Microflow injection analysis based on modular 3D platforms and colorimetric detection for Fe(III) monitoring in a wide concentration range.

A modular microflow injection analysis (microFIA) system for the determination of Fe(III) in a bioleaching reactor has been designed, developed and validated. The different modules of the analyzer (mixer, diluter, disperser and detector) were 3D-printed. Fe(III) quantification is due by measuring the color intensity of the chelate formed between Fe(III) and salicylic acid at 525 nm. The device has been designed to dilute, disperse and detect high Fe(III) concentrations in the form of an inexpensive multi-step photometric flow cell that uses an light-emitting diode (LED) as a light source and an light-dependent resistor (LDR) as a light intensity detector. This microFIA system has been shown to be suitable for automatic and continuous determination of Fe(III) in the operation of a bioreactor for the oxidation of Fe(II). The device has a good repeatability (less than 5% of coefficient of variation in the whole range of concentrations) and accuracy of around 100%. The analyzer features an exceptional wide linear range, between 25 and 6000 mg·L-1. The device was successfully applied to the determination of Fe(III) in real samples. The obtained results proved that the method is applicable for accurate, precise, rapid, and low-cost colorimetric analysis and didn't show significant differences with a conventional UV-Vis method.

Exploring Current Concepts and Challenges in the Identification and Management of Early-Stage COPD.

The need to improve health outcomes, as well as disease prognosis, has led clinicians and researchers to propose new ways of identifying COPD in its earliest forms. This initiative is based on the hypothesis that an earlier intervention would have a greater prognostic impact. However, the operational definition of a patient in the initial stages of the disease is complex, and there is still no unanimously accepted definition. GOLD has recently proposed different concepts to identify COPD in its early stages, such as COPD in young people or COPD with mild functional impairment. In addition, GOLD proposes two other concepts, called pre-COPD (symptomatic non-obstructive patients) and PRISm (preserved ratio with impaired spirometry), which aim to identify the patient at risk of developing this chronic airflow obstruction. However, despite the attractiveness of these concepts, none have been taken up universally by the medical community. A universally accepted identification of how to define COPD in its early stages is necessary as a preliminary step in order to design clinical trials to find out the best way to treat these patients. This review deals with these concepts of COPD at the onset of the disease, highlighting their importance and the problems involved in identifying them as therapeutic targets in real clinical practice.

Child-Robot Interactions Using Educational Robots: An Ethical and Inclusive Perspective.

The Qui-Bot H2O project involves developing four educational sustainable robots and their associated software. Robots are equipped with HRI features such as voice recognition and color sensing, and they possess a humanoid appearance. The project highlights the social and ethical aspects of robotics applied to chemistry and industry 4.0 at an early age. Here, we report the results of an interactive study that involved 212 students aged within the range of 3-18. Our educational robots were used to measure the backgrounds, impact, and interest of students, as well as their satisfaction after interacting with them. Additionally, we provide an ethical study of the use of these robots in the classroom and a comparison of the interactions of humanoid versus non-humanoid educational robots observed in early childhood learning. Our findings demonstrate that these robots are useful in teaching technical and scientific concepts in a playful and intuitive manner, as well as in increasing the number of girls who are interested in science and engineering careers. In addition, major impact measures generated by the project within a year of its implementation were analyzed. Several public administrations in the area of gender equality endorsed and participated in the Qui-Bot H2O project in addition to educational and business entities.

A novel bioscrubber for the treatment of high loads of ammonia from polluted gas.

This work presents a novel bioscrubber configuration for the treatment of high ammonia loads at short contact times. The biological reactor was designed to work as a moving-bed biofilm rector (MBBR) increasing biomass retention time. This configuration is still unexplored for the treatment of waste gases. Long-term operation of a lab-scale bioscrubber under different inlet concentrations of ammonia (60-570 ppmv) and a gas contact time of 4 s was performed to study the system operational limits during 250 days. The effect of the dissolved oxygen concentration on the nitrification rate was also evaluated. Under these conditions, a critical elimination capacity (EC) of 250 NH3·m-3·h-1 and a maximum EC of 300 g NH3·m-3·h-1 were obtained. The maximum nitrification rate obtained was 0.5 kg N·m-3·day-1. However, this nitrification rate only was possible to be achieved under partial nitrification. For complete nitrification, the critical nitrification rate was 0.3 kg N·m-3·day-1. These results confirm that bioscrubber coupled to a MBBR is a good alternative to treat high ammonia loads with remarkable advantages, such as the retention of properly biomass concentration without auxiliary equipment.

