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Ultrasound imaging is extensively used in biomedical science and clinical practice. Imaging resolution and tunability of imaging plane are key performance indicators, but both remain challenging to be improved due to the longer wavelength compared with light and the lack of zoom lens for ultrasound. Here, the ultrasound zoom imaging based on a stretchable planar metalens that simultaneously achieves the subwavelength imaging resolution and dynamic control of the imaging plane is reported. The proposed zoom imaging ultrasonography enables precise bone fracture diagnosis and comprehensive osteoporosis assessment. Millimeter-scale microarchitectures of the cortical bones at different depths can be selectively imaged with a 0.6-wavelength resolution. The morphological features of bone fractures, including the shape, size and position, are accurately detected. Based on the extracted ultrasound information of cancellous bones with healthy matrix, osteopenia and osteoporosis, a multi-index osteoporosis evaluation method is developed. Furthermore, it provides additional biological information in aspects of bone elasticity and attenuation to access the comprehensive osteoporosis assessment. The soft metalens also features flexibility and biocompatibility for preferable applications on wearable devices. This work provides a strategy for the development of high-resolution ultrasound biomedical zoom imaging and comprehensive bone quality diagnosis system.
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INTRODUCTION: In the transition to the postpandemic era, adolescents are working to shift their focus back to school. However, the prevalence of academic procrastination is reflective of that the aftereffects of the pandemic are persisting. Literature documents the increases in the negative parenting behaviors and internet use of adolescents during the pandemic. The excessive internet use has to do with adolescents' self-regulatory capabilities and self-regulation is profoundly shaped by parents' parenting practices. Given the connections among these factors, the present study seeks to understand how maladaptive parenting practices during the pandemic influenced adolescents' academic procrastination postpandemic through the mediation of self-regulation and problematic internet use. METHOD: Using three waves of data from a total of 1062 Chinese adolescents (Mage = 14.9 years old, SD = 1.6, 13-18 years old; 45% female), we used structural equation modeling to examine the direct effect of maladaptive parenting on academic procrastination and its indirect effect via self-regulation and problematic internet use. RESULTS: Maladaptive parenting during the pandemic did not directly predict adolescent academic procrastination post-pandemic. Yet, maladaptive parenting indirectly influenced academic procrastination both through self-regulation solely and self-regulation and problematic internet use sequentially. CONCLUSION: The findings demonstrate that parents can contribute to adolescents' academic procrastination by influencing their self-regulation ability, which further impacts their internet use. Self-regulation serves as a robust mediator between parenting and adolescents' problematic behaviors related to internet use and learning. Implications for parents and intervention oriented toward adolescents are discussed.
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Chimeric antigen receptor T-cell (CAR-T) therapy has revolutionized the treatment approach for patients with relapsed/refractory non-Hodgkin lymphoma (R/R NHL). However, the long-term prognosis has been discouraging. Moreover, the urgent resolution of two critical issues is necessary: minimize tumor burden before CAR-T infusion and control fatal toxicities post CAR-T therapy. By combining radiotherapy (RT), the safety and efficacy of CAR-T can be improved. RT can serve as bridging therapy, reducing the tumor burden before CAR-T infusion, thus enabling safe and successful CAR-T infusion, and as salvage therapy in cases of CAR-T therapy failure. This review aims to discuss the current evidence supporting the use of RT in CAR-T therapy for patients with R/R NHL. Although most studies have shown a positive role of RT in combined modality treatments for patients undergoing CAR-T therapy, the synergy gained from these remains uncertain. Furthermore, the optimal dose/fraction and radiation response require further investigation.
