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1.
Biomacromolecules ; 23(10): 4327-4338, 2022 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-36069679

RESUMEN

As the utilization of degradable polymer coatings increased, the accompanying trade-off between good degradability and high-efficiency antidiatom adhesion due to their hydrophobic nature remains unresolved. The study presents a new hydrophobic surface-fragmenting coating consisting of degradable hyperbranched polymers (hereafter denoted as h-LLAx) synthesized by reversible complexation-mediated copolymerization with isobornyl acrylate (IBOA) and divinyl-functional oligomeric poly(l-lactide) (OLLA-V2), both derived from biomass, that exhibited superior resistance (∼0 cell mm-2) to marine diatom Navicula incerta (N. incerta) attachment with higher OLLA content. The combined impact of the microscale hollow semisphere micelles that self-assembled degradable hyperbranched copolymers and hydrolysis-driven self-renewable surfaces following immersion in seawater may account for the remarkable resistance of h-LLAx coatings against N. incerta. Detailed investigations were conducted across multiple perspectives, from hydrolytic degradation to broad-spectrum antibacterial attachment to ecotoxicity assessment. The excellent features of high resistance to marine diatoms and bacterial attachment, degradability, and environmental friendliness make the as-prepared h-LLAx coatings widely sought after for antifouling coating applications.


Asunto(s)
Incrustaciones Biológicas , Diatomeas , Antibacterianos , Micelas , Polímeros/química , Polímeros/farmacología , Propiedades de Superficie
2.
Environ Res ; 212(Pt D): 113391, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35597293

RESUMEN

Taihu Lake is the most important drinking water source of the major cities in the Yangtze River Delta. The pollution of endocrine disruptors (EDCs)in Taihu Lake has been increasing recently, the accurate determination is an important guide for predicting its health risks and developing appropriate controls. Monitoring organic pollutants in water using the diffusive gradient in thin film technique (DGT) has attracted much attention due to more accuracy and convenience than the grab sampling methods. In this study, a novel cyclodextrin polymer (CDP) synthesized by the simple and green method in water was taken as an adsorbent for the binding gel. Four endocrine-disrupting chemicals (EDCs), bisphenol A (BPA), 17α-ethinylestradiol (EE2), 17ß-estradiol (E2), and estriol (E3), were taken as models to determine the diffusion coefficients (4.68 × 10-6, 3.38 × 10-6, 3.34 × 10-6 and 4.31 × 10-6 cm2/s) and to test the performance of DGT, such as adsorption capacity and deployment time (1-5 day). The assembled CDP-DGT was adopted to determine four EDCs in a simulated water environment (3-9 of pH, 0.001-0.5 M of ionic strength (IS), and dissolved organic matter (DOM) of 0-20 mg/L). The ability of CDP-DGT sampling was verified in the Jiuxiang River and was carried out for a large-scale field application of in situ sampling EDCs in Taihu Lake basin. The results show that the total EDCs concentration range and the estradiol equivalent concentrations (EEQ) in Taihu Lake and its main rivers are 2.78 ng/L to 11.08 ng/L and 2.62 ng/L to 10.91 ng/L, respectively. The risk quotients (RQs) of all sampling sites in the region were greater than 1, indicating that EDCs pose a serious threat to aquatic organisms in the area. Therefore, the monitoring of EDCs in the Taihu Lake basin should be further strengthened.


Asunto(s)
Disruptores Endocrinos , Contaminantes Químicos del Agua , Celulosa , China , Ciclodextrinas , Disruptores Endocrinos/análisis , Monitoreo del Ambiente/métodos , Estradiol , Geles , Lagos/química , Medición de Riesgo , Ríos/química , Agua , Contaminantes Químicos del Agua/análisis
3.
J Nanobiotechnology ; 19(1): 446, 2021 Dec 23.
Artículo en Inglés | MEDLINE | ID: mdl-34949198

