Aqueous Component Research Articles

Reel silk from cocoons: Optimized fabrication of chitosan-sodium tripolyphosphate imprinted polymers for high-efficiency and selective capture of hexavalent chromium

The structure–function relationship of ion-imprinted polymers for toxic hexavalent chromium (Cr(VI)) is poorly understood. In this study, a series of Cr(VI)-imprinted chitosan (CS)-sodium tripolyphosphate (STPP) composites were prepared by sol–gel method using different alkali/acid combinations and drying modes. The elution of CS-STPP polymer with 1 M NaOH+5 mM HNO3 followed by freeze drying produced the optimal IIP-B+5A-fd material. The distinct structural stabilities and surface charges of imprinted CS-STPP composite determined their disparate Cr(VI) sorption abilities. The Cr(VI) sorption ratio on IIP-B+5A-fd kept higher than 97 % at pH<7, while that on non-imprinted NIP-B+5A-fd decreased from ∼ 73 % to ∼ 28 % as the solution pH rose from 4 to 7. The Cr(VI) sorption kinetics on IIP-B+5A-fd reached equilibrium after 12 h, faster than 24 h on NIP-B+5A-fd. The maximum Cr(VI) sorption capacity of IIP-B+5A-fd (41.29 mg/g) surpassed those of NIP-B+5A-fd (26.00 mg/g) and various previously reported adsorbents. IIP-B+5A-fd exhibited a much better Cr(VI) sorption efficiency (∼83 %) than NIP-B+5A-fd (∼20 %) in the presence of mixed aqueous components. The Cr(VI) sorption mechanism on IIP-B+5A-fd was electrostatic attraction–redox–inner-sphere complexation. Overall, the prepared IIP-B+5A-fd polymer holds a promising potential for highly efficient and selective removal of Cr(VI) from a polluted water environment.

Physicochemical and phytochemical characterization of opuntia dillenii: A promising source of bioactive compounds

ABSTRACT The objective of this ongoing research is to investigate and assess the aqueous extracts, vegetable oil, and residual plant components derived from O. dillenii by use of HPLC, and GC-MS. Subsequent investigations employed colorimetric techniques to identify reducing and soluble sugars. We developed and validated an energy-dispersive X-ray fluorescence (EDXRF) method for determining the concentrations of essential chemical elements (O, C, Ca, Mg, K, S, P) in seeds, juice, and peel, as well as their residues. HPLC analysis yielded results indicating that extracts from O. dillenii seeds, juice, and peel from distinct regions (Oujda, Nador, and Essaouira) contained elevated concentrations of metabolites. Specifically, peel and juice extracts exhibited the highest levels of organic acids and betanin compared to O. dillenii seeds. Conversely, seed oils displayed a noteworthy tocopherol content, predominantly δ-tocopherol. Similarly, an examination of organic acid composition in juice, peel, and seeds from three different regions revealed their elevated levels. Citric acid and oxalic acid emerged as predominant components in the juice. Overall, Opuntia dillenii’s physicochemical and phytochemical characterization improves in understanding its potential as a bioactive chemical promoter, which could lead to the creation of new medicinal medicines or functional food ingredients.

Temperature effects on chemical reactions and product yields in the Co-pyrolysis of wood sawdust and waste tires: An experimental investigation

This study investigates the effects of varying temperatures on the co-pyrolysis of wood sawdust (WS) and waste tires (WT) within a stainless steel fixed-bed reactor under a nitrogen atmosphere. The experiments were conducted at three different temperatures: 400 °C, 500 °C, and 600 °C, focusing on the thermal behavior and resultant product yields. At 600 °C, WS produced the highest oil yield (63.6 wt%), suggesting a tendency to generate more aqueous and volatile components. Conversely, WT alone showed an optimal oil yield of 46.4 wt% at 500 °C, while the WS-WT blend achieved 55.6 wt%. Gas chromatography-mass spectrometry (GC-MS) analyses of the pyrolytic oils indicated that WS-heavy mixtures were rich in aliphatic compounds, whereas WT-dominant samples had increased aromatic and phenolic contents, demonstrating the potential for creating valuable chemicals from waste. Additionally, gas analysis highlighted significant variations in syngas composition, with increased methane and decreased CO2 levels at higher temperatures, emphasizing the role of the water-gas shift reaction. These findings underscore the critical importance of temperature control in optimizing the efficiency and quality of products from co-pyrolysis, presenting a viable method for enhancing the value derived from waste materials.

