RESUMO
The multi-soil-layering (MSL) systems is an emerging solution for environmentally-friendly and cost-effective treatment of decentralized rural domestic wastewater. However, the role of the seemingly simple permeable layer has been overlooked, potentially holding the breakthroughs or directions to addressing suboptimal nitrogen removal performance in MSL systems. In this paper, the mechanism among diverse substrates (zeolite, green zeolite and biological ceramsite) coupled microorganisms in different systems (activated bacterial powder and activated sludge) for rural domestic wastewater purification was investigated. The removal efficiencies performed by zeolite coupled with microorganisms within 3 days were 93.8% for COD, 97.1% for TP, and 98.8% for NH4+-N. Notably, activated sludge showed better nitrification and comprehensive performance than specialized nitrifying bacteria powder. Zeolite attained an impressive 89.4% NH4+-N desorption efficiency, with a substantive fraction of NH4+-N manifesting as exchanged ammonium. High-throughput 16S rRNA gene sequencing revealed that aerobic and parthenogenetic anaerobic bacteria dominated the reactor, with anaerobic bacteria conspicuously absent. And the heterotrophic nitrification-aerobic denitrification (HN-AD) process was significant, with the presence of denitrifying phosphorus-accumulating organisms (DPAOs) for simultaneous nitrogen and phosphorus removal. This study not only raises awareness about the importance of the permeable layer and enhances comprehension of the HN-AD mechanism in MSL systems, but also provides valuable insights for optimizing MSL system construction, operation, and rural domestic wastewater treatment.
Assuntos
Eliminação de Resíduos Líquidos , Eliminação de Resíduos Líquidos/métodos , Nitrificação , Nitrogênio/metabolismo , Solo/química , Desnitrificação , Águas Residuárias/química , Esgotos/microbiologia , Microbiologia do Solo , Zeolitas/química , Fósforo/metabolismo , Reatores Biológicos/microbiologia , Bactérias/metabolismoRESUMO
Nitrogen oxides (NOx) from diesel engine exhaust, is one of the major sources of environmental pollution. Currently, selective catalytic reduction with ammonia (NH3-SCR) is considered to be the most effective protocol for reducing NOx emissions. Nowadays, zeolite-based NH3-SCR catalysts have been industrialized and widespread used in this field. Nevertheless, with the increasingly stringent environmental regulations and implementation of the requirement of "zero emission" of diesel engine exhaust, it is extremely urgent to prepare catalysts with superior NH3-SCR activity and exceptional resistance to poisons (SO2, alkali metals, hydrocarbons, etc.). Core-shell structure zeolite-based catalysts (CSCs) have shown great promise in NH3-SCR of NOx in recent years by virtue of its relatively higher low-temperature activity, broader operation temperature window and outstanding resistance to poisons. This review mainly focuses on the recent progress of CSCs for NH3-SCR of NOx with three extensively investigated SSZ-13, ZSM-5, Beta zeolites as cores. The reaction mechanisms of resistance to sulfur poisoning, alkali metal poisoning, hydrocarbon poisoning, and hydrothermal aging are summarized. Moreover, the important role of interfacial effect between core and shell in the reaction of NH3-SCR was clarified. Finally, the future development and application outlook of CSCs are prospected.
Assuntos
Poluentes Atmosféricos , Óxidos de Nitrogênio , Emissões de Veículos , Zeolitas , Zeolitas/química , Óxidos de Nitrogênio/química , Catálise , Poluentes Atmosféricos/química , Emissões de Veículos/análise , Poluição do Ar/prevenção & controle , Amônia/químicaRESUMO
Herein, coupling of noble metal-free plasmonic copper nanoparticles with tungsten suboxide and supporting on zeolite nanoclay (Cu/WO3-x@ZNC) composite will be introduced for bi-functional photocatalytic ciprofloxacin (CIP) degradation and water photothermal evaporation under visible/infrared (Vis/IR) exposure. Reduced band-gap of WO3-x via oxygen vacancies creation and localized surface plasmon resonance (LSPR) formation by Cu nanoparticles contributed significantly the extension and intensification of composite's photo-absorption range. Furthermore, small mesoporous structure of ZNC enhanced CIP adsorption and charge carriers separation where the reported photocatalytic efficiencies were 88.3 and 81.7% upon IR and Vis light exposure respectively. It was evidenced that plasmonic hot electrons (e-.s) and hydroxyl radicals (OHâ¢-) performed the basic functions of the photocatalytic process. At the other side, oxygen vacancies existence, plasmonic effect, and confining thermal characteristics of WO3-x, Cu, and ZNC correspondingly induced water photothermal evaporation with efficiencies up to 97.5 and 72.8% under IR and Vis illumination respectively. This work introduces synthesis of a novel bi-functional photocatalytic-photothermal composite by metal sub-oxide and non-noble metal plasmonic coupling and supporting on naturally-derived carrier for water restoration under broad spectral exposure.