RESUMEN

The integrin αvß3 receptor and Lactoferrin receptor (LfR) are over-expressed in both cerebral microvascular endothelial cells and glioma cells. RGD tripeptide and Lf can specifically bind with integrin αvß3 receptor and LfR, respectively. In our study, RGD and Lf dual-modified liposomes loaded with docetaxel (DTX) were designed to enhance the brain targeting effect and treatment of glioma. Our in vitro studies have shown that RGD-Lf-LP can significantly enhance the cellular uptake of U87 MG cells and human cerebral microvascular endothelial cells (hCMEC/D3) when compared to RGD modified liposomes (RGD-LP) and Lf modified liposomes (Lf-LP). Free RGD and Lf competitively reduced the cellular uptake of RGD-Lf-LP, in particular, free RGD played a main inhibitory effect on cellular uptake of RGD-Lf-LP in U87 MG cells, yet free Lf played a main inhibitory effect on cellular uptake of RGD-Lf-LP in hCMEC/D3 cells. RGD-Lf-LP can also significantly increase penetration of U87 MG tumor spheroids, and RGD modification plays a dominating role on promoting the penetration of U87 MG tumor spheroids. The results of in vitro BBB model were shown that RGD-Lf-LP-C6 obviously increased the transport of hCMEC/D3 cell monolayers, and Lf modification plays a dominating role on increasing the transport of hCMEC/D3 cell monolayers. In vivo imaging proved that RGD-Lf-LP shows stronger targeting effects for brain orthotopic gliomas than that of RGD-LP and Lf-LP. The result of tissue distribution confirmed that RGD-LF-LP-DTX could significantly increase brain targeting after intravenous injection. Furthermore, RGD-LF-LP-DTX (a dose of 5 mg kg-1 DTX) could significantly prolong the survival time of orthotopic glioma-bearing mice. In summary, RGD and LF dual modification are good combination for brain targeting delivery, RGD-Lf-LP-DTX could enhance brain targeting effects, and is thus a promising chemotherapeutic drug delivery system for treatment of glioma.


Asunto(s)
Antineoplásicos/farmacología , Docetaxel/química , Integrina alfaVbeta3/antagonistas & inhibidores , Liposomas/química , Receptores de Superficie Celular/antagonistas & inhibidores , Animales , Antineoplásicos/química , Antineoplásicos/metabolismo , Antineoplásicos/uso terapéutico , Neoplasias Encefálicas/diagnóstico por imagen , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/patología , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Docetaxel/metabolismo , Docetaxel/farmacología , Docetaxel/uso terapéutico , Glioma/diagnóstico por imagen , Glioma/tratamiento farmacológico , Glioma/patología , Humanos , Integrina alfaVbeta3/metabolismo , Liposomas/farmacocinética , Ratones , Ratones Desnudos , Oligopéptidos/química , Tamaño de la Partícula , Receptores de Superficie Celular/metabolismo , Tasa de Supervivencia , Distribución Tisular
4.
Environ Res ; 180: 108796, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31629085

RESUMEN

Adsorption is one of the most preferred techniques in the advanced treatment of dyeing wastewater. Magnetic porous materials with good adsorption performance, excellent reusability, and a green synthesis route are highly desirable adsorbents in commerce. In this study, we synthesized a magnetic ß-cyclodextrin polymer (MNP-CM-CDP) containing many macro- and ultramicropores in aqueous phase. CO2 adsorption-desorption isotherms and a dye adsorption method provided Langmuir specific surface areas for the MNP-CM-CDP of 114.4 m2 g-1 and 153 m2 g-1, respectively. Model pollutants (BPA, MB, BO2, RhB, Cr(III), Pb(II), Zn(II), and Cu(II)) were rapidly and efficiently removed from the aqueous solution by the MNP-CM-CDP. In addition, the polymer could be easily separated from the solution under an external magnetic field. The adsorption of the contaminants was dependent on pH, while the effects of ionic strength and humic acid were slight in the concentration range studied. The polymer could be easily regenerated at room temperature and retained good adsorption performance. Moreover, the MNP-CM-CDP showed good feasibility for the removal of pollutants from actual dyeing wastewater samples.


Asunto(s)
Contaminantes Ambientales , Metales Pesados , Aguas Residuales , Contaminantes Químicos del Agua , Adsorción , Celulosa , Ciclodextrinas , Fenómenos Magnéticos , Polímeros
5.
Bioprocess Biosyst Eng ; 42(3): 445-454, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30478779