Energy recovery from syngas and pyrolysis wastewaters with anaerobic mixed cultures

The anaerobic digestion of aqueous condensate from fast pyrolysis is a promising technology for enhancing carbon and energy recovery from waste. Syngas, another pyrolysis product, could be integrated as a co-substrate to improve process efficiency. However, limited knowledge exists on the co-fermentation of pyrolysis syngas and aqueous condensate by anaerobic cultures and the effects of substrate toxicity. This work investigates the ability of mesophilic and thermophilic anaerobic mixed cultures to co-ferment syngas and the aqueous condensate from either sewage sludge or polyethylene plastics pyrolysis in semi-batch bottle fermentations. It identifies inhibitory concentrations for carboxydotrophic and methanogenic reactions, examines specific component removal and assesses energy recovery potential. The results show successful co-fermentation of syngas and aqueous condensate components like phenols and N-heterocycles. However, the characteristics and load of the aqueous condensates affected process performance and product formation. The toxicity, likely resulting from the synergistic effect of multiple toxicants, depended on the PACs’ composition. At 37 °C, concentrations of 15.6 gCOD/gVSS and 7.8 gCOD/gVSS of sewage sludge-derived aqueous condensate inhibited by 50% carboxydotrophic and methanogenic activity, respectively. At 55 °C, loads between 3.9 and 6.8 gCOD/gVSS inhibited by 50% both reactions. Polyethylene plastics condensate showed higher toxicity, with 2.8 gCOD/gVSS and 0.3 gCOD/gVSS at 37 °C decreasing carboxydotrophic and methanogenic rates by 50%. At 55 °C, 0.3 gCOD/gVSS inhibited by 50% CO uptake rates and methanogenesis. Increasing PAC loads reduced methane production and promoted short-chain carboxylates formation. The recalcitrant components in sewage sludge condensate hindered e-mol recovery, while plastics condensate showed high e-mol recoveries despite the stronger toxicity. Even with challenges posed by substrate toxicity and composition variations, the successful conversion of syngas and aqueous condensates highlights the potential of this technology in advancing carbon and energy recovery from anthropogenic waste streams.Graphical

Formulation and evaluation of nanoemulgel loaded with essential oils with mosquito repellent activities

The mosquito repellent potential of plant materials, including essential oils, has been exploited for centuries. However, due to the volatility of essential oils, the protection against mosquitoes is short-lived. This study aimed to formulate citronella oil (CO) (Cymbopogon nardus) and palmarosa oil (PO) (C. martini) in the form of nanoemulgel (NEG) to delay their volatility and prolong protection time against mosquitoes. Nanoemulsions (NE) of both essential oils were prepared using ultrasonication after suitable hydrophilic-lipophilic balance (HLB) selection and phase diagram development. NEGs were formulated by mixing NEs and Carbopol 934 gel. Physicochemical characterizations, including in vitro release and permeation studies were conducted. Tween 80, Transcutol P and distilled water with 40 % glycerol were selected as surfactant, co-surfactant and aqueous components of the NEs, respectively. HLB values of 11 and 12 were found to be appropriate for CO and PO NEs preparation, respectively. The NEGs were kinetically stable and the formulation components were chemically compatible with each other. The NEG formulations prolonged the release of both essential oils for 24 h and significantly reduced the percentage permeation via cellulose acetate membrane as compared to NEs. Consequently, NEG could be a potential formulation to prolong the mosquito repellent activity of essential oils.

TiO2 Nanoparticles with Adjustable Phase Composition Prepared by an Inverse Microemulsion Method: Physicochemical Characterization and Photocatalytic Properties.

