Separation Experiments Research Articles

An advanced separation method for the acquisition of 212Pb/212Bi from natural thorium

212Pb/212Bi hold significant potential for targeted cancer therapy; however, their supply remains severely limited. The extraction of 212Pb/212Bi from natural thorium is expected to fundamentally address this issue. This study proposes and verifies a new, efficient and low-cost method for separating 212Pb/212Bi from natural 232Th by investigating the separation behavior and mechanism of a silica-supported anion exchange resin (SiPyR-N4) toward multiple types of metal cations in hydrochloric solution. The experimental results demonstrated that SiPyR-N4 was successfully prepared with a uniform shape, porous structure, and containing quaternary amines. SiPyR-N4 showed extremely high selectivity for Pb2+ and Bi3+, but no affinity for Th4+, La3+, and Ba2+. The adsorption speed was more than six times as fast as traditional resins, providing significant advantages in the separation of short-lived nuclides. The hot separation experiment suggested that 212Pb and 212Bi were successfully isolated from natural 232Th by using natural thorium as the raw material, and the long-lived nuclides were removed completely. The selective separation mechanism was attributed to Pb2+ and Bi3+ forming anionic complexes in the hydrochloric acid medium, while Th4+, Ra2+, and Ac3+ did not form such complexes. Pb2+ and Bi3+ were bound to the active sites via chloride bridges, with [PbCl3]− and [BiCl6]3− serving as the main adsorbed species. This study is the first to report the direct and selective separation of 212Pb and 212Bi from 232Th decay chains using non-crown ether materials, and it provides an excellent material candidate for the separation of short-lived nuclides, showing significant application potential in the future.

Membranes Fouling Propensity of PSF/GO Hollow Fiber Mixed Matrix Membranes for Water Treatment Ultrafiltration Application.

The study focused on investigating the fouling propensity of polysulfone (PSF) hollow fiber (HF) mixed matrix membranes modified with 1.0 wt % graphene oxide (GO). Through a comprehensive set of analyses including scanning electron microscopy (SEM), atomic force microscopy (AFM), water contact angle (WCA), and mechanical assessments, the structural characteristics and properties of both untreated and GO-modified PSF HF membranes were thoroughly examined. The scope of evaluation encompassed filtration and separation experiments involving not only pure water but also a range of model contaminants with distinct sizes, such as bovine serum albumin (BSA), humic acid (HA), E. coli bacteria, and oil-in-water emulsion. Remarkably, the incorporation of graphene oxide (GO) into the PSF HF membranes led to a substantial enhancement in their antifouling performance. The GO-modified membranes exhibited an impressive recovery rate of over 90 % of their initial pure water flux during filtration experiments involving humic acid (HA) and oil, demonstrating their exceptional resistance to irreversible fouling. Moreover, the GO-modified membranes exhibited superior oil separation efficiency, further underscoring their efficacy in real-world separation applications. It is noteworthy that the fouling parameters in the case of bovine serum albumin (BSA) were relatively similar for both the unmodified and GO-modified PSF HF membranes. This observation suggests that the introduction of graphene oxide might not significantly influence the interaction between the membrane and BSA molecules. Interestingly, while both types of PSF HF membranes displayed high retention capabilities for E. coli bacteria, the addition of graphene oxide did not result in any noticeable improvement in this regard.

Engineering Trifluoromethyl Groups in Porous Coordination Polymers to Enhance Stability and Regulate Pore Window for Hexane Isomers Separation.

