preparation of ultra-high-performance SPME coatings with extremely high extraction efficiency, exceptional thermal stability, and long service life, and greatly expands the variety of MOF SPME coatings.
Biofilm formation mechanisms of mixed antibiotic-resistant bacteria in water: Bacterial interactions and horizontal transfer of antibiotic-resistant plasmids
Xia L, Wang J, Chen M, Li G, Wang W and An T
Over 95 % of bacteria on water supply pipeline surfaces exist in biofilms, which are hotspots for antibiotic resistance gene (ARG) transmission. This study established mixed biofilm culture systems on a metal iron substrate using Escherichia coli: antibiotic-sensitive bacteria (ASB) and antibiotic-resistant bacteria (ARB). The growth rate and extracellular polymeric substances (EPS) content of mixed biofilm surpassed single-species biofilms due to synergistic interactions among different bacteria. However, the composition of mixed biofilms formed by ASB and ARB became unstable after 72 h, linked to reduced polysaccharide proportions in EPS and inter-bacterial competition. The bacterial composition and conjugative transfer frequency of ARGs in mixed biofilms indicate that biofilm formation significantly enhances horizontal transfer of ARGs. Notably, the conjugative transfer frequency of the mixed biofilm formed by two ARB increased 100-fold within five days. In contrast, the conjugative transfer frequency in the mixed biofilm formed by ASB and ARB was unstable; inter-bacterial competition led to plasmid loss associated with horizontal transfer of ARGs, ultimately resulting in biofilm shedding. Furthermore, genes associated with ARG transfer and biofilm growth up-regulated by 1.5 - 6 and 2 - 7 times, respectively, in mixed biofilm. These findings highlight a mutually reinforcing relationship between biofilm formation and horizontal ARG transmission, with significant environmental implications.
Cotransport of fullerene nanoparticles and clay colloids in porous media: The relation between aggregation and transport
Zhan W, Liu G, Hu E, Zhang J, Huo L and Zhong H
In the study, cotransport of fullerene nanoparticles (nC) and mobile clay colloids (illite (ILL), kaolinite (KL), montmorillonite (ML)) in aquifer porous media and its relation to the aggregative interaction between these two types of particles was investigated. Minimal interaction occurred between nC and ILL, resulting in unaffected transport. Strong heteroaggregation between ML and nC resulted in not only significant retention of both particles during their cotransport but also the retention of nC in the media pre-injected with ML. Strong homoaggregation of KL caused strong straining effect and consequently retention of both KL and nC during their cotransport, however, the pre-emplacement of KL did not cause retention of nC during the sequential injection of KL and nC. Such aggregation behaviors were well demonstrated by the adsorption-sedimentation experiment, microscopic observation, the size and zeta-potential test, and model simulation. Based on the surface chemistry analysis, divalent-cation bridging between ML and nC and hydrogen bonding between KL particles were responsible for the heteroaggregation and the homoaggregation, respectively. The study demonstrated the specificity of the aggregation between the mobile clays and nC to the chemistry of the clays and its consequent effect on the cotransport of the particles, which is critical for assessment of the environmental risk of nC.