RESUMEN

Start-up of membrane bioreactor under different NaCl stress was investigated in this study. Results showed that nearly 90% chemical oxygen demands and ammonia nitrogen ([Formula: see text]-N) was oxidized in none and 0.5% NaCl condition during the start-up stage. While 1% NaCl dramatically depressed the utilization of [Formula: see text]-N and about 4 weeks were required for adaption of sludge biomass to saline condition. In addition, the accumulation of nitrite high to 11.84 mg/L was observed in 1% NaCl stress, indicating the more inhibition on the activity of nitrite oxidizing bacteria. Microbial community responded to the different salinity levels. The phylum Proteobacteria and Bacteroidetes occupied over 60% in all the three MBRs. Salinity enriched the relative abundance of Maribacter, Methyloversatilis, Aeromonas and Curvibacter, while reducing the proportion of Nitrospira and Haliscomenobacter. Nitrospirae decreased sharply at 1% NaCl accounting for the accumulation of nitrite. Higher content of soluble microbial products (SMP) under saliferous MBR were released, which deteriorated the permeability of membrane module. Protein-like substances and humic substances were the main ingredients of SMP, of which the former contributed more to membrane flux decline. This study provided better understanding on the impact of salinity on the start-up of MBR.


Asunto(s)
Bacterias/crecimiento & desarrollo , Reactores Biológicos , Membranas Artificiales , Estrés Salino/efectos de los fármacos , Cloruro de Sodio/farmacología , Salinidad
6.
J Environ Manage ; 210: 273-279, 2018 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-29353116

RESUMEN

Natural-polymer based water treatment agents have recently received much more attention due to their environmental friendliness, widespread availability, and prominent structural features. Starch-graft-poly(acrylic acid) (St-g-PAA) is a simple natural-polymer based material that can be obtained easily by a one-step graft copolymerization. When used as a water treatment agent, St-g-PAA exhibits both effective scale-inhibition performance and high turbidity removal efficiency. The scale-inhibition efficiency of St-g-PAA against calcium carbonate (CaCO3) is approximately 94% at the optimal dose in a static test of approximately 40 mg/L. Dispersion, crystal lattice distortion, and chelating effects all play important roles in the scale inhibition. When St-g-PAA is used as a coagulant aid for polyaluminum chloride (PAC) in the flocculation of a real hairwork wastewater, the highest reduction of the optimal PAC dose is more than 30% while the turbidity reduction is about 97% at the same time, both floc size and compactness increase, and the final settling efficiency also improves evidently. The efficient bridging flocculation effects account for the effective turbidity removal. The prominent scale-inhibition and flocculation dual-functionality of St-g-PAA is intrinsically ascribed to its distinct anionic linear branched-chain structure.


Asunto(s)
Resinas Acrílicas/química , Almidón/química , Purificación del Agua , Floculación
7.
Environ Sci Technol ; 50(18): 10015-23, 2016 09 20.
Artículo en Inglés | MEDLINE | ID: mdl-27574832

RESUMEN

Sulfamethoxazole (SMZ) adsorption by a series of amine-modified polystyrene-divinylbenzene resins (PSA/B/C/D) was investigated. All resins showed a similar pH dependent adsorption of SMZ but their capacities were linearly related with the contents of primary amines (-NH2) rather than secondary amines (-NH-). Mechanisms of SMZ adsorption by PSA (highest -NH2 content) were discussed as an example. Due to comparable pKa, H-bonding interactions of -NH2(0) with SMZ(0) (regular H-bond) and SMZ(-) (negative charge-assisted H-bond, (-)CAHB) successively contributed most adsorption (pH 4-9). At weakly acidic pH, -NH2(0) was partially protonated and electrostatic attraction between -NH3(+) and SMZ(-) occurred concurrently, but could be hindered by increased loading of SMZ(0). Hydrophobic/ π-π interactions were not major mechanisms as phenanthrene and nitrobenzenes had little effect on SMZ adsorption. At alkaline pH, where SMZ(-) and -NH2(0) prevailed, adsorption was accompanied by the stoichiometric (∼1.0) proton exchange with water, leading to OH(-) release and the formation of (-)CAHB [SO2N(-)···H···NH2]. The interaction and SMZ spatial distribution in the resin-phase were further confirmed by FTIR and Raman spectra. SMZ was uniformly adsorbed on external and interior surfaces. SMZ adsorption by PSA had low-interference from other coexistent matter, but high stability after multiple regenerations. The findings will guide new adsorbent designs for selectively removing target organics.


