Fractionation of hydro-ethanolic extracts from grape pomace through membrane processing: the effect of membrane and extracting media on process performance

The EM3E Master is an Education Programme supported by the European Commission, the European Membrane Society (EMS), the European Membrane House (EMH), and a large international network of industrial companies, research centers and universitiesGrape pomace are generated as waste in juice and winemaking industry in huge quantities. Studies have shown that nutrient extracts from these particular plant matrices garner myriad of benefits in health and nutraceuticals sector. Moreover, the newer recognition of monomeric and oligomeric phenolic compounds as bioactive molecules of commercial value such as gallic acid, catechin, epicatechin, quercetin and resveratrol gives scope for its extensive study and extraction from the pomace. The need for optimizing the biocompatible solvent extraction of ethanolic-water composition is realized and the kinetics of extraction time is demonstrated. The work focusses on novel use of membrane technology for separation and fractionation of lower flavan-3-ols from the crude extract. Four different membranes of varied pore size, chemical nature and material were chosen. Of these, Duramem 900, a class of Organic Solvent Nanofiltration membrane showed lower rejections of monomeric and oligomeric phenolic compounds. This membrane was then subjected to the comparative study of nanofiltration and diananofiltration.European Commissio

Membrane Emulsification—A Novel Solution for Treatment and Reuse of Produced Water from Oil Field

Produced water (PW) is, by volume, the largest waste product of the oil- and gas-exploration industry and contains pollutants such as hydrocarbons and heavy metals. To meet the stringent environmental regulations, PW must be treated before discharging into the environment. The current study proposes a novel treatment method where PW is used to prepare oil-in-water emulsion with potential applications within the oil-exploration industry. The emulsions are prepared by applying hollow fiber membrane emulsification (ME) on PW, which inherently contains oil, as to-be-dispersed phase. The results demonstrate that the average droplet size of the emulsions is a function of pressure applied on to-be-dispersed phase and could be customized from 0.24 to 0.65 µm by varying the pressure from 0.25 to 1 bar, respectively. Stability of the emulsions was verified under high pressure and a temperature and storage period of more than 24 h. The calculations showed that an ME unit with <100 kg weight and <1 m(3) volume is appropriate to transform the daily average volume of PW from the Danish part of the North Sea into the emulsions. The study provides a novel route, which also complies well with the requirements (low-weight and small spatial footprints) of the offshore oil rigs, to treat and reuse PW within the oil production process and, therefore, eliminates its environmental footprint

Antifungal activity of biosynthesized silver nanoparticles from Candida albicans on the strain lacking the CNP41 gene

The upsurge of immunocompromised patients has led to extensive study of fungal infections with Candida albicans being the frontline model of pathogenic yeast in humans. In the quest to find novel antifungal agents, this study reports the potential usage of wild-type C. albicans strain C86 to biosynthesise silver nanoparticles by microwave assisted technique. Visual colour change and UV-spectrophotometer were used for primary detection of silver nanoparticles. Additionally, the FTIR peaks confirm the particles' formation and surface characterisation techniques such as FESEM and EDX suggests that the silver nanoparticles were sized in the range of 30-70 nm. Furthermore, pioneering work of homologous recombination technique was systematically employed to delete uncharacterized gene orf19.3120 (CNP41) in the C86 strain creating the deletion strain C403 of C. albicans. To amalgamate the two significant findings, biosynthesized silver nanoparticles were subjected to antifungal studies by disk diffusion assay on the strain C403 that lacks the gene orf19.3120 (CNP41) of C. albicans. As a synergetic approach, combinational effect was studied by incorporating antifungal drug fluconazole. Both individual and enhanced combinational antifungal effects of silver nanoparticles and fluconazole were observed on genetically modified C403 strain with 40% increase in fold area compared to wild-type C86 strain. This can be attributed to the synergetic effect of the bonding reaction between fluconazole and AgNPs. Taken together, this first-ever interdisciplinary study strongly suggests that the CNP41 gene could play a vital role in drug resistance in this fungal pathogen.publishersversionpublishe