Effective separation of hexane (C6) isomers is critical for a variety of industrial applications but conventional distillation methods are energy-intensive. Adsorptive separations based on porous coordination polymers (PCPs) offer a promising alternative due to their exceptional porosity and tunable properties. However, there is still an urgent need to develop PCPs with high stability and separation performance. This study investigates how substituting a methyl (-CH3) group with a trifluoromethyl (-CF3) group can regulate pores and hydrophobicity in PCPs. This precise adjustment aims to enhance stability and improve the kinetic separation performance of hydrophobic C6 isomers by considering the size and hydrophobicity of the trifluoromethyl group. Two isostructural PCPs with pcu topology, PCP-CH3 and PCP-CF3, were synthesized to vary pore diameters and hydrophobicity based on the presence of -CH3 or -CF3 groups. PCP-CF3 showed greater stability in water compared to PCP-CH3. While PCP-CH3 had high adsorption capacities, it lacked selectivity, whereas PCP-CF3 demonstrated improved selectivity, particularly in excluding dibranched isomers. Dynamic column separation experiments revealed that PCP-CF3 could selectively adsorb linear and monobranched isomers over dibranched isomers at room temperature. These findings highlight the potential of fluorine-modified PCPs for efficient isomer separation and underscore the importance of stability improvement strategies.

Glycopolymer-Mediated Selective Separation of Middle Rare Earth Elements.

The selective separation of rare earth elements (REEs), particularly middle REEs (MREEs) with intermediate ionic radii, poses significant challenges for current methods. In this study, we introduce a novel approach that leverages negatively charged glycopolymers for size-specific separation of MREEs. By varying glycopolymer properties such as degree of polymerization (DP) and charge density, we achieved a distinct U-shaped selectivity profile, with a pronounced preference for Samarium (Sm) and Europium (Eu) over other REEs like Cerium (Ce), Gadolinium (Gd), and Holmium (Ho). Enrichment experiments demonstrated the practical potential of this methodology, achieving over 10% selectivity for Sm in Ce/Sm and Ho/Sm mixtures (10:1 ratios). Further, a separation experiment with a 1:1 Ce/Sm mixture yielded 15% enrichment after five filtration cycles with minimal glycopolymer, underscoring the approach's effectiveness. This work highlights the promise of glycopolymer-based strategies for targeted MREE separation, offering an efficient and tunable pathway for refining separation processes in REE applications.

Glycopolymer‐Mediated Selective Separation of Middle Rare Earth Elements

The selective separation of rare earth elements (REEs), particularly middle REEs (MREEs) with intermediate ionic radii, poses significant challenges for current methods. In this study, we introduce a novel approach that leverages negatively charged glycopolymers for size‐specific separation of MREEs. By varying glycopolymer properties such as degree of polymerization (DP) and charge density, we achieved a distinct U‐shaped selectivity profile, with a pronounced preference for Samarium (Sm) and Europium (Eu) over other REEs like Cerium (Ce), Gadolinium (Gd), and Holmium (Ho). Enrichment experiments demonstrated the practical potential of this methodology, achieving over 10% selectivity for Sm in Ce/Sm and Ho/Sm mixtures (10:1 ratios). Further, a separation experiment with a 1:1 Ce/Sm mixture yielded 15% enrichment after five filtration cycles with minimal glycopolymer, underscoring the approach's effectiveness. This work highlights the promise of glycopolymer‐based strategies for targeted MREE separation, offering an efficient and tunable pathway for refining separation processes in REE applications.

Preparation of temperature-responsive smart sponge and its application in oil-water separation and dye adsorption

At present, researchers are committed to studying new intelligent response materials to deal with severe water pollution problems. Using PU sponge as the substrate, dopamine was first modified to construct a rough surface while introducing active groups. The monomer N-isopropylacrylamide (NIPAM) and itaconic acid (IA) were grafted and polymerized onto the polydopamine coating on the sponge surface by vinyltrimethoxysilane (VTMS). The obtained DINA-PU sponge has good temperature response and switchable wettability characteristics, and has good adsorption-desorption cycle function. Moreover, a micro-filtration device was designed to separate heavy (light) oil-water mixtures. The separation efficiency can reach more than 95 % and 99 % for heavy and light oil-water, respectively. In addition, the adsorption capacity of the material for methylene blue (MB) can reach 660 mg·g−1. The separation efficiency in the oil-water separation-dye adsorption integrated separation experiment can reach more than 99 %.

