Conventional water resources in many regions are insufficient to meet the water needs of growing populations, thus reuse is gaining acceptance as a method of water supply augmentation. Recent ...advancements in membrane technology have allowed for the reclamation of municipal wastewater for the production of drinking water, i.e., potable reuse. Although public perception can be a challenge, potable reuse is often the least energy-intensive method of providing additional drinking water to water stressed regions. A variety of membranes have been developed that can remove water contaminants ranging from particles and pathogens to dissolved organic compounds and salts. Typically, potable reuse treatment plants use polymeric membranes for microfiltration or ultrafiltration in conjunction with reverse osmosis and, in some cases, nanofiltration. Membrane properties, including pore size, wettability, surface charge, roughness, thermal resistance, chemical stability, permeability, thickness and mechanical strength, vary between membranes and applications. Advancements in membrane technology including new membrane materials, coatings, and manufacturing methods, as well as emerging membrane processes such as membrane bioreactors, electrodialysis, and forward osmosis have been developed to improve selectivity, energy consumption, fouling resistance, and/or capital cost. The purpose of this review is to provide a comprehensive summary of the role of polymeric membranes and process components in the treatment of wastewater to potable water quality and to highlight recent advancements and needs in separation processes. Beyond membranes themselves, this review covers the background and history of potable reuse, and commonly used potable reuse process chains, pretreatment steps, and advanced oxidation processes. Key trends in membrane technology include novel configurations, materials, and fouling prevention techniques. Challenges still facing membrane-based potable reuse applications, including chemical and biological contaminant removal, membrane fouling, and public perception, are highlighted as areas in need of further research and development.
The agri-food supply-chain represents a complex System-of-System (SoS), because it crosses different other sectors and involves many different actors. The System Engineering (SE) approach helps to ...identify boundaries as a line of demarcation between the system itself and its greater context, including the operating environment, without neglecting any aspect. Model-Based System Engineering (MBSE) was used, due to its capacity to realise more readable and compact documentation than other models. It uses System Modeling Language (SysML) to construct a structure, the behaviours, the requirements and the constraints of the system. The modelling method developed to design and implement a model is based on one of the main purposes of the agri-food SoS: the need of tracking and tracing useful information to realize a traceable and sustainable system. Agri-food supply-chain SoS was analysed through an iterative procedure model – developed in Papyrus open-source – that has the system requirements as the centre. The requirement diagram is composed of: consumer requirements, business requirements, legislation requirements and environmental requirements. The typical structure of the requirement package in SysML has inherent the parent-child relationship and responds in an appropriate manner to the system traceability. Papyrus can directly validate the designed model, without complex simulations, especially in the case of a high level of abstraction, which would be missing some implementation parameters necessary for the simulation of the technical phase. This type of validation allowed to check better and faster what has been developed through project simulations. This work presents the main results of the SE approach applied to the agri-food supply-chain. It represents a starting point for the choice of the technical traceability solution.
•The prognosis of coronavirus diseases 2019 (COVID-19) is gender-related.•TMPRSS2 plays a key role in COVID-19; androgen receptor regulates its expression.•Severe acute respiratory syndrome ...coronavirus-2 (SARS-CoV-2) can damage the testes.•Low serum testosterone at diagnosis is predictive of severe COVID-19.•Low serum testosterone predicts for longer hospitalization and hyperinflammation.
To investigate the association between sex hormones and the severity of coronavirus disease 2019 (COVID-19). Furthermore, associations between sex hormones and systemic inflammation markers, viral shedding and length of hospital stay were studied.
This case–control study included a total of 48 male patients with COVID-19 admitted to an Italian reference hospital. The 24 cases were patients with PaO2/FiO2 <250 mmHg and who needed ventilatory support during hospitalization (severe COVID-19). The 24 controls were selected in a 1:1 ratio, matched by age, from patients who maintained PaO2/FiO2 >300 mmHg at all times and who may have required low-flow oxygen supplementation during hospitalization (mild COVID-19). For each group, sex hormones were evaluated on hospital admission.