Titania nanoparticles (NPs) find wide application in photocatalysis, photovoltaics, gas sensing, lithium batteries, etc. One of the most important synthetic challenges is maintaining control over the polymorph composition of the prepared nanomaterial. In the present work, TiO2 NPs corresponding to anatase, rutile, or an anatase/rutile/brookite mixture were obtained at 80 °C by an inverse microemulsion method in a ternary system of water/cetyltrimethylammonium bromide/1-hexanol in a weight ratio of 17:28:55. The only synthesis variables were the preparation of the aqueous component and the nature of the Ti precursor (Ti(IV) ethoxide, isopropoxide, butoxide, or chloride). The materials were characterized with X-ray diffraction, scanning/transmission electron microscopy, N2 adsorption-desorption isotherms, FTIR and Raman vibrational spectroscopies, and diffuse reflectance spectroscopy. The synthesis products differed significantly not only in phase composition, but also in crystallinity, textural properties, and adsorption properties towards water. All TiO2 NPs were active in the photocatalytic decomposition of rhodamine B, a model dye pollutant of wastewater streams. The mixed-phase anatase/rutile/brookite nanopowders obtained from alkoxy precursors showed the best photocatalytic performance, comparable to or better than the P25 reference. The exceptionally high photoactivity was attributed to the advantageous electronic effects known to accompany multiphase titania composition, namely high specific surface area and strong surface hydration. Among the single-phase materials, anatase samples showed better photoactivity than rutile ones, and this effect was associated, primarily, with the much higher specific surface area of anatase photocatalysts.

Bio-efficacy of mustard seed extracts against Bihar hairy caterpillar Spilosoma obliqua (Erebidae: Lepidoptera) & assessment of mustard allelo-chemicals in response to mustard aphid Lipaphis erysimi (Aphididae: Hemiptera) infestation

Mustard seed contains glucosinolate-myrosinase system of substrate-enzyme metabolism, accompanied with compartmentalized cells. Upon rupture, enzyme myrosinase leads to breakdown of glucosinolates and its metabolized products like allyl, benzyl, phenyl type of isothiocyantes and many other types like nitriles are released. The myrosinase activity is tested in three globally utilized different seed coat color mustards viz., brown mustard (Brassica juncea), white mustard (Sinapis alba) and black mustard (Brassica nigra) to demonstrate the release of glucosinolates which are known to deter insect pests. Aqueous seed extracts of these mustard types were subjected to anti-feedant activity analysis and oil extracted from these mustard seeds was subjected to insecticidal activity analysis against Spilosoma obliqua 4th instars on castor leaves. Meanwhile, the mustard leaves in open field were allowed for natural aphid infestation during early months from January to March. Thereafter, the leaf twigs of white, black and brown mustard, infested and uninfested by aphids, were collected and myrosinase activity of plants was analyzed with varying levels of important pest inflicted biochemicals in plant, viz., Total phenols, ortho-dihydric phenols and flavonols. Gas Chromatography–Mass Spectrometry analysis of mustard oil used in insecticidal activity was performed to elucidate the role of biochemicals involved in action. These compounds along with fatty acids and sterols compounds are known to have anti-feedant & insecticidal activities. Aqueous extract components were also subjected to total glucosinolate analysis, spectrophotometrically for knowing their concentration, with highest in brown (85.81 µmol/g) followed by black (59.32 µmol/g) and lowest in white mustard (47.63 µmol/g). The amount of glucosinolates, free fatty acids & sterol compounds present in different coat color mustard seed types are being correlated here with their potential bioactivities against biological plant pests. Bio-control of potentially harmful insect pests is possible by utilizing anti-feeding & insecticidal potential of mustard seed extracts.