Asunto(s)
Poliestirenos , Sulfametoxazol , Adsorción , Aminas , Interacciones Hidrofóbicas e Hidrofílicas
8.
Water Sci Technol ; 69(9): 1879-85, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24804663

RESUMEN

A novel method was proposed for efficient co-removal of Cu (II) and phthalic acid (PA) using self-synthesized polyamine resin (R-NH(2)). The adsorption properties of R-NH(2) were thoroughly investigated by equilibrium, kinetic and dynamic tests in sole and binary systems at pH 5.0. The Freundlich model was a good fit for all the isotherm data, showing higher Kf values in the binary system than the sole system. The pseudo-second-order kinetic equation showed a better correlation to the experimental data in all cases and PA uptake was much faster than that of Cu (II). R-NH(2) showed highest adsorption capacities to both Cu (II) and PA among the five tested resins. Moreover, the presence of PA markedly enhanced the adsorption of Cu (II), being around 3.5 times of that of the sole system. The adsorption of PA was also slightly increased when Cu (II) was coexistent. Furthermore, using Fourier transform infrared spectrometry (FTIR) and species calculations, possible mechanisms were proposed that Cu (II) coordinated with -NH(2) and negative PA species interacted with -NH(3)(+) by electrostatic attraction. [Cu-PA] complex in the binary system possessed a much higher affinity than free Cu (II) to chelating with -NH(2), resulting in mutual enhancement.


Asunto(s)
Cobre/química , Ácidos Ftálicos/química , Poliaminas/química , Resinas Sintéticas/química , Contaminantes Químicos del Agua/química , Estereoisomerismo , Purificación del Agua/métodos
9.
Chemosphere ; 350: 141045, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38154671

RESUMEN

Supercritical water (SCW) treatment of plastics is a clean technology in the 'waste-to-energy' path. In this work, PP and PET plastics were processed by sub-/supercritical water. The results showed that temperature was the most important factor of the PP and PET degradation. The influence of factors on the degradation of plastics follows the following order: temperature > residence time > plastic/water ratio. These factors influenced the yield of gas products by promoting or inhibiting various reactions (such as reverse water gas shift reaction, methylation reaction, and Fischer-Tropsch synthesis reaction). Besides, the composition of liquid oil was also analyzed. The main composition of the liquid oil produced by PET was benzoic acid and acetaldehyde, which were generated from the decarboxylation of terephthalic acid (TPA) and dehydration reaction of ethylene glycol (EG). The liquid oil from PP was mainly long-chain olefins, long-chain alkanes, cycloalkanes, etc., which were formed by the interaction of various methyl, alkyl, hydroxyl, and other free radicals. This study could build fundamental theories of plastic mixture treatment.


Asunto(s)
Tereftalatos Polietilenos , Polipropilenos , Plásticos , Temperatura , Polietileno
10.
Int J Nanomedicine ; 19: 3071-3086, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38562611

RESUMEN

Introduction: The high mortality rate of malignant ovarian cancer is attributed to the absence of effective early diagnosis methods. The LHRH receptor is specifically overexpressed in most ovarian cancers, and the integrin αvß3 receptor is also overexpressed on the surface of ovarian cancer cells. In this study, we designed LHRH analogues (LHRHa)/RGD co-modified paclitaxel liposomes (LHRHa-RGD-LP-PTX) to target LHRH receptor-positive ovarian cancers more effectively and enhance the anti-ovarian cancer effects. Methods: LHRHa-RGD-LP-PTX liposomes were prepared using the thin film hydration method. The morphology, physicochemical properties, cellular uptake, and cell viability were assessed. Additionally, the cellular uptake mechanism of the modified liposomes was investigated using various endocytic inhibitors. The inhibitory effect of the formulations on tumor spheroids was observed under a microscope. The co-localization with lysosomes was visualized using confocal laser scanning microscopy (CLSM), and the in vivo tumor-targeting ability of the formulations was assessed using the IVIS fluorescent imaging system. Finally, the in vivo anti-tumor efficacy of the formulations was evaluated in the armpits of BALB/c nude mice. Results: The results indicated that LHRHa-RGD-LP-PTX significantly enhanced cellular uptake in A2780 cells, increased cytotoxicity, and hand a more potent inhibitory effect on tumor spheroids of A2780 cells. It also showed enhanced co-localization with endosomes or lysosome in A2780 cells, improved tumor-targeting capability, and demonstrated an enhanced anti-tumor effect in LHRHR-positive ovarian cancers. Conclusion: The designed LHRHa-RGD-LP-PTX liposomes significantly enhanced the tumor-targeting ability and therapeutic efficacy for LHRH receptor-positive ovarian cancers.