DLAT promotes triple-negative breast cancer progression via YAP1 activation

ABSTRACT Background Breast cancer (BC) is the most prevalent malignant tumor in women globally. Triple-negative breast cancer (TNBC) represents the most malignant and invasive subtype of BC. New therapeutic targets are urgently needed for TNBC owing to its receptor expression characteristics, which render it insensitive to traditional targeted and endocrine therapies for BC. The role and mechanisms of dihydrolipoamide S-acetyltransferase (DLAT) as a crucial molecule in glycometabolism and cuproptosis-related biological processes in tumors remain to be explored. Methods DLAT expression was investigated using bioinformatics methods and quantitative real-time polymerase chain reaction. Subsequently, the MTT assay, colony formation assay, and migration-invasion assay were performed to validate the effect of DLAT on TNBC cell viability, proliferation, and migration. Cytoplasmic-nuclear separation experiments, western blot analysis, and co-immunoprecipitation assays were performed to elucidate the underlying molecular mechanisms. Results This study revealed a robust correlation between elevated DLAT expression in BC and unfavorable prognosis in patients, with higher expression of DLAT compared to other subtypes in TNBC. Functional cytology experiments indicated that DLAT plays a tumor-promoting role in TNBC. Mechanistic studies showed that DLAT directly interacts with YAP1, leading to the dephosphorylation and activation of YAP1 and its increased nuclear translocation, thereby transcriptionally activating and regulating downstream oncogenes, promoting the malignant phenotype of TNBC. Rescue experiments indicated that DLAT promotes the malignant behavior of TNBC through a YAP1-dependent pathway. Conclusions Our research unveiled the significant involvement of DLAT in TNBC, along with the potential for modulating DLAT/YAP1 activity as a targeted treatment strategy for TNBC.

Fouling Resistant Liquid-Infused membranes for oil separations

Bioinspired membranes offer an alternative approach to improving the fouling resistance of commercial membranes for oil separations. Here, two perfluoropolyether oils, a lower viscosity Krytox 103 (K103) and a higher viscosity Krytox 107 (K107), were infused into commercial polyvinylidene fluoride (PVDF) ultrafiltration membranes to mimic the Nepenthes pitcher plant. The transmembrane pressure required to perform long-term oil permeance tests was optimized by testing the liquid-infused membranes at different applied pressures. Crystal violet staining and variable pressure scanning electron microscopy qualitatively suggest that the oil layer remained on the membranes after the oil separation experiments were conducted. Over 5 cycles, K103- and K107- liquid-infused membranes exhibited a consistent permeance of ∼ 30000 L m-2h−1 bar−1 at 1.0 bar and ∼ 14500 L m-2h−1 bar−1 at 0.5 bar, respectively. The steady performance further supports a long-lasting oil layer persists on the membrane surface and inside membrane’s pores. Next, experiments were conducted to determine the stability of the Krytox oil post accelerated cleaning tests using bleach. No structural changes to the Krytox oils were detected by thermogravimetric analysis or nuclear magnetic resonance spectroscopy. Dynamic fouling experiments using Escherichia coli K12 revealed that the liquid-infused membranes had higher flux recovery ratios (∼95 %) than the bare PVDF control membranes (∼55 %). Our results demonstrate that liquid-infused membranes exhibit chlorine stability and superior fouling resistance, presenting a promising bioinspired membrane that can be used in pressure-driven oil separation applications.