Enhanced nitrogen fixation and Cd passivation in rhizosphere soil by biochar-loaded nitrogen-fixing bacteria: Chemisorption and microbial mechanism
Chang Y, Lin L, Shen J, Lin Z, Deng X, Sun W, Wu X, Wang Y, Li Y and Xu Z
This study developed a biochar-loaded Ac material and clarified its chemical and microbial mechanisms for cadmium (Cd) immobilization and plant growth promotion. Results showed that biochar-loaded nitrogen-fixing bacteria (Azotobacter chroococcum; BAc) enhanced Cd adsorption by forming stable complexes with bacterial secretions and activating biochar functional groups. Compared with BC and Ac, after BAc application, Ac successfully colonized the lettuce rhizosphere, tagged with green fluorescent protein. It improved plant nitrogen by 47.39-72.47 % and increased root and shoot biomass by 50.35-107.32 % through nitrogen fixation and amino acid release. BAc reduced soil Cd bioavailability by 16.67-46.42 % and Cd accumulation in root and shoot by 14.28-69.74 %. This occurred through increasing soil pH and converting exchangeable Cd to carbonate-bound and Fe/Mn oxide-bound fractions. Importantly, BAc improved the rhizosphere nutrient environment and promoted the deterministic assembly of the rhizosphere microbial community. It also increased microbial diversity and attracted taxa like Actinomycetales (7.59 %), Solirubrobacteriales (5.17 %), Rhizobiales (5.17 %), and Sphingomonadales (5.17 %), all associated with nitrogen fixation, plant growth promotion, and Cd immobilization. Structural equation modeling (SEM) confirmed that BAc increased nitrogen utilization efficiency in lettuce and facilitated biotic immobilization of soil Cd by optimizing the microbial structure. This study provides insights into how biochar-loaded Ac improve plant growth and control soil Cd pollution.
Simultaneous effects of nanoscale zero-valent iron on wastewater decontamination and energy generation: Mechanisms of sulfamethoxazole degradation and methanogenesis
Zhou L, Li J, Lu X, Zhang W, Pan B and Hua M
The presence of sulfamethoxazole (SMX) can adversely affect the anaerobic digestion process, reducing the efficiency of wastewater treatment and methane production. In this study, the addition of exogenous nanoscale zero-valent iron (nZVI) enhanced the efficient treatment of SMX and promoted the energy recovery from antibiotic wastewater. The results showed that the removal of SMX in the reactor pairs with 0.5 g/L nZVI increased by 20 %, 35 %, and 27 %, and the methane production increased by 21.6 %, 40.9 %, and 26.6 %, respectively, compared with the control reactor at different SMX influent concentrations (50, 100, and 200 mg/L). The microbial community distribution indicated that the nZVI facilitated efficient cooperation between acid-producing and methanogens by regulating the relative abundance of functional bacteria, such as Anaerolinea and Methanothrix. Meanwhile, nZVI can effectively facilitate the direct interspecies electron transfer (DIET) and enhance electron transport system (ETS) activity by functioning as a conductive particle and increasing the abundance of genes related to cytochrome C (Cyt C) and type IV pili. In addition, nZVI can reduce the risk of antibiotic resistance genes (ARGs) transmission by decreasing the relative abundance of ARGs. In summary, this study could provide new insights and theoretical support for efficient anaerobic bioremediation and energy recovery of antibiotic wastewater containing SMX.
Corrigendum to "Cobalt induces neurodegenerative damages through Pin1 inactivation in mice and human neuroglioma cells" [J Hazard Mater 419 (2021) 126378]
Zheng F, Li Y, Zhang F, Sun Y, Zheng C, Luo Z, Wang YL, Aschner M, Zheng H, Lin L, Cai P, Shao W, Guo Z, Zheng M, Zhou XZ, Lu KP, Wu S and Li H
The characteristic and bio-accessibility evaluation of mercury species in various kinds of seafood collected from Fujian of China for mercury risk assessment
Sun C, Yin M, Peng Y, Lin C, Wu Y, Fu F and Lin Y
Seafood consumption is the major source of total Hg (tHg) and methyl mercury (MeHg) for humans. Lack of broad-representative bio-accessibility of mercury species makes accurate assessment on health risk of seafood's mercury impossible. Herein, the concentrations and in vitro bio-accessibilities of mercury species in 93 seafood samples with 71 different species were extensively investigated. Results indicated that all shellfish and fish samples, and most seaweed samples contained both Hg and MeHg, while some seaweed samples contained only Hg. The concentrations of mercury species varied depending on the differences in species/individuals of seafood and sampling regions. MeHg in seafood can be partly de-methylated into Hg during gastrointestinal digestion, which reduced the toxicity of mercury in seafood. The mean demethylation rate of MeHg varied as follows: seaweeds (⁓62.1 %) > shellfishes/shrimps (⁓19.7 %) > fishes (⁓9.2 %). The mean bio-accessibility of Hg and tHg varied as follows: seaweeds (⁓97.7 % and ⁓90.1 %) > shellfishes/shrimps (⁓65.1 % and ⁓67.9 %) ≈ fishes (⁓65.1 % and ⁓66.7 %), while that of MeHg varied as follows: fishes (⁓57.7 %) > shellfishes/shrimps (50.8 %) > seaweeds (⁓11.6 %). The simulated calculation of target hazard quotient (THQ) revealed that the health risk of seafood's mercury may be accurately assessed using tHg, not mercury species, even without considering bio-accessibility. This offers a simple but protective approach for assessing the health risk of seafood's mercury. Results of this study provide the potential broad-representative bio-accessibilities of mercury species existing in various kinds of seafood and novel insights for scientifically assessing the health risk of seafood's mercury and revising the mercury limitation in seafood.