Equilibrium, Thermodynamic, and Kinetic Studies

Publisher Copyright: © 2022 Razia Sulthana et al.The economic viability of adsorbing crystal violet (CV) using pepper seed spent (PSS) as a biosorbent in an aqueous solution has been studied. A parametrical investigation was conducted considering parameters like initial concentration of dye, time of contact, pH value, and temperature variation. The analysis of experimental data obtained was carried out by evaluating with the isotherms of Freundlich, Sips, Tempkin, Jovanovic, Brouers-Sotolongo, Toth, Vieth-Sladek, Radke-Prausnitz, Langmuir, and Redlich-Peterson. The adsorption kinetics were studied by implementing the Dumwald-Wagner, Weber-Morris, pseudo-first-order, pseudo-second-order, film diffusion, and Avrami models. The experimental value of adsorption capacity (Qm=129.4 mg g-1) was observed to be quite close to the Jovanovic isotherm adsorption capacity (Qm=82.24 mg g-1) at (R2), coefficient of correlation of 0.945. The data validation was found to conform to that of pseudo-second-order and Avrami kinetic models. The adsorption process was specified as a spontaneous and endothermic process owing to the thermodynamic parametrical values of ΔG0, ΔH0, and ΔS0. The value of ΔH0 is an indicator of the process's physical nature. The adsorption of CV to the PSS was authenticated from infrared spectroscopy and scanning electron microscopy images. The interactions of the CV-PSS system have been discussed, and the observations noted suggest PSS as a feasible adsorbent to extract CV from an aqueous solution.publishersversionpublishe

Comparative studies of ultrasound and membrane emulsification for the production of stable Perfluorocarbon-in-water nanoemulsions

Low-molecular weight perfluorocarbons (PFCs) are usually chemically and biologically inert, clear, colorless liquids, presenting a high affinity for many gases, namely for O2, NO and CO2, which turn them particularly suitable in various biomedical applications involving gas capture, transport and release. In fact, PFC-in-Water emulsions were one of the two major classes of systems proposed as blood substitutes and for O2/NO therapeutics. However there are still some important issues concerning this type of systems which have limited their efficiency, approval and commercial success, namely those related to emulsion stability, hydrodynamic size distribution and reduced shelf-lives. Stability issues can easily lead to PFC diffusion in water, to aggregation and to the consequent hydrodynamic size increase and emulsion degradation [1]. Nanoemulsions (typically within a range of hydrodynamic sizes of 10-100 nm) exhibit various advantages over typical microemulsions [2]. Hence, our aim is to produce monodisperse PFC nanoemulsions presenting larger surface-to-volume ratios, enhanced stabilities and more efficient gas capture/delivery properties. A first approach to achieve these goals is to prepare and to study a mixed surfactant system based on Tween 80 and on a perfluorinated surfactant (perfluorooctyl phosphocholine) at different relative compositions. PFC-in-Water nanoemulsions were produced by using the traditional ultrasound emulsification method (500W). The effects of co-surfactants relative compositions on CMC values, on the kinetics of emulsion formation and on the corresponding stabilities of prepared nanoemulsions were evaluated. Hydrodynamic sizes and Zeta-potentials were also assessed, being able to obtain stable nanoemulsions with hydrodynamic sizes between 150 and 200 nm. In a comparative study, PFC-in-Water nanoemulsions were also produced by membrane emulsification. This low energy-intensive technique has received increasing interest as it allows more flexible operating conditions. Regenerated cellulose membranes such as Nadir UC500 and Millipore Ultracel RC100, polyethersulphone membranes such as Nadir UP150 and Millipore PBHK04310, and a promising polycarbonate Whatman Track-ethched 30 nm Nuclepore membrane, were employed to produce nanoemulsions, and using the same mixed surfactant system and relative compositions. The energy inputs of these two methods were compared and discussed along with their efficiencies in terms of producing nanoemulsions presenting improved stabilities, smaller hydrodynamic sizes and narrower hydrodynamic size distributions. References [1] M.P. Krafft, A. Chittofrati, J.G. Riess, Curr Opin in Colloid Interface Sci., 8 (2003) 251–258 [2] E. Piacentini, E. Drioli, L. Giorno, J. of Membr. Sci., 468 (2014) 410–42