Assuntos
Ciprofloxacina , Cobre , Tungstênio , Ciprofloxacina/química , Cobre/química , Tungstênio/química , Catálise , Poluentes Químicos da Água/química , Óxidos/química , Nanopartículas Metálicas/química , Água/química , Zeolitas/química , Raios Infravermelhos , Fotólise , Processos Fotoquímicos , Ressonância de Plasmônio de Superfície , AdsorçãoRESUMO
Achieving timely and effective hemorrhage control is imperative for the survival of individuals with severe bleeding. Hemostatic materials, by enhancing the natural cell-based coagulation response, are essential tools in modern and military medical practice for controlling bleeding, especially in emergency and surgical settings. Here, we report a new type of composite hemostatic material with two different aluminosilicate-based components, kaolin and zeolite, which synergistically work together in different stages of the coagulation cascade reactions. Kaolin can effectively activate the clotting factor FXII in the early stage, and zeolite can accumulate and assemble FXa and FVa on its surface and thereafter lead to the formation of highly active thrombin in the later stage. The synergistic action mechanism between kaolin and zeolite significantly boosts the levels of FXIIa and FXa, and it also greatly enhances plateau thrombin activity. For practical application, a kaolin-modified zeolite gauze is fabricated, and it demonstrates excellent hemostatic effectiveness. Compared to the combat gauze currently used in front-line treatment, it reduces blood loss by 75% and shortens hemostasis time by 33% in a rabbit femoral artery injury model. In addition, this kaolin-zeolite gauze has no heat release problem and a nearly zero particle shedding rate, which greatly decreases the safety risk compared to current commercial inorganic-based hemostatic gauzes.
Assuntos
Hemorragia , Hemostáticos , Caulim , Zeolitas , Caulim/química , Caulim/farmacologia , Zeolitas/química , Zeolitas/farmacologia , Animais , Coelhos , Hemorragia/tratamento farmacológico , Hemostáticos/química , Hemostáticos/farmacologia , Coagulação Sanguínea/efeitos dos fármacos , Trombina/química , HumanosRESUMO
OBJECTIVE: To develop a novel calcium silver zeolite (Ca-Ag-Zeo) and assess its biocompatibility, physiochemical properties and antimicrobial effects. METHODS: Ca-Ag-Zeo was synthesized using ion-exchange method with calcium chloride, silver nitrate and Zeolite X (Zeo). Silver zeolite X (Ag-Zeo) and Zeo were set as control. The chemical structure, morphology, crystal structure and elemental composition of Ca-Ag-Zeo was characterized by X-ray diffraction spectrum, scanning electron microscopy, transmission electron microscopy and energy dispersive spectroscopy, respectively. Its biocompatibility on the human gingival fibroblasts was assessed by cell counting kit-8 assay. Its physiochemical properties were determined by the released calcium and silver ion using Inductive Coupled Plasma Emission Spectrometry for up to 12 weeks. The antimicrobial properties on Streptococcus mutans, Lactobacillus acidophilus, Lactobacillus casei, and Candida albicans were assessed by minimum bactericidal concentration (MBC) or minimum fungicidal concentration (MFC) assay. RESULTS: Ca-Ag-Zeo with a hexagonal cage structure was synthesized. As for biocompatibility, the half-maximal inhibitory concentration (± SD in mg/mL) of Ca-Ag-Zeo, Ag-Zeo and Zeo in human gingival fibroblasts were 0.52 ± 0.05, 0.15 ± 0.01 and 3.35 ± 0.58, respectively (Zeo > Ca-Ag-Zeo > Ag-Zeo; p < 0.05). As for physiochemical properties, the accumulated ion release (± SD in mg) of Ca-Ag-Zeo, Ag-Zeo and Zeo were 0.011 ± 0.003, 0 and 0 for calcium ion, respectively (Ca-Ag-Zeo > Ag-Zeo, Zeo; p < 0.001), and 0.213 ± 0.032, 0.209 ± 0.019 and 0 for silver ion, respectively (Ca-Ag-Zeo, Ag-Zeo > Zeo; p < 0.001). As for anti-microbial ability, the MBC/MFC (mg/mL) of Ca-Ag-Zeo, Ag-Zeo and Zeo were 32, 16 and > 256 against Streptococcus mutans; 32, 16, > 256 against Lactobacillus acidophilus; 16, 16, and 256 against Lactobacillus casei; 0.25, 0.125; and 2, 1, > 256 against Candida albicans, respectively. CONCLUSION: A novel Ca-Ag-Zeo was developed. It presented better biocompatibility compared to Ag-Zeo. It released calcium and silver ions sustainably, and it could inhibit the growth of common cariogenic microorganisms.
