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An accurate assessment of the recommended calcium (Ca) intake may contribute to reducing the risk of fractures and chronic diseases, ultimately improving quality of life. This review was performed to summarize key findings of Ca studies, investigate the effect of Ca intake on health outcomes, and determine the adequacy of evidence to revise the 2015 Dietary Reference Intakes for Koreans (KDRIs) for Ca in 2020. Databases were searched for intervention studies that assessed health outcomes by providing Ca in diets or as supplements. The framework of the systematic review comprised conducting literature searches, data extraction, quality assessment of the literature, and summarizing key findings relevant to set the Estimated Average Requirement (EAR) and Tolerable Upper Intake Level (UL) for Ca for the 2020 KDRI. The final search was performed in June 2019. A total of 13,309 studies were identified through databases and manual search. Sixtyfive studies were included in the final quality assessment and were summarized according to health indicators. As bone health was used as an indicator of the EAR for Ca, literature reports on bone health were further categorized by the life-cycle stage of the participants. This systematic review did not find new evidence that could be applied to the general Korean adult population, including postmenopausal women, for defining a new EAR for Ca in the 2020 KDRIs. Evidence in most of the reviewed literature was considered weak; however, some evidence was found that could improve the criteria on how the EAR for Ca was determined in children and adolescents. A review of the literature for the 2020 KDRIs for Ca did not find strong evidence in order to change the recommended values of the 2015 KDRIs. More clinical interventions are required among Koreans to strengthen the body of evidence to warrant the revision of the KDRIs.
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The UV/Cl2 process (also known as chlorine photolysis, which is the combination of chlorine and simultaneous irradiation of UV light) is conventionally applied at acidic mediums for drinking water treatment and further treatment of wastewater effluents for secondary reuse. This is because the quantum yield of HO⢠from HOCl (ÏHOâ¢, 254â¯=â¯1.4) is greater than the one from OCl- (ÏHOâ¢, 254â¯=â¯0.278) by approximately 5 times. Moreover, chlorine photolysis in acidic mediums also tends to have lower radical quenching rates than that of their alkaline counterparts by up to 1000 times. The aim of this research is to investigate the applicability of the UV/Cl2 process by assessing its efficacy on the removal of trimethoprim (TMP) at not only acidic to neutral conditions (pH 6-7), but also alkaline mediums (pH 8-9). At alkaline pH, free chlorine exists as OCl- and since OCl- has a higher molar absorption coefficient as compared to HOCl at higher wavelengths, there would be higher reactive chlorine species (RCS) formation and contribution. TMP removal followed pseudo-first order kinetics and depicted that a maximum fluence based constant (kf' = 0.275 cm2/mJ) was obtained using 42.25 µM (3 mg/L) of chlorine at pH 9, with an irradiation of 275 nm. At alkaline conditions, chlorine photolysis performance followed the trend of UV (275)/Cl2 > UV (265)/Cl2 > UV (310)/Cl2 > UV (254)/Cl2. RCS like Clâ¢, Cl2-⢠and ClO⢠contributed to the degradation of TMP. When the pH was increased from 6 to 8, contribution from hydroxyl radicals (HO⢠) was decreased whilst that of RCS was increased. Application of UV (310)/Cl2 had the highest HO⢠generation, contributing to TMP removals up to 13% to 48% as compared to 5% to 27% in UV (254, 265, 275)/Cl2 systems at pH 6-9. Artificial neural networks modelling was found to be able to verify and predict the contribution of HO⢠and RCS conventionally calculated via the general kinetic equations in the UV/Cl2 system at 254, 265, 275 and 310 nm.
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Poluentes Químicos da Água , Purificação da Água , Cloro , Cinética , Redes Neurais de Computação , Oxirredução , Trimetoprima , Raios UltravioletaRESUMO
As the marine industry develops, the importance of seawater treatment process is increasing. To treat seawater, oxidation processes have primarily been used, such as ballast water treatment systems, aquaculture farm operations, aquarium management, and seawater desalination. However, dissolved organic matter in seawater, whose characteristics vary spatially and seasonally, affects the efficiency of oxidation processes. Therefore, in this study, seawater samples were acquired from various locations in the Republic of Korea to understand the spatio-temporal patterns of marine dissolved organic matter. It was reported that the characterization of marine dissolved organic matter using liquid chromatography-organic carbon detector and excitation-emission matrix-parallel factor modeling. Furthermore, the effects of marine dissolved organic matter were evaluated on ozonation, an oxidation process. The results demonstrate that marine dissolved organic matter varies in its aquagenic, pedogenic, and intermediate characteristics based on region and season. These variations affect ozonation by influencing the consumption of oxidants (e.g., bromine). As a result, it was concluded that characterizing marine dissolved organic matter can help improve the effectiveness of oxidation processes, particularly ozonation.