Aging behaviour and mechanical characterisation of maltenes and asphaltenes

The analysis of bitumen is challenging due to its complex and ever-changing chemical composition. Fractionation techniques based on solubility and polarity properties facilitate the examination process, shedding more light on composition, structure and aging behaviour. However, these separation experiments are often performed post-aging, making it difficult to understand the behaviour and mechanical properties of individual subfractions. Hence, the focus of this study was to separate maltenes and asphaltenes in large quantities and age them at various temperatures (80, 130 and 180°C), followed by analysis with chemical and mechanical methods. Results showed that both maltenes and asphaltenes display viscoelastic properties: maltenes are more viscous, while asphaltenes are more elastic compared to the base binder. Maltenes aged at 180°C became extremely stiff with a nearly temperature-independent phase angle, while asphaltenes aged at 130°C exhibited the stiffest and most elastic behaviour. Decomposition of sulfoxides at high temperatures was observed for both fractions, while additional decarboxylation occurred in the asphaltenes. During the aging of the maltenes, a significant amount of asphaltenes were formed, which most likely originated from both the aromatics and resins fraction. Furthermore, no major discrepancies between oxidation products in bitumen and in the maltenes were detected, indicating that asphaltenes might not crucially influence the qualitative aging process. This study demonstrated a possible approach for obtaining bituminous subfractions in large quantities, allowing for a detailed analysis of their mechanical and aging properties.

Biogas purification using cellulose nanocrystals/polyvinyl alcohol coated facilitated transport hollow fiber membranes with L‐arginine as CO2 carrier

AbstractThe composition of biogas consists mainly of CH4 (~60%) and CO2 (40%). To be considered a clean fuel, CH4 concentration in biogas must be increased to over 95%. In this study, membranes which were stacked in a chamber were utilized to purify biogas by passing biogas over them. These membranes were composed of polyethersulfone hollow fiber substrate coated with a “selective layer” made of cellulose nanocrystals (CNC‐0–2 wt) in polyvinyl alcohol (PVA) and l‐arginine as a CO2 carrier. Of the different CNC concentrations in PVA‐LA, CNC1/PVA‐LA (1.0 wt% CNC in PVA‐LA) displayed the lowest water contact angle of 17° (corresponding to higher moisture absorbing ability). With further increase in CNC concentration, even though CNC1.5/PVA‐LA showed the higher crystallinity (66%), and water contact angle increased (20°); reducing the chances of facilitated transport of CO2 through it. Biogas separation experiments were conducted at 90% RH and different feed pressures (0.8–1 bar) for various CNC concentrations. Increasing the CNC concentration led to a thicker selective layer, enhancing the CO2 permeability and selectivity up to CNC1/PVA‐LA. However, with the further addition of CNC, both permeability and selectivity decreased. At 90% RH and 1 bar feed pressure, the CNC1/PVA‐LA setup demonstrated a CO2 permeability of 20,522 Barrer and a selectivity of 33, making it suitable for low‐pressure biogas storage systems with lower energy requirements.

Bifunctional TiO2-Coated SSM for Efficient Emulsion Separation and Photocatalytic Degradation of Soluble Organic Pollutants.

The oily wastewater containing complex organic pollutants poses a great threat to the environment and human beings. At present, the membrane used to treat oily wastewater has some problems, such as complicated preparation and serious membrane pollution. Superhydrophilic/underwater superoleophobic membranes overcome the problems of the surface of the membrane being easily polluted or even blocked by oil, so they have been widely studied by many researchers. In this work, we used an electrochemical deposition method to uniformly load titanium dioxide (TiO2) nanoparticles onto pretreated stainless-steel mesh for efficient oil-in-water (O/W) emulsion separation (TiO2@SSM). The membrane of TiO2@SSM exhibited superior superhydrophilicity and underwater superoleophobicity, ensuring high O/W separation efficiency, reaching 99.8%, and fast water flux of up to 208.0 L·m-2·h-1 for various O/W emulsions. Meanwhile, the membrane possessed a desirable photocatalytic degradation property under visible light irradiation and a degradation efficiency of 98.1% for RhB pollutant. Specially, the as-prepared membrane had long-lasting robustness, sustainability, and recyclability through the cyclic experiments of emulsion separation and photocatalytic degradation. Our results provide a simple and universally applicable route to construct a multifunctional membrane for simultaneously achieving water purification in complex oily wastewater.