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Inmunoterapia Adoptiva , Linfoma no Hodgkin , Receptores Quiméricos de Antígenos , Humanos , Linfoma no Hodgkin/terapia , Linfoma no Hodgkin/radioterapia , Inmunoterapia Adoptiva/métodos , Inmunoterapia Adoptiva/efectos adversos , Receptores Quiméricos de Antígenos/uso terapéutico , Receptores Quiméricos de Antígenos/inmunología , Terapia Combinada/métodos , Recurrencia Local de Neoplasia/terapiaRESUMEN
Chimeric antigen receptor T-cell therapy (CAR-T) has been widely applied in the clinical practice of relapse/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) due to its promising effects. Hyperprogressive disease (HPD) has gained attention for rapid tumor progression and has become a therapeutic and prognostic challenge. Here, we present a patient who had suffered from several recurrences previously and controlled well with a very small tumor lesion left was infused with CD19/CD22 bispecific CAR-T, with no immune effector cell-associated neurotoxicity syndrome, or cytokine release syndrome observed. However, rapid deterioration, subsequent imaging examination, circulating tumor DNA, and serum biomarkers detection identified HPD. The patient did not respond to salvage treatment and died 40 days after infusion. To our knowledge, only one case of HPD in DLBCL after CAR-T therapy has been reported. This fatal case alarmed the risk of HPD and the ctDNA profile monitoring we used was performed as a non-invasive method to diagnose HPD, providing far-reaching practical instruction for CAR-T therapy.
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Ultrasound focusing plays an important role in biomedical therapy and diagnosis. Acoustic metalens has showcased remarkable focusing performance but yet to be implemented to the practical ultrasound therapeutic applications. We design a planar metalens operating at megahertz and experimentally demonstrate the distinct thermal effect on biological tissues induced by the high-resolution focusing. A prominent temperature rise of 50°C is experimentally observed in the biological phantom, with a much lower input ultrasound power of 4 W compared with the traditional methods. We further study the thermal effect on fresh porcine liver and investigate the morphological changes under different physical parameters. Visible lesions are observed in in vitro tissues at the lowest input ultrasound power of 2.6 W within 10 s. This study facilitates the practical biomedical application of acoustic metalens, providing a feasible approach for the precise, safe, and reliable therapeutic ultrasound with the simple and compact metalens.
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A longstanding pursuit in information communication is to increase transmission capacity and accuracy, with multiplexing technology playing as a promising solution. To overcome the challenges of limited spatial information density and systematic complexity in acoustic communication, here real-time spatiotemporal communication is proposed and experimentally demonstrated by a single sensor based on the rotational Doppler effect. The information carried in multiplexed orbital-angular-momentum (OAM) channels is transformed into the physical quantities of the temporal harmonic waveform and simultaneously detected by a single sensor. This single-sensor configuration is independent of the channel number and encoding scheme. The parallel transmission of complicated images is demonstrated by multiplexing eight OAM channels and achieving an extremely-low bit error rate (BER) exceeding 0.02%, owing to the intrinsic discrete frequency shift of the rotational Doppler effect. The immunity to inner-mode crosstalk and robustness to noise of the simple and low-cost communication paradigm offers promising potential to promote relevant fields.
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It remains a challenge to develop cost-effective, high-performance oxygen electrocatalysts for rechargeable metal-air batteries. Herein, zinc-mediated zeolitic imidazolate frameworks are exploited as the template and nitrogen and carbon sources, onto which is deposited a Fe3 O4 layer by plasma-enhanced atomic layer deposition. Controlled pyrolysis at 1000 °C leads to the formation of high density of Fe3 O4- x few-atom clusters with abundant oxygen vacancies deposited on an N-doped graphitic carbon framework. The resulting nanocomposite (Fe3 O4- x /NC-1000) exhibits a markedly enhanced electrocatalytic performance toward oxygen reduction reaction in alkaline media, with a remarkable half-wave potential of +0.930 V versus reversible hydrogen electrode, long-term stability, and strong tolerance against methanol poisoning, in comparison to samples prepared at other temperatures and even commercial Pt/C. Notably, with Fe3 O4- x /NC-1000 as the cathode catalyst, a zinc-air battery delivers a high power density of 158 mW cm-2 and excellent durability at 5 mA cm-2 with stable 2000 charge-discharge cycles over 600 h. This is ascribed to the ready accessibility of the Fe3 O4- x catalytic active sites, and enhanced electrical conductivity, oxygen adsorption, and electron-transfer kinetics by surface oxygen vacancies. Further contributions may arise from the highly conductive and stable N-doped graphitic carbon frameworks.