Identification of mine water source based on TPE-LightGBM

Mine water inrush is a serious threat to mine safety production. It is very important to identify water inrush source types quickly to prevent and control water damage. In this study, the aqueous chemical components Na+ + K+, Ca2+, Mg2+, Cl−, SO42− and HCO3− of different aquifers in Pingdingshan coalfield were selected as the characteristic values, and the Surface water, Quaternary pore water, Carboniferous limestone karst water, Permian sandstone water, and Cambrian limestone karst water were used as the labels. An intelligent water source discrimination model is proposed by combining data mining, classification models, and reinforcement learning. As outlier data in the samples may interfere with the model recognition ability, the data distribution range was analyzed using box plots, and 20 groups of abnormal samples were excluded. The processed water chemistry data were divided into 80% learning samples and 20% test samples, and the learning samples were fed into a light gradient boosting machine (LightGBM) for training. The tree-structured parson estimator (TPE) obtains the optimal values of the main parameters of LightGBM in a very short time. Substituting the hyperparameters back into the model yields a 13.9% improvement in the accuracy of the model, proving the effectiveness of the TPE algorithm. To further validate the performance of the model, TPE-LightGBM is compared and analyzed with a Random Search-Multi Layer Perceptron Machine (RS-MLP) and Genetic Algorithm-Extreme Gradient Boosting Tree (GA-SVM). The accuracy of TPE-LightGBM, RS-MLP, and GA-SVM is 0.931, 0.759, 0.724 in that order, and the generalization error RMSE is 0.415, 1.05, and 1.313 in that order. The results show that TPE-LightGBM is more advantageous in water source identification and is more resistant to overfitting. By calculating and comparing the information gain of each variable, the contribution of Ca2+ is the highest, so it is necessary to pay attention to the change in Ca2+ concentration. TPE-LightGBM’s high accuracy and generalization ability have a good prospect for the identification of sudden water source types.

Cornus officinalis Sieb. Et Zucc. attenuates Aβ25–35-induced mitochondrial damage and neuroinflammation in mice by modulating the ERK pathway

BackgroundCornus officinalis Sieb. Et Zucc. has the efficacy of tonifying the marrow and filling up the essence, breaking up the accumulation and opening up the orifices. Our research team found that CoS extracts were protective against Aβ25–35-induced memory impairment in mice. However, the pharmacodynamic components and mechanisms by which CoS improves AD have yet to be thoroughly explored and investigated. PurposeThis study focused on exploring the bioactive components and pharmacodynamic mechanisms of CoS aqueous extract underlying mitochondrial damage and neuroinflammation to improve Aβ25–35-induced AD. MethodsAD mouse models were generated using Aβ25–35 brain injections. Different doses of CoS aqueous extract were orally administered to mice for 28 days. The cognitive function, neuronal and synaptic damage, mitochondrial damage (mitochondrial length, mitochondrial fusion fission-related protein expression), neuroglial activation, and immune inflammatory factor and ERK pathway-related protein levels of mice were assessed. The CoS aqueous extracts components were identified using UPLC-TQ/MS and screened for cellular activity. Midivi-1 (Drp1 inhibitor) or PD98059 (ERK inhibitor) was added to Aβ25–35-exposed PC12 cells to assess whether CoS and its active compounds mMorB and CorE regulate mitochondrial fission through ERK/Drp1. PC12-N9 cells were cocultured to investigate whether mMorB and CorE could regulate mitochondrial division through the ERK pathway to modulate neuroinflammation. ResultsCoS improved exploration and memory in AD mice, reduced synaptic and mitochondrial damage in their hippocampus, and modulated disturbed mitochondrial dynamics. Moreover, CoS inhibited ERK pathway signaling and attenuated abnormal activation of glial cells and secondary immune inflammatory responses. Additionally, in vitro experiments revealed that CoS and its compounds 7β-O-methylmorroniside (mMorB) and Cornusdiridoid E (CorE) ameliorated mitochondrial injury caused by Aβ25–35 in PC12 cells through inhibition of the ERK/Drp1 pathway. Meanwhile, mMorB and CorE ameliorated cellular inflammation by inhibiting the Ras/ERK/CREB signaling pathway. ConclusionCoS aqueous extract ameliorates behavioral deficits and brain damage in Aβ25–35-induced AD mice by modulating the ERK pathway to attenuate mitochondrial damage and neuroinflammation, and the compounds mMorB and CorE are the therapeutically active ingredients.