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Ozônio , Purificação da Água , Aquicultura , República da Coreia , Água do Mar , Espectrometria de FluorescênciaRESUMO
Taurine is a free amino acid and exhibits various biological functions such as brain development, retinal photoreceptor activity, reproduction, normal growth development and antioxidant activity. Taurine is mainly contained in meat and fish foods. Although taurine is inferred to be implicated in the development of the fetus, there are few reports of taurine intake and neonatal growth in pregnant women. Therefore, the purpose of this study was to evaluate the nutrient and taurine intake of pregnant women during the late gestation period using the food intake frequency method. The study was approved by the Institutional Review Board of the Keimyung University. The daily taurine intake of the pregnant women was 104.2 mg. The daily taurine intakes of the pregnant women were divided into three groups for analysis; low, middle, high (<60 mg, 60-120 mg, and >120 mg). The body weight of the top taurine group (3.37 kg) was significantly higher than that of the low and middle groups (3.16 kg, 3.20 kg). Also, the heights of the infants were 49.9 cm, 49.8 cm, and 51.1 cm for each group, showing significantly high measure in the group of taurine intake more than 120 mg/day. There was a positive correlation between the taurine intake of the pregnant women and the height of the newborns. In conclusion, weight and height at birth were significantly higher in the high taurine intake group of the pregnant women. There was a positive correlation between maternal taurine intake and birth length.
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Dieta , Fenômenos Fisiológicos da Nutrição Materna , Taurina/administração & dosagem , Animais , Estatura , Peso Corporal , Feminino , Peixes , Humanos , Recém-Nascido , Carne , GravidezRESUMO
Hydroxyl radical (â¢OH) water demand is a key parameter which impacts the design and operation of UV/H2O2 process for water treatment. Long-term monitoring of the â¢OH water demand in water sources used for drinking water production indicated significant seasonal variations of this parameter (1.59 × 104 to 4.98 × 104 s-1), which coincided with the occurrence of algal blooming events. Pilot-scale tests at a drinking water treatment plant confirmed that the UV/H2O2 process performance for contaminant removal is predictable when the â¢OH water demand is accurately determined through a validated experimental method. A predictive tool was developed to identify the optimum operating conditions of the UV system with the UV/H2O2 process and it was used to demonstrate the significant impact of seasonal variations of â¢OH water demand on the operating costs.
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Água Potável , Poluentes Químicos da Água , Purificação da Água , Peróxido de Hidrogênio , Oxirredução , Raios UltravioletaRESUMO
The seed of Moringa oleifera (MO) is a well-known coagulant used in water and wastewater treatment, especially in developing countries. The main mechanism of MO seed extract in coagulation is the positive protein component for charge neutralization. The method for efficient extraction of MO seed is very important for high coagulation activity. In this study, the effects of extraction mixing speed and extraction time of MO on coagulation activity were evaluated using a distilled water extraction method. Although the rotation per minute for extraction did not affect the coagulation efficiency, the extraction time strongly affected the coagulation efficiency of the extract. To evaluate the characteristic change of MO extract by extraction time, the charge of MO extract and protein characteristic in MO extract were analysed. As the extraction time was short, more positive charge and higher protein content were observed. For detailed protein analysis, the fluorescence spectroscopic study (EEM analysis) was performed. The tryptophan-like peak increased at longer extraction times. For efficient extraction of MO seed, a short extraction time is strongly recommended.
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Moringa oleifera/química , Extratos Vegetais/química , Eliminação de Resíduos Líquidos/métodos , Sementes , Águas Residuárias/química , Poluentes da Água/químicaRESUMO
The aim of this study was to investigate the reactivity of intracellular algogenic organic matter (IOM) with hydroxyl radicals (·OH), a key reaction species in advanced oxidation processes. IOM was extracted from two green algae, Chlamydomonas reinhardtii and Scenedesmus sp., and two blue-green algae, Anabaena sp. and Microcystis aeruginosa using a freeze-thaw method. The second-order rate constants of the extracted IOM with ·OH were determined as 7.95â¯×â¯108 MC-1 s-1 (Chlamydomonas reinhardtii), 6.71â¯×â¯108 MC-1 s-1 (Scenedesmus sp.), 4.02â¯×â¯108 MC-1 s-1 (Anabaena sp.), and 4.45â¯×â¯108 MC-1 s-1 (Microcystis aeruginosa). These rate constants were significantly higher than values reported for dissolved organic matter in various water sources. This implies that IOM formation during algal bloom season could change the ·OH water matrix demand and adversely affect the performance of advanced oxidation processes. To investigate the physical and chemical composition characteristics of IOM and their relationship to the rate constants determined for the reaction between IOM and ·OH, liquid chromatography-organic carbon detection (LC-OCD) and fluorescence excitation-emission matrix & parallel factor analysis (FEEM-PARAFAC) were used. The IOM mainly consisted of low molecular weight (LMW) matter and protein-related compounds, as evidenced LMW neutrals (38-65%), biopolymers (7-19%), and tryptophan-like compounds (74-94%). Based on the composition characteristics of IOM, it was concluded that the molecular weight and the presence of nitrogen-containing compounds are influential parameters for determining the reactivity of IOM with ·OH.