Assuntos
Cálcio , Candida albicans , Cárie Dentária , Fibroblastos , Testes de Sensibilidade Microbiana , Prata , Streptococcus mutans , Zeolitas , Humanos , Zeolitas/farmacologia , Zeolitas/química , Streptococcus mutans/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Cárie Dentária/prevenção & controle , Cárie Dentária/microbiologia , Prata/farmacologia , Prata/química , Lactobacillus acidophilus/efeitos dos fármacos , Difração de Raios X , Gengiva/efeitos dos fármacos , Gengiva/citologia , Lacticaseibacillus casei/efeitos dos fármacos , Microscopia Eletrônica de Varredura , Materiais Biocompatíveis/farmacologia , Microscopia Eletrônica de Transmissão , Teste de Materiais , Nitrato de Prata/farmacologia , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologiaRESUMO
The high speed enrichment of benzoylurea insecticides (BUs) in complex matrices is an essential and challenging step. The present study focuses on the synthesis of a hierarchical pore nitrogen-doped carbon material for magnetic solid phase extraction (MSPE) of BUs. This material was prepared through the carbonization of a composite material ZIF-67@MCA which assembly with hydrogen-bonded organic frameworks (melamine-cyanurate, MCA) and zeolitic imidazolate framework (ZIF-67) at room temperature. The optimal adsorption effect is achieved when the mass ratio of ZIF-67 to MCA is 1/3, and the carbonization was performed at 600 °C, the such obtained carbon material was denoted as 1/3ZIF-67@MCA-DCs-600. The material was characterized with various physical methods including X-ray diffractometry (XRD), Fourier transform infrared spectrometry (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET), vibrating sample magnetometer (VSM), water contact angle measurement, Raman spectrometry. 1/3ZIF-67@MCA-DCs-600 exhibits a macro-mesoporous 3D structure with a high degree of nitrogen doping and relatively large specific surface area, making it suitable for magnetic solid phase extraction (MSPE). The adsorption of BUs with concentration of 100 ng mL-1 can reach equilibrium within 5 s. The interaction between BUs and the adsorbent, facilitated by π-π stacking, hydrophobic interactions, hydrogen bonding forces, as well as the material's porosity, enables efficient extraction recoveries ranging from 45 % to 92 %. The enrichment of BUs was achieved through the establishment of an MSPE method under optimized conditions, which was further coupled with high performance liquid chromatography (HPLC) for the determination of the four BUs. The linear range spans from 5 ng ml-1 to 1000 ng ml-1 with the correlation coefficient (R2) of ≥ 0.99, Meanwhile, the detection limit for these four BUs falls within the range of 0.01 to 0.10 ng ml-1. The material exhibits good reusability and can be reused for at least 5 cycles. Inter day and intra-day precision ranges from 2.1-7.9 % and 1.0-5.4 %, respectively. The method demonstrates a high level of reliability in practical applications for the determination of BUs.
Assuntos
Carbono , Ligação de Hidrogênio , Inseticidas , Nitrogênio , Extração em Fase Sólida , Inseticidas/análise , Inseticidas/química , Inseticidas/isolamento & purificação , Extração em Fase Sólida/métodos , Adsorção , Carbono/química , Nitrogênio/química , Estruturas Metalorgânicas/química , Porosidade , Triazinas/química , Triazinas/isolamento & purificação , Limite de Detecção , Ureia/química , Zeolitas/químicaRESUMO
Damaged skin is susceptible to invasion by harmful microorganisms, especially Staphylococcus aureus and Escherichia coli, which can delay healing. Epigallocatechin-3-gallate (EGCG) is a natural compound known for effectively promoting wound healing and its potent anti-inflammatory effects. However, its application is limited due to its susceptibility to oxidation and isomerization, which alter its structure. The use of zeolitic imidazolate framework-8 (ZIF-8) can effectively tackle these issues. This study introduces an oxygen (O2) and hydrogen peroxide (H2O2) self-supplying ZIF-8 nanoplatform designed to enhance the bioavailability of EGCG, combining photodynamic therapy (PDT) and chemodynamic therapy (CDT) to improve antibacterial properties and ultimately accelerate wound healing. For this purpose, EGCG and indocyanine green (ICG), a photosensitizer, were successively integrated into a ZIF-8, and coated with bovine serum albumin (BSA) to enhance biocompatibility. The outer layer of this construct was further modified with manganese dioxide (MnO2) to promote CDT and calcium peroxide (CaO2) to supply H2O2 and O2, resulting in the final nanoplatform EGCG-ICG@ZIF-8/BSA-MnO2/CaO2 (EIZBMC). In in vitro experiments under 808 nm laser, EIZBMC exhibited synergistic antibacterial effects through PDT and CDT. This combination effectively released reactive oxygen species (ROS), which mediated oxidative stress to inhibit the bacteria. Subsequently, in a murine model of wound infection, EIZBMC not only exerted antibacterial effects through PDT and CDT but also alleviated the inflammatory condition and promoted the regeneration of collagen fibers, which led to accelerated wound healing. Overall, this research presents a promising approach to enhancing the therapeutic efficacy of EGCG by leveraging the synergistic antibacterial effects of PDT and CDT. This multifunctional nanoplatform maximizes EGCG's anti-inflammatory properties, offering a potent solution for promoting infected wound healing.