Efficacy and safety of artificial tears containing Artemia salina extract with dinucleotides for dry eye

ABSTRACT Clinical relevance This clinical trial was conducted as part of the marketing procedures for a medical device comprising artificial tears containing Artemia salina extract with dinucleotides. These molecules previously demonstrated secretagogue properties by enhancing the production of aqueous, mucinous, and lipidic components of the tears. Background After confirming the efficacy of artificial tears containing Artemia salina extract in an animal model, this study proceeded to evaluate their efficacy and safety on dry eye participants. Methods A randomised controlled clinical trial was performed on 36 dry eye participants (41.6 ± 20.6 years). Half of the participants were treated with saline solution as a placebo for four weeks, while the other half were treated with artificial tears containing Artemia salina, randomly assigned. After a wash-out period of two weeks, the treatments were crossed for another four weeks. Participants were assessed at baseline and after one week, two weeks, and four weeks. Efficacy variables were: eye dryness frequency (primary), eye comfort, visual satisfaction, tear secretion, tear break-up time, corneal staining, conjunctival staining, and conjunctival hyperaemia. Safety variables were: high- and low-contrast visual acuity, intraocular pressure, and eye fundus images analysis. Results Compared with the baseline, the saline solution showed no significant changes in any of the studied variables after four weeks of treatment (p ≥ 0.05). However, the topical instillation of the artificial tears with Artemia salina for four weeks significantly improved eye dryness frequency (p = 0.014) and corneal staining (p = 0.010). No systemic or ocular adverse events were reported during the clinical trial. Conclusion The topical instillation of artificial tears containing Artemia salina in mild to moderate dry eye participants for four weeks slightly improved their symptoms related to eye dryness frequency and reduced corneal damage, with no undesirable side effects observed.

The Marine Alga Sargassum horneri Is a Functional Food with High Bioactivity

Functional food factors can play a preventive and therapeutic role in several human diseases. The marine alga Sargassum horneri (S. horneri) has restorative effects in several types of metabolic disorders, including osteoporosis, diabetes, inflammatory conditions, and cancer cell growth. Osteoporosis is widely recognized as a major public health problem. Bone loss associated with ageing and diabetic states was prevented through the intake of bioactive compounds from S. horneri water extract in vivo by stimulating osteoblastic bone formation and inhibiting osteoclastic bone resorption in vitro. The intake of S. horneri water extract was found to have preventive effects on diabetic findings with an increase in serum glucose and lipid components. Furthermore, the S. horneri component has been shown to suppress adipogenesis from rat bone marrow cells and inflammatory conditions in vitro. Notably, the growth of bone metastatic human breast cancer MDA-MB-231 cells, which induce bone loss with osteolytic effects, was suppressed through culturing with the S. horneri water extract component in vitro. The S. horneri component, which has a molecular weight of less than 1000, was found to suppress the activation of NF-κB signaling by tumor necrosis factor-α, a cytokine associated with inflammation, in osteoblastic cells and macrophage RAW264.7 cells in vitro, suggesting a molecular mechanism. The bioactive component of S. horneri may play a multifunctional role in the prevention and treatment of metabolic disorders. This review outlines the advanced knowledge of the biological activity of the aqueous extract components of S. horneri and discusses the development of health supplements using this material.

A New Immortalized Human Lacrimal Gland Cell Line.

The lacrimal gland is crucial for maintaining ocular health by producing the aqueous component of the tear film, which hydrates and nourishes the ocular surface. Decreased production of this component results in dry eye disease, a condition affecting over 250 million people worldwide. However, the scarcity of primary human material for studying its underlying mechanisms and the absence of a cell model for human lacrimal gland epithelial cells present significant challenges. Here, we describe the generation of immortalized human lacrimal gland cell lines through the introduction of an SV40 antigen. We successfully isolated and characterized three cell clones from a female lacrimal gland donor, confirming their epithelial identity through genomic and protein analyses, including PCR, RNAseq, immunofluorescence and cultivation in a 3D spheroid model. Our findings represent a significant advancement, providing improved accessibility to investigate the molecular pathogenesis mechanisms of dry eye disease and potential therapeutic interventions. We identified the expression of typical epithelial cell marker genes and demonstrated the cells' capability to form 2D cell sheets and 3D spheroids. This establishment of immortalized human lacrimal gland cells with epithelial characteristics holds promise for future comprehensive studies, contributing to a deeper understanding of dry eye disease and its cellular mechanisms.