Spent lithium-ion battery recycling: Process optimization and carbon footprint analysis based on thermal mechanical force

ABSTRACT With the increasing number of spent lithium-ion batteries, the development of efficient and environmentally friendly recycling technologies has become a key research focus. This study aims to establish a physical recycling method that integrates thermal treatment and mechanical separation to enhance the recovery rate of LiFePO4 materials while minimizing environmental impact. The process combines thermal treatment, mechanical separation, and air separation, with key factors influencing material separation and recovery efficiency analyzed through single-factor and variance analyses. Additionally, the carbon footprint of the recycling process was assessed using SimaPro software. The experimental results indicate that within a temperature range of 270°C–300°C, thermal treatment effectively separates LiFePO4 from aluminum foil, achieving a recovery rate of 96.88%. The air separation experiments further demonstrate that at an airflow speed of 20 m/s, the cathode material and current collector can be efficiently separated. Moreover, the carbon footprint analysis shows that this method significantly reduces carbon emissions.

Separation of no-carrier-added Bi and stable Bi from thallium

Abstract No carrier added 204,206Bi radioisotopes were produced by alpha induced reaction on Tl2CO3 target. Liquid liquid extraction method using 18-crown-6 dissolved in nitrobenzene and HClO4 was developed for the separation of NCA 204,206Bi from bulk Tl target. Bulk Tl was observed to be extracted by the organic phase at higher HClO4 concentrations leaving NCA Bi radioisotopes in the aqueous phase. At 0.01 M 18-crown-6 concentration with 2 M HClO4, separation factor (S Tl/Bi) as high as 3.7 × 103 was achieved. The separation experiment was repeated with stable isotopes of Bi and Tl. The extent of separation was monitored by ICP-OES and the results corroborated with radiometric methods.

Tannic Acid Film Based on One-Dimensional Supramolecular Self-Assembly for Electrical Conductivity and Oil-Water Separation.

Tannic acid is widely regarded as one of the most promising natural polyphenolic compounds. However, current research predominantly focuses on the utilization of its phenolic hydroxyl groups, with limited exploration of the functional potential of its aromatic structure. Herein, one-dimensional nanofibers based on supramolecular self-assembly were successfully prepared through the simple alkylation reaction of tannic acid and the π-π stacking of aromatic structures. These fibers, with lengths reaching tens of micrometers and an average height of 10 nm, were clearly observed using SEM and AFM. A film with excellent electrical conductivity (σ = 37.9 μS/cm) was fabricated by vacuum filtering the organic suspension of these fibers, which was 100-fold higher than that of the TA film. Additionally, the hydrophobic and lipophilic properties of Bn-TA were further investigated through oil-water separation experiments, where the Bn-TA membrane displayed excellent separation efficiency and durability, maintaining stable performance over multiple cycles. This strategy presents opportunities for the high-value utilization of tannic acid.

An Anchored Fe-Cu LDH onto a Polyvinylidene Fluoride Membrane with Strong Peroxymonosulfate Activation-Induced Degradation of Methylene Blue and Self-Cleaning Property of Oil/Water Separation.

Developing a strong catalytic antifouling membrane to achieve efficient sewage purification has great potential for alleviating water crisis. In this work, we designed and prepared an Fe/Cu-layered double hydroxide (Fe-Cu LDH)-coated polyvinylidene fluoride (PVDF) composite membrane (PVDF/Fe-Cu LDHs) with strong antifouling and activating peroxymonosulfate (PMS) catalytic degradation performance through polydopamine-coordination anchoring and hydrothermal reaction. The results showed that abundant hydroxyl groups of the LDH surface endowed the superhydrophilicity (water contact angle <10°) and underwater superoleophobicity (underwater-oil contact angle >150°) of the membrane surface, which displayed outstanding resistance to crude oil adhesion. With assistance of the LDH surface-bound sulfate radical of the peroxymonosulfate system, the PVDF/Fe-Cu LDH membrane demonstrated robust catalytic degradation performance for the methylene blue (MB) in the dark; the degradation rate constant (k, min-1) reached 0.96. Meanwhile, facing the oily wastewater, the selective wettability and charge effect of LDH of the surface made the PVDF/Fe-Cu LDH membrane realize the separation for the various surfactant-free and surfactant-stabilized emulsions. Importantly, the PMS-activation catalytic produced the ROS (•SO4-,•OH, •O2-, and 1O2), which enhanced the regeneration of the fouled PVDF/Fe-Cu LDH membrane and obtained a high flux recovery ratio in the dark (94.7%) after 10 cycles of separation experiments. Hence, we believed that the PVDF/Fe-Cu LDH membrane can provide inspiration for the development and further practical application of antifouling membranes.