Machine learning models with innovative outlier detection techniques for predicting heavy metal contamination in soils
Proshad R, Asharaful Abedin Asha SM, Tan R, Lu Y, Abedin MA, Ding Z, Zhang S, Li Z, Chen G and Zhao Z
Machine learning (ML) models for accurately predicting heavy metals with inconsistent outputs have improved owing to dataset outliers, which influence model reliability and accuracy. A comprehensive technique that combines machine learning and advanced statistical methods was applied to assess data outlier's effects on ML models. Ten ML models with three outlier detection methods predicted Cr, Ni, Cd, and Pb in Narayanganj soils. XGBoost with density-based spatial clustering of applications with noise (DBSCAN) improved model efficacy (R). The R2 of Cr, Ni, Cd, and Pb was considerably enhanced by 11.11 %, 6.33 %, 14.47 %, and 5.68 %, respectively, indicating that outliers affected the model's HM prediction. Soil factors affected Cr (80 %), Ni (72.61 %), Cd (53.35 %), and Pb (63.47 %) concentrations based on feature importance. Contamination factor prediction showed considerable contamination for Cr, Ni, and Cd. LISA revealed Cd (55.4 %), Cr (49.3 %), and Pb (47.3 %) as the significant pollutant (p < 0.05). Moran's I index values for Cr, Ni, Cd, and Pb were 0.65, 0.58, 0.60, and 0.66, respectively, indicating strong positive spatial autocorrelation and clusters with similar contamination. Finally, this work successfully assessed the influence of data outliers on the ML model for soil HM contamination prediction, identifying crucial regions that require rapid conservation measures.
Regulation of electron density in Pt nanoparticles via bimetallic metal-organic frameworks for enhancing photothermal catalysis of toluene decomposition
Luo S, Fan S, Yuan J, Xiao J, Sun X, Wang L, Zhang Y, Zhang Z, Fu X and Dai W
Volatile Organic Compounds (VOCs) are omnipresent in the sphere of human industrial, harboring latent adverse consequences for health and the ecological system. The photothermal catalytic oxidation of VOCs is an advanced integrated technology that harnesses the combined effects of light and heat energy to enhance the efficiency of VOCs degradation. Herein, a bimetallic Metal-Organic Framework (MOF) was synthesized with the incorporation of Ce into the UiO-66-NH(Zr) (i.e., UNH(Zr)), UiO-66-NH(ZrCe) (i.e., UNH(ZC)), which was achieved with Ce atom substituting for a portion of Zr atom within the Zr-oxo clusters. Pt nanoparticles (NPs) are integrated with MOFs to form composites using the dual-solvent method. Ce-oxo fulfills a bifunctional role: it not only facilitates the enhancement of the ligand-to-metal charge transfer (LMCT), but also establishes interaction with Pt NPs. Ce-oxo mediates an enhancement of electron density on Pt NPs. This phenomenon enhances the adsorption and activation of oxygen, significantly boosting the photocatalytic performance for toluene degradation, as demonstrated by a reduction of 30 ℃ for complete mineralization of toluene as compared to that of Pt@UiO-66-NH(Zr) (i.e., PUNH(Zr)). This study potentially offers new insights into the relationship between electron transfer effects in bimetallic MOF-based catalysts and their efficient catalytic performance for VOCs degradation.