Assuntos
Antibacterianos , Catequina , Escherichia coli , Verde de Indocianina , Fotoquimioterapia , Fármacos Fotossensibilizantes , Staphylococcus aureus , Cicatrização , Animais , Catequina/química , Catequina/análogos & derivados , Catequina/farmacologia , Cicatrização/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/química , Camundongos , Verde de Indocianina/química , Verde de Indocianina/farmacologia , Escherichia coli/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Peróxido de Hidrogênio/farmacologia , Estruturas Metalorgânicas/química , Estruturas Metalorgânicas/farmacologia , Óxidos/química , Óxidos/farmacologia , Compostos de Manganês/química , Compostos de Manganês/farmacologia , Zeolitas/química , Zeolitas/farmacologia , Nanopartículas/química , Testes de Sensibilidade Microbiana , Imidazóis/química , Imidazóis/farmacologia , PeróxidosRESUMO
The global attention towards waste management and valorization has led to significant interest in recovering valuable components from sludge incineration ash (SIA) for the synthesis of functional environmental materials. In this study, the SIA was converted to an S-doped Fe2+-zeolite type catalyst (FZA) for the treatment of emerging contaminants (ECs), exemplified by sulfamethoxazole (SMX). Results demonstrate that FZA effectively catalyzed the activation of peracetic acid (PAA), achieving a remarkable degradation of 99.8% under optimized conditions. Mechanistic investigations reveal that the FZA/PAA system can generate ·OH, 1O2, O2·ï¼, and Fe(â £), with ·OH playing a dominant role in ECs degradation. Additionally, the doped S facilitated electrochemical performance, Fe2+ regeneration and fixation in FZA. Practical application elucidated that the FZA/PAA system can work in complex environments to degrade various ECs without generating high-toxicity ingredients. Overall, valorizing SIA to FZA provides dual achievement in waste management and ECs removal.
Assuntos
Incineração , Esgotos , Sulfametoxazol , Zeolitas , Sulfametoxazol/química , Zeolitas/química , Esgotos/química , Catálise , Gerenciamento de Resíduos/métodos , Ferro/químicaRESUMO
An efficient electrochemiluminescence (ECL) emitter, Ir(ppy)3-based molecules has recently been reported to exhibit aggregation-induced electrochemiluminescence (AIECL) phenomenon. However, it remains a significant challenge to control the aggregation states of these molecules and achieve uniform aggregates with intense ECL emission. In this work, a biosensor was developed to detect microcystin-LR (MC-LR) based on Ir(ppy)3-functionalized zeolitic imidazolate framework-8 (Ir-ZIF-8) as the ECL emitter and the trans-cleavage activity of CRISPR-Cas12a as the methodological strategy. The Ir-ZIF-8, a functional metal-organic framework (MOF), exhibited the AIECL phenomenon via the spatial domain-limiting effect of encapsulating Ir(ppy)3 into the mesopores of ZIF-8, while the porosity and highly ordered topological structure of ZIF-8 effectively limited the molecular motion of Ir(ppy)3. CRISPR-Cas12a was employed to indiscriminately cleave double-stranded DNA decorated with carboxy tetramethylrhodamine (TAMRA), which quenched the ECL signal of Ir-ZIF-8 by resonance energy transfer and then separated the quencher from Ir-ZIF-8 to reactivate the signal. The concentration of MC-LR was designed to correlate with both the quencher amount and the activity of Cas12a. Then, two linear regression equations for MC-LR detection were constructed to improve the accuracy of the biosensor, and the constructed biosensor showed remarkable reproducibility, stability, and selectivity. The accurate detection of MC-LR with limits of detection of 1.2 and 5.9 pg/mL was made possible by the high quenching efficiency of TAMRA and the effective cutting ability of the editable CRISPR-Cas12a system.