In situ Product Recovery of Microbially Synthesized Ethyl Acetate from the Exhaust Gas of a Bioreactor by Membrane Technology

ABSTRACTEthyl acetate is at present exclusively produced from fossil resources. Microbial synthesis of this ester from sugar‐rich waste as an alternative is an aerobic process. Ethyl acetate is highly volatile and therefore stripped with the exhaust gas from the bioreactor which enables in situ product recovery. Previous research on microbial formation of ethyl acetate has focused on the kinetics of ester synthesis and in part on the ester stripping, while the separation of the ester from the exhaust gas has hardly been investigated. A mixed matrix membrane was developed consisting of Silikalite‐1 embedded in polydimethylsiloxane which was installed in a radial–symmetrical membrane module. Evaluation of the separation of ethyl acetate was based on the analysis of the composition of the feed and retentate gas by mass spectrometry. The separation efficiency of the membrane was first tested with varied flows of artificial exhaust gas, containing defined amounts of ethyl acetate. A model for describing the separation process was parametrized by the measured data and used to design a real separation experiment. Ethyl acetate produced from delactosed whey permeate by Kluyveromyces marxianus DSM 5422 in a stirred bioreactor gassed with 0.5 vvm air was successfully separated from the exhaust gas by membranes; 93.6% of the stripped ester was separated. Liquid ethyl acetate was recovered by cooling the permeate gas to ‒78°C, whereby 99.75% of the condensed organic compounds were ethyl acetate. This study demonstrates for the first time that microbially produced and stripped ethyl acetate can be effectively separated from the exhaust gas of bioreactors by membrane technology to obtain the ester in high yield and purity.

Recycling mixed polymer particles using a spiral tube tribo‐electrostatic separation device

AbstractAt present, research on the electrostatic separation of polymers is primarily concentrated in the WEEE field, with limited studies addressing the electrostatic separation of vehicle polymers. In this study, tribo‐charging separation of PA66/PP (modified)/PE three‐component vehicle polymer mixed particles was investigated using a spiral tube tribo‐charged separation device. Firstly, a force model of particle movement in the spiral tube was established, and the theoretical analysis determined that the critical rotational speed of particle centrifugal movement is 70 rpm. Secondly, the optimal charging parameters were determined by single‐factor experiments and orthogonal experiments, and the effect of the blanking baffle on the particle charging was also investigated. Finally, high‐voltage electrostatic separation simulations and experiments were carried out, achieving separation purities of 92.8% for PA66, 80.7% for PP (modified), and 86.6% for PE, respectively. Results provide both theoretical and experimental reference for one‐pass electrostatic separation of three kinds of plastic particles by spiral tube turbo‐charged separation device.Highlights Separation of vehicle polymers is crucial for its high‐value‐added recycling. A spiral tube tribo‐electrostatic separation device is developed. The critical rotational speed of particle centrifugal movement is analyzed. The influence of the blanking baffle on the particle charge is investigated.

Music source feature extraction based on improved attention mechanism and phase feature

Music source feature extraction is an important research direction in music information retrieval and music recommendation system. To extract the features of music sources more effectively, the study introduces the jump attention mechanism and combines it with the convolutional attention module. Also, a feature extraction module based on Unet + + and spatial attention module is proposed. In addition, the phase feature information of the mixed music signals is utilized to improve the network performance. Results showed that this model was studied to perform well in music source separation experiments of vocals and accompaniment. For vocal separation on the MIR-1K dataset, the model achieves 11.25 dB, 17.34 dB, and 13.83 dB for each metric, respectively. Meanwhile, for drum separation on the DSD100 dataset, the model achieves a median signal-to-source distortion ratio of 4.36 dB, which is 2.91 dB better than that of the Spectral Hierarchical Network model. For the separation of the bass sound and the human voice, the model's in the separation of bass and human voice, the median distortion ratio of the model is as high as 4.87 dB and 6.09 dB, which is better than that of the Spectral Hierarchical Network model. This indicates the significant performance advantages in feature extraction and separation of music sources, and it has important application values in music production and speech recognition.

