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RSC Advances Jun 2024Because of its great efficiency and widespread application, reverse osmosis (RO) is a popular tool for water desalination and purification. However, traditional RO... (Review)
Review
Because of its great efficiency and widespread application, reverse osmosis (RO) is a popular tool for water desalination and purification. However, traditional RO membranes have a short lifespan due to membrane fouling, deterioration, decreased salt rejection rate, and the low water flux with aging. As a result, membrane modification has received a lot of attention recently, with nanomaterials being extensively researched to improve membrane efficacy and lifespan. Herein, we present an in-depth analysis of recent advances of RO membranes modification utilizing nanomaterials. An overview of the various nanomaterials used for membrane modification, including metal oxides, zeolites, and carbon nanomaterials, is provided. The synthesis techniques and methods of integrating these nanomaterials into RO membranes are also discussed. The impacts of nanomaterial change on the performance of RO membranes are addressed. The underlying mechanisms responsible for RO membrane enhancements by nanomaterials, such as improved surface hydrophilicity, reduced membrane fouling surface repulsion and anti-adhesion properties, and enhanced structural stability, are discussed. Furthermore, the review provides a critical analysis of the challenges and limitations associated with the use of nanomaterials to modify RO membranes. Overall, this review provides valuable insights into the modification of RO membranes with nanomaterials, providing a full grasp of the benefits, challenges, and future prospects of this challenging topic.
PubMed: 38873545
DOI: 10.1039/d4ra01796j -
Frontiers in Microbiology 2024DNA extraction yield from drinking water distribution systems and premise plumbing is a key metric for any downstream analysis such as 16S amplicon or metagenomics...
DNA extraction yield from drinking water distribution systems and premise plumbing is a key metric for any downstream analysis such as 16S amplicon or metagenomics sequencing. This research aimed to optimize DNA yield from low-biomass (chlorinated) reverse osmosis-produced tap water by evaluating the impact of different factors during the DNA extraction procedure. The factors examined are (1) the impact of membrane materials and their pore sizes; (2) the impact of different cell densities; and (3) an alternative method for enhancing DNA yield via incubation (no nutrient spiking). DNA from a one-liter sampling volume of RO tap water with varying bacterial cell densities was extracted with five different filter membranes (mixed ester cellulose 0.2 μm, polycarbonate 0.2 μm, polyethersulfone 0.2 and 0.1 μm, polyvinylidene fluoride 0.1 μm) for biomass filtration. Our results show that (i) smaller membrane pore size solely did not increase the DNA yield of low-biomass RO tap water; (ii) the DNA yield was proportional to the cell density and substantially dependent on the filter membrane properties (i.e., the membrane materials and their pore sizes); (iii) by using our optimized DNA extraction protocol, we found that polycarbonate filter membrane with 0.2 μm pore size markedly outperformed in terms of quantity (DNA yield) and quality (background level of 16S gene copy number) of recovered microbial DNA; and finally, (iv) for one-liter sampling volume, incubation strategy enhanced the DNA yield and enabled accurate identification of the core members (i.e., and as the most abundant indicator taxa) of the bacterial community in low-biomass RO tap water. Importantly, incorporating multiple controls is crucial to distinguish between contaminant/artefactual and true taxa in amplicon sequencing studies of low-biomass RO tap water.
PubMed: 38855767
DOI: 10.3389/fmicb.2024.1339844 -
Next Materials Jan 2024Per- and polyfluoroalkyl substances (PFAS) are oxidatively recalcitrant organic synthetic compounds. PFAS are an exceptional group of chemicals that have significant...
Per- and polyfluoroalkyl substances (PFAS) are oxidatively recalcitrant organic synthetic compounds. PFAS are an exceptional group of chemicals that have significant physical characteristics due to the presence of the most electronegative element (i.e., fluorine). PFAS persist in the environment, bioaccumulate, and have been linked to toxicological impacts. Epidemiological and toxicity studies have shown that PFAS pose environmental and health risks, requiring their complete elimination from the environment. Various separation technologies, including adsorption with activated carbon or ion exchange resin; nanofiltration; reverse osmosis; and destruction methods (e.g., sonolysis, thermally induced reduction, and photocatalytic dissociation) have been evaluated to remove PFAS from drinking water supplies. In this review, we will comprehensively summarize previous reports on the photodegradation of PFAS with a special focus on photocatalysis. Additionally, challenges associated with these approaches along with perspectives on the state-of-the-art approaches will be discussed. Finally, the photocatalytic defluorination mechanism of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) following complete mineralization will also be examined in detail.