Evaluation of per- and polyfluoroalkyl substances (PFAS) in landfill liquids from Pennsylvania, Colorado, and Wisconsin

Perand polyfluoroalkyl substances (PFAS) have been measured in aqueous components within landfills. To date, the majority of these studies have been conducted in Florida. This current study aimed to evaluate PFAS concentrations in aqueous components (leachate, gas condensate, stormwater, and groundwater) from four landfills located outside of Florida, in Pennsylvania, Colorado, and Wisconsin (2 landfills). The Pennsylvania landfill also provided the opportunity to assess a leachate treatment system. Sample analyses were consistent across studies including the measurements of 26 PFAS and physical-chemical parameters. For the four target landfills, average PFAS concentrations were 6,900, 22,000, 280, and 260 ng L−1 in the leachate, gas condensate, stormwater, and groundwater, respectively. These results were not significantly different than those observed for landfills in Florida except for the significantly higher PFAS concentrations in gas condensate compared to leachate. For on-site treatment at the Pennsylvania landfill, results suggest that the membrane biological bioreactor (MBBR) system performed similarly as aeration-based leachate treatment systems at Florida landfills resulting in no significant decreases in ∑26PFAS. Overall, results suggest a general consistency across US regions in PFAS concentrations within different landfill liquid types, with the few differences observed likely influenced by landfill design and local climate. Results confirm that leachate exposed to open air (e.g., in trenches or in treatment systems) have lower proportions of perfluoroalkyl acid precursors relative to leachate collected in enclosed pipe systems. Results also confirm that landfills without bottom liner systems may have relatively higher PFAS levels in adjacent groundwater and that landfills in wetter climates tend to have higher PFAS concentrations in leachate.

Some theoretical considerations on an empirical hydrophobicity index in reversed-phase liquid chromatography

This study is analyzing the chromatographic hydrophobicity index (denoted by HIV) in reversed-phase liquid chromatography based on the linear dependence of the logarithm of experimental retention factor (log k) on the content of the organic component from mobile phase (retention function). In the literature HIV is given by the ratio between the logarithm of the extrapolated retention factor for water as mobile phase (log kw) and the slope (S) of the linear equation describing the dependence of log k on the organic solvent fraction () from mobile phase composition. The paper demonstrates that the parameter HIV is related to the extrapolated values of the retention factor for the extreme compositions of the mobile phase, namely to 100% aqueous component (log kw) and 100% organic component (log korg), respectively. A new empirical hydrophobicity descriptor (denoted by HIL) is proposed as an alternative to HIV, which is related only to slope S as a square root of (1 + S2). Some examples and correlations are discussed and compared using retention data acquired for different HPLC columns and mobile phase compositions, showing that HIL correlates better than HIV with octanol-water partition constant (log Kow) of studied solutes.

The effect of microfabric heterogeneity on shear wave properties in fine-grained sediments

The water-sediment interface is highly susceptible to physical, biological, and chemical processes, which can create significant levels of heterogeneity in sediment biogeoacoustic properties at various spatial scales that affect transmission and scattering of elastic waves. Using a suite of microscopy, spectroscopy, and medical sonoelastography techniques, relationships between heterogeneity in the sediment microfabric and shear wave speed can be investigated at spatial scales ranging from centimeters to micrometers. Here, we study fine-grained sediments extracted from two unique intertidal mudflats in the Great Bay Estuary, New Hampshire, USA. Shear waves were excited via acoustic radiation force and external vibration in the 50–200 Hz frequency band, and particle velocity was sensed in the top 2 centimeters of sediment at approximately 0.5-micrometer spatial resolution using a research-grade medical imaging array. By directly imaging the propagating shear wave, spatial heterogeneity of shear wave speed was directly measured. Next, subsamples were extracted and prepared for microscopy, where volume fraction and orientation of organic, mineral, and aqueous components were studied at various spatial scales. A comparison of between shear wave speed and microfabric parameters will be presented. [Work sponsored by ONR.]

The role of suspended biomass in PFAS enrichment in wastewater treatment foams

Foaming in aerated bioreactors at wastewater treatment plants (WWTPs) has been identified as an operational issue for decades. However, the affinity of per- and polyfluoroalkyl substances (PFAS) for air-liquid interfaces suggests that foam harvesting has the potential to become a sustainable method for PFAS removal from sewage. Aerated bioreactors’ foams are considered three-phase systems, comprising air, aqueous and solid components, the latter consisting of activated sludge biomass. To achieve a comprehensive understanding of the capability of aerated bioreactors’ foams to enrich PFAS, we analysed PFAS concentrations from WWTPs in both the solid and aqueous phases of the collapsed foams (foamate) and underlying bulk mixed liquors. Our findings show that PFAS enrichment occurs not only in the aqueous phase but also in the solid phase of the foamate. This suggests that previous field studies that only analysed the aqueous phase may have underestimated the capability of the aerated bioreactors’ foams to enrich PFAS. Fractions of PFOA and PFOS sorbed to the solid phase of the foamate can be as high as 60 % and 95 %, respectively. Our findings highlight the importance of implementing effective foamate management strategies that consider both the aqueous and solid phases.

Evaluation of per- and polyfluoroalkyl substances (PFAS) released from two Florida landfills based on mass balance analyses

Per- and polyfluoroalkyl substances (PFAS) have been found at high levels within landfill environments. To assess PFAS distributions, this study aimed to evaluate PFAS mass flux leached from disposed solid waste and within landfill reservoirs by mass balance analyses for two full-scale operational Florida landfills. PFAS mass flux in different aqueous components within landfills were estimated based on PFAS concentrations and water flow rates. For PFAS concentration, 26 PFAS, including 18 perfluoroalkyl acids (PFAAs) and 8 PFAA-precursors, were measured in samples collected from the landfills or estimated based on previous studies. Flow rates of aqueous components (rainfall, evapotranspiration, runoff, stormwater, groundwater, leakage, gas condensate, and leachate) were evaluated through the Hydrologic Evaluation of Landfill Performance model, water balance, and Darcy’s Law. Results showed that the average PFAS mass flux leached from the solid waste standardized by area was estimated as 36.8 g/ha-yr, which was approximately 1 % to 3 % of the total amount of PFAS within the solid waste. The majority of PFAS leached from the solid waste (95 % to 97 %) is captured by the leachate collection system, with other aqueous components representing much smaller fractions (stormwater system at 3 % to 5 %, and gas condensate and groundwater at < 1 %). Also, based on the results, we estimate that PFAS releases will likely occur at least over 40 years. Overall, these results can help prioritize components for waste management and PFAS treatment during the anticipated landfill release periods.

Avaliação da porção aquosa da lágrima em Shih-Tzu: comparação do teste lacrimal de Schirmer 1 com a altura do menisco lacrimal

ABSTRACT The aqueous portion of the tear film has been characterized as an essential structure for ocular surface health. Among various assessment tests, some measure the aqueous portion, such as Schirmer Tear Test 1, Meniscometry using a strip, and the test to determine Tear Meniscus Height (TMH). Conversely, few studies have specifically evaluated tear meniscus height, especially those utilizing ocular surface analyzers. Therefore, the aim of this study was to comparatively evaluate the results obtained from employing Tear Meniscus Height (TMH) using an Ocular Surface Analyzer and Schirmer Tear Test 1 (STT-1) in Shih Tzu dogs. To achieve this, the eyes of 18 brachycephalic Shih Tzu dogs of both sexes and varying ages were assessed and compared. The results revealed that the TMH for the right eye was 0.59±0.29mm, and for the left eye was 0.88±0.27mm; p=0.0135. For STT-1, it was found that the right eye had a value of 19.06±4.87mm/min, and the left eye had a value of 23.11±4.80mm/min; p=0.0238. Furthermore, the Pearson correlation test applied between TMH and STT-1 yielded the following results for the right eye (r=0.601; p=0.008) and the left eye (r=-0.032; p=0.8979). The TMH shows potential as an alternative to STT-1 for evaluating the aqueous component of tear film in a similar manner. However, further research is warranted, particularly for establishing reference values for TMH and conducting a comprehensive comparison between STT-1 and TMH. This research is especially important for gathering information that can contribute to the understanding of ophthalmic and systemic conditions that directly influence the physiological composition of tears. Critical for establishing the values obtained when measuring the canine lacrimal meniscus using different techniques is the consideration of associated functional factors.