Assuntos
Técnicas Biossensoriais , Sistemas CRISPR-Cas , Técnicas Eletroquímicas , Medições Luminescentes , Toxinas Marinhas , Microcistinas , Microcistinas/análise , Microcistinas/química , Toxinas Marinhas/química , Sistemas CRISPR-Cas/genética , Técnicas Biossensoriais/métodos , Zeolitas/química , Estruturas Metalorgânicas/química , Imidazóis/química , Limite de Detecção , Proteínas Associadas a CRISPR/metabolismo , Proteínas Associadas a CRISPR/químicaRESUMO
5-fluorouracil (5-FU), a chemotherapeutic agent against oral squamous cell carcinoma (OSCC), is limited by poor pharmacokinetics and toxicity. The pH-sensitive zeolite imidazolate framework-8 (ZIF-8) may increase the selectivity and length of 5-FU released into the acidic tumor microenvironment. This study examined the in vitro 5-FU absorption and release profiles of ZIF-8, and then progressed to cytotoxicity assays using the OSCC primary cell line SCC7. The 5-FU loading capacity of ZIF-8 was calculated with UV-vis spectroscopy (λ = 260 nm). 5-FU release was quantified by submerging 5-FU@ZIF-8 in pH 7.4 and 5.5 acetate buffer over 48 h. For the cytotoxicity assays, 5-FU, ZIF-8, and 5-FU@ZIF-8 were added to SCC7 cultures at 25, 50, and 100 µg/mL. Cell viability was assessed through toluidine blue staining and further quantified through transcriptomic RNA sequencing. ZIF-8 stabilized at a maximum absorption of 2.71 ± 0.22 mg 5-FU, and released 0.66 mg more 5-FU at pH 5.5 than 7.4 for at least 72 h. The cytotoxicity assays showed that 5-FU@ZIF-8 had a synergistic inhibitory effect at 50 µg/mL. The RNA sequencing analysis further revealed the molecular targets of 5-FU@ZIF-8 in SCC7. 5-FU@ZIF-8 may release 5-FU based on the pH of the surrounding microenvironments and synergistically inhibit OSCC.
Assuntos
Carcinoma de Células Escamosas , Fluoruracila , Neoplasias Bucais , Fluoruracila/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Neoplasias Bucais/tratamento farmacológico , Neoplasias Bucais/patologia , Neoplasias Bucais/metabolismo , Linhagem Celular Tumoral , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Sobrevivência Celular/efeitos dos fármacos , Estruturas Metalorgânicas/química , Estruturas Metalorgânicas/farmacologia , Zeolitas/química , Microambiente Tumoral/efeitos dos fármacos , Liberação Controlada de Fármacos , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Nanopartículas/química , ImidazóisRESUMO
Due to the limited efficacy and evident side effects of traditional chemotherapy drugs attributed to their lack of specificity and selectivity, novel strategies are essential for improving cancer treatment outcomes. Here, we successfully engineered Fe3O4 magnetic nanoparticles coated with zeolitic imidazolate framework-8 (ZIF-8). The resulting nanocomposite (Fe3O4@ZIF-8) demonstrates efficient adsorption of a substantial amount of doxorubicin (DOX) due to the porous nature of ZIF-8. The drug-loaded nanoparticles, Fe3O4@ZIF-8/DOX, exhibit significant accumulation at the tumor site in SW620 colon-cancer-bearing mice when guided by an external magnetic field. Within the acidic microenvironment of the tumor, the ZIF-8 framework collapses, releasing DOX and effectively inducing tumor cell death, thereby inhibiting cancer progression while not causing undesired side effects, as confirmed by a variety of in vitro and in vivo characterizations. In comparison to free DOX, Fe3O4@ZIF-8/DOX nanoparticles show superior efficacy in colon cancer treatment. Our findings suggest that Fe3O4@ZIF-8 holds promise as a carrier for small-molecule drug adsorption and its ferromagnetic properties provide drug targeting capabilities, thereby enhancing therapeutic effects on tumors at the same drug dosage. With excellent biocompatibility, Fe3O4@ZIF-8 demonstrates potential as a drug carrier in targeted cancer chemotherapy. Our work suggests that a combination of magnetic targeting and acid-responsiveness holds great promise for advancing targeted cancer therapy in precision nanomedicine.
Assuntos
Neoplasias do Colo , Doxorrubicina , Nanopartículas de Magnetita , Estruturas Metalorgânicas , Doxorrubicina/química , Doxorrubicina/farmacologia , Doxorrubicina/uso terapêutico , Animais , Estruturas Metalorgânicas/química , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/patologia , Camundongos , Humanos , Nanopartículas de Magnetita/química , Nanopartículas de Magnetita/uso terapêutico , Portadores de Fármacos/química , Linhagem Celular Tumoral , Zeolitas/química , Camundongos Endogâmicos BALB C , Antibióticos Antineoplásicos/química , Antibióticos Antineoplásicos/farmacologia , Antibióticos Antineoplásicos/uso terapêutico , ImidazóisRESUMO
Rising concerns over water scarcity, driven by industrialization and urbanization, necessitate the need for innovative solutions for wastewater treatment. This study focuses on developing an eco-friendly and cost-effective biochar-zeolite composite (BZC) adsorbent using waste materials-spent coffee ground biochar (CGB) and steel slag zeolite (SSZ). Initially, the biochar was prepared from spent coffee ground, and zeolite was prepared from steel slag; their co-pyrolysis resulted in novel adsorbent material. Later, the physicochemical characteristics of the BZC were examined, which showed irregular structure and well-defined pores. Dye removal studies were conducted, which indicate that BZC adsorption reach equilibrium in 2 h, exhibiting 95% removal efficiency compared to biochar (43.33%) and zeolite (74.58%). Moreover, the removal efficiencies of the novel BZC composite toward dyes methyl orange (MO) and crystal violet (CV) were found to be 97% and 99.53%, respectively. The kinetic studies performed with the dyes and phosphate with an adsorbent dosage of 0.5 g L-1 suggest a pseudo-second-order model. Additionally, the reusability study of BZC proves to be effective through multiple adsorption and regeneration cycles. Initially, the phosphate removal remains high but eventually decreases from 92% to 70% in the third regeneration cycle, highlighting the robustness of the BZC. In conclusion, this study introduces a promising, cost-effective novel BZC adsorbent derived from waste materials as a sustainable solution for wastewater treatment. Emphasizing efficiency, reusability, and potential contributions to environmentally conscious water treatment, the findings highlight the composite's significance in addressing key challenges for the removal of toxic pollutants from the aqueous solutions. PRACTITIONER POINTS: A novel biochar-zeolite composite (BZC) material has been synthesized. Excellent removal of dyes by BZC (~95%) was achieved as compared to their counterparts The kinetic studies performed suggest a pseudo-second-order model. BZC proves to be highly effective for multiple adsorption studies. Excellent reusability showed potential as a robust adsorbent.