Perspectives on using peat records to reconstruct past atmospheric Hg levels
Li C, Enrico M, Bishop K, Roberts SJ, Hodgson DA, Lamentowicz M, Mauquoy D, Mestrot A and Grosjean M
Anthropogenic mercury (Hg) emissions to the atmosphere have increased the concentration of this potent neurotoxin in terrestrial and aquatic ecosystems. The magnitude of regional variation in atmospheric Hg pollution levels raises questions about the interactions between natural processes and human activities at local and regional scales that are shaping global atmospheric Hg cycling. Peatlands are potentially valuable and widespread records of past atmospheric Hg levels that could help address these questions. This perspective aims to improve the utility of peatlands as authentic Hg archives by summarizing the processes that could affect Hg cycling in peatlands. We identify the overlooked role of peat vegetation species and their primary productivity in Hg sequestration under climatic and anthropogenic activities. We provide recommendations to improve the reliability of using peat cores to reconstruct the atmospheric Hg levels from past decades to millennia. Better information from peatland archives on regional variation in atmospheric Hg levels will be of value for testing hypotheses about the processes controlling global Hg cycling. This information can also contribute to evaluating how well international efforts under the UNEP Minamata Convention are succeeding in reducing atmospheric Hg levels and deposition in different regions.
Methane seepage leads to a specific microplastic aging process in the simulated cold seep environment
Chen X, Wu XN, Feng JC, Wang B, Li CR, Lin YL, Huang YJ, Zhong S, Zhang XC, Hu JL and Zhang S
Marine microplastics pose a significant threat to ecosystems, and deep-sea regions serve as critical sinks for these pollutants. Among these regions, cold seeps harbor relatively high concentrations of microplastics. However, research on the aging of microplastics under low-temperature, dark, methane-abundant, and high-pressure conditions remains limited. Seawater and sediment were collected from various Haima cold seepage sites to simulate seepage environments in 200-mL high-pressure reactors. Four types of microplastics at high concentrations (approximately 10 %) were cultured and monitored over two months to explore how they aged. The key findings are as follows: (1) Compared to areas of weak seepage, methane seepage accelerated microplastic aging, as evidenced by increased surface roughness, enhanced C-O and (CO)-O bond formation, increased microbial colonization, and reduced contact angles. (2) Microplastic aging is more pronounced in sediments than in seawater, with biodegradable polylactic acid (PLA) exhibiting the most significant aging characteristics and carbon contribution. (3) Aged microplastics induce greater disturbances in inorganic nutrient levels than in organic matter, impacting nitrogen cycle processes involving nitrate, nitrite, and ammonium. This study results reveal the fundamental aging characteristics of microplastics in extremely deep seas and highlight their potential ecological effects.
Phase conversion characteristics of lead sulfate in ferric sulfate medium
Sun P, Wang J, Li X, Wei C, Deng Z and Li M
The phase transformation characteristics of lead sulfate (PbSO) in a sulfuric acid (HSO) system were studied, focusing on the effects of temperature, HSO concentration, ferric iron (Fe) concentration, sodium sulfate (NaSO), and potassium sulfate (KSO). The conversion of PbSO was analyzed by characterizing the composition and structure of the solid product through XRD, SEM/BSE-EDS, and FT-IR. The results indicated that the effect of temperature on PbSO transformation was influenced by HSO concentration. The temperature threshold for PbSO conversion to lead jarosite (Pb-J) decreased from 150 to 90 ℃ as HSO concentration decreased from 20 to 5 g/L. At 150 ℃, the amount of jarosite generated decreased significantly from 86.04 to 9.76 %. Subsequently, when HSO concentration exceeded 40 g/L, PbSO was essentially unchanged. Concurrently, Pb-J formation correlated with the partial formation of hydronium jarosite (H-J). The production of jarosite was inhibited when the solution pH was ∼ 0.3 or lower. Furthermore, the increase in Fe concentration facilitated Pb-J formation, whereas NaSO and KSO inhibited Pb-J formation, leading to the formation of potassium jarosite (K-J) and sodium jarosite (Na-J), respectively. This study provided insights into regulating PbSO conversion during sulfide ore oxygen pressure leaching.