Design of Enzyme Loaded W/O Emulsions by Direct Membrane Emulsification for CO2 Capture

Publisher Copyright: © 2022 by the authors.Membrane-based gas separation is a promising unit operation in a low-carbon economy due to its simplicity, ease of operation, reduced energy consumption and portability. A methodology is proposed to immobilise enzymes in stable water-in-oil (W/O) emulsions produced by direct membrane emulsification systems and thereafter impregnated them in the pores of a membrane producing emulsion-based supported liquid membranes. The selected case-study was for biogas (CO2 and CH4) purification. Upon initial CO2 sorption studies, corn oil was chosen as a low-cost and non-toxic bulk phase (oil phase). The emulsions were prepared with Nadir® UP150 P flat-sheet polymeric membranes. The optimised emulsions consisted of 2% Tween 80 (w/w) in corn oil as the continuous phase and 0.5 g.L−1 carbonic anhydrase enzyme with 5% PEG 300 (w/w) in aqueous solution as the dispersed phase. These emulsions were impregnated onto a porous hydrophobic PVDF membrane to prepare a supported liquid membrane for gas separation. Lastly, gas permeability studies indicated that the permeability of CO2 increased by ~15% and that of CH4 decreased by ~60% when compared to the membrane without carbonic anhydrase. Thus, a proof-of-concept for enhancement of CO2 capture using emulsion-based supported liquid membrane was established.publishersversionpublishe

Isotherm, kinetic and modeling studies

Funding Information: Funding: The Deanship of Scientific Research at King Khalid University General Research Project under the grant number (R.G.P.2/138/42) and Taif University researchers supporting project number (TURSP–2020/157), Taif University, Taif, Saudi Arabia. Funding Information: Acknowledgments: The co‐author Ali E. Anqi would like to extend his appreciation to the Deanship of Scientific Research at King Khalid University for the support he received through General Re‐ search Project under the grant number (R.G.P.2/138/42). This work was supported by Taif Univer‐ sity researchers supporting project number (TURSP–2020/157), Taif University, Taif, Saudi Arabia. The first author was thankful to the Directorate of Minorities, Govt. of Karnataka for providing PhD fellowship to conduct the research. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.The first-ever use of halloysite nanotube (HNT), a relatively low-cost nanomaterial abun-dantly available with minor toxicity for removing brilliant green dye from aqueous media, is re-ported. The factors affecting adsorption were studied by assessing the adsorption capacity, kinetics, and equilibrium thermodynamic properties. All the experiments were designed at a pH level of around 7. The Redlich-Peterson isotherm model fits best amongst the nine isotherm models studied. The kinetic studies data confirmed a pseudo model of the second order. Robotic investigations pro-pose a rate-controlling advance being overwhelmed by intraparticle dispersion. The adsorbent fea-tures were interpreted using infrared spectroscopy and electron microscopy. Process optimization was carried out using Response Surface Methodology (RSM) through a dual section Fractional Fac-torial Experimental Design to contemplate the impact of boundaries on the course of adsorption. The examination of fluctuation (ANOVA) was utilized to consider the joined impact of the boundaries. The possibilities of the use of dye adsorbing HNT (“sludge”) for the fabrication of the composites using plastic waste are suggested.publishersversionpublishe