Asunto(s)
Neoplasias Ováricas , Animales , Ratones , Humanos , Femenino , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/patología , Liposomas/química , Receptores LHRH , Integrina alfaVbeta3 , Línea Celular Tumoral , Ratones Desnudos , Paclitaxel/uso terapéutico , Oligopéptidos/química
11.
Water Res ; 250: 121078, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38159540

RESUMEN

Disinfection is vital in ensuring water safety. However, the traditional chlorine disinfection process is prone to producing toxic and harmful disinfection by-products (DBPs). The combination of quaternary ammonium polymer and the chlorine disinfection process can solve this shortcoming. Currently, research on the control of DBPs through the combined process is not systematic and the control effect between reducing the dosage of disinfectants and DBPs remains to be studied. Quaternized cyclodextrin polymers have attracted increasing attention due to their excellent adsorption and antibacterial properties, but their synergistic effect with chlorine disinfection is still unclear. In this study, a magnetic quaternized cyclodextrin polymer (MQCDP) is synthesized in an ionic liquid green system, and a combined process of MQCDP treatment and chlorine disinfection is established. The disinfection performance of the combined process on the actual water body along with its reducing effect on the amount of chlorine disinfectant as well as the trihalomethanes (THMs) and haloacetic acids (HAAs) DBPs are explored. MQCDP has a porous structure with a specific surface area of 825 m2 g-1 and is easily magnetically separated. MQCDP can remove most of the natural organic matter (UV254 absorbance decreased by 97 %) in the water at the dosage of 1 g L-1 and kill bacteria with a sterilization rate of 85 %. Compared with disinfection using chlorine alone, the combined process has higher disinfection efficiency and significantly reduces the amount of disinfectant used. A concentration of 5 mg/L of NaClO was needed to meet the standard by chlorine disinfectant alone, while only 2 mg/L of NaClO can meet the standard for the combined process, indicating 60 % of the chlorine demand was reduced. More importantly, the combined process can significantly reduce the generation potential of DBPs. When 10 mg/L of NaClO is added, the THMs and HAAs generated by the combined process decreased by 65 % and 34 %, respectively, compared with the levels produced by single chlorine disinfection. The combined process can reduce the dosage of chlorine disinfectant and MQCDP can adsorb humic acid DBP precursors in raw water, thus lowering the generation of DBPs during disinfection. In summary, MQCDP has excellent separation and antibacterial ability, and its synergistic effects combined with the chlorine disinfection process are of great significance for controlling the amount of disinfectant and the formation potential of DBPs, which has potential applications in actual water treatment.


Asunto(s)
Celulosa , Ciclodextrinas , Desinfectantes , Contaminantes Químicos del Agua , Purificación del Agua , Desinfección , Cloro/química , Desinfectantes/química , Cloruros/química , Halogenación , Trihalometanos/química , Antibacterianos/farmacología , Fenómenos Magnéticos , Contaminantes Químicos del Agua/análisis
12.
Environ Sci Technol ; 47(23): 13652-60, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24164273

RESUMEN

Highly efficient coremoval of Cu(II) and p-nitrophenol (PNP) was accomplished using a newly synthesized polyamine chelating resin (CEAD) as compared to three other commercial resins. The mutual effects and inner mechanisms of their adsorption onto CEAD were systematically investigated by binary, preloading, thermodynamic, and dynamic adsorption procedures. PNP was adsorbed onto both hydrophobic and hydrophilic sites, while Cu(II) only interacted with hydrophilic amine group sites. In both preloading and binary systems, the adsorption of PNP was inhibited to the same degree by the presence of Cu(II) because of selective recognition and direct competition. On the other hand, the presence of PNP obviously enhanced the adsorption of Cu(II) by more than 7%, which was related to PNP loading on the hydrophobic surface. As proved by structural characterization, hydroxyl groups facing outward create new sites for coordination with Cu(II). Moreover, ionic strength exerted some positive influence on the properties of CEAD. Finally, more than 98% of PNP and 99% of Cu(II) could be sequentially recovered with dilute NaClO3 and HCl. These superior properties demonstrated with CEAD indicate that it could be applied to wastewaters containing both heavy metals and PNP, even for high saline aqueous media.