Sparking the Interest of Girls in Computer Science via Chemical Experimentation and Robotics: The Qui-Bot H2O Case Study.

We report a new learning approach in science and technology through the Qui-Bot H2O project: a multidisciplinary and interdisciplinary project developed with the main objective of inclusively increasing interest in computer science engineering among children and young people, breaking stereotypes and invisible social and gender barriers. The project highlights the social aspect of robotics applied to chemistry, at early ages. We successfully tested the project activities on girls between 3 to 13 years old. After taking part in the project, the users rated their interest in science and technology to be higher than before. Data collected during experiences included background information on students, measurements of the project's impact and students' interest in it, and an evaluation of student satisfaction of this STEM activity. The Qui-Bot H2O project is supported by the actions of territorial public administrations towards gender equality and the contributions of humanistic and technological universities and entities which specialize in education and business.

A review of biotechnologies for the abatement of ammonia emissions.

Ammonia emissions are found in a wide range of facilities such as wastewater treatment plants, composting plants, pig houses, as well as the fertilizer, food and metallurgy industries. Effective management of these emissions is important for minimizing the detrimental effects they can have on health and the environment. Physical-chemical (thermal oxidation, absorption, catalytic oxidation, etc.) treatments are the most common techniques for the abatement of ammonia emissions. However, the requirement for more eco-friendly techniques has increased interest in biological alternatives. Accordingly, several bio-based process configurations (biofilters, biotrickling filters and bioscrubbers) have been reported for ammonia abatement in a wide spectrum of conditions. Due to ammonia is a highly soluble compound, bioscrubber seems to be the best option for ammonia abatement. However, this technology is still not widely studied. The proper managements of the ammonia bio-oxidation sub-products is a key parameter for the correct operation of the process. The aim of this review is to critically examine the biotechnologies currently used for the treatment of ammonia gas emissions highlighting the pros and cons of each technology. The key parameters for each configuration used in both full-scale and lab-scale bioreactors are analyzed and summarized according to previous publications.

Optimization of SO2 and NOx sequential wet absorption in a two-stage bioscrubber for elemental sulphur valorisation.

Flue gases contain SO2 and NOx that can be treated together for elemental sulphur recovery in bioscrubbers, a technology that couples physical-chemical and biological processes for gaseous emissions treatment in a more economic manner than classical absorption. Sequential wet absorption of SO2 and NOx from flue gas is thoroughly studied in this work in a two-stage bioscrubber towards elemental sulphur valorisation pursuing reuse of biological process effluents as absorbents. The optimal operating conditions required for SO2 and NOx absorption in two consecutive spray absorbers were defined using NaOH-based absorbents. Overall, removal efficiencies of 98.9% and 55.9% for SO2 and NOx abatement were obtained in two in-series scrubbers operated under a gas contact time of 1 and 100 s, and a liquid-to-gas ratio of 7.5 and 15 L m-3, respectively. Higher NOx removal efficiency to clean gas emission was obtained by oxidants dosing in the absorber for NOx absorption. High NaHCO3 concentration in a two-stage bioscrubber effluent was exploited as alkaline absorbent for flue gas treatment. The performance of scrubbers using an absorbent mimicking a reused effluent exhibited the same removal efficiencies than those observed using NaOH solutions. In addition, the reuse of bioprocess effluent reduced reagents' consumption by a 63.7%. Thus, the two-stage bioscrubber proposed herein offers an environmentally friendly and economic alternative for flue gas treatment.

Oxidative and inflammatory effects of pulmonary rehabilitation in patients with bronchiectasis. A prospective, randomized study.