Patients with severe COVID-19 (cases) had a significantly lower testosterone level compared with patients with mild COVID-19 (controls). Median total testosterone (TT) was 1.4 ng/mL in cases and 3.5 ng/mL in controls (P = 0.005); median bioavailable testosterone (BioT) was 0.49 and 1.21 in cases and controls, respectively (P = 0.008); and median calculated free testosterone (cFT) was 0.029 ng/mL and 0.058 ng/mL in cases and controls, respectively (P = 0.015). Low TT, low cFT and low BioT were correlated with hyperinflammatory syndrome (P = 0.018, P = 0.048 and P = 0.020, respectively) and associated with longer length of hospital stay (P = 0.052, P = 0.041 and P = 0.023, respectively). No association was found between sex hormone level and duration of viral shedding, or between sex hormone level and mortality rate.
A low level of testosterone was found to be a marker of clinical severity of COVID-19.
Catalytic membrane reactors have been widely used in different production industries around the world. Applying a catalytic membrane reactor (CMR) reduces waste generation from a cleaner process ...perspective and reduces energy consumption in line with the process intensification strategy. A CMR combines a chemical or biochemical reaction with a membrane separation process in a single unit by improving the performance of the process in terms of conversion and selectivity. The core of the CMR is the membrane which can be polymeric or inorganic depending on the operating conditions of the catalytic process. Besides, the membrane can be inert or catalytically active. The number of studies devoted to applying CMR with higher membrane area per unit volume in multi-phase reactions remains very limited for both catalytic polymeric and inorganic membranes. The various bio-based catalytic membrane system is also used in a different commercial application. The opportunities and advantages offered by applying catalytic membrane reactors to multi-phase systems need to be further explored. In this review, the preparation and the application of inorganic membrane reactors in the different catalytic processes as water gas shift (WGS), Fisher Tropsch synthesis (FTS), selective CO oxidation (CO SeLox), and so on, have been discussed.
The rheological properties of model doughs based on a resistant maize starch, rich in amylose, and vegetable proteins (either soy or hemp) were investigated, with the aim of assessing their potential ...use in the production of bread without gluten and rich in new vegetable proteins and fibre. With the purpose of improving the structural properties of investigated doughs, a cross-linking enzyme, i.e. transglutaminase (TG), was also added to evaluate its potential effects on adopted proteins, whereas no further hydrocolloid was added to the mixture. A rheological characterisation based on shear tests, in linear conditions at different temperatures, and elongational tests, in non linear conditions, was performed, to evaluate the potential properties of the dough for breadmaking use. In addition, a qualitative analysis of baked samples was performed to investigate a potential relation between rheological properties and crumb texture. It was observed that doughs prepared with hemp protein exhibit properties closer to those of a wheat dough and yield loaves with higher height. TG affects the properties of dough prepared with hemp protein increasing both dynamic moduli and gelatinisation temperatures. On the other hand, when soy protein is used, relevant effects of TG are observed mainly on the onset of gelatinisation that is shifted towards higher values. Obtained results evidence that hemp protein and the adopted resistant starch can be interesting raw materials for bread production even if further work is necessary to improve the dough characteristics.
Adsorption of the phosphotriesterase on a polysulfone membrane surface was investigated in this paper through a double-scale computational approach. Surface charges of the enzyme, as well as ...membrane, were calculated at sub and nanoscale while protein adsorption was simulated at larger scale. Adsorption energies were calculated as a function of the enzyme–surface distance, and for each distance, several protein rotations were tested to find the most stable orientations of the macromolecule. The results of this model were useful in obtaining information about the adhesion of the enzyme and to give indications on the orientations of its binding site. Adsorption energies agreed with the literature data. Furthermore, the binding site of the immobilized phosphotriesterase was less accessible with respect to native enzymes due to the steric hindrance of the polymer surface; thus, a reduction of its efficiency is expected. The proposed methodology made use of fundamental quantities, calculated without resorting to adjustable or empirical parameters, providing basic outputs useful for ascertaining enzymatic catalysis rate.
The primary focus of this work was to recover lignin and investigate the structural changes in sugarcane bagasse after pretreatment with ionic liquid 1-ethyl-3-methylimidazolium acetate (EMIMoAc). ...90% lignin recovery was achieved while bagasse was treated with EMIMoAc at 140 °C, 120 min reaction time and 1:20 bagasse to the ionic liquid ratio (w/w). The impact of ionic liquid pretreatment on bagasse was confirmed by qualitative analysis of untreated and pretreated bagasse. Scanning electron microscopy analysis exhibited the porous and irregular structure of bagasse after pretreatment. X-ray powder diffraction analysis verified a decrease in crystallinity as a result of the pretreatment process by showing a 14.7% reduction of Crystallinity index after ionic liquid treatment. The efficacy of EMIMoAc on bagasse treatment was also examined by enzymatic hydrolysis which manifested an increase in reducing sugar yield as a result of pretreatment. Maximum yield of 54.3% reducing sugar was obtained after 72 h enzymatic hydrolysis of pretreated bagasse. Recovered lignin was analyzed qualitatively. 1D NMR spectroscopy of lignin revealed the presence of essential functional groups whereas 2D NMR spectroscopy showed the dominance of etherified syringyl unit. Further ionic liquid recovery and reuse were substantiated by Gel permeation chromatography analysis of lignin. Weight average molecular weight (
M
w
) of lignin extracted by fresh EMIMoAc was obtained as 1769 g/mol (in the previous study) while lignin recovered by recycled EMIMoAc showed almost equal
M
w
1765 g/mol in this study. Thus, the current investigation corroborated satisfactory performance of EMIMoAc in lignocellulose processing which further enhanced enzymatic hydrolysis in the subsequent step.
•Polyelectrolyte assisted ultrafiltration (PAUF) was used to retain methylene blue.•The principal process factors were optimized using response surface methodology.•Dye rejection as high as 99% and ...permeate flux over 71L/m2h were thus achieved.•The observed data were well within the 95% prediction intervals.•The Langmuir-type binding isotherm gauged the degree of dye binding to the polymer.
The present study employed polyelectrolyte assisted ultrafiltration (PAUF) to bring about cationic phenothiazine dye remediation. The effects of the primary process factors on the PAUF-induced retention of methylene blue (MB) from its aqueous solutions were explored using a suitable central composite design. The efficiency of the PAUF technique was gauged by two principal responses, namely, dye rejection efficiency and permeation flux. The recorded dye rejection and permeation rate, especially under response surface methodology (RSM) prescribed optimal process conditions, were over 99% and 71L/m2h respectively. Besides, the observed response values were well within the 95% confidence interval of the predicted response levels, and were within the confines of the 95% prediction intervals. Suitable response surface (RS) plots graphically manifested the effects of the process factors on the responses. Moreover, the degree of MB ion complexation with the PSS polyelectrolyte was investigated using the Langmuir-type binding isotherm. Herein the values of the binding parameters, namely, Keq and n, were as high 1.48×105M−1 and 187.94 respectively, under the statistically determined optimal process factor settings, identified, in particular, by a solution pH of 9. The results reflected appreciable interaction between the cationic dye molecules and the polyanion. Besides, the permeation rate under optimal process conditions was over 69L/m2h, even after two hours of operation. The overall observations indicated that following the judicious selection of the accompanying polymeric binding agents and the process parameter levels, toxic residual dyes can be appreciably separated from the process stream using PAUF technology.
The aim of the present work is the formulation of a theoretical model describing the simultaneous transfer of momentum, heat and mass occurring in a convective drier where hot dry air flows under ...turbulent conditions around a food sample. The proposed model does not rely on the specification of interfacial heat and mass transfer coefficients and, therefore, represents a general tool capable of describing the behavior of real driers over a wide range of process and fluid-dynamic conditions. The system of non-linear unsteady-state partial differential equations modeling the behavior of a cylindrical-shaped vegetable sample in a drier, has been solved by using finite elements method. It has been observed that air characteristics influence drying performance only when external resistance to mass transfer is the rate controlling step. An experimental study was undertaken which shows very good agreement between model predictions and experimental results.
In the present paper, three different approaches are proposed to model the convective drying of food. The performance of thin-layer, pure neural network and hybrid neural model is compared in a wide ...range of operating conditions, with two different vegetables, available either as cylinders or as slabs with different characteristic dimensions. It was found that the thin-layer model was adequate to describe food drying behavior, but it could be applied only as a fitting procedure. Pure neural models gave accurate predictions in some situations, but exhibited poor performance when tested outside the range of operating conditions exploited during their development. Finally, it was shown that hybrid neural models, formulated as a combination of both theoretical and neural network models, are capable of offering the most accurate predictions of system behavior with average relative errors never exceeding 10%, even in operating conditions unexploited during the definition of the neural part of the model. The results obtained proved that the hybrid neural paradigm is a novel and efficient modeling technique that could be used successfully in food processing, thus allowing drying process optimization to be achieved, and efficient and fast on-line controllers to be implemented.
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