A recent study on remediation of direct blue 15 dye using halloysite nanotubes

R.G.P.2/138/42 TURSP–2020/157A set of lab‐scale experiments were designed and conducted to remedy Direct Blue 15 (DB15) dye using nontoxic halloysite nanotubes (HNT) with the view to be utilized in a textile industrial effluent (TIE). The DB15 adsorbed‐HNT “sludge” was used as a reinforcing agent and plas-tic waste to fabricate the composite. To advance the knowledge and further understand the chemical phenomena associated with DB15 adsorption on HNT, different factors like pH value, adsorbate initial concentration, adsorbent dosage, and temperature on the composite were affected experi-mentally tested. To estimate the adsorption capacity of HNT, nine isotherm models were applied, and it was identified that the Brouers–Sotolongo adsorption isotherm model represented the best accuracy for predicting the adsorption behavior of the HNT. Likewise, the pseudo‐second‐order reaction was the predominant mechanism for the overall rate of the multi‐step dye adsorption pro-cess. Additionally, it was demonstrated that the mass transfer during the process is diffusion‐con-trolled, and thermodynamic assessments showed that the process is physisorption.publishersversionpublishe

Sustainable Production of Perfluorocarbon, Ionic Liquid and Deep Eutectic Solvents based Nanoemulsions by Membrane Emulsification for Biomedical and Bioprocessing Applications

In the quest to replace toxic, volatile and harsh solvents, and to abide by the principles of green and sustainable chemistry and engineering, various functional solvents have been in-troduced in the last two decades. The synthesis of perfluorocarbons and hydrophobic ana-logues of ionic liquids (ILs) and deep eutectic solvents (DESs) are some of the examples pub-licising hydrophobic designer solvents. However, in order to potentiate bio-based applica-tions, wherein polar media is usually encountered, the low solubility of these hydrophobic solvents in water was tackled in this work by dispersing them as nanoemulsions. Membrane emulsification was introduced in the end of the last century as an energy-efficient method to produce microemulsions. In the current study, various nuances of membrane emulsification processes were re-visited and re-established for the sustainable production of nanoemulsions. For a comparative analysis, the traditional ultrasound emulsification tech-nique was employed. Perfluorodecalin-in-water nanoemulsions with enhanced stability were formulated using a 30 nm isoporous polymeric membrane by ‘direct membrane emulsifica-tion’ with reduced energy consumption. The high viscosity of ionic liquids (ILs) was ad-dressed for the first-time by ‘premix membrane emulsification’ to formulate IL-in-water nanoemulsions by using the aforementioned membrane. Subsequently, the preparation of novel PVA membranes embedded with micro/nano capsules of silica(shell)/ionic liquid (core) resulted in enhanced CO2 capture. In another case-study, the unique observation of self-as-sembly of DES enabled the formulation of hydrophobic DES-in-water nanoemulsions by iso-porous membranes with nominal pore sizes of 30 – 1000 nm. This phenomenon termed as ‘membrane-assisted nanoemulsification’ was harnessed by fabricating microengineered iso-porous metallic membranes with high physicochemical stability and reusability to formulate DES-in-water nanoemulsions. These nanoemulsions exhibited enhanced antimicrobial activ-ity and improved drug solubility for drug delivery applications. Lastly, this study reinforces the use of membrane emulsification processes as sustainable approaches to formulate cheaper and contamination-free nanoemulsions with controlled size and dispersity when compared to conventional energy-intensive emulsification techniques.Na procura de alternativas a solventes tóxicos, voláteis e agressivos, e para cumprir os princípios da química e engenharia sustentável, foram introduzidos vários solventes funcionais nas últimas duas décadas. A síntese de perfluorocarbonetos e análogos hidrofóbicos de líquidos iónicos e de solventes eutéticos profundos (deep eutectic solvents, DESs) são alguns dos exemplos reportados destes solventes hidrofóbicos. No entanto, a fim de potencializar aplicações de base biológica, em que normalmente são encontrados meios polares, a baixa solubilidade destes solventes hidrofóbicos em água foi ultrapassada neste trabalho, dispersando-os como nanoemulsões. A emulsificação com membranas foi introduzida no final do século passado como um método eficiente em termos de energia para produção de microemulsões. Neste estudo, foram revisitadas variantes de processos de emulsificação com membranas para a produção sustentável de nanoemulsões. Para uma análise comparativa, foi utilizada a técnica tradicional de emulsificação por ultrassons. As nanoemulsões de perfluorodecalina-em-água foram formuladas usando uma membrana polimérica isoporosa de 30 nm por "emulsificação direta com membranas" com estabilidade melhorada e consumo de energia reduzido. A elevada viscosidade dos líquidos iónicos foi abordada pela primeira vez pela "emulsificação com membranas de uma pré-mistura" para formular nanoemulsões de líquidos iónicos-em-água usando a membrana acima mencionada. Posteriormente, a preparação de novas membranas de álcool polivinílico (PVA) incorporadas com micro / nano cápsulas de sílica e núcleo de líquido iónico resultou numa maior captura de CO2. Num outro caso de estudo, a observação inesperada de um auto-rearranjo do DES possibilitou a formulação de nanoemulsões DES-em-água hidrofóbicas por membranas isoporosas com tamanhos de poros nominais de 30 - 1000 nm. Este fenómeno, denominado de 'nanoemulsificação assistida por membrana' envolveu a fabricação de membranas metálicas isoporosas com alta estabilidade físico-química e capacidade de reutilização para formular nanoemulsões DES-em-água. Estas nanoemulsões exibiram uma atividade antimicrobiana melhorada e uma maior solubilidade do fármaco para aplicações de libertação controlada. Por fim, este estudo reforça o uso de processos de emulsificação com membranas como abordagens sustentáveis para formular nanoemulsões mais económicas, livres de contaminação e com maior controlo do seu tamanho tamanho e estabilidade quando comparadas com processos convencionais de emulsificação com elevado consumo energético. Palavras-chave: Nanoemulsões; emulsificação com membranas; emulsificação por ultrassons; perfluorocarbonetos; líquido iónico; solventes eutéticos profundos; consumo de energia