INTRODUCTION: Background: systemic inflammation and oxidative stress are important factors in the pathogenesis of bronchiectasis. Pulmonary rehabilitation (PR) is recommended for bronchiectasis, but there is no data about its effect on the inflammatory and REDOX status of these patients. Aims: to investigate the effect of PR in non-cystic-fibrosis bronchiectasis (NCFB) patients, and to compare it with the effect of PR plus a hyperproteic oral nutritional supplement (PRS) enriched with beta-hydroxy-beta-methylbutyrate (HMB) on serum inflammatory and oxidative biomarkers. Materials and methods: this was an open randomized, controlled trial. Thirty individuals (65 years old or younger with a body mass index over 18.5, older than 65 years with a body mass index over 20) were recruited from September 2013 to September 2014, and randomly assigned to receive PR or PRS. Total neutrophils, and inflammatory and oxidative biomarker levels were measured at baseline, and then at 3 and 6 months. Results: in the PRS group neutrophil levels were decreased from baseline at 6 months. A significantly different fold change was found between the PR and PRS groups. In the PR group, IL-6 and adiponectin were increased by the end of the study while TNFα levels were decreased from baseline at 6 months. REDOX biomarkers remained stable throughout the study except for 8-isoprostane levels, which were increased from baseline at 6 months in both groups of patients. Conclusions: a PR program induced a pro-oxidative effect accompanied by changes in circulating inflammatory cytokine levels in NCFB patients. Our results would also suggest a possible beneficial effect of the HMB enriched supplement on neutrophil level regulation in these patients. The information provided in this study could be useful for choosing the right therapeutic approach in the management of bronchiectasis.

INTRODUCCIÓN: Introducción: la inflamación sistémica y el estrés oxidativo son factores importantes en la patogénesis de la bronquiectasia. La rehabilitación pulmonar (PR) está recomendada en los sujetos con bronquiectasias, pero no hay datos sobre sus posibles efectos sobre el estado inflamatorio y REDOX de estos pacientes. Objetivos: investigar el efecto de la PR en pacientes con bronquiectasias no asociadas a fibrosis quística (NCFB) sobre los biomarcadores oxidativos e inflamatorios, y compararlo con los efectos de la PR junto con la suplementación oral de un suplemento hiperproteico (PRS) enriquecido con beta-hidroxi-beta-metilbutirato (HMB). Material y métodos: ensayo clínico abierto, aleatorizado y controlado. Treinta pacientes (de 65 años o menos con un índice de masa corporal por encima de 18,5, y mayores de 65 años con un índice de masa corporal de más de 20) se aleatorizaron para recibir PR o PRS. Los niveles circulantes de neutrófilos totales y los de biomarcadores de estado inflamatorio y oxidativo se determinaron al inicio del estudio y a los 3 y 6 meses. Resultados: los niveles de neutrófilos en el grupo de PRS se redujeron desde el inicio a los 6 meses, presentando una tasa de cambio significativamente diferente según el tratamiento. En el grupo de PR, la IL-6 y la adiponectina aumentaron al final del estudio, mientras que los niveles de TNFα disminuyeron desde el inicio a los 6 meses. Los biomarcadores de estrés oxidativo se mantuvieron estables durante todo el estudio excepto por los niveles de 8-isoprostano, que aumentaron desde el inicio a los 6 meses en ambos grupos de pacientes. Conclusión: el programa de PR indujo un efecto pro-oxidativo acompañado de cambios en los niveles de citoquinas inflamatorias circulantes en pacientes con NCFB. Nuestros resultados también sugieren un posible efecto beneficioso del suplemento nutricional sobre la regulación de los niveles de neutrófilos de estos pacientes.

Computational and Experimental Investigation of Biofilm Disruption Dynamics Induced by High-Velocity Gas Jet Impingement.

Experimental data showed that high-speed microsprays can effectively disrupt biofilms on their support substratum, producing a variety of dynamic reactions such as elongation, displacement, ripple formation, and fluidization. However, the mechanics underlying the impact of high-speed turbulent flows on biofilm structure is complex under such extreme conditions, since direct measurements of viscosity at these high shear rates are not possible using dynamic testing instruments. Here, we used computational fluid dynamics simulations to assess the complex fluid interactions of ripple patterning produced by high-speed turbulent air jets impacting perpendicular to the surface of Streptococcus mutans biofilms, a dental pathogen causing caries, captured by high-speed imaging. The numerical model involved a two-phase flow of air over a non-Newtonian biofilm, whose viscosity as a function of shear rate was estimated using the Herschel-Bulkley model. The simulation suggested that inertial, shear, and interfacial tension forces governed biofilm disruption by the air jet. Additionally, the high shear rates generated by the jet impacts coupled with shear-thinning biofilm property resulted in rapid liquefaction (within milliseconds) of the biofilm, followed by surface instability and traveling waves from the impact site. Our findings suggest that rapid shear thinning under very high shear flows causes the biofilm to behave like a fluid and elasticity can be neglected. A parametric sensitivity study confirmed that both applied force intensity (i.e., high jet nozzle air velocity) and biofilm properties (i.e., low viscosity and low air-biofilm surface tension and thickness) intensify biofilm disruption by generating large interfacial instabilities.IMPORTANCE Knowledge of mechanisms promoting disruption though mechanical forces is essential in optimizing biofilm control strategies which rely on fluid shear. Our results provide insight into how biofilm disruption dynamics is governed by applied forces and fluid properties, revealing a mechanism for ripple formation and fluid-biofilm mixing. These findings have important implications for the rational design of new biofilm cleaning strategies with fluid jets, such as determining optimal parameters (e.g., jet velocity and position) to remove the biofilm from a certain zone (e.g., in dental hygiene or debridement of surgical site infections) or using antimicrobial agents which could increase the interfacial area available for exchange, as well as causing internal mixing within the biofilm matrix, thus disrupting the localized microenvironment which is associated with antimicrobial tolerance. The developed model also has potential application in predicting drag and pressure drop caused by biofilms on bioreactor, pipeline, and ship hull surfaces.