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Cianobactérias/química , Eutrofização , Radical Hidroxila/química , Scenedesmus/química , Chlamydomonas reinhardtii/química , Cromatografia Líquida/métodos , Substâncias Húmicas/análise , Microcystis/química , Peso Molecular , Oxirredução , Espectrometria de Fluorescência/métodos , Triptofano/química , Água , Purificação da Água/métodosRESUMO
The aim of this study is to evaluate the micropollutant removal capacity of a 275â¯nm light-emitting diode (LED)-UV/chlorine system. The sulfamethoxazole, ibuprofen, and nitrobenzene removal efficiencies of this system were compared with those of a conventional 254â¯nm low-pressure (LP)-UV system as a function of the UV dose. In a direct photolysis system, the photon reactivity of sulfamethoxazole is higher than that of nitrobenzene and ibuprofen at both wavelengths. The molar absorption coefficients and quantum yields of each micropollutant were as follows: sulfamethoxazole (εSMX, 275 nmprotonatedâ¯=â¯17,527â¯M-1â¯cm-1, ΦSMX, 275 nmprotonatedâ¯=â¯0.239, εSMX, 275 nmdeprotonatedâ¯=â¯8430â¯M-1â¯cm-1, and ΦSMX, 275 nmdeprotonatedâ¯=â¯0.026), nitrobenzene (εNB, 275 nmâ¯=â¯7176â¯M-1â¯cm-1 and ΦNB, 275 nmâ¯=â¯0.057), and ibuprofen (εNB, 275 nmâ¯=â¯200â¯M-1â¯cm-1 and ΦIBF, 275 nmâ¯=â¯0.067). The photon reactivity of chlorine species, i.e., HOCl and OCl-, were determined at 275â¯nm (εHOCl, 275 nmâ¯=â¯28â¯M-1â¯cm-1, ΦHOCl, 275 nmâ¯=â¯1.97, εOCl-, 275 nmâ¯=â¯245â¯M-1â¯cm-1, and ΦOCl-, 275 nmâ¯=â¯0.8), which indicate that the decomposition rate of OCl- is higher and that of HOCl is lower by 275â¯nm photolysis than that by 254â¯nm photolysis (εHOCl, 254 nmâ¯=â¯60â¯M-1â¯cm-1, ΦHOCl, 254 nmâ¯=â¯1.46, εOCl-, 254 nmâ¯=â¯58â¯M-1â¯cm-1, and ΦOCl-, 254 nmâ¯=â¯1.11). In the UV/chlorine system, the removal rates of ibuprofen and nitrobenzene were increased by the formation of OH and reactive chlorine species. The 275-nm LED-UV/chlorine system has higher radical yields at pHâ¯7 and 8 than the 254â¯nm LP-UV/chlorine system.
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Cloro/química , Ibuprofeno/química , Nitrobenzenos/química , Sulfametoxazol/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Cloretos , Cloro/análise , Ibuprofeno/análise , Nitrobenzenos/análise , Sulfametoxazol/análise , Raios Ultravioleta , Poluentes Químicos da Água/análiseRESUMO
Ozonation is an effective treatment for removing various organic pollutants from aquatic systems. The Rct concept, which is defined as the ratio of OH exposure to O3 exposure, has been widely used to predict the removal efficiency of target compounds, but it has significant variations by water temperature and initial O3 dose which are crucial parameters in drinking water plant. The ROH,O3 concept, which is defined as the OH exposure by O3 consumption, was proposed as a kinetic parameter for characterization and kinetic modeling for ozonation. The ROH,O3 concept is independent of temperature and initial O3 dose. A higher ROH,O3 value indicates a higher OH formation when the same amount of O3 is consumed in different water samples; therefore, the OH yield from O3 decomposition of the water samples can be compared using the ROH,O3 values. The ROH,O3 concept can also be used to characterize and model the initial ozone demand phase, and it is more convenient method compared to Rct concept. Using the ROH,O3 concept, the dynamic O3 and OH kinetics and the removal efficiencies of iopromide and ibuprofen were well predicted (R2 = 0.98) over a wide range of experimental conditions (n = 124).