Asunto(s)
Quelantes/química , Cobre/aislamiento & purificación , Nitrofenoles/aislamiento & purificación , Poliaminas/química , Resinas Sintéticas/química , Contaminantes Químicos del Agua/análisis , Purificación del Agua/métodos , Adsorción , Cobre/química , Modelos Teóricos , Estructura Molecular , Nitrofenoles/química , Espectroscopía de Fotoelectrones , Espectrofotometría Atómica , Espectrofotometría Ultravioleta , Espectroscopía Infrarroja por Transformada de Fourier , Termodinámica
13.
J Environ Sci (China) ; 25(7): 1291-9, 2013 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-24218839

RESUMEN

The study evaluated the adsorption of two antibiotics by four engineered adsorbents (hypercrosslinked resin MN-202, macroporous resin XAD-4, activated carbon F-400, and multi-walled carbon nanotubes (MWCNT)) from aqueous solutions. The dynamic results demonstrated the dominant influence of pore size in adsorption. The adsorption amounts of antibiotics on XAD-4 were attributed to the hydrophobic effect, whereas steric hindrance or micropore-filling played a main role in the adsorption of antibiotics by F-400 because of its high microporosity. Aside from F-400, similar patterns of pH-dependent adsorption were observed, implying the importance of antibiotic molecular forms to the adsorption process for adsorbents. Increasing the ionic concentration with CaC12 produced particular adsorption characteristics on MWCNT at pH 2.0 and F-400 at pH 8.0, which were attributed to the highly available contact surfaces and molecular sieving, respectively. Its hybrid characteristics incorporating a considerable portion of mesopores and micropores made hypercross linked MN-202 a superior antibiotic adsorbent with high adsorption capacity. Furthermore, the adsorption capacity of MWCNT on the basis of surface area was more advantageous than that of the other adsorbents because MWCNT has a much more compact molecular arrangement.


Asunto(s)
Antibacterianos/química , Sulfadimetoxina/química , Sulfapiridina/química , Contaminantes Químicos del Agua/química , Adsorción , Concentración de Iones de Hidrógeno , Resinas de Intercambio Iónico , Nanotubos de Carbono/química , Concentración Osmolar , Poliestirenos/química , Polivinilos/química , Temperatura , Eliminación de Residuos Líquidos/instrumentación , Eliminación de Residuos Líquidos/métodos
14.
J Hazard Mater ; 459: 132338, 2023 10 05.
Artículo en Inglés | MEDLINE | ID: mdl-37604037

RESUMEN

The widespread use of surgical masks made of polyolefin and face shields made of polyester during pandemics contributes significantly to plastic pollution. An eco-friendly approach to process plastic waste is using supercritical water, but the reaction of mixed polyolefin and polyester in this solvent is not well understood, which hinders practical applications. This study aimed to investigate the reaction of waste surgical masks (SM) and face shields (FS) mixed in supercritical water. Results showed that the optimal treatment conditions were 400 °C and 60 min, achieving a liquid oil yield of 823.03 mg·g-1 with 25 wt% FS. The interaction between polypropylene (PP), polyethylene terephthalate (PET), and iron (Fe) in SM and FS mainly determined the production of liquid oil products such as olefins and benzoic acid. The methyl-branched structure of PP enhanced PET hydrolysis, resulting in higher production of terephthalic acid (TPA). The degradation of PP was facilitated by the acidic environment created by TPA and benzoic acid in the reaction. Moreover, the hydrolysis of PET produced carboxylic acid, which coordinated with Fe3+ to form Fe-H that catalyzed the polymerization of small olefins, contributing to higher selectivity for C9 olefins. Therefore, this study provides valuable insights into the degradation mechanism of mixed PPE waste in supercritical water and guidance for industrial treatment.


Asunto(s)
Máscaras , Agua , Poliésteres , Plásticos , Polipropilenos , Alquenos , Ácido Benzoico
15.
Environ Sci Pollut Res Int ; 30(22): 61977-61999, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36933134

RESUMEN

Solar drying represents an attractive way to implement an efficient and green development strategy. The viability of open sorption thermal energy storage (OSTES) can compensate for the inherent shortcomings of intermittency and instability of solar energy for ensuring the continuity of the drying process. Nevertheless, the existing solar-powered OSTES technologies only allow a batch mode while being severely restricted by sunlight's availability, thereby heavily limiting the flexibility in managing OSTES on demand. Herein, a novel proof-of-concept that a standalone solar dryer integrated with a reversible solid-gas OSTES unit is presented. Using in situ electrothermal heating (in situ ETH) could rapidly release adsorbed water of activated carbon fibers (ACFs) in an energy-efficient manner to achieve a charging process with faster kinetics. Applying electrical power by a photovoltaic (PV) module, particularly during sunlight-absent or insufficient time, allowed multiple OSTES cycles to proceed. Moreover, ACFs cylindrical cartridges can be flexibly interconnected in either series or parallel, forming universal assemblies with well-controlled in situ ETH capacity. The mass storage density of ACFs with a water sorption capacity of 570 mg/g is 0.24 kW·h·kg-1. The desorption efficiencies of ACFs are higher than 90%, corresponding to 0.057 kW·h maximum energy consumption. The resulting prototype can diminish the fluctuation of air humidity along the night and provide a relatively steady and lower air humidity for the drying chamber. The energy-exergy and environment analysis of the drying section for both setups are estimated, respectively.