A Minimally Invasive Microsensor Specially Designed for Simultaneous Dissolved Oxygen and pH Biofilm Profiling.

A novel sensing device for simultaneous dissolved oxygen (DO) and pH monitoring specially designed for biofilm profiling is presented in this work. This device enabled the recording of instantaneous DO and pH dynamic profiles within biofilms, improving the tools available for the study and the characterization of biological systems. The microsensor consisted of two parallel arrays of microelectrodes. Microelectrodes used for DO sensing were bare gold electrodes, while microelectrodes used for pH sensing were platinum-based electrodes modified using electrodeposited iridium oxide. The device was fabricated with a polyimide (Kapton®) film of 127 µm as a substrate for minimizing the damage caused on the biofilm structure during its insertion. The electrodes were covered with a Nafion® layer to increase sensor stability and repeatability and to avoid electrode surface fouling. DO microelectrodes showed a linear response in the range 0-8 mg L-1, a detection limit of 0.05 mg L-1, and a sensitivity of 2.06 nA L mg-1. pH electrodes showed a linear super-Nernstian response (74.2 ± 0.7 mV/pH unit) in a wide pH range (pH 4-9). The multi-analyte sensor array was validated in a flat plate bioreactor where simultaneous and instantaneous pH and DO profiles within a sulfide oxidizing biofilm were recorded. The electrodes spatial resolution, the monitoring sensitivity, and the minimally invasive features exhibited by the proposed microsensor improved biofilm monitoring performance, enabling the quantification of mass transfer resistances and the assessment of biological activity.

Pulmonary Rehabilitation Only Versus With Nutritional Supplementation in Patients With Bronchiectasis: A RANDOMIZED CONTROLLED TRIAL.

PURPOSE: Pulmonary rehabilitation (PR) is recommended for bronchiectasis, but there is little evidence of its efficacy in these patients. The aim of this study was to assess the effect of PR in normally nourished patients with noncystic fibrosis bronchiectasis compared with the effect of PR plus an oral nutritional supplement (PRONS). METHODS: A single-center randomized controlled trial, parallel treatment design in which participants were randomly assigned to receive PR for 12 wk or PR plus a high-protein nutritional supplement enriched with beta-hydroxy-beta-methylbutyrate. Outcome assessments were performed at baseline, 12 and 24 wk including cardiopulmonary exercise testing, health-related quality of life (HRQOL), bronchorrhea, dyspnea, psychological symptoms, spirometry, and exacerbations. RESULTS: Thirty patients were randomized into 2 groups of 15 participants. In both groups, cardiopulmonary exercise testing, HRQOL, dyspnea, and spirometry parameters significantly increased from baseline at 3 and/or 6 mo. CONCLUSION: PR improved exercise capacity, HRQOL, and respiratory parameters. The use of PRONS did not have a significant effect on the results.

Body Composition Measurement in Bronchiectasis: Comparison between Bioelectrical Impedance Analysis, Skinfold Thickness Measurement, and Dual-Energy X-ray Absorptiometry before and after Pulmonary Rehabilitation.

