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关键词： Constructed wetlands   Personal care products   Pharmaceuticals   Physicochemical properties   Predictive models   Steroidal hormones  

摘要： This study investigates the prediction of the removal efficiency of emerging organic contaminants (EOCs) (pharmaceuticals-PhCs, personal care products-PCPs, and steroidal hormones-SHs) in constructed wetlands based on their physicochemical properties (e.g., molecular weight-MW, octanol-water partition coefficient-Log Kow, soil organic carbon sorption coefficient-Log Koc, octanol-water distribution coefficient-Log Dow, and dissociation constant-pKa). The predictive models are formed based on statistical analysis underpinned by principle component, correlation, and regression analyses of a global data set compiled from peer-reviewed publications. The results show that the physicochemical properties of EOCs emerged as good predictors of their removal efficiency. Log Koc, Log Dow, and Log Kow are the most significant predictors, and combination with MW and/or pKa often improved the reliability of the predictions. The best performing model for PhCs was composed of MW, Log Dow, and Log Koc (coefficient of determination-R2: 0.601;probability value-p < 0.05;root mean square error-RMSE: training set: 11%;test set: 27%). Log Kow and Log Koc for PCPs (R2: 0.644;p < 0.1;RMSE: training set: 14%;test set: 14%), and a combination of MW, Log Kow, and pKa for SHs (R2: 0.941;p < 0.1;RMSE: training set: 3%;test set: 15%) formed the plausible models for predicting the removal efficiency. Similarly, reasonably good combined models could be formed in the case of PhCs and SHs or PCPs and SHs, although their individual models were comparatively better. A novel decision support tool, named as REOCWPCP, was developed to readily estimate the removal efficiency of EOCs, and facilitate the decision-making process.

关键词： Bioremediation   Physicochemical remediation   Actinobacteria   Fe nanoparticles   Co-contamination  

摘要： A restoration strategy was developed for the treatment of two artificial liquid systems (Minimal Medium, MM, and Water Carbon Nitrogen, WCN) contaminated with Cr(VI), lindane (gamma-HCH), phenanthrene (Phe), and reactive black 5 (RB5), through the use of an actinobacteria consortium, coupled with a physicochemical treatment using a column filled with nano-scale zero valent iron particles immobilized on dried Macrocystis pyrifera algae biomass. The Sequential Treatment A (STA: physicochemical followed by biological method) removed the three organic compounds with different effectiveness;however, it was very ineffective for Cr(VI) removal. The Sequential Treatment B (STB: biological followed by the physicochemical method) removed the four compounds with variable efficiencies. The removal of gamma-HCH, Phe, and RB5 in both effluents did not present significant differences, regardless of the sequential treatment used. The highest removal of Cr(VI) and total Cr was observed in MM and WCN, respectively. Ecotoxicity tests (L. sativa) of the effluents treated with both methodological couplings demonstrated that the toxicity of WCN only decreased at the end of STA, while that of MM decreased at all stages of both sequential treatments. Therefore, MM would be more appropriate to perform both treatments.

关键词： Computer simulation   Doping   Diffusion   Point defects   Single crystal growth   Sapphire  

摘要： An original physico-chemical model is proposed that accounts for the conversion mechanism between Ti3+ and Ti4+ during Ti:sapphire crystal growth process. This model involves release of O-2 from the crystal surface, which consumes aluminum vacancies. Consequently, these vacancies diffuse from the bulk crystal toward the surface, leading to the conversion of Ti4+ into Ti3+. A set of mass balance differential equations is established for these chemical species, taking into account diffusion and chemical reaction. The boundary condition for concentration of aluminum vacancies on crystal surface is given as the function of P-O2 and temperature. A preliminary numerical simulation is performed to study the proposed model, using COMSOL Multiphysics (R) software. The obtained radial concentration distribution profiles of Ti3+ and Ti4+ are in qualitative agreement with the experimental results, showing that the proposed model has potential for further studying point defect reactions during crystal growth of ionic crystals.

关键词： Hydroxyapatite   Vanadium   Methylene blue   Optical   Dye degradation  

摘要： Degradation of pollutants, including organic dyes via photocatalysis technique, has attracted great concern last decade. Thus, modified hydroxyapatite (HAP) with vanadate ions (VO43-) has been fabricated using the co-precipitation method at different vanadate contributions. The obtained compositions have been investigated upon their structure, morphology, and optical properties. The structural calculations indicated that a-axis increased from 9.483 to 9.562 angstrom for the lowest and the highest additional vanadate ions. Moreover, the average roughness developed from 30.5 to 56.3 nm upon the vanadate insertion. Moreover, the direct bandgap decreased from 3.9 to 3.82 eV upon the additional vanadate ions, while the refractive index increased slightly from 1.86 to 1.87. Further, the removal of methylene blue through aqueous solutions has been examined and showed that the removal effectiveness increased from 89.3 to 97.2% after 120 min of irradiation using visible light. These modified HAP crystals could encourage their utilization for potential applications incusing water treatment, besides their usages for biomedical applications. (C) 2021 Elsevier B.V. All rights reserved.

关键词： Biocompatibility  

摘要： Calcium phosphate cement (CPC), which exhibits excellent biocompatibility and bioactivity, is a well-established material for the repair of bone defects. However, its disadvantages such as poor washout resistance and low mechanical strength limit its clinical applications. In this study, CPC with enhanced washout resistance and mechanical properties has been developed by the in situ crosslinking of glycidyl methacrylate modified gamma-polyglutamic acid (m-PGA) within the cement matrix, forming an interpenetrating network. Compared with unmodified CPC, the final setting time of the composite cements was shortened and its washout resistance was significantly improved. In addition, the composite cements showed enhanced mechanical strength and degradation properties. An in vitro study demonstrated that the composite cements exhibited good biocompatibility. The in vivo results showed that the composite cements promoted bone formation. These results suggest that the biocompatible, injectable alpha-tricalcium phosphate (alpha-TCP)/m-PGA cements may have the potential to be used as bone filling materials for future clinical applications.