Scale-up construction of stable multifunctional hydrogel interfaces for large-scale purification of complex oil-water emulsions and oil recovery
Qiao H, Zhao Q, Li J, Lu H, Wu J, Yang L, Ma Y, Yin Y, Guo F, Wang Y and Wang W
Inspired by the multi-level structure of grass clumps in nature, a novel filter with plexiform-structured hydrogel interface was constructed using sepiolite-derived silica nanofiber (SiNF) as the supporter and crosslinked polyvinyl alcohol (cl-PVA) hydrogel as the coating. Experimental test, DFT and MD calculations have confirmed that the addition of SiNF can not only enhance oil-water separation efficiency, but also improve the stability of hydrogel coating. The hydrogel interface with excellent stability and superhydrophilic/underwater superoleophobicity can be manufactured on a large copper mesh (1 m × 1.2 m) to achieve large-scale production. The surface-engineered mesh (named cl-PVA/SiNF@Ag-Cu) can be assembled on a self-designed equipment for continuous purification of emulsion wastewater (processing capacity: 576.00 L/day), achieving a high separation efficiency of 99.7 % for complex oily emulsion only under the action of gravity, and can simultaneously recover oils. After being treated under extreme conditions such as strong acid/alkali, high/low temperature (100 °C, 200 °C, and -18 °C), high salt concentration, sandpaper wear, and long-term aging, the surface structure of cl-PVA/SiNF@Ag-Cu filter remains stable. The antifouling, antibacterial, and anticorrosion capabilities of the filter give it the potential for long-term and large-scale purification processes. Planting and breeding experiments have confirmed that purified water is harmless to animals and plants.
Metagenomics and metaproteomics reveal the effects of sludge types and inoculation modes on N,N-dimethylformamide degradation pathways and the microbial community involved
Xian Y, Cao L, Lu Y, Li Q, Su C, He Y, Zhou G, Chen S and Gao S
This study demonstrated the effects of the sludge type and inoculation method on the N,N-dimethylformamide degradation pathway and associated microbial communities. The sludge type is critical for DMF metabolism, with acclimatized aerobic sludge having a significant advantage in terms of DMF metabolism performance, whereas acclimatized anaerobic sludge has a reduced DMF metabolism capacity. Metagenomic revealed increased abundances of Methanosarcina, Pelomona and Xanthobacter in the adapted anaerobic sludge, suggesting that anaerobic sludge can utilize the methyl products produced by DMF metabolism for growth. Adapted aerobic sludge had high Mycobacterium abundance, significantly boosting DMF hydrolysis. In addition, a large number of dmfA2 genes were found in aerobic sludge, more so in acclimatized sludge, indicating stronger DMF metabolism. Conversely, acclimatized anaerobic sludge showed lower abundance of dmd-tmd and mauA/B, qhpA genes, implying long-term DMF toxicity reduced anaerobic microbial activity. Metaproteomic analysis showed that Methanosarcina and Methanomethylovorans enzymes in anaerobic sludge metabolized dimethylamine and methylamine to methane, aiding DMF degradation. In the aerobic sludge, aminohydrolase proteins, which hydrolyze DMF, were significantly upregulated. These findings provide insights into DMF wastewater treatment.