BACKGROUND: In individuals with bronchiectasis, fat-free mass depletion may be common despite a low prevalence of underweight and is considered a risk factor for increased morbidity and mortality. Techniques to adequately estimate fat-free mass and its changes over time are needed. OBJECTIVE: The purpose of this study was to assess agreement among values obtained with three different body composition techniques: skinfold thickness measurement (STM), bioelectrical impedance analysis (BIA), and dual-energy x-ray absorptiometry (DXA). DESIGN: The study was a secondary analysis of data from a randomized controlled trial. PARTICIPANTS/SETTING: A respiratory rehabilitation program was administered for 3 months to individuals with bronchiectasis from the bronchiectasis unit of the Regional University Hospital in Malaga, Spain, from September 2013 to September 2014. Individuals with a body mass index (calculated as kg/m2) >18.5 who were aged 65 years or younger and those with a body mass index >20 who were older than 65 years were included. MAIN OUTCOME MEASURES: At baseline and at 3 and 6 months, body composition was determined by DXA and STM. STATISTICAL ANALYSES PERFORMED: Statistical concordance was assessed with the intraclass correlation coefficient (ICC), kappa coefficient, and the degree of agreement using the Bland Altman method. For comparison of the quantitative variables at baseline vs at 3 months and 6 months, the paired sample t test (or the Wilcoxon test) was used. RESULTS: Thirty participants were included. Strong agreement was observed between body composition values determined by BIA and DXA in fat mass (ICC: 0.92) and fat-free mass (ICC: 0.87). Strong agreement was observed between STM and DXA in the values for fat-free mass (ICC: 0.91) and fat mass (ICC: 0.94), and lower agreement was observed for the longitudinal data and in the regional values. The mean difference between fat-free mass determined by BIA and DXA was + 4.7 with a standard deviation of 2.4 kg in favor of BIA. The mean difference between fat-free mass determined by STM and DXA was +2.3 with a standard deviation of 2.7 kg in favor of STM. Six individuals were classified as having a low fat-free mass index (20%) by DXA vs four by STM (13%; kappa: 0.76) and only two by BIA (6.6%; kappa: 0.44) compared with DXA. CONCLUSIONS: Despite good statistical agreement among values obtained with DXA, STM, and BIA, the study findings indicate that STM and BIA, above all, tended to overestimate fat-free mass compared with DXA.

Biotrickling filter modeling for styrene abatement. Part 2: Simulating a two-phase partitioning bioreactor.

A dynamic model describing styrene abatement was developed for a two-phase partitioning bioreactor operated as a biotrickling filter (TPPB-BTF). The model was built as a coupled set of two different systems of partial differential equations depending on whether an irrigation or a non-irrigation period was simulated. The maximum growth rate was previously calibrated from a conventional BTF treating styrene (Part 1). The model was extended to simulate the TPPB-BTF based on the hypothesis that the main change associated with the non-aqueous phase is the modification of the pollutant properties in the liquid phase. The three phases considered were gas, a water-silicone liquid mixture, and biofilm. The selected calibration parameters were related to the physical properties of styrene: Henry's law constant, diffusivity, and the gas-liquid mass transfer coefficient. A sensitivity analysis revealed that Henry's law constant was the most sensitive parameter. The model was successfully calibrated with a goodness of fit of 0.94. It satisfactorily simulated the performance of the TPPB-BTF at styrene loads ranging from 13 to 77 g C m-3 h-1 and empty bed residence times of 30-15 s with the mass transfer enhanced by a factor of 1.6. The model was validated with data obtained in a TPPB-BTF removing styrene continuously. The experimental outlet emissions associated to oscillating inlet concentrations were satisfactorily predicted by using the calibrated parameters. Model simulations demonstrated the potential improvement of the mass-transfer performance of a conventional BTF degrading styrene by adding silicone oil.

Biotrickling filter modeling for styrene abatement. Part 1: Model development, calibration and validation on an industrial scale.

A three-phase dynamic mathematical model based on mass balances describing the main processes in biotrickling filtration: convection, mass transfer, diffusion, and biodegradation was calibrated and validated for the simulation of an industrial styrene-degrading biotrickling filter. The model considered the key features of the industrial operation of biotrickling filters: variable conditions of loading and intermittent irrigation. These features were included in the model switching from the mathematical description of periods with and without irrigation. Model equations were based on the mass balances describing the main processes in biotrickling filtration: convection, mass transfer, diffusion, and biodegradation. The model was calibrated with steady-state data from a laboratory biotrickling filter treating inlet loads at 13-74 g C m-3 h-1 and at empty bed residence time of 30-15 s. The model predicted the dynamic emission in the outlet of the biotrickling filter, simulating the small peaks of concentration occurring during irrigation. The validation of the model was performed using data from a pilot on-site biotrickling filter treating styrene installed in a fiber-reinforced facility. The model predicted the performance of the biotrickling filter working under high-oscillating emissions at an inlet load in a range of 5-23 g C m-3 h-1 and at an empty bed residence time of 31 s for more than 50 days, with a goodness of fit of 0.84.