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Ozônio , Purificação da Água , Radical Hidroxila , Cinética , Oxirredução , Poluentes Químicos da ÁguaRESUMO
The objective of this study was to investigate the association of nutrient intake and pregnancy outcome mediated by weight gain during pregnancy, job status, and household income. Maternal age, educational level, self-reported pre-pregnancy weights, educational level, and household income were collected from the women at 2 months postpartum. For each offspring, weight at birth, length at birth, and gestational age were collected. Participants were asked to report the frequency of consumption of foods between 28-42 weeks into the pregnancy. Diet was assessed by using a validated 106-item semi-quantitative food-frequency questionnaire (SQFFQ) and women were asked portions and quantities based on pictures, food models, and measuring tools such as cups or teaspoons. Results showed that women who gained below the recommended weight gain during pregnancy, within, and over were 25.3%, 38.7%, 36.0%, respectively. In comparison to weight gain and the offspring's length and weight at birth, the offspring of mothers with a lower weight gain had a higher length. Energy, protein, vitamin B2, vitamin C, calcium, and potassium were significantly lower at employed group. We did not observe a significant difference between birth characteristics and maternal nutrient intake by income. Infants with a higher ponderal index at birth were born to women with a higher pre-pregnancy body mass index (BMI).
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The aim of this study was to evaluate the formation of oxidants and by-products by using different electrode materials, such as Pt/Ti, RuO2/Ti, and IrO2/Ti, in the electrochemical process. The harmful by-products ClO3- and ClO4- were formed during the electrolysis of a Cl- electrolyte solution, as well as active chlorine, which is the most common water disinfectant. With regard to drinking water treatment, the most efficient electrode was defined as that leading to a higher formation of active chlorine and a lower formation of hazardous by-products. Overall, it was found that the Pt/Ti electrode should not be used for drinking water treatment applications, while the IrO2/Ti and RuO2/Ti electrodes are ideal for use.
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Cloro/isolamento & purificação , Eletrodos , Irídio/química , Platina/química , Compostos de Rutênio/química , Titânio/química , Cloro/química , Eletroquímica/instrumentação , Eletroquímica/métodos , Desenho de Equipamento , Análise de Falha de Equipamento , Teste de Materiais , Oxidantes/síntese química , Oxirredução , Purificação da Água/instrumentaçãoRESUMO
Since ballast water affects the ocean ecosystem, the International Maritime Organization (IMO) sets a standard for ballast water management and might impose much tighter regulations in the future. The aim of this study is to evaluate the inactivation efficiency of ozonation, electrolysis, and an ozonation-electrolysis combined process, using B. subtilis spores. In seawater ozonation, HOBr is the key active substance for inactivation, because of rapid reactivity of ozone with Br(-) in seawater. In seawater electrolysis, it is also HOBr, but not HOCl, because of the rapid reaction of HOCl with Br(-), which has not been recognized carefully, even though many electrolysis technologies have been approved by the IMO. Inactivation pattern was different in ozonation and electrolysis, which has some limitations with the tailing or lag-phase, respectively. However, each deficiency can be overcome with a combined process, which is most effective as a sequential application of ozonation followed by electrolysis.
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Desinfecção/métodos , Oxidantes Fotoquímicos/toxicidade , Ozônio/toxicidade , Água do Mar/microbiologia , Navios , Esporos Bacterianos/efeitos dos fármacos , Purificação da Água/métodos , Bacillus subtilis/efeitos dos fármacos , Bacillus subtilis/fisiologia , Eletrólise , Viabilidade MicrobianaRESUMO
Effects of various electrodes and prefiltration to minimize disinfection byproducts (DBPs) in electrochemical water disinfection was evaluated. The target microorganism, Escherichia coli O157:H7, was effectively inactivated even applying a solar-charged storage battery for the electrolysis process. Extent of microbial inactivation decreased with lower water temperature and higher pH in the free chlorine disinfection system. The RuO2/Ti electrode was most efficient because it produced the lowest concentration of chlorate and the highest generation of free chlorine. Prefiltration using a ceramic filter inhibited formation of halogenated DBPs because it removed precursors of DBPs. For safe point-of-use water treatment, the use of a hybrid prefiltration stage with the electrolysis system is strongly recommended to reduce risks from DBPs. The system is particularly suited to use in developing regions.
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The aim of this study is to evaluate the removal efficiency of iopromide using electron beam (E-beam) irradiation technology, and its degradation characteristics with hydroxyl radical (OH) and hydrated electron (e(aq)(-)). Studies are conducted with different initial concentrations of iopromide in pure water and in the presence of hydrogen peroxide, bicarbonate ion, or sulfite ion. E-beam absorbed dose of 19.6 kGy was required to achieve 90% degradation of 100 µM iopