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The purpose of this research is to investigate the effectiveness of Digital Content Marketing (DCM) on a Mixed Reality (MR) training platform environment with the consideration of online purchase intention (OPI) through social media. E-commerce today encounters several common issues that cause customers to have reservations to purchase online. With the absence of physical contact points, customers often perceive more risks when making purchase decisions. Furthermore, online retailers often find it hard to engage customers and develop long-term relationships. In this research, a Structural Equation Model (SEM) is proposed to examine the efficacy of DCM from both immediate and long-term OPI. The results examine whether adopting DCM on an MR training platform environment through social media brings positive results in OPI. Empirical research was carried out through online questionnaires collected in 2021 and 2022. A total of 374 questionnaires were qualified for data analysis in this study, conducted with IBM SPSS and AMOS. The results imply that DCM is critical to stimulating both immediate and long-term OPI. The immediate OPI is positively affected by increasing perceived value through MR in DCM. Regarding the long-term OPI, increased customer engagement with DCM under MR environment can cultivate brand trust and significantly affect the long-term OPI.
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Microbial fuel cells (MFCs) are an ecologically friendly technology that can recover electricity and simultaneously treat wastewater. Among all the influential factors, cathode material and catalyst play a crucial role in electricity production and oxygen reduction. In this study, Pt nanocatalysts deposited on single-walled carbon nanotubes (Pt/SWCNTs) were synthesized by the deposition-precipitation (DP) method under optimal conditions. The results show that DP might be a promising method for the preparation of Pt/SWCNTs due to its simple, cost-effective and time-saving procedure, in addition to being highly efficient at creating small Pt particles (0.9 nm) that were very uniformly distributed. The synthesized Pt/SWCNTs suspension was spray-coated on to carbon cloth and then used as a cathode for MFCs. The electricity generation of MFCs equipped with a Pt/SWCNTs cathode was evaluated in terms of open circuit voltage (0.6954 V), internal resistance (63.3 ꃛm2) and maximum power density (2,022 mW/m2). The chemical oxygen demand removal, biological oxygen demand removal, total dissolved solids removal, total suspended solids removal and silver recovery was satisfactory at 84.5%, 74.0%, 45.7%, 60.0% and 99.0%, respectively. Therefore, Pt/SWCNTs from the DP method was identified as a potential candidate to replace commercial Pt-carbon cloth for MFC cathodes.
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Fuentes de Energía Bioeléctrica , Nanotubos de Carbono/química , Platino (Metal)/química , Análisis de la Demanda Biológica de Oxígeno , Catálisis , Electricidad , Electrodos , Aguas Residuales/químicaRESUMEN
BACKGROUND: The gold standard for categorisation of weight status is clinically measured body mass index (BMI), but this is often not practical in large epidemiological studies. OBJECTIVES: To determine if a child's weight perception or a mother's perception of a child's weight status is a viable alternative to measured height and weight in determining BMI classification. Secondary outcomes are to determine the influence of a mother's BMI on her ability to categorise the child's BMI and a child's ability to recognise his/her own BMI. METHODS: Cross-sectional analysis of the growing up in Ireland cohort study, a nationally representative cohort of 8568 9-year-old children. The variables considered for this analysis are the child's gender, BMI (International Obesity Taskforce grade derived from measured height and weight) and self-perceived weight status, and the mother's weight perception of the child, BMI (derived from measured height and weight) and self-perceived weight status. Cohen's weighted-kappa was used to evaluate the strength of the agreement between pairwise combinations of the BMI variables. Cumulative and adjacent categories logistic regression were used to predict how likely a person rates themselves as under, normal or overweight, based on explanatory variables. RESULTS: Mothers are more accurate at correctly classifying their child's BMI (κ=0.5; confidence intervals (CI) 0.38-0.51) than the children themselves (κ=0.25; CI 0.23-0.26). Overweight mothers are better raters of their child's BMI (κ=0.51; CI 0.49-0.54), compared with normal (κ=0.44; CI 0.41-0.47) or underweight mothers (κ=0.4; CI 0.22-0.58), regardless of whether the mother's BMI is derived from measured height and weight or self-perceived. The mother's perception of the child's weight status is not an influencing factor on the child's ability to correctly classify him/herself, but the child's self-perceived weight status influences the mother's ability to correctly classify the child. CONCLUSIONS: A mother's BMI classification of her child is a viable alternative to BMI measurement in large epidemiological studies.
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Índice de Masa Corporal , Madres/psicología , Obesidad Infantil/psicología , Autoinforme , Adulto , Peso Corporal , Niño , Estudios Transversales , Femenino , Conocimientos, Actitudes y Práctica en Salud , Encuestas Epidemiológicas , Humanos , Irlanda/epidemiología , Modelos Logísticos , Estudios Longitudinales , Masculino , Obesidad Infantil/epidemiología , Factores SocioeconómicosRESUMEN
OBJECTIVE: This study explores (1) the motivations and challenges facing family caregiving for cancer in Singapore and (2) suggests a possible framework to guide culturally sensitive future work on caregivers. DESIGN: Twenty caregivers of patients being treated for cancer at a public hospital in Singapore were interviewed. A semi-structured interview format and inductive thematic analysis were used to analyse the data. Caregivers were asked about their motivations for caregiving and the challenges they faced. RESULTS: Caregivers' motivations grouped into three categories: personal value and fulfilment, giving care because of societal expectations such as filial piety, and practical need. Challenges were grouped into interpersonal challenges, disclosure and finding balance. Caregivers with different primary motivations varied in their responses to these challenges. More autonomous caregivers cited learning points and reprioritised more effectively than less autonomous caregivers, who reported more internal conflict and less control over their situation. CONCLUSIONS: In Singapore and Asia, sociocultural values of family caregiving are not uniformly experienced as positive, and may be burdensome for caregivers who give care primarily for extrinsic motivations. As family caregiving needs increase, targeted psychosocial support for caregivers with less autonomous behavioural orientations may pre-empt caregiver burnout and burden.
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Cuidadores/psicología , Costo de Enfermedad , Motivación , Neoplasias/psicología , Adulto , Características Culturales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/terapia , Investigación Cualitativa , Singapur , Valores Sociales , Adulto JovenRESUMEN
The microbial fuel cell (MFC) is an innovative technology for producing electricity directly from biodegradable organic matter using bacteria. Among all the influenceable factors, anode materials play a crucial role in electricity generation. Recently, carbon nanotubes (CNTs) have exhibited promising properties as electrode material due to their unique structural, and physical and chemical properties. In this study, the impacts of CNT types in CNT-based anodes were investigated to determine their effect on both efficiency of wastewater treatment and power generation. The CNTs, namely single-walled CNT with carboxyl group (SWCNT), multi-walled CNT with carboxyl group (MWCNT-COOH) and multi-walled CNT with hydroxyl group (MWCNT-OH) were used to fabricate CNT-based anodes by a filtration method. Overall, MWCNTs provided better results than SWCNTs, especially in the presence of the -OH groups. The highest power and treatment efficiencies in MFC were achieved with an anode made of MWCNT-OH filtered on Poreflon membrane; the open circuit voltage attained was 0.75 V and the maximum power density averaged 167 mW/m(2), which was 130% higher than that obtained with plain carbon cloth. In addition, MWCNT-OH is more cost-effective, further suggesting its potential to replace plain carbon cloth generally used for the MFC anode.
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Fuentes de Energía Bioeléctrica , Nanotubos de Carbono , Electrodos , Escherichia coli/ultraestructuraRESUMEN
OBJECTIVES. To investigate the demographic characteristics and insulin resistance in local overweight/obese Chinese children with and without acanthosis nigricans, and the associations of acanthosis nigricans with insulin resistance and other cardiometabolic co-morbidities. DESIGN. Case series with cross-sectional analyses. SETTING. A regional hospital in Hong Kong. PATIENTS. Chinese children assessed between January 2006 and December 2010 at Tseung Kwan O Hospital for being overweight or obese. MAIN OUTCOME MEASURES. The demographics, anthropometric data, acanthosis nigricans status, and biochemical results were analysed. RESULTS. A total of 543 overweight/obese children were studied with 64% being boys and 29% had insulin resistance. Adolescents aged 12 to 18 years, compared with children aged 5 to 11 years, were more likely to have acanthosis nigricans (63% vs 47%; P<0.001) and insulin resistance (37% vs 25%; P=0.005). Compared with overweight children, those who were obese were more likely to have the two conditions: acanthosis nigricans (59% vs 44%; P=0.005) and insulin resistance (35% vs 19%; P=0.001). Compared with those without acanthosis nigricans, those with the condition had significantly higher mean values for systolic blood pressures (P<0.001), 2-hour post-oral glucose tolerance test glucose level (P=0.021), fasting insulin level (P<0.001), homeostasis model of assessment-insulin resistance (P<0.001), fasting triglyceride level (P<0.001), and alanine aminotransferase level (P=0.002), but a lower high-density lipoprotein cholesterol level (P<0.001). Those with acanthosis nigricans were also more likely to have insulin resistance (P<0.001), hypertension (P=0.021), fatty liver (P=0.001), and abnormal glucose homeostasis (P=0.003). CONCLUSION. Obese Chinese children and adolescents with acanthosis nigricans had a higher chance of having insulin resistance and cardiometabolic co-morbidities. Acanthosis nigricans is an important clinical feature warranting early attention and evaluation to facilitate timely interventions and monitoring.
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Acantosis Nigricans/complicaciones , Resistencia a la Insulina , Sobrepeso/complicaciones , Obesidad Infantil/complicaciones , Acantosis Nigricans/epidemiología , Acantosis Nigricans/patología , Adolescente , Pueblo Asiatico , Enfermedades Cardiovasculares/epidemiología , Niño , Preescolar , Estudios Transversales , Femenino , Prueba de Tolerancia a la Glucosa , Hong Kong/epidemiología , Humanos , Masculino , Enfermedades Metabólicas/epidemiología , Estudios RetrospectivosRESUMEN
Pharmaceutical wastewater generated by an antibiotics (penicillin) company was treated by aerobic membrane bioreactors (MBRs) and sequencing batch reactors (SBRs). At a low organic loading rate of 0.22 kg-COD m(-3)d(-1), both types of reactors were capable of treating the wastewater such that the treated effluent met the discharge regulation except for the total dissolved solids. However, when the loading rate was increased to 2.92 kg-COD m(-3)d(-1), foaming issues resulted in unstable performance. Overall, the MBRs achieved better solid removal but the SBRs performed better in regards to the degradation of aromatic compounds, as determined by UV absorbance (UVA). Finally, ozonation was applied on two different streams and showed promise on the strong stream - that corresponds to the formulation effluent and contains most of the biorefractory compounds. Ozonation successfully reduced the UVA, lowered the pH and increased the biochemical oxygen demand : chemical oxygen demand (BOD5 : COD) ratio of the strong stream. However, it was less efficient on the effluent having undergone pre-treatment by a biofilter due to a lack of selectivity towards refractory compounds.
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Antibacterianos/química , Reactores Biológicos , Industria Farmacéutica , Residuos Industriales , Eliminación de Residuos Líquidos , Filtración/métodos , Ozono , Microbiología del AguaRESUMEN
This study deals with the ozonation of amoxicillin in real pharmaceutical wastewater and its efficacy as a pre-treatment, prior to biological degradation by a mixed culture of bacteria in a sequencing batch reactor (SBR). An ozone utilization of 0.27 g/g-COD (chemical oxygen demand) lowered the pH of the wastewater to 6.6, reduced the specific ultraviolet absorption by 43% and increased the biochemical oxygen demand (BOD) concentration by 37%. The BOD:COD ratio became equal to 0.89, making the ozonated wastewater seemingly suitable for biological treatment; however, when the ozonated effluent was fed to the SBR, the reactor performance degraded, an effect which was attributed to ozonation by-products. In conclusion, ozonation might not be a suitable pre-treatment for pharmaceutical wastewater containing amoxicillin, and biotreatment with properly acclimated biomass may be a better option for treatment of such pharmaceutical wastewater.
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Amoxicilina/química , Ozono/química , Contaminantes Químicos del Agua/química , Purificación del Agua , Reactores BiológicosAsunto(s)
Virus BK/efectos de los fármacos , Cistitis/tratamiento farmacológico , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Trasplante de Células Madre Hematopoyéticas/métodos , Septicemia Hemorrágica/tratamiento farmacológico , Infecciones por Polyomavirus/prevención & control , Infecciones Tumorales por Virus/prevención & control , Cistitis/inmunología , Septicemia Hemorrágica/inmunología , Humanos , Infecciones por Polyomavirus/tratamiento farmacológico , Infecciones por Polyomavirus/virología , Infecciones Tumorales por Virus/tratamiento farmacológico , Infecciones Tumorales por Virus/virologíaRESUMEN
The microbial fuel cell (MFC) is a novel and innovative technology that could allow direct harvesting of energy from wastewater through microbial activity with simultaneous oxidation of organic matter in wastewater. Among all MFC parts, electrode materials play a crucial role in electricity generation. A variety of electrode materials have been used, including plain graphite, carbon paper and carbon cloth. However, these electrode materials generated only limited electricity or power. Recently, many research studies have been conducted on carbon nanotubes (CNTs) because of their unique physical and chemical properties that include high conductivity, high surface area, corrosion resistance, and electrochemical stability. These properties make them extremely attractive for fabricating electrodes and catalyst supports. In this study, CNT-based electrodes had been developed to improve MFC performance in terms of electricity generation and treatment efficiency. Multi-walled carbon nanotubes (MWCNTs) with carboxyl groups have been employed to fabricate electrodes for single-chamber air-cathode MFCs. The quality of the prepared MWCNTs-based electrodes was evaluated by morphology, electrical conductivity and specific surface area using a field emission scanning electron microscope, four-probe method and Brunauer-Emmerr-Teller method, respectively. The performance of MFCs equipped with MWCNT-based electrodes was evaluated by chemical analysis and electrical monitoring and calculation. In addition, the performance of these MFCs, using MWCNTs as electrodes, was compared against that using commercial carbon cloth.
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Fuentes de Energía Bioeléctrica , Nanotubos de Carbono , Biopelículas , Conductividad Eléctrica , Electrodos , Microscopía Electrónica de Rastreo , Compuestos Orgánicos/aislamiento & purificaciónRESUMEN
A membrane electrode assembly (MEA) for microbial fuel cells (MEA-MFC) was developed for continuous electricity production while treating domestic wastewater concurrently. It was optimized via three upgraded versions (noted α, ß and γ) in terms of design (current collectors, hydrophilic separator nature) and operating conditions (hydraulic retention time, external resistance, aeration rate, recirculation). An overall rise of power by over 100% from version α to γ shows the importance of factors such as the choice of proper construction materials and prevention of short-circuits. A power of 2.5 mW was generated with a hydraulic retention time of 2.3 h when a Selemion proton exchange membrane was used as a hydrophilic separator in the MEA and 2.8 mW were attained with a reverse osmosis membrane. The MFC also showed a competitive value of internal resistance (≈40-50 Ω) as compared to the literature, especially considering its large volume (3 L). However, the operation of our system in a complete loop where the anolyte was allowed to trickle over the cathode (version γ) resulted in system failure.
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Fuentes de Energía Bioeléctrica/normas , Eliminación de Residuos Líquidos/métodos , Electrodos , Diseño de Equipo , Eliminación de Residuos Líquidos/instrumentaciónRESUMEN
Fouling characteristics of aerobic submerged membrane bioreactors were analysed under two different membrane materials. Polyethersulfone (PES) membranes were found to foul faster at sub-critical flux than polyolefin (PO) membranes. Physico-chemical characterisation, by means of comparison of extracellular polymeric substances (EPS) and soluble microbial products (SMP) concentrations, as well as the mixed liquor suspended solids (MLSS) concentration were unable to explain the differences in membrane fouling of the contrasting membrane materials. The use of confocal laser scanning microscopy (CLSM) to image organic foulants directly on the membrane surface, coupled with image analyses showed that membrane fouling mechanism shifted from a biofilm initiated process on PO membranes to a bio-organic dominated process on PES membranes under sub-critical flux conditions. These results show that physico-chemical characterisation of an MBR process may not effectively distinguish the effectiveness of different membrane materials, so long as operating conditions are identical, and that characterisation of foulants on the membrane surfaces was necessary to elucidate the differences in membrane fouling.
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Reactores Biológicos , Membranas Artificiales , Eliminación de Residuos Líquidos/métodos , Aerobiosis , Contaminantes Químicos del AguaRESUMEN
AIMS: Vascular calcification is a common complication among dialysis patients and its pathogenesis involves a variety of factors. The roles of pro-inflammatory cytokines and residual kidney function (RKF) in peritoneal dialysis (PD) patients with vascular calcification have not been investigated. MATERIALS AND METHODS: 157 stable PD patients were enrolled. All patients had plain X-ray film examination including chest (posterior-anterior view, CXR) and pelvis. Vascular calcification was interpreted as calcified deposit over aortic arch and linear calcification of pelvic arteries. Relevant biochemical data, pro-inflammatory markers, and PD-related factors were measured and collected. RESULTS: Vascular calcification prevalence in CXRs was higher than that in pelvis films (38.2% vs. 22.3%, p < 0.05). Patients with vascular calcification in CXR had higher incidence of calcification in pelvis films (p < 0.05). Only a minor portion (14.6%) had two calcification sites. Regression analysis revealed that age, PD duration, body mass index, and RKF were independent factors associated with vascular calcification in CXR. Age, diabetes, IL-10 and RKF were factors associated in pelvis films. Factors independently related to vascular calcification in both films were age, duration, diabetes, IL-10, and RKF. CONCLUSIONS: Besides traditional risk factors, IL-10 and RKF were important factors associated with vascular calcification in PD patients.
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Calcinosis/etiología , Interleucina-10/fisiología , Riñón/fisiopatología , Diálisis Peritoneal/efectos adversos , Enfermedades Vasculares/etiología , Adulto , Anciano , Femenino , Humanos , Interleucina-10/sangre , Masculino , Persona de Mediana Edad , Radiografía Torácica , Factores de RiesgoRESUMEN
BACKGROUND AND PURPOSE: Lymphangioleiomyomatosis (LAM) is characterized by the abnormal growth of smooth muscle-like cells (LAM cells) and cystic destruction of the lung parenchyma. LAM cell-derived matrix metalloproteinases (MMPs) are thought to play a prominent role in the tissue destruction. The aim of this study was to determine whether doxycycline, a known MMP inhibitor, can inhibit LAM cell proliferation or mitochondrial function and/or modulate MMPs and their tissue inhibitors (TIMPs). EXPERIMENTAL APPROACH: Wild-type and tuberous sclerosis complex-2 (TSC2)-null mouse embryonic fibroblasts (MEFs) were cultured in DMEM containing 10% fetal bovine serum (FBS). Human LAM cells were derived from the lungs of LAM patients and airway smooth muscle cells from control subjects. Cells were stimulated with FBS with or without doxycycline for up to 9 days. Proliferation was assessed by manual cell counts and MTT assay, MMP production by zymography and ELISA, and TIMP production using elisa. KEY RESULTS: Doxycycline did not change FBS-induced proliferation in MEFs or human cells. However, doxycycline did reduce metabolic activity of both wild-type and TSC2-null MEFs and LAM cells, but had no effect on control cells. Furthermore, doxycycline reduced MMP-2 from MEFs and decreased active-MMP-2 from LAM cells but had no effect on TIMP-1 and TIMP-2 from human LAM cells. CONCLUSIONS AND IMPLICATIONS: Doxycycline decreased MMP levels and cell metabolic activity, which raises the possibility of therapeutic efficacy in LAM.
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Doxiciclina/farmacología , Linfangioleiomiomatosis/tratamiento farmacológico , Linfangioleiomiomatosis/metabolismo , Inhibidores de la Metaloproteinasa de la Matriz , Proteínas Supresoras de Tumor/deficiencia , Animales , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Femenino , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Fibroblastos/enzimología , Fibroblastos/metabolismo , Humanos , Linfangioleiomiomatosis/patología , Metaloproteinasa 2 de la Matriz/biosíntesis , Metaloproteinasa 2 de la Matriz/metabolismo , Ratones , Persona de Mediana Edad , Mitocondrias/efectos de los fármacos , Miocitos del Músculo Liso/metabolismo , Inhibidor Tisular de Metaloproteinasa-1/metabolismo , Inhibidor Tisular de Metaloproteinasa-2/metabolismo , Proteína 2 del Complejo de la Esclerosis Tuberosa , Células Tumorales Cultivadas , Proteínas Supresoras de Tumor/metabolismoRESUMEN
Self-focused acoustic ejectors using the Fresnel zone plate (FZP) have been developed for ejecting viscous liquids, without nozzle, in the drop-on-demand mode. The FZP is composed of a lead zirconate titanate piezoelectric plate patterned with a series of annular electrodes, with the unelectroded region of the plate removed. Our results show that the acoustic waves are effectively self-focused by constructive interference in glycerin (with a viscosity of 1400 mPa s), giving small focal points with a high pressure. Due to the high attenuation, the wave pressure decreases significantly with the distance from the FZP. Nevertheless, the pressure at the focal points 2.5 and 6.5 mm from the FZP is high enough to eject glycerin droplets in the drop-on-demand mode. Driven by a simple wave train comprising a series of sinusoidal voltages with an amplitude of 35 V, a frequency of 4.28 MHz, and a duration of 2 ms, the ejector can eject fine glycerin droplets with a diameter of 0.4 mm at a repetition frequency of 120 Hz in a downward direction. Droplets of other viscous liquids, such as the prepolymer of an epoxy with a viscosity of 2000 mPa s, can also be ejected in the drop-on-demand mode under similar conditions.
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AIMS: To assess the biodiversity of a large number of microbial fuel cell (MFC) anodes from a variety of MFC designs, all enriched with domestic wastewater, using a molecular fingerprinting method. METHODS AND RESULTS: We optimized a protocol allowing the rapid characterization of MFC communities using terminal restriction fragment length polymorphism (T-RFLP) with two different sets of primers and a varying number of restriction enzymes. This protocol was further validated by direct comparison with bacterial clone libraries. Twenty-one MFC anodes were analysed by T-RFLP. We also provided a statistical comparison with other bacterial communities from environments sharing common features. CONCLUSIONS: Bacterial communities were dominated by ß-Proteobacteria, mostly belonging to the Burkholderiales order, that are known to play an active role in the cycle of metals such as iron and manganese. This property may allow them to properly pass electrons to the anode of an MFC. SIGNIFICANCE AND IMPACT OF THE STUDY: Unlike other groups, ß-Proteobacteria have seldom been acknowledged as potentially efficient electrochemically active bacteria (EAB) in MFCs. Yet, they are plentiful in natural environments like biocorrosion biofilms and acid mine drainages that consequently show some potential for MFC enrichment.
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Betaproteobacteria/clasificación , Fuentes de Energía Bioeléctrica/microbiología , Microbiología del Agua , Análisis del Polimorfismo de Longitud de Fragmentos Amplificados , Betaproteobacteria/genética , Betaproteobacteria/aislamiento & purificación , Biodiversidad , Biopelículas , Electrodos , Filogenia , Polimorfismo de Longitud del Fragmento de Restricción , ARN Ribosómico 16S/genética , Eliminación de Residuos LíquidosRESUMEN
This study was to experimentally investigate the performance and organic fouling behaviour in a 1-m long RO membrane channel with or without spacer for desalting. It was found that local permeate flux distributed heterogeneously along the long membrane channel without a spacer inserted due to exponential growth of concentration polarization, which also resulted in decreasing salt rejection and increasing organic fouling along the membrane channel in the downstream direction. This heterogeneity could be lessened by inserting a spacer into the channel, which mitigated concentration polarization due to the enhanced turbulence caused by a spacer, especially at the downstream portion of the channel. However, in the upstream of the channel, inserting a spacer exerted an additional vertical resistance which might counteract the effect of concentration polarization mitigation by a spacer and caused a lower permeate flux. This suggests that it is necessary to consider the integral effect of spacer for designing an RO membrane module and an overall RO system in order to prevent extra resistance, reduce concentration polarization and membrane fouling.
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Membranas Artificiales , Ósmosis , Purificación del Agua/instrumentaciónRESUMEN
Two 6-L submerged anaerobic membrane bioreactors (SAMBR) with SRT of 30 and 60 d (denoted as R30 and R60, respectively) were set up and operated for five months, with a mixture of glucose as substrate. Feasibility of SAMBR was studied for treatment of low-strength wastewater. First two months were identified as acclimation stage. A COD removal efficiency was achieved stably at around 99% and biogas productions were maintained at 0.023 and 0.028 L CH4/gMLVSSd for R30 and R60, respectively. Even though R60 contained higher MLVSS concentration, no significant difference of treatment performances between both reactors was found due to the low organic loading rate and high purification function of membrane. In the investigation of membrane fouling, less irreversible fouling was observed for R30 compared to R60. High non-flocculent concentration of R60 would be responsible for membrane internal pore blocking and deteriorated effluent quality.
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Reactores Biológicos , Membranas Artificiales , Eliminación de Residuos Líquidos , Purificación del Agua/instrumentación , Anaerobiosis , Bacterias/metabolismo , Biodegradación Ambiental , Ácidos Grasos Volátiles/análisis , Estudios de Factibilidad , Floculación , Gases , Nefelometría y Turbidimetría , Oxígeno/análisis , Aguas del Alcantarillado/microbiología , Factores de TiempoRESUMEN
Fouling is still one of the main issues in the operation of membrane bioreactors (MBRs). While most attention has been paid to extracellular polymeric substances (EPS) and soluble microbial products (SMP) in the bulk solution, changes in membrane filterability may be more adequately described by the structural characteristic of the fouling layer or biofilm. This study shows that membrane filterability and the rise in TMP is associated to the changes in the biofiom structure, and polysaccharides may be the most significant fraction that affects fouling.