PubMed: 38840836
DOI: 10.1016/j.nxmate.2023.100077 -
The European Physical Journal. E, Soft... Jun 2024In this study, we demonstrate the fabrication of polymersomes, protein-blended polymersomes, and polymeric microcapsules using droplet microfluidics. Polymersomes with...
In this study, we demonstrate the fabrication of polymersomes, protein-blended polymersomes, and polymeric microcapsules using droplet microfluidics. Polymersomes with uniform, single bilayers and controlled diameters are assembled from water-in-oil-in-water double-emulsion droplets. This technique relies on adjusting the interfacial energies of the droplet to completely separate the polymer-stabilized inner core from the oil shell. Protein-blended polymersomes are prepared by dissolving protein in the inner and outer phases of polymer-stabilized droplets. Cell-sized polymeric microcapsules are assembled by size reduction in the inner core through osmosis followed by evaporation of the middle phase. All methods are developed and validated using the same glass-capillary microfluidic apparatus. This integrative approach not only demonstrates the versatility of our setup, but also holds significant promise for standardizing and customizing the production of polymer-based artificial cells.
Topics: Artificial Cells; Polymers; Emulsions; Capsules; Microfluidics; Water; Microfluidic Analytical Techniques; Proteins
PubMed: 38829453
DOI: 10.1140/epje/s10189-024-00428-5 -
PeerJ 2024The burgeoning issue of landfill leachate, exacerbated by urbanization, necessitates evaluating its biological impact, traditionally overshadowed by physical and...
The burgeoning issue of landfill leachate, exacerbated by urbanization, necessitates evaluating its biological impact, traditionally overshadowed by physical and chemical assessments. This study harnesses , a model organism, to elucidate the physiological toxicity of landfill leachate subjected to different treatment processes: nanofiltration reverse osmosis tail water (NFRO), membrane bioreactor (MBR), and raw leachate (RAW). Our investigation focuses on the modulation of sugar metabolism, particularly trehalose-a disaccharide serving dual functions as an energy source and an anti-adversity molecule in invertebrates. Upon exposure, showcased a 60-70% reduction in glucose and glycogen levels alongside a significant trehalose increase, highlighting an adaptive response to environmental stress by augmenting trehalose synthesis. Notably, trehalose-related genes in the NFRO group were up-regulated, contrasting with the MBR and RAW groups, where trehalose synthesis genes outpaced decomposition genes by 20-30 times. These findings suggest that predominantly counters landfill leachate-induced stress through trehalose accumulation. This research not only provides insights into the differential impact of leachate treatment methods on but also proposes a molecular framework for assessing the environmental repercussions of landfill leachate, contributing to the development of novel strategies for pollution mitigation and environmental preservation.
Topics: Animals; Caenorhabditis elegans; Trehalose; Water Pollutants, Chemical; Stress, Physiological
PubMed: 38799059
DOI: 10.7717/peerj.17332 -
Chemosphere May 2024The present study describes a novel double-modified strategy for developing high-performance thin-film composite reverse osmosis (TFC-RO) membranes by incorporating...
The present study describes a novel double-modified strategy for developing high-performance thin-film composite reverse osmosis (TFC-RO) membranes by incorporating titanium-based metal organic frameworks (NH-MIL-125) and functionalised multiwalled carbon nanotubes (MWCNTs) into the support layer and selective layer, respectively. Initially, the support layer was subjected to successive modifications using NH-MIL-125 mixed with polysulfone (PSF) in dimethylformamide DMF solution to investigate their impact on the performance and properties of the support layer and resultant TFC-RO membranes. Results indicated that the new structure of the modified support layer had significant influences on the developed TFC-RO membranes. Notably, the pristine PSF support exhibited a large surface pore size, medium porosity, and strong hydrophobicity, resulting in a low-flux TFC-RO membrane. However, after modification with NH-MIL-125, the optimal blend support demonstrated a small surface pore size, high porosity, and improved hydrophilicity, favouring the formation of a high performance TFC-RO membrane. The incorporation of functionalised MWCNTs nanochannels into the selective layer, using the optimal NH-MIL-125-PSF blended support, resulted in a smoother and more hydrophilic TFC-RO membrane with enhanced negative charge to improve antifouling properties against negative foulants (i.e., nanoplastics (NPs) and bovine serum albumin (BSA)). The double-modified membrane (TFC-RO-DM) exhibited superior performance over the conventional PSF-TFC-RO membrane. Notably, the maximum water flux reached 39 L m.h with 98.4% NaCl rejection. The membrane exhibited a high flux recovery rate of 92% following a 30-min physical cleaning process. Additionally, the TFC-RO-DM membrane displayed reduced fouling against NPs suggesting the great promise of this innovative double-modification approach for the advancement of high-performance TFC-RO membranes.