Bioremediation of Textile Industrial Effluents Using Nutraceutical Industrial Spent: Laboratory-Scale Demonstration of Circular Economy

This research reports the first-ever study on abundantly available, environmentally friendly, low-cost and ready-for-use Nutraceutical Industrial Cumin Seed Spent (NICUS) as an innovative adsorbent for bioremediation of a bisazo Acid Red 119 (AR119) dye, a probable mutagen from textile industrial effluents (TIEs). The experiment at the laboratory scale is designed to suit the concepts of sustainability and valorisation under the domain of circular economy. The experimental qe value obtained was 96.00 mg g&minus;1. The optimised conditions of parameters are as follows: pH of 2; adsorption time, 210 min; adsorbent dosage, 0.300 g L&minus;1; particle size, 175 &micro;M; initial dye concentration, 950 mg L&minus;1; orbital shaking, 165 rpm and temperature, 50 &deg;C, producing an impressive value of 748 mg of dye adsorbing on 1 g of dry NICUS. The adsorption capacity of NICUS obtained from the quadratic model developed for process optimisation gave values of 748 mg g&minus;1. As a prelude to commercialisation, five variables that affect the adsorption process were experimentally studied. For the feasibility and efficiency of the process, a two-level fractional factorial experimental design (FFED) was applied to identify variables that influence the adsorption capacity of NICUS. The identified variables were applied to scale experiments by three orders. Nine isotherm models were used to analyse the adsorption equilibrium data. The Vieth&ndash;Sladek adsorption isotherm model was found to be the best fit. The pseudo-second-order reaction was the appropriate mechanism for the overall rate of the adsorption process. Mechanistic studies related to mass transfer phenomena were more likely to be dominant over the diffusion process. Techniques such as SEM, FTIR and CHN analysis were used to characterise NICUS. The dye-adsorbed NICUS obtained as &ldquo;sludge&rdquo; was used as a reinforcing material for the fabrication of composites using plastic waste. The physicomechanical and chemical properties of thermoplastic and thermoset composite using dye-adsorbed NICUS were evaluated and compared with NICUS composites. Prospects of integrating Small and Medium Enterprises (SMEs) into the circular economy of Nutraceutical Industrial Spent (NIS) are discussed