Emitted droplets and aerosols and their transmission when drying hands under an air-jet dryer
Gao Z, Li Y, Wang F, Duanmu L and Zhang TT
When drying hands with a high-speed air jet dryer, the jet impingement on hands can quickly atomize the remnant water on the hand skins into droplets and aerosols. Emission of droplets and liquid aerosols, their spatial transport and the possible inhaling exposure to the hand dryer user remain unclear. This investigation measured the jet flows from a downward air jet dryer, by the particle image velocimetry (PIV), the helium bubble trajectory analysis, and an ultrasonic anemometer. Emission of the droplets when turning over the hands, the droplet spatial motion, and their deposition on human body were photographed by a high speed camera. Concentrations of the liquid aerosols were monitored and the total emitted aerosol numbers and size spectrum were analyzed. The possible inhalation exposure to the emitted liquid aerosols was examined. It is found that number of droplets in size of 0.1 to 0.6 mm can deposit on the mouth and nose and the surrounding face. A typical hand drying process may emit approximately 10 liquid aerosols, of which 93 % are in the submicron size. A hand dryer user may inhale thousands of the emitted liquid aerosols if drying hands without wearing face mask.
Exogenous additives reshape the microbiome and promote the reduction of resistome in co-composting of pig manure and mushroom residue
Zhang L, Jiang L, Yan W, Tao H, Yao C, An L, Sun Y, Hu T, Sun W, Qian X and Gu J
Comprehensive understanding of the microbiome and resistome evolution in compost is crucial for guaranteeing the safety of organic fertilizers. Current studies using different composting systems and sequencing technologies have yielded varying conclusions on the efficacy of exogenous additives (EAs) in reducing antibiotic resistance genes (ARGs) in compost. This study employed metagenomics to investigate the impact of various EAs on microbial communities, ARGs, their coexistence with mobile genetic elements (MGEs), and ARG hosts in co-composting. Our results demonstrated that EAs significantly reshaped the microbial communities and facilitated a notable reduction in total ARG abundance and diversity, primarily by decreasing core ARGs. Cooperative rather than antagonistic relationships among bacteria. The RA changes in total ARGs are mainly caused by a decrease in the prevalence of core ARGs. Furthermore, EAs showed significant efficacy in reducing clinical ARGs, including cfxA, tetX1, cfxA6, vanA, and aac (6')-Ib', with diatomite (5 %) and zeolite (5 %) being the most effective. The effect of EAs on ARGs and microbial community assembly were stochastic processes. Composting stage and EAs jointly reduced the association between ARGs and MGEs in the composting system. The reduction of ARGs attributed to a decreased abundance of potential pathogenic ARG-associated hosts and diminished associations with MGEs. In conclusion, EAs present a straightforward and effective approach for promoting ARGs reduction in compost, offering crucial insights for assessing the environmental risks associated with the release of agricultural ARGs.
New insights into aqueous Hg(II) photoreduction from paddy field system to natural water: Gear effect of straw returning and soil tillage
Fei Z, Wang Z, Wang J, He S, Wu Q and Wu P
Soil dissolved organic matter (SDOM) has a strong complex with divalent mercury (Hg(II)) and can affect the fate of aqueous Hg(II) photoreduction. However, little is known about the influence of straw returning and soil tillage on the composition of SDOM in paddy soil and Hg(II) photoreduction in paddy water. Here, we demonstrate that the combined drivers of long-term straw returning and tillage can result in higher degrees of aromatization, and the enrichment of oxygen-containing functional groups in surface SDOM. Hg(II) photoreduction under low Hg/DOC conditions is mainly constrained by the composition of SDOM, whereas solar radiation emerged as a dominant controlling factor associated with high ratio of Hg/DOC. By increasing the release of SDOM and mobility of Hg(II), reducing the stability of Hg(II)-SDOM complexes, and potentially enhancing generation of reactive intermediates, gear effect of straw returning and soil tillage significantly enhanced Hg(II) photoreduction in the presence of surface SDOM from 0-40 cm (maximum photoreduction percentage can reach 44.76 ± 2.24 %). Previous inventories of Hg(0) emissions from paddy field system may have overlooked or underestimated this critical process. Future modeling work should be carried out to evaluate the role of straw returning and soil tillage on global Hg cycle.