PubMed: 38795918
DOI: 10.1016/j.chemosphere.2024.142401 -
Medicina (Kaunas, Lithuania) May 2024Cellulite, or edemato-fibro-sclerotic panniculopathy (EFP), is characterized by dermal and hypodermal changes leading to adipose tissue accumulation and compromised... (Randomized Controlled Trial)
Randomized Controlled Trial
Clinical and Ultrasound Efficacy of Topical Hypertonic Cream (Jovita Osmocell) in the Treatment of Cellulite: A Prospective, Monocentric, Double-Blind, Placebo-Controlled Study.
Cellulite, or edemato-fibro-sclerotic panniculopathy (EFP), is characterized by dermal and hypodermal changes leading to adipose tissue accumulation and compromised venous circulation. This study investigates the efficacy of a hypertonic cream containing concentrated sodium chloride (Jovita Osmocell) in addressing water retention and structural alterations in adipose tissue, aiming to interrupt the cellulite formation process. A 12-week, prospective, monocentric, double-blind, placebo-controlled study enrolled 30 female subjects with grade II or III cellulite. Patients were randomized to receive hypertonic cream or a placebo. Thigh circumference, ultrasound evaluations, and standardized photographs were collected at baseline, intermediate, and endpoint visits. Adverse events were monitored. After 84 days, the hypertonic cream group exhibited a significant reduction in thigh circumference compared to the placebo group ( = 0.0037). B-mode ultrasound examinations revealed significant changes in the parameters studied, such as the thickness of the subcutaneous tissue. No statistically significant changes were noticed in the placebo group. Volunteers reported the investigational product's pleasantness and good anti-cellulite activity, with no reported adverse events. The hypertonic cream demonstrated efficacy in reducing thigh circumference, addressing water retention and structural alterations in adipose tissue. The proposed mechanism involves osmosis, releasing accumulated fluids between fat cells, supporting drainage, and reducing inflammation. This study supports the efficacy and safety of hypertonic sodium chloride emulsions in cellulite treatment and confirms safety and user satisfaction.
Topics: Humans; Female; Double-Blind Method; Prospective Studies; Cellulite; Adult; Middle Aged; Ultrasonography; Thigh; Treatment Outcome; Skin Cream; Administration, Topical
PubMed: 38792964
DOI: 10.3390/medicina60050781 -
Molecules (Basel, Switzerland) May 2024Two-stage reverse osmosis (RO) processes with intermediate concentrate demineralization (ICD) provide an efficient strategy to treat brines with high CaSO contents and...
Two-stage reverse osmosis (RO) processes with intermediate concentrate demineralization (ICD) provide an efficient strategy to treat brines with high CaSO contents and reduce concentrate discharge. In this paper, an SRO concentrate is treated using ICD to remove CaSO and then mixed with a PRO concentrate for further desalination in SRO, thereby reducing the discharge of the concentrate. We investigate the selection and degradation of scale inhibitors, as well as seeded precipitation in the two-stage RO process with ICD, to achieve a high water recovery rate. A scale inhibitor is added to restrain CaSO crystallization on the membrane surface, and the optimized scale inhibitor, RO-400, is found to inhibit calcium sulfate scaling effectively across a wide range of the saturation index of gypsum (SIg) from 2.3 to 6. Under the optimized parameters of 40 W UV light and 70 mg/L HO, UV/HO can degrade RO-400 completely in 15 min to destroy the scale inhibitor in the SRO concentrate. After scale inhibitor degradation, the SRO concentrate is desaturated by seeded precipitation, and the reaction degree of CaSO reaches 97.12%, leading to a concentrate with a low SIg (1.07) for cyclic desalination. Three UVD-GSP cycle tests show that the reused gypsum seeds can also ensure the effect of the CaSO precipitation process. This paper provides a combined UVD-GSP strategy in two-stage RO processes to improve the water recovery rate for CaSO-contained concentrate.
PubMed: 38792025
DOI: 10.3390/molecules29102163 -
International Journal of Molecular... May 2024Phenolic compounds from a hydroalcoholic extract of wet olive pomace were purified and concentrated by an integrated membrane process in organic media. First, UF010104...
Integrated Membrane Process in Organic Media: Combining Organic Solvent Ultrafiltration, Nanofiltration, and Reverse Osmosis to Purify and Concentrate the Phenolic Compounds from Wet Olive Pomace.