Asunto(s)
Arctium , Energía Solar , Luz Solar , Fibra de Carbono , Carbón Orgánico
16.
Chemosphere ; 341: 140056, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37696480

RESUMEN

Pillararene polymers have been widely used as excellent adsorbents for water treatment, but pillararene polymers with ultra-high specific surface area and versatility are still rarely reported. Herein, a quaternary ammonium salt modified pillar [5] arene polymer, QPBP [5], with specific surface area of 1844 m2 g-1 was successfully synthesized. Since QPBP [5] has abundant different adsorption sites, it exhibits excellent performance for the simultaneously removal of organic pollutants with different charges from water. The selected three model pollutants, Rhodamine B (RhB, positively charged), Sulfamethazine (SMT, electrically neutral) and Fulvic acid (FA, negatively charged), could be rapidly and efficiently removed from water by QPBP [5] within 10 min, which are much faster than them by most of the reported adsorbents. RhB and SMT are mainly adsorbed through hydrophobic interactions with the QPBP [5] surface, while FA is mainly removed through ion exchange. In addition, QPBP [5] also showed excellent reusability and adsorption performance for the environmentally relevant concentration of pollutants. Furthermore, the quaternary ammonium groups on QPBP [5] makes it a solid disinfectant with excellent antibacterial properties. In conclusion, QPBP [5] is a promising multifunctional adsorbent for the treatment of complex pollutants in water.


Asunto(s)
Desinfectantes , Contaminantes Ambientales , Purificación del Agua , Porosidad , Desinfectantes/farmacología , Polímeros
17.
Appl Microbiol Biotechnol ; 95(5): 1313-21, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22159739

RESUMEN

3,3',4',5-Tetrachlorosalicylanilide (TCS) is an effective metabolic uncoupler utilized for microbial yield reduction. However, its potential impact, in particular on the soluble microbial products (SMP) formation, is unknown yet. Herein we study the effect of TCS on SMP production and analyze the related mechanism. The addition of TCS in activated sludge system led to an increased production of SMP, especially proteins. The SMP were produced in proportion to the substrate utilization at a low TCS concentration, while more non-substrate-associated SMP were released at a high TCS concentration. TCS simulated the production of extracellular polymeric substances (EPS) and enhanced cell lysis, which both contributed to SMP production. FTIR and EEM analyses show that the SMP, EPS, and cell lysis products have similar functional groups and fluorescence properties, indicating a similar origin of these substances. In addition, a dose of TCS increased the release of high molecular weight compounds due to cell lysis. This study might benefit for a better understanding of the response of activated sludge to metabolic uncouplers like TCS.


Asunto(s)
Biopolímeros/metabolismo , Salicilanilidas/metabolismo , Aguas del Alcantarillado/microbiología , Metagenoma , Análisis Espectral
18.
J Chromatogr A ; 1678: 463322, 2022 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-35872535

RESUMEN

2,4,6-trihalorophenol disinfection by-products (DBPs) have strong toxicity to be needed for monitoring. In this study, two kind of molecularly imprinted polymeric fibers were prepared using 2,4,6-trichlorophenol as template and tricuronic phloroglucinol (MOP) as pseudo-template, respectively. The two fibers were assembled as solid phase microextraction (SPME) fiber to extract 2,4,6-trihalophenol DBPs from water and detect them by gas chromatography coupled to electron capture detector (GC-ECD). The results of F-test and t-test stated that there are significant difference in the analytical results of 2,4,6-trichlorophenol between using the fiber based on 2, 4, 6-trichlorophenol as template and MOP as pseudo-template. It was found that the carry-over of template (2,4,6-trichlorophenol) leaked from the fiber in GC thermal desorption, resulting in the wrong quantitative analytical result for 2,4,6-trichlorophenol in water. Hence, molecularly imprinted polymeric fibers based on MOP as pseudo-template was applied for the determination of 2,4,6-trihalophenol DBPs in water combined with GC-ECD. The selectivity of the fiber for 2,4,6-trihalophenol DBPs was investigated and demonstrated. Under the optimized condition, the method has much lower limit of detection (0.5-1.1 pg mL-1) than most reported methods. The method was applied for the determination of 2,4,6-trihalophenol DBPs in environmental water and the relative recoveries were found to be in the range from 77.1% to 105.6% and the relative standard deviation was 0.5-9.4%. 2,4,6-tribromophenol was found at concentration of 0.054 ng mL-1 in a swimming pool.