关键词： Binary mixtures   Alcohols   Liquids   Sound velocity   Mixtures  

摘要： In this paper, experimental values of densities, speeds of sound, and refractive indices in a temperature range of 293.15-323.15 K have been measured as a function of composition for the binary liquid mixtures of 1,2-dimethoxyethane with alcohols such as methanol, propan-1-ol, propan-2-ol, and butan-2-ol. From these experimental values, excess/derived properties such as excess molar volume, isentropic compressibility, deviation in isentropic compressibility, and deviation in the refractive index have been calculated. Excess/derived properties have been correlated using the Redlich-Kister equation and physicochemical properties modeled using the cubic plus association equation of state for pure and binary mixtures. The results are interpreted with respect to possible molecular interactions between components.

关键词： Maltodextrin   pomegranate juice powder   spray drying   total phenolic compounds  

摘要： Pomegranate juice powder could be applied as a valuable ingredient in other food and pharmaceutical products and be accessible throughout the year. In this research, pomegranate juice was spray dried at three maltodextrin levels (25, 35 and 45% w/w) and two inlet air temperatures (124 and 143 degrees C) and physicochemical and nutritional characteristics of the powder in terms of moisture content, pH value, ash content, color values, total phenolic compounds, along with microstructural properties of the pomegranate juice powders were analyzed. Inlet air temperature just could affect ash content of the powder while maltodextrin level could influence all properties of the final powder. SEM analysis revealed that lower maltodextrin levels and higher inlet air temperatures resulted in smaller but smoother particles. In conclusion, pomegranate juice powders produced at 25% maltodextrin level and 143 degrees C, with a low moisture content of 3.19%, high ash content of 0.58%, safe pH value of 3.4 and considerable total phenolic compounds of around 903 mg gallic acid/g db, are suitable and nutritionally-rich choices for industrial production.

关键词： cell-bound exopolysaccharide   Limosilactobacillus   antioxidant   intestinal epithelial cells   gene expression  

摘要： This study investigated the physicochemical characteristics and antioxidative role of novel acidic cell-bound exopolysaccharide (EPS-b) from probiotic Limosilactobacillus fermentum (MTCC 5898) and gained an insight into the structure-function relationship. The physicochemical analysis of EPS-b isolated by ultrasonication method revealed a heteropolysaccharide molecule with an average MW of 96.97 kDa composed of glucose and galactose subunits present in random-coiled conformation. Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) analyses further supported the observation and indicated the presence of alpha-(1 -> 6) linkages. The analyses implicated the significant influence of structural features on the antioxidative activity of EPS-b by showing remarkable ABTS scavenging, reducing, and metal chelating potential with increasing concentration. Besides, the EPS-b by its scavenging potential also maintained the oxidative balance in the Caco-2 cells under oxidative stress and preserved the cellular antioxidative defense system (CAT, GPx, SOD, HO1, and GCLC) at the basal level.

关键词： Starch  

摘要： Non-thermal plasma treatment is an emerging and effective starch modification technique. In this paper, plasma pretreatment was used to modify citrate naked barley starch for enhancing the ability of citric acid to access the starch structure. Plasma treatment did not alter the granule morphology and crystalline type of starch, but degraded the starch molecules and caused more short chains. Plasma pretreatment could etch the starch surface and depolymerize the starch molecules, which increased the accessibility of citric acid for uniform hydrolysis in the subsequent esterification reaction. Therefore, plasma pretreatment significantly promoted the structural and physicochemical modification of the citrate starch, including the enhancement of the degree of substitution, the short-range ordered degree and gelatinization temperatures, and the decreases in the molecular weight, long chains of amylopectin and pasting viscosities. Meanwhile, plasma pretreatment improved the efficiency of acid hydrolysis and decreased the enzymatic digestibility, so that it showed a higher resistant starch content in comparison with its corresponding citrate starch. This paper could provide a new insight into the lower digestion rate and improved functional properties of citrate starch.

关键词： Iron ore tailings   Concrete waste   Sludge from anodizing aluminum process   Lime production waste   Structure formation processes   Sustainable construction materials  

摘要： To replace completely natural raw materials were developed new sustainable concrete-like construction composites from 10 -40% iron ore tailings, 10-35% aluminum anodizing sludge, 25-30% concrete waste, and 15-25% lime production waste with mechanical and physical properties that meet the requirements of the Brazilian standards. The composition's axial compression resistance reached 4.49 MPa on the 3rd day and 11.24 MPa on the 730th day of cure. All mechanical, physical, and chemical properties of newly developed composites from these industrial wastes met Brazilian standards for producing construction materials like ecological. Dilatation coefficient values varied between 0.95 and 2.35% on the 3rd day of cure, and it ranged from 1.35 to 2.05% on the 730th day. The apparent specific mass increased during two years from 3.38 -3.67% to 3.47-3.75. Such properties met the requirements of Brazilian standards for producing sustainable road bases, bricks, and blocks. The studies of structure formation processes during 730 days of outdoor cure showed the synthesis of mainly amorphous sol-gel new formations with a slight inclusion of crystalline carbonate content. The main novelty of this research study is the scientifically and experimentally proven possibility to produce new environmentally clean construction composites only from four types of hazardous industrial waste to replace traditional natural raw materials like sand, gravel, crushed stone. The use of this laboratory study's results at the industrial level will reduce the irreversible destruction of nature by quarries of construction materials, noticeably improving our planet's sustainability. (c) 2021 Elsevier Ltd. All rights reserved.