Assuntos
Carvão Vegetal , Café , Corantes , Fosfatos , Poluentes Químicos da Água , Zeolitas , Zeolitas/química , Corantes/química , Corantes/isolamento & purificação , Carvão Vegetal/química , Adsorção , Poluentes Químicos da Água/química , Fosfatos/química , Café/química , Aço/química , Purificação da Água/métodos , Eliminação de Resíduos Líquidos/métodos , Resíduos IndustriaisRESUMO
The excessive utilization of antimicrobials in humans and animals has resulted in considerable environmental contamination, necessitating the development of high-performance antibiotic adsorption media. A significant challenge is the development of composite nanofibrous materials that are both beneficial and easy to fabricate, with the aim of improving adsorption capacity. Herein, a new kind of zeolitic imidazolate framework-8 (ZIF-8)-modified regenerated cellulose nanofibrous membrane (ZIF-8@RC NFM) was designed and fabricated by combining electrospinning and in situ surface modification technologies. Benefiting from its favorable surface wettability, enhanced tensile strength, interconnected porous structure, and relatively large specific surface area, the resulting ZIF-8@RC NFMs exhibit a relatively high adsorption capacity for tetracycline hydrochloride (TCH) of 105 mg g-1 within 3 h. Moreover, a Langmuir isotherm model and a pseudo-second-order model have been demonstrated to be more appropriate for the description of the TCH adsorption process of ZIF-8@RC-3 NFMs. Additionally, this composite fibrous material could keep a relatively stable adsorption capability under various ionic strengths. The successful fabrication of the novel ZIF-8@RC NFMs may shed light on the further development of wastewater adsorption treatment materials.
Assuntos
Celulose , Nanofibras , Tetraciclina , Zeolitas , Tetraciclina/química , Nanofibras/química , Adsorção , Celulose/química , Zeolitas/química , Imidazóis/química , Poluentes Químicos da Água/química , Estruturas Metalorgânicas/química , Membranas Artificiais , Purificação da Água/métodosRESUMO
Medical treatment of severe blood loss during labor is crucial, and the early warning indicator of postpartum hemorrhage (PPH) is essential for labor medical treatment. Measurement of blood loss conventionally looks dirty, reluctant, and less hygienic since some of the blood might be spilled out in the maternity bed, while commercially existing pads have low blood absorption capacity. A new design composite pad composed of absorbent materials, including cellulose rayon, super absorbent polymer (SAP), and zeolite was fabricated and characterized. The SAP and zeolite show properties as crystalline and amorphous materials, respectively. The surface area of natural zeolite was 19.79 (m2/g). The newly fabricated composite pad showed a high blood absorption capacity (>500-600 mL) with a blood absorption rate of 55.56-85.84 mL/min (depending on the blood volume), showing better performance as compared to the commercial pads. These characteristics suggest that the new composite pad could function not only as a sanitary pad but also as an early warning indicator for PPH if the rate and blood volume reach the dangerous category (≥600 mL or at ≥13 mL/min rate).