Asunto(s)
Impresión Molecular , Microextracción en Fase Sólida , Cromatografía de Gases/métodos , Desinfección , Impresión Molecular/métodos , Polímeros/química , Microextracción en Fase Sólida/métodos , Agua
19.
Sci Total Environ ; 808: 151892, 2022 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-34826470

RESUMEN

Poyang Lake is the first freshwater lake in China, which is an important drinking water source. In recent years, industrial pollution has led to the increased phthalate acid esters (PAEs) in Poyang Lake. PAEs are a class of typical endocrine disruptors that can accumulate in organisms and interfere with their secretion systems. Thus, the accurate determination of PAEs in Poyang Lake is important for health risk prediction and the development of corresponding control means. Monitoring organic pollutants in water using the diffusive gradient in thin films technique (DGT) has attracted much attention due to more accuracy and convenience than the traditional methods. This study used an inexpensive amphiphilic cyclodextrin polymer (PBCD) as the sorbent for the binding gel. This new binding gel has an ultra-high specific surface area and excellent adsorption performance. Diffusion coefficients of the five PAEs were determined, and the performance of DGT such as adsorption capacity and deployment time (1-4 days) was tested using five PAEs as models. The assembled PBCD-DGT was used to examine the performance in a complex simulated water environment. The sampling capability of PBCD-DGT was verified in Yangshan Lake, and a large-scale field application was conducted in Poyang Lake basin. The results of 11 sampling points showed that the concentration ranges of dimethyl phthalate, diethyl phthalate, diallyl phthalate, dipropyl phthalate, and dibutyl phthalate were 434-2594 ng/L, 40-314 ng/L, 80-527 ng/L, 45-308 ng/L, and ND-182 ng/L, respectively. The health risk index (HI) and ecological risk quotient (RQ) values of PAEs in the Poyang Lake watershed were far below 1, indictating a lower health and ecological risk. Considering that PAEs are bioaccumulative and persistent, it is very necessary to continue to pay attention to its pollution status and health and ecological risk changes in Poyang Lake Basin in the future.


Asunto(s)
Agua Potable , Ácidos Ftálicos , Contaminantes Químicos del Agua , Celulosa , China , Ciclodextrinas , Dibutil Ftalato/análisis , Monitoreo del Ambiente , Ésteres/análisis , Lagos , Ácidos Ftálicos/análisis , Medición de Riesgo , Tecnología , Contaminantes Químicos del Agua/análisis
20.
Chemosphere ; 289: 133009, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34808201

RESUMEN

The research on preparing high-quality pellets by combining torrefaction and densification of biomass has received widespread attention. This paper investigated the influence of torrefaction temperature on biomass and evaluated the quality of three kinds of pellets (raw pellets, ex-situ torrefied densified pellets and in-situ torrefied densified pellets). When the torrefaction temperature was raised to 300 °C, the energy yield of rice straw (RS) and rice husk (RH) quickly decreased to 71.08% and 77.62%, and the cellulose was decomposed significantly. The results proved that 250 °C was an optimum temperature for RS and RH torrefaction. The densities of RS and RH in-situ torrefied densified pellets were 1236.84 kg/m3 and 1277.50 kg/m3 under 150 MPa, respectively. The density, Meyer hardness, hydrophobicity, and mechanical specific energy consumption of the pellet increased with the increase of molding pressure. The in-situ pellets had higher Meyer hardness, hydrophobicity, and lower mechanical specific energy consumption under the same molding pressure than raw pellets and ex-situ torrefied densified pellets. In addition, the bonding mechanism was studied by using scanning electron microscopy and ultraviolet auto-fluorescence. In-situ torrefaction and densification facilitated the formation of self-locking and the migration of lignin between particles. Compared with RH pellets, RS pellets had higher quality due to the higher hemicellulose content, which was necessary for forming stable hydrogen bonds.


Asunto(s)
Oryza , Biomasa , Celulosa , Interacciones Hidrofóbicas e Hidrofílicas , Temperatura
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