Simulation of Filter-Cake Formations on Vertical and Inclined Wells Under Elevated Temperature and Pressure

Summary Drilling fluids consist of colloidal suspensions that are made up of solid particles suspended in liquid. The aqueous component of the drilling mud invades a permeable formation due to differential pressure, leaving solid deposits on the drilled formation walls, forming a filter cake. Typical drilling fluids should create a thin, slick filter cake and fluid loss control to seal permeable zones as swiftly as possible. Tight holes, elevated levels of rotational resistance and friction, wellbore obstruction, fluid loss into formations, suboptimal well-log data, and reservoir formation impairment result from thick filter cakes and excessive filtration. Controlling infiltration of fluids to establish a minimal, low-porosity filter cake is frequently required to avoid drilling and production issues. In this study, we used computational fluid dynamics (CFD) to model the development of filter cakes induced by pipe rotation in vertical and inclined wellbore walls under elevated temperature and pressure during deep drilling. Multiple tests validate the basic model for application in both shallow and deep drilling operations. By use of an Eulerian-Eulerian approach to describe drilling fluids as a binary-phase system, including particles in suspension in the non-Newtonian fluid, our research investigates the power-law and Herschel-Bulkley rheological models. These models successfully predict the flow pattern of drilling fluid at the bottom region of deep drilling operations. The study further explores filter-cake formation by examining the influence of overbalanced pressure on filter-cake thickness at various pressures. Drilling simulations, incorporating pipe rotation and eccentricity effects under realistic operating parameters, accurately project filter-cake thickness, aligning closely with experimental measurements and existing CFD literature in this domain.

Optimized synthesis of cysteine-functionalized nanocrystalline hydroxyapatite for synchronous decontamination of Cd(II) and Pb(II)

The synchronous removal of toxic heavy metals (e.g., cadmium (Cd), lead (Pb), and etc.) from the contaminated water environment is an urgent demand in the pollution control field. Herein, an innovative adsorbent synthesis idea was proposed and a series of cysteine-functionalized nanohydroxyapatite (CysHAP) composites were prepared by adopting different reaction temperatures, cysteine/HAP ratios, and synthesis methods. According to the single factor tests, a co-precipitation temperature of 25 °C with a molar cysteine/HAP ratio of 2.0 was selected to synthesize the optimum CysHAP2.0–25 composite. Multiple characterization results showed that cysteine markedly altered the morphology, crystallinity, and crystal structure of HAP, leading to the formation of CysHAP2.0–25 composite with a superior dispersity, a smaller crystal size, a higher specific surface area, and a greater number of binding sites. Compared with HAP-25, the CysHAP2.0–25 composite exhibited a better Cd(II) sorption performance and a 100% Pb(II) removal in a wide range of solution pH and background electrolyte concentration. The removal performance of CysHAP2.0–25 composite towards Cd(II) was suppressed by the coexisting aqueous components with an obviously stronger inhibiting action of humic acid (HA) than low molecular weight organic acids (LMWOAs) and mixed inorganic components (IC). Pb(II) slightly reduced the sorption ratio of Cd(II) and forced Cd(II) to bind on the -SOx sites derived from sulfhydryl oxidation. In contrast, Cd(II) had no impact on the sorption behaviors of Pb(II). Overall, the synthesized CysHAP2.0–25 composite could be potential applied for the purification of Cd- and Pb-bearing water systems.