Decoding the zeolite cage effect in one-step ethylene purification from CO2/C2H2/C2H4 mixtures

Utilizing physical adsorption for ethylene purification from complex mixtures can significantly reduce the energy cost for production. The purification of multi-component systems through a single adsorption process presents a considerable challenge, largely stemming from the absence of customized strategies and thorough investigations into adsorption behaviours. We aim to understand adsorbents through a unique cage recognition approach and leverage these insights to develop an effective purification adsorbent, with the successful synthesis of SSZ-16 zeolite meeting requirements for multi-component purification. This zeolite, featuring a long aft supercage and a narrow gme cage construct two adsorption cages. The dense π-electron cloud of C2H2 enables a stronger interaction in aft cage, while CO2 is selectively captured within the environmentally compatible gme cage, demonstrating significantly higher C2H2 and CO2 adsorption capacity. The separation experiments reveal that SSZ-16 exhibits exceptional performance, with an unprecedented polymer-grade C2H4 productivity of 2099.16 L/kg from the CO2/C2H2/C2H4 mixture.

STUB1-mediated K63-linked ubiquitination of UHRF1 promotes the progression of cholangiocarcinoma by maintaining DNA hypermethylation of PLA2G2A

BackgroundCholangiocarcinoma (CCA) is a highly malignant tumor characterized by a lack of effective targeted therapeutic strategies. The protein UHRF1 plays a pivotal role in the preservation of DNA methylation and works synergistically with DNMT1. Posttranscriptional modifications (PTMs), such as ubiquitination, play indispensable roles in facilitating this process. Nevertheless, the specific PTMs that regulate UHRF1 in CCA remain unidentified.MethodsWe confirmed the interaction between STUB1 and UHRF1 through mass spectrometry analysis. Furthermore, we investigated the underlying mechanisms of the STUB1-UHRF1/DNMT1 axis via co-IP experiments, denaturing IP ubiquitination experiments, nuclear‒cytoplasmic separation and immunofluorescence experiments. The downstream PLA2G2A gene, regulated by the STUB1-UHRF1/DNMT1 axis, was identified via RNA-seq. The negative regulatory mechanism of PLA2G2A was explored via bisulfite sequencing PCR (BSP) experiments to assess changes in promoter methylation. The roles of PLA2G2A and STUB1 in the proliferation, invasion, and migration of CCA cells were assessed using the CCK-8 assay, colony formation assay, Transwell assay, wound healing assay and xenograft mouse model. We evaluated the effects of STUB1/UHRF1 on cholangiocarcinoma by utilizing a primary CCA mouse model.ResultsThis study revealed that STUB1 interacts with UHRF1, resulting in an increase in the K63-linked ubiquitination of UHRF1. Consequently, this facilitates the nuclear translocation of UHRF1 and enhances its binding affinity with DNMT1. The STUB1-UHRF1/DNMT1 axis led to increased DNA methylation of the PLA2G2A promoter, subsequently repressing its expression. Increased STUB1 expression in CCA was inversely correlated with tumor progression and overall survival. Conversely, PLA2G2A functions as a tumor suppressor in CCA by inhibiting cell proliferation, invasion and migration.ConclusionsThese findings suggest that the STUB1-mediated ubiquitination of UHRF1 plays a pivotal role in tumor progression by epigenetically silencing PLA2G2A, underscoring the potential of STUB1 as both a prognostic biomarker and therapeutic target for CCA.Graphical