Fabrication of superporous cryogels with amidoxime chelation sites and customizable 3D printing for targeted palladium recovery from secondary resources
Wu F, Haleem A, Ullah M, Chen L, Li H and Pan J
Recovering precious metals such as palladium from secondary resources faces significant challenges, including the scarcity of efficient adsorbents capable of withstanding harsh acidic conditions and needing materials with high selectivity, mechanical stability, and scalability. In response to these challenges, we developed highly porous cryogels functionalized with sulfonic and amidoxime groups, achieving a unique combination of hydrophilicity, flexibility, and selectivity for Pd(II) ions. Using a redox cryopolymerization method, these cryogels attained a gel fraction of 100 % and a maximum adsorption capacity of 425.3 mg g at 318 K, as the Langmuir isotherm model fitted. This work also combined 3D printing technology with cryopolymerization to create a highly selective, high mechanical strength and customizable shape adsorption material, overcoming traditional adsorption materials' limitations in acid conditions. This innovative combination fills the gap in selective palladium recovery in customizable super macroporous materials, offering a sustainable solution for precious metal recovery and setting a foundation for broader applications in adsorption separation.
Enhanced NO-assisted soot combustion by cobalt doping to weaken mullite Mn-O bonds for lattice oxygen activation
Guo Q, Liu Y, Zhang X, Xu Y, Liu P and Zhang C
Catalytic combustion is widely regarded as the most efficient technique for removing soot particulates from diesel engine exhaust, with its efficiency largely dependent on the performance of catalysts. In this study, a series of YMnCoO catalysts were synthesized using a hydrothermal method to investigate their catalytic properties in soot oxidation. Among these catalysts, YMCo-0.2 exhibited the highest catalytic activity, achieving 90 % soot conversion at 392 °C and demonstrating robust tolerance in the presence of water vapor and SO. Structural characterization revealed that Co doping did not alter the fundamental crystal structure of YMnO mullite. Through some characterization comprehensive analysis, and DFT calculations further supported the experimental findings, indicate that Co substitution significantly increased the lattice oxygen mobility and surface active oxygen content. Compared to the surface lattice oxygens at other positions, the weakening of the Mn-O bond results in the lattice oxygens in the Co-O-Mn sites in the catalysts exhibiting higher reactivity. Additionally, the catalyst displayed strong NO and O adsorption and activation capabilities, indicating its potential for efficient NO-assisted soot combustion. This study provides insights for designing and optimizing mullite catalysts for soot combustion.
Tactfully introducing amphoteric group into electroactive membrane motivates highly efficient HO splitting for reversible removal and recovery of nickel(II)
Yu Y, Liu H, Wang P, Kong X, Jin H, Chen X, Chen J and Chen D
Membrane-based electro-deposition (MED) is an original process promising for reversible removal and recovery of toxic heavy metal ions from wastewater. The removal efficiency of heavy metal ions, however, was limited by the poor membrane surface HO splitting in the conventional ion exchange membrane (IEM). Inspired by the amphoteric interface-triggered ion exchange resin regeneration phenomenon in electro-deionization, herein we subtly introduced the amphoteric group into IEM as a proof of concept to solve the above bottleneck. By virtue of the "electronic porter" role of the amphoteric OS-R-N(CH), the electron extraction from adsorbed HO could be accelerated, extending the HO splitting from the conventional membrane surface to the bulk membrane interior. Such an HO splitting extension favorably produced an intensified and well-modeled OH production region at the anodic side of IEM, enhancing the Ni basic deposition accordingly. This special characteristic allowed our MED to realize a super-eminent metal ion removal rate (10.5 mol·h·m) along with an ultra-low specific energy consumption (0.1 kWh·mol) for Ni removal, which considerably surpassed those of state-of-the-art heavy metal ion removal processes reported yet. Further, the deposited Ni could be in situ recovered in conjunction with the facile polarity reversal method. The amphoteric electroactive membrane with high HO splitting activity is expected to pave the path to engineering MED for efficient heavy metal ion removal and recovery.
Corrigendum to "Global air quality enhancement pathways to health benefits and environmental justice" [J Hazard Mater 480 (2024) 136460]
Xu Y, Zhou SC, Feng YX, Zou B and He C