Inflammation and Oxidation Biomarkers in Patients with Cystic Fibrosis: The Influence of Azithromycin.

OBJECTIVE: In addition to their antibiotic effect, macrolides appear to modulate the inflammatory response in cystic fibrosis (CF) and could influence oxidative stress. The objective of this study was to assess oxidation biomarkers and levels of inflammation and to determine whether there is an association between these parameters and the intake of macrolides. MATERIALS AND METHODS: The subjects included in this cross-sectional study were, on the one hand, clinically stable patients with CF and, on the other, healthy controls. The following serum and plasma inflammatory and oxidative stress biomarkers were measured: interleukin-6 (IL-6), reactive C protein (RCP), tumor necrosis alpha (TNF-α), glutathione peroxidase (GPx), total antioxidant capacity (TAC), catalase (CAT), and superoxide dismutase (SOD), together with markers of lipid peroxidation (8-isoprostanes and thiobarbituric acid reactive substances [TBARS]). Clinical, anthropometric, lung function, radiological, and analytical variables (albumin, prealbumin, vitamins, and zinc) were also recorded. RESULTS: We studied 36 adults with CF and 41 controls. No differences were observed in age, gender, or anthropometric variables. The patients had significantly higher levels of IL-6, TNF-α, RCP, TBARS, and isoprostanes, and lower levels of SOD than the controls. Twenty-three of the patients were treated with azithromycin, and they had more severe clinical and radiological parameters than those who were not but nevertheless presented significantly lower levels of TNF-α. No differences were observed in the markers of oxidation. CONCLUSION: Inflammation and oxidation biomarkers were increased in patients with CF compared with controls. The use of azithromycin was associated with reduced TNF-α levels and did not influence oxidation parameters.

Oxidation of methane in biotrickling filters inoculated with methanotrophic bacteria.

The oxidation of methane (CH4) using biofilters has been proposed as an alternative to mitigate anthropogenic greenhouse gas emissions with a low concentration of CH4 that cannot be used as a source of energy. However, conventional biofilters utilize organic packing materials that have a short lifespan, clogging problems, and are commonly inoculated with non-specific microorganisms leading to unpredictable CH4 elimination capacities (EC) and removal efficiencies (RE). The main objective of this work was to characterize the oxidation of CH4 in two biotrickling filters (BTFs) packed with polyethylene rings and inoculated with two methanotrophic bacteria, Methylomicrobium album and Methylocystis sp., in order to determine EC and CO2 production (pCO2) when using a specific inoculum. The repeatability of the results in both BTFs was determined when they operated at the same inlet load of CH4. A dynamic mathematical model that describes the CH4 abatement in the BTFs was developed and validated using mass transfer and kinetic parameters estimated independently. The results showed that EC and pCO2 of the BTFs are not identical but very similar for all the conditions tested. The use of specific inoculum has shown a faster startup and higher EC per unit area (0.019 gCH4 m-2 h-1) in comparison to most of the previous studies at the same CH4 load rate (23.2 gCH4 m-3 h-1). Global mass balance showed that the maximum reduction of CO2 equivalents was 98.5 gCO2eq m-3 h-1. The developed model satisfactorily described CH4 abatement in BTFs for a wide range of conditions.

Dynamic characterization of external and internal mass transport in heterotrophic biofilms from microsensors measurements.