Phenolic compounds from a hydroalcoholic extract of wet olive pomace were purified and concentrated by an integrated membrane process in organic media. First, UF010104 (Solsep BV) and UP005 (Microdyn Nadir) membranes were tested to be implemented in the ultrafiltration stage, with the aim of purifying the extract and obtaining a permeate enriched in phenolic compounds. Despite the high flux observed with the UF010104 membrane (20.4 ± 0.7 L·h·m, at 2 bar), the UP005 membrane was selected because of a more suitable selectivity. Even though some secoiridoids were rejected, the permeate stream obtained with this membrane contained high concentrations of valuable simple phenols and phenolic acids, whereas sugars and macromolecules were retained. Then, the ultrafiltration permeate was subjected to a nanofiltration step employing an NF270 membrane (DuPont) for a further purification and fractionation of the phenolic compounds. The permeate flux was 50.2 ± 0.2 L·h·m, working at 15 bar. Hydroxytyrosol and some phenolic acids (such as vanillic acid, caffeic acid, and ferulic acid) were recovered in the permeate, which was later concentrated by reverse osmosis employing an NF90 membrane. The permeate flux obtained with this membrane was 15.3 ± 0.3 L·h·m. The concentrated phenolic mixture that was obtained may have important applications as a powerful antioxidant and for the prevention of diabetes and neurodegenerative diseases.
Topics: Olea; Ultrafiltration; Phenols; Membranes, Artificial; Osmosis; Solvents; Plant Extracts
PubMed: 38791271
DOI: 10.3390/ijms25105233 -
Journal of Dairy Science May 2024Residual lipids (RL) in whey protein isolate (WPI) are detrimental to optimal functional applications (like foaming and low turbidity) and contribute to off-flavor...
Residual lipids (RL) in whey protein isolate (WPI) are detrimental to optimal functional applications (like foaming and low turbidity) and contribute to off-flavor development during powder storage. The objective of this research was to prepare an experimental WPI by removing RL without using the traditional microfiltration (MF) process and compare its properties with commercially available WPIs made using MF and some other whey powders. We hypothesize that by adjusting the pH of whey to < 5.0, we would be close to the isoelectric point of any remaining denatured proteins (DP) and phospholipoproteins (PLP), and therefore reduce electrostatic repulsion between these molecules. Further, demineralization of the acidified whey protein solution by ultrafiltration (UF) combined with diafiltration (DF) should reduce ionic hindrance to aggregation and thereby help with the aggregation of these denatured proteins as well as most RL; centrifugation or clarification could be used to remove these materials. Calcium should also be more extensively removed by this approach, which should improve the heat stability of the experimental WPI. Demineralization was achieved on a pilot scale by acidifying liquid (cheese) whey protein concentrate (WPC-34) to pH 4.5 using HCl, and UF the whey protein solution along with extensive DF using acidified (pH∼3.5) reverse osmosis filtered (RO) water. Demineralized whey protein solution was adjusted to various combinations of pH (4.1 to 4.9), conductivities (500 to 2000 μS.cm), and protein concentrations (1 to 7%) and then centrifuged at 10,000 × g for 10 min. The effective sedimentation (precipitation) of RL in these treatments was estimated by measuring the turbidity of the supernatants. Maximum precipitation was observed at pH 4.5-4.7. Reducing conductivity via UF/DF increased the precipitation of RL due to reduced ionic hindrance to aggregation Maximum sedimentation of RL was observed at protein concentrations ≤3% because of a higher density difference between the precipitate and serum phase. SDS-PAGE analysis confirmed the sedimentation of PLPs, caseins, and DPs upon isoelectric precipitation at pH ∼4.5, while native whey proteins or undenatured whey proteins remained soluble in the supernatant, unaffected by the pretreatment. To scale up the process, 750 L of fluid WPC34 was acidified and demineralized by UF (volume concentration factor = 1.35) and DF until the permeate solids reached 0.1% (when desired demineralization was achieved), clarified using a pilot-scale desludging clarifier to remove RL, neutralized, ultrafiltered to concentrate the protein, and then spray-dried to produce an experimental WPI (91% protein and 1.8% fat db). In another trial, demineralized UF concentrate was clarified by gravity sedimentation and the supernatant was neutralized, ultrafiltered, and spray-dried to produce a second experimental WPI (91% protein and < 1% fat db). These experimental WPI powders were compared with several commercially available WPI powders to assess functional properties like solubility, heat stability, foamability and foam strength, gelation, and sensory attributes over accelerated storage. Experimental WPI had excellent functional properties, had low turbidity, were highly heat stable and only developed very slight to slight off-flavors upon accelerated storage, their properties were comparable to the WPI manufactured commercially using MF even after accelerated storage.
PubMed: 38788845
DOI: 10.3168/jds.2024-24671