Assuntos
Hemorragia Pós-Parto , Zeolitas , Hemorragia Pós-Parto/sangue , Zeolitas/química , Humanos , Feminino , Gravidez , Celulose/química , Celulose/análogos & derivados , Absorventes HigiênicosRESUMO
Typical cracking catalysts, called equilibrium catalyst (E-Cat) are ultra-stable Y (USY) zeolite often used with 15% commercial ZSM-5 zeolite additive (ZSM-5(COM)) to boost olefin yield. In this study, similar additive zeolites with different pore sizes and acidic character were synthesized by rapid ageing of precursor solution and used in the co-cracking of low-density polyethylene (LDPE) and heavy vacuum gas oil (HVGO). Three ZSM-5 zeolites additives with Si/Al ratio 25 (ZSM-5(25)), 50 (ZSM-5(50)) and 75 (ZSM-5(75)) were synthesized and combined with E-Cat to form E-Cat/ZSM-5(25), E-Cat/ZSM-5(50) and E-Cat/ZSM-5(75) respectively. The E-Cat/ZSM-5(50) has slightly better endothermic conversion (cracking) of a mixture of dissolved LDPE and HVGO into H2, C1 to C4 gases and C2-C4 light olefins (total conversion of E-Cat 80.0%, E-Cat/ZSM-5(COM) 75.0% and E-Cat/ZSM-5(50) 83.7% respectively), with different gas, liquid and coke distributions. The E-Cat/ZSM-5(75) has 81% conversion, and highest yield of light olefins (38.4%). Structural (surface area, pore size) and chemical (acid sites) characteristics of the synthetized ZSM-5(75) zeolite explain the observed higher light olefin selectivity by different and competing catalytic routes. The ZSM-5(75) has demonstrated to be a good zeolite additive for converting dissolved plastic in HVGO into light olefins.
Assuntos
Alcenos , Plásticos , Zeolitas , Zeolitas/química , Alcenos/química , Plásticos/química , Vácuo , Catálise , Polietileno/químicaRESUMO
Despite global efforts to manage water eutrophication, the continual release of ammonia nitrogen from sediments maintains the eutrophic state of water bodies, presenting serious challenges to the management. In order to find an efficient method for sediment remediation, the experiment of using signal molecules to enhance the adhesion of microorganisms on zeolite was carried out. Five different zeolitic ammonium adsorptions were examined using two different signal molecules, N-(3-oxohexanoyl)-L-homoserine lactone (OHHL) and N-(ß-ketocaproyl)-DL-homoserine lactone (C6), to enhance microbial attachment on two types of zeolites. The results showed that the modified microbial attached Z1 zeolite reinforced with signal molecule C6 had the best effect. The effect was better in the case of high ammonium adsorption, and the TN removal could reach 7.99 mg·L-1 with an inhibition rate of 90.08%. The ammonia nitrogen removal reached 4.75 mg·L-1 with an inhibition rate of 87.64%, and the ammonia nitrogen and total nitrogen of the overlying water reached the surface III water quality standard. In addition, the addition of the signal molecule increased the zeta potential on the surface of the bacterial colloid. In addition, the amount of protein I in the dissolved organic matter (DOM) fraction increased, improving microbial adhesion ability and facilitating their attachment to the zeolite surface. The signal molecule C6 could increase the zeta potential of microbial surface and promote the production of protein I, thus strengthening the attachment of zeolite biofilm and improving the water quality.
Assuntos
Amônia , Nitrogênio , Zeolitas , Zeolitas/química , Amônia/química , Sedimentos Geológicos/microbiologia , Sedimentos Geológicos/química , Adsorção , Poluentes Químicos da Água , EutrofizaçãoRESUMO
In this paper, a biological aerated filter (BAF) based on ferromanganese oxide-biochar (FMBC) was constructed to investigated the removal performance and mechanism for conventional pollutants and four kinds of antibiotic, in contrast of conventional zeolite loaded BAF (BAF-A) and bamboo biochar filled BAF (BAF-B). Results showed that the average removal efficiency of total nitrogen (TN), total phosphorus (TP) and antibiotics in a FMBC-BAF (named by BAF-C) were 52.97 ± 2.27%, 51.58 ± 1.92% and 70.36 ± 1.00% ~ 81.65 ± 0.99% respectively in running period (39-100 d), which were significantly higher than those of BAF-A and BAF-B. In the BAF-C, the expression of denitrification enzyme activities and the secretion of extracellular polymeric substance (EPS) especially polyprotein (PN) were effectively stimulated, as well as accelerated electron transfer activity (ETSA) and lower electrochemical impedance spectroscopy (EIS) were acquired. After 100 days of operation, the abundance of nitrogen, phosphorus and antibiotic removal functional bacteria like Sphingorhabdus (4.52%), Bradyrhizobium (1.98%), Hyphomicrobium (2.49%), Ferruginibacter (7.80%), unclassified_f_Blastoca tellaceae (1.84%), norank_f_JG30-KF-CM45 (6.82%), norank_f_norank_o_SBR1031 (2.43%), Nitrospira (2.58%) norank_f_Caldilineaceae (1.53%) and Micropruina (1.11%) were enriched. Mechanism hypothesis of enhanced performances of nutrients and antibiotics removal pointed that: The phosphorus was removed by adsorption and precipitation, antibiotics removal was mainly achieved through the combined action of adsorption and biodegradation, while nitrogen removal was realized by biologic nitrification and denitrification in a FMBC-BAF for aquaculture wastewater treatment.