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The oxygen based membrane biofilm (O2-MBfR) has been proved to be a novel technology in treating greywater (GW) and response surface methodology (RSM) was used to model the removal of chemical oxygen demand (COD) and total nitrogen (TN) with operation parameters COD/TN ratio, system pH and lumen air pressure (LAP). Results indicated that the all target single factors affect GW treatment efficiency, and the regression model with central composite design (CCD) showed good agreement with the experimental results with high R2 and R2 adj values (all >0.97) for all the target responses. Statistical evaluation revealed that system pH was the most significant parameter affecting COD and TN removal, followed by COD/TN ratio and LAP. The interaction between COD/TN ratio and system pH also played an important role on the GW treatment. The optimized maximum removal of COD (96.48%) and TN (133â¯gâ¯N/m2-day) were achieved with the COD/TN ratio 17.76â¯g COD/g TN, system pHâ¯7.10 and LAP 1.00â¯psi. Thus, RSM combined with CCD could be used for predicting the organics and nitrogen removal during GW treatment in the O2-MBfR.
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Reactores Biológicos , Eliminación de Residuos Líquidos , Biopelículas , Análisis de la Demanda Biológica de Oxígeno , Nitrógeno/análisis , Oxígeno , Aguas ResidualesRESUMEN
Anaerobic ammonium oxidation (anammox) has the merit of saving the carbon source and aeration energy for nitrogen (N) removal, but it is normally a challenge to achieve mainstream anammox. In this study, the potential to enhance the N-removal capability of an existing University of Cape Town membrane bioreactor system (UCT-MBR) system is evaluated through process modeling. In addition to external carbon addition, the UCT-MBR system is proposed to be converted into an anoxic-oxic (AO) configuration with two operation plans: one is single-sludge (suspended sludge) and the other is double-sludge (suspended sludge and biofilm). The choice between pushing anammox and enhancing conventional heterotrophic denitrification is assessed. The simulation result indicates it is feasible to strategically adjust the spatial-temporal balance between electron donors and electron acceptors to achieve enhanced N-removal by utilizing the influent organic carbon other than adding external carbon. Although anammox can be promoted in the double-sludge-based AO under low-DO conditions, pushing anammox will weaken the system's resilience to influent fluctuations and carries no economic advantage over the single-sludge-based AO. Overall, this study concurs with the United Nations Sustainable Development Goal that the wastewater industry should seek more energy-efficient measures for wastewater treatment.
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Nitrógeno , Aguas Residuales , Anaerobiosis , Reactores Biológicos , Desnitrificación , Oxidación-Reducción , Aguas del AlcantarilladoRESUMEN
Sludge drying bed (SDB) treatment is a valuable alternative to conventional sludge treatment methods. However, changes in sludge hydrotexture during dewatering present a barrier for direct modeling of the SDB process. This study proposes a modeling strategy to simulate the sludge stabilization process in SDB treatment by separating sludge dewatering and sludge solids stabilization into independent processes. Two cell decay theories widely used by activated sludge models (ASM), death-regeneration concept and endogenous respiration theory, are compared to describe the biokinetic processes of sludge digestion. Both cell decay theories are found to adequately describe effluent total COD, NH4-N, NO3-N, and sludge layer composition, but have pronounced differences in describing effluent COD compositions. Results show that natural aeration does not maintain adequate aerobic/anoxic sludge digestion within the sludge layer to fully nitrify NH4-N released by cell decay. Results also indicate that the kinetics of sludge digestion are adaptable over time, indicating the need to adopt lumped values for biokinetic simulations. While lowered sludge dewatering rates (outflow) can increase biodegradable COD for cell metabolism, increased sludge loading rates (inflow) lead to higher effluent COD and NH4-N concentrations. Contrary to conventional judgement, this study demonstrates the merit of sludge layer formation to reduce leaching loss of biodegradable COD. Overall, the proposed modeling strategy is proven capable of simulating deposited sludge digestion processes in an SDB.
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Aguas del Alcantarillado , Eliminación de Residuos Líquidos , Reactores Biológicos , CinéticaRESUMEN
A novel CeO2 doped high silica ZSM-5(CeO2@HSZSM-5) composite was originally fabricated via ammonia precipitation for the catalytic ozonation of sulfamethoxazole (SMX). Physicochemical properties have been investigated through electron microscope, Raman spectroscopy, X-ray photoelectron spectroscopy, etc. The prepared nanometer CeO2@HSZSM-5 had a much higher specific surface (348-395 m2/g), a finer crystallite size (8.2-33.5 nm) and superior stability. Temperature-programmed desorption and reduction analysis revealed that the formed CeO2 nanoparticles on the surface of CeO2@HSZSM-5 could improve the reducibility of surface-capping oxygen, induce more oxygen vacancies and promote oxygen migration. CeO2@HSZSM-5 exhibited excellent catalytic performance for SMX mineralization in the pH range of environmental waters. The great enhancement of CeO2@HSZSM-5 catalytic activity was ascribed to the conversion of O3 into active oxygen involved in SMX mineralization, including .OH, O2.- and 1O2. This work provides a reference for the removal of pollutants by zeolite supported Ce catalytic ozonation process in water.
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White matter hyperintensities (WMH) are common in elderly individuals and cause brain network deficits. However, it is still unclear how the global brain network is affected by the focal WMH. We aimed to investigate the diffusion of WMH-related deficits along the connecting white matters (WM). Brain magnetic resonance imaging data and neuropsychological evaluations of 174 participants (aged 74 ± 5 years) were collected and analyzed. For each participant, WMH lesions were segmented using a deep learning method, and 18 major WM tracts were reconstructed using automated quantitative tractography. The diffusion characteristics of distal WM tracts (with the WMH penumbra excluded) were calculated. Multivariable linear regression analysis was performed. We found that a high burden of tract-specific WMH was related to worse diffusion characteristics of distal WM tracts in a wide range of WM tracts, including the forceps major (FMA), forceps minor (FMI), anterior thalamic radiation (ATR), cingulum cingulate gyrus (CCG), corticospinal tract (CST), inferior longitudinal fasciculus (ILF), superior longitudinal fasciculus-parietal (SLFP), superior longitudinal fasciculus-temporal (SLFT), and uncinate fasciculus (UNC). Furthermore, a higher mean diffusivity (MD) of distal tracts was linked to worse attention and executive function in the FMI, right CCG, left ILF, SLFP, SLFT, and UNC. The effect of WMH on the microstructural integrity of WM tracts may propagate along tracts to distal regions beyond the penumbra and might eventually affect attention and executive function.
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Envejecimiento/patología , Imagen de Difusión Tensora/métodos , Fibras Nerviosas Mielínicas/patología , Vías Nerviosas/diagnóstico por imagen , Vías Nerviosas/patología , Sustancia Blanca/diagnóstico por imagen , Sustancia Blanca/patología , Anciano , Anciano de 80 o más Años , Envejecimiento/fisiología , Atención/fisiología , Aprendizaje Profundo , Función Ejecutiva/fisiología , Femenino , Humanos , Interpretación de Imagen Asistida por Computador , Leucoaraiosis/diagnóstico por imagen , Leucoaraiosis/patología , Masculino , Tractos Piramidales/diagnóstico por imagen , Tractos Piramidales/patologíaRESUMEN
Studies have shown that the central renin-angiotensin system is involved in neurological disorders. Our previous studies have demonstrated that angiotensin II receptor type 1 (AT1R) in the brain could be a potential target against methamphetamine (METH) use disorder. The present study was designed to investigate the underlying mechanisms of the inhibitory effect of AT1R on various behavioural effects of METH. We first examined the effect of AT1R antagonist, candesartan cilexetil (CAN), on behavioural and neurotoxic effects of METH. Furthermore, we studied the role of phospholipase C beta 1 (PLCß1) blockade behavioural and neurotoxic effects of METH. The results showed that CAN significantly attenuated METH-induced behavioral disorders and neurotoxicity associated with increased oxidative stress. AT1R and PLCß1 were significantly upregulated in vivo and in vitro. Inhibition of PLCß1 effectively alleviated METH-induced neurotoxicity and METH self-administration (SA) by central blockade of the PLCß1 involved signalling pathway. PLCß1 blockade significantly decreased the reinforcing and motivation effects of METH. PLCß1 involved signalling pathway, as well as a more specific role of PLCß1, involved the inhibitory effects of CAN on METH-induced behavioural dysfunction and neurotoxicity. Collectively, our findings reveal a novel role of PLCß1 in METH-induced neurotoxicity and METH use disorder.
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Metanfetamina/administración & dosificación , Metanfetamina/toxicidad , Fosfolipasa C beta/metabolismo , Transducción de Señal/efectos de los fármacos , Animales , Conducta Animal/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Estimulantes del Sistema Nervioso Central , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Masculino , Actividad Motora , Síndromes de Neurotoxicidad , Fosfolipasa C beta/genética , Interferencia de ARN , ARN Interferente Pequeño , Ratas , Ratas Sprague-DawleyRESUMEN
The sustainability of rural sanitation includes the long-term welfare of both rural and urban societies. As a commonly used rural sanitation technology, operation of intermittent sand filters (ISF) is impacted by biofilm clogging inside the ISF. In this study ISF performance is studied at low hydraulic loading rates (HLR) to explore the interaction between biofilm growth and wastewater treatment efficiency. CW2D/HYDRUS, a simulation model which does not include media hydraulic property changes caused by biofilm growth, is utilized as a numerical control to contrast the effects of biofilm growth inside an experimental ISF. A paired experiment with simulation demonstrate that biofilm clogging comprised dominantly of heterotrophs occurred in the top layers of the ISF. Lowered HLR slows clogging development but not final clogging extent. The biofilm clogging development zone offers adequate removal of applied biodegradable COD and NH4+ - N. However, the spatial distribution of heterotrophs and biodegradable COD does not match the denitrification requirement of the resulting NO3- - N. A simultaneous nitrification and denitrification (SND) potential is manifested in the clogging development zone, but lowered HLR reduces media moisture level to a less favorable level for denitrification. Furthermore, slowed water movement under lower HLR aggravates the accumulation of NO3- - N, which can potentially result in counterproductive salt accumulation. Since biofilm growth is a natural and self-adaptive response to wastewater application, this study suggests accepting limited, managed biofilm growth and clogging in ISFs. In addition, this study calls for further research to manage biofilm growth and clogging for long-term ISF sustainability.
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Filtración , Arena , Biopelículas , Reactores Biológicos , Desnitrificación , Nitrógeno , Dióxido de Silicio , Eliminación de Residuos Líquidos , Aguas ResidualesRESUMEN
To promote the environmental sustainability of rural sanitation, a soil moisture controlled wastewater subsurface drip irrigation (SDI) dispersal system was field tested in the Black Belt Prairie of Alabama, USA. The soil moisture control strategy was designed to regulate wastewater disposal timing according to drain field conditions to prevent hydraulic overloading and corresponding environmental hazard. CW2D/HYDRUS simulation modeling was utilized to explore difficult-to-measure aspects of system performance. While the control system successfully adapted hydraulic loading rate to changing drain field conditions, saturated field conditions during the dormant season presented practical application challenges. The paired field experiment and simulation model demonstrate that soil biofilm growth was stimulated in the vicinity of drip emitters. Although biofilm growth is critical in maintaining adequate COD and NH4+-N removal efficiencies, the efficient removal of biodegradable COD itself by soil biofilm limits denitrification of formed NO3--N . Furthermore, stimulated soil biofilm growth can create soil clogging around drip emitters, which was discerned in the field experiment along with salt accumulation, both of which were verified by simulation. Comparable modeling of system performance in sand and clay media demonstrate that the placement of soil moisture sensors within the drain field can have pronounced impacts on system hydraulic performance, depending on the soil permeability. Overall, the soil moisture control strategy tested is shown as a viable supplemental technology to promote the environmental sustainability of rural sanitation systems.
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Suelo , Aguas Residuales , Alabama , Pradera , Eliminación de Residuos LíquidosRESUMEN
A biochar material made from corncobs was tested for its capability in BTEX adsorption/interception in stormwater filtration systems. Batch experiments were conducted to examine the adsorption kinetics, adsorption isotherms, and adsorption thermodynamics of BTEX onto this biochar. The feasibility of applying this biochar in stormwater filtration was studied by dynamic transport experiments and model simulations. The result showed that this biochar can adsorb BTEX and the adsorption is a thermodynamically spontaneous, and endothermic process. The BTEX adsorption kinetic experiment and adsorption retarded BTEX transport experiment indicated that the BTEX adsorption kinetics can be changed by the driving force between the BTEX concentrations and the active adsorption site as well as the contact time between BTEX and the biochar. In terms of applying this biochar in stormwater filtration, the Monte Carlo uncertainty analysis indicated that the BTEX interception is sensitive to the hydraulic conductivity of the biochar filter and the adsorption kinetics of the biochar material. Although this corncob-made biochar demonstrated effective pollutant adsorption capability, the biochar adsorption capability should be utilized to retain the pollutant long enough for biodegradation to take effect for ultimate pollutant attenuation.
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Contaminantes Químicos del Agua , Zea mays , Adsorción , Carbón Orgánico , Filtración , Cinética , Contaminantes Químicos del Agua/análisisRESUMEN
Adsorption characteristics of high-silica zeolites (HSZSM-5) for two selected sulfonamide antibiotics (SAs) (sulfamethoxazole and sulfadiazine) were investigated. The SAs were almost completely (>90%) removed from the water by HSZSM-5. Adsorption followed second-order kinetics with liquid-film diffusion as the dominant mechanism. SA adsorption capacity on high-silica zeolites was examined in terms of pH, temperature, and the presence of natural organic matter (NOM). HSZSM-5 had better adsorption performance in acidic conditions, and the apparent distribution coefficient indicated that SA0 species were the major contribution to the overall adsorption at pH of 2-10. Adsorption of SAs on HSZSM-5 was a spontaneous and exothermic physisorption process. SA removal by HSZSM-5 was a mixed mechanism through ion-exchange and hydrophobic interaction. HSZSM-5 has potential application prospects in removing SAs from wastewater.
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Antibacterianos/análisis , Sulfonamidas/análisis , Contaminantes Químicos del Agua/análisis , Purificación del Agua/métodos , Adsorción , Cinética , Dióxido de SilicioRESUMEN
Sludge treatment beds (STBs) have been used widely in many countries due to low energy consumption, low operating and maintenance costs, and better environmental compatibility. Penetration, evaporation, and transpiration are the main processes for sludge dewatering in STBs. However, the leachate quality from STBs usually cannot meet discharge limits. Moreover, such leachate has very low COD/N ratio, which makes it difficult to treat. In the present study, two subsurface flow (SSF) constructed wetlands (CWs) were investigated for the treatment of leachate from STBs under three different hydraulic retention time (HRT) (3 days, 4 days, 6 days), aiming for evaluating the effects of plants and HRT on treatment performance, as well as the potential of SSF CWs to treat sludge leachate with low COD/N ration. The results showed that plants play an important role in leachate treatment. The best treatment performance was achieved with HRT of 4 days. In this condition, the mean removal efficiencies of COD (chemical oxygen demand), NH4+-N, TN (total nitrogen), and TP (total phosphorus) in the planted and the unplanted CWs were 61.6% (unplanted - 3.7%), 76.6% (unplanted 43.5%), 70% (unplanted 41%), and 65.6% (unplanted 6%), respectively. Heavy metal concentrations were below the Chinese integrated wastewater discharge standard during the experimental period in the planted CW, and the removal efficiencies in the planted CW system were higher than in the unplanted CW system. In all, planted SSF CWs can be an effective approach in removing leachate from sludge treatment beds. Furthermore, considering to temperature and seasonal variation, the leachate from STBs needs to be further studied in pilot- and full-scale condition.
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Eliminación de Residuos Líquidos/métodos , Contaminantes del Agua/análisis , Humedales , Análisis de la Demanda Biológica de Oxígeno , Metales Pesados , Nitrógeno/análisis , Fósforo/análisis , Plantas , Aguas del Alcantarillado , Aguas Residuales , Purificación del AguaRESUMEN
To predict the membrane fouling phenomena in the membrane filtration operation, the individual models derived from Darcy's law and the corresponding combined models were employed to investigate the kind of models that provided better fits. The filtration of the mixed liquid from membrane bioreactors with different sludge retention time (SRT) at a constant pressure was carried out. The variation of applied pressure had significantly effect on the kind of the individual model provided better fit for the data at longer SRT and less effect for the data at shorter SRT, though it had less effect on the kind of the combined model that provided better fit. The kind of model that provided better fit did not change when the concentration of the diluted mixed liquor was at a certain range, even though the dilution ratio would lead to the variation of the prediction results. The cake-standard model and the complete-standard model provided good fits at different pressure and at different dilution ratio, respectively. The cake-standard and complete-standard models may be applicable to systems where these models are consistent with the experimentally observed fouling mechanisms.
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Incrustaciones Biológicas , Reactores Biológicos , Membranas Artificiales , Modelos Biológicos , Filtración/métodos , Presión , Aguas del Alcantarillado , Eliminación de Residuos Líquidos/métodosRESUMEN
Despite extensive research demonstrating the influence of organic matter and inorganic phosphate on the stability of TiO2 nanoparticles (NPs), far less research has assessed the impact of myo-inositol hexakisphosphate (IHP), a common organic phosphate widely present in the environment. In this study, the adsorption of IHP on TiO2 NPs and its impact on their colloidal stability were investigated using batch experiments, dynamic light scattering (DLS) techniques, in situ attenuated total reflectance Fourier transform infrared (ATR-FTIR) and solid-state (31)P nuclear magnetic resonance (NMR) spectroscopy. Inorganic orthophosphate (Pi) adsorption was run for comparison. The ratio of the Pi/IHP adsorption density (1.528: 0.453) at pH5.0 suggested that IHP may complex on the TiO2 surface through three of its six phosphate groups. Zeta potential measurements, ATR-FTIR and NMR spectra indicated that IHP/Pi adsorbed onto TiO2 NPs by forming inner-sphere complexes and modified the surface charge of these NPs, which exerted a great impact on their colloidal stability. Interactions between NPs measured by sedimentation and aggregation size highly depended on the pH, surface phosphorus coverage, and surface phosphorus species. The impact of IHP on the aggregation and dispersion of TiO2 NPs was significantly larger than that of Pi, in agreement with the calculation from the DLVO theory. This study highlighted the impact of IHP relative to Pi on the colloidal stability of TiO2 NPs in phosphorus-enriched environments.