Knowledge of mass transport mechanisms in biofilm-based technologies such as biofilters is essential to improve bioreactors performance by preventing mass transport limitation. External and internal mass transport in biofilms was characterized in heterotrophic biofilms grown on a flat plate bioreactor. Mass transport resistance through the liquid-biofilm interphase and diffusion within biofilms were quantified by in situ measurements using microsensors with a high spatial resolution (<50 µm). Experimental conditions were selected using a mathematical procedure based on the Fisher Information Matrix to increase the reliability of experimental data and minimize confidence intervals of estimated mass transport coefficients. The sensitivity of external and internal mass transport resistances to flow conditions within the range of typical fluid velocities over biofilms (Reynolds numbers between 0.5 and 7) was assessed. Estimated external mass transfer coefficients at different liquid phase flow velocities showed discrepancies with studies considering laminar conditions in the diffusive boundary layer near the liquid-biofilm interphase. The correlation of effective diffusivity with flow velocities showed that the heterogeneous structure of biofilms defines the transport mechanisms inside biofilms. Internal mass transport was driven by diffusion through cell clusters and aggregates at Re below 2.8. Conversely, mass transport was driven by advection within pores, voids and water channels at Re above 5.6. Between both flow velocities, mass transport occurred by a combination of advection and diffusion. Effective diffusivities estimated at different biofilm densities showed a linear increase of mass transport resistance due to a porosity decrease up to biofilm densities of 50 g VSS·L(-1). Mass transport was strongly limited at higher biofilm densities. Internal mass transport results were used to propose an empirical correlation to assess the effective diffusivity within biofilms considering the influence of hydrodynamics and biofilm density.

Phosphate removal and recovery from water using nanocomposite of immobilized magnetite nanoparticles on cationic polymer.

A novel nanocomposite (NC) based on magnetite nanoparticles (Fe3O4-NPs) immobilized on the surface of a cationic exchange polymer, C100, using a modification of the co-precipitation method was developed to obtain magnetic NCs for phosphate removal and recovery from water. High-resolution transmission electron microscopy-energy-dispersive spectroscopy, scanning electron microscopy , X-ray diffraction, and inductively coupled plasma optical emission spectrometry were used to characterize the NCs. Continuous adsorption process by the so-called breakthrough curves was used to determine the adsorption capacity of the Fe3O4-based NC. The adsorption capacity conditions were studied under different conditions (pH, phosphate concentration, and concentration of nanoparticles). The optimum concentration of iron in the NC for phosphate removal was 23.59 mgFe/gNC. The sorption isotherms of this material were performed at pH 5 and 7. Taking into account the real application of this novel material in real water, the experiments were performed at pH 7, achieving an adsorption capacity higher than 4.9 mgPO4-P/gNC. Moreover, Freundlich, Langmuir, and a combination of them fit the experimental data and were used for interpreting the influence of pH on the sorption and the adsorption mechanism for this novel material. Furthermore, regeneration and reusability of the NC were tested, obtaining 97.5% recovery of phosphate for the first cycle, and at least seven cycles of adsorption-desorption were carried out with more than 40% of recovery. Thus, this work described a novel magnetic nanoadsorbent with properties for phosphate recovery in wastewater.

Oral supplement enriched in HMB combined with pulmonary rehabilitation improves body composition and health related quality of life in patients with bronchiectasis (Prospective, Randomised Study).

BACKGROUND & AIMS: Pulmonary Rehabilitation (PR) is recommended for bronchiectasis but there is no data about its effect on body composition. The aim of this study is to assess the effect of Pulmonary Rehabilitation (PR) for 12 weeks in normally-nourished non-cystic-fibrosis bronchiectasis patients compared with the effect of PR plus a hyperproteic oral nutritional supplement enriched with beta-hydroxy-beta-methylbutyrate (HMB) on body composition, muscle strength, quality of life and serum biomarkers. METHODS: single center randomized controlled trial, parallel treatment design: Participants were randomly assigned to receive PR for 12 weeks or PR plus ONS (PRONS) (one can per day). Outcome assessments were performed at baseline, 12 weeks and 24 weeks: body composition (Dual-energy X-Ray Absorptiometry (DEXA), mid-arm muscle circumference (MAMC), phase angle by Bio-impedance), health related quality of life (Spanish QOL-B-V3.0, Physical Functioning Scale), handgrip strength, diet questionnaire, and plasma levels of prealbumin, myostatin and somatomedin-c. RESULTS: Thirty patients were randomized (15 per group) without differences in clinical and respiratory variables. In the PRONS group bone mineral density (BMD), mean and maximum handgrip dynamometry, MAMC, QOLB and prealbumin were significantly increased from baseline at 12 and 24 weeks and Fat free Mass (FFM) and FFM index, at 12 weeks. In the PR group only mean handgrip dynamometry and prealbumin were significantly increased at 12 and 24 weeks. In both groups plasma myostatin was reduced at 12 weeks (without significant differences). CONCLUSION: The addition of a hyperproteic ONS enriched with HMB to Pulmonary Rehabilitation could improve body composition, BMD, muscle strength and health related quality of life in bronchiectasis patients. Clinical Trials Number NCT02048397.