Assuntos
Antibacterianos , Aquicultura , Carvão Vegetal , Nitrogênio , Fósforo , Águas Residuárias , Fósforo/química , Nitrogênio/química , Águas Residuárias/química , Águas Residuárias/microbiologia , Carvão Vegetal/química , Antibacterianos/química , Zeolitas/química , Óxidos/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , DesnitrificaçãoRESUMO
The increasing use of hexavalent chromium (Cr(VI)) has exposed large populations to this environmental and occupational carcinogenic agent. Therefore, researchers have been interested in removing this substance through adsorbents. This study aimed to investigate the efficiency of natural zeolite in the direct adsorption of Cr(VI) from airflow and its adsorption modeling. In this study, a nebulizer device produced the Cr(VI) mist. The efficiency of natural zeolite in Cr(VI) adsorption from airflow, modeling of fixed column adsorption, and the effective parameters on adsorption efficiency including the initial concentration of chromium, airflow rate, and adsorption bed depth were studied. To facilitate the prediction of the performance of natural zeolite's adsorption column, Yoon-Nelson, Thomas, BDST, and Buhart-Adams models were used. The results showed that the adsorption capacity diminished with increased airflow rate and initial concentration, while it increased with elevated height of the adsorption bed. Yoon-Nelson, Thomas, and BDST models corresponded to experimental data with a correlation coefficient of 0.9933, but the information of the Buhart-Adams model had a lower correlation coefficient (around 0.6677). In conclusion, natural zeolite can be used as an efficient low-cost adsorbent for directly Cr(VI) removing from the airflow in a fixed bed column.
Assuntos
Cromo , Zeolitas , Zeolitas/química , Cromo/química , Cromo/isolamento & purificação , Adsorção , Poluentes Atmosféricos/química , Poluentes Atmosféricos/isolamento & purificação , Modelos TeóricosRESUMO
The microbial fuel cell (MFC) is a device that simultaneously achieves electricity generation and sewage degradation. In this study, a novel cathode catalyst metal-organic frameworks (MOFs) have been fabricated by two-step hydrothermal and dual-solution method (CuCo-MOF@ZIF-8). The synthesized trimetal MOFs exhibited a 3D badminton-like structure morphology and porosity. The results of the characterizations showed that CuCo-MOF@ZIF-8 possesses greater surface area porosity and novel functional groups. The Trimetal MOF-on-MOF mode not only demonstrated the stability of the structure but also enhanced its mechanism. Molecular mechanism analysis revealed changes in the organic ligand and metal binding site due to the transformation of Cu2+ to Cu+, Co2+ to Co3+, and Zn-N to Zn-O organic connection. Furthermore, differences between the two fabrication methods were compared. The solid-state single preparation (CuCo-MOF@ZIF-8-1), was synthesized using the two-step hydrothermal method; the liquid mixed preparation material (CuCo-MOF@ZIF-8-2), was synthesized using the dual-solution method; they exhibited completely different chemical structures and morphologies during material testing and characterization. The maximum output power density of CuCo-MOF@ZIF-8-2-MFC was 246.38 mW/m2, about 2.49 times of ZIF-8 (98.72 mW/m2). The output voltage of CuCo-MOF@ZIF-8-1-MFC was measured at 357 mV over 10 d, while that of CuCo-MOF@ZIF-8-2-MFC reached 365 mV over 12 d.
Assuntos
Fontes de Energia Bioelétrica , Cobre , Estruturas Metalorgânicas , Estruturas Metalorgânicas/química , Cobre/química , Catálise , Eletrodos , Técnicas Eletroquímicas/métodos , Zeolitas/química , Técnicas Biossensoriais/métodosRESUMO
The objective of this research was to develop and assess chitosan-grafted copolymer/HZSM5 zeolite Schiff base nanofibers for Cu2+ and Zn2+ adsorption from aqueous media. Nanofibers were prepared via electrospinning and characterized using XRD, FTIR, 1H NMR, FESEM, TGA, BET, and XPS. The study evaluated the effect of unmodified HZSM5 and Schiff base functionalization on adsorption capacities. Incorporating 10.0 wt% zeolite Schiff base as the optimum content into the chitosan-grafted copolymer significantly enhanced adsorption, achieving increases of 98.2 % for Zn2+ and 42.2 % for Cu2+. Specifically, Zn2+ adsorption increased from 27.6 to 54.7 mg/g, and Cu2+ from 67.1 to 95.4 mg/g. Factors such as temperature, pH, adsorption time, and initial cation concentration were analyzed. Kinetic studies revealed a double-exponential model, and isotherm analysis indicated a good fit with the Redlich-Peterson model, showing maximum monolayer capacities of 310.1 mg/g for Cu2+ and 97.8 mg/g for Zn2+ (pH 6.0, 240 min, 45 °C). The adsorption thermodynamics indicated a spontaneous and endothermic adsorption. Reusability tests showed minimal capacity loss (4.91 % for Cu2+ and 5.59 % for Zn2+) after five cycles. The nanofiber displayed greater selectivity for Cu2+ over Zn2+ in multi-ion systems and real electroplating wastewater, highlighting its potential for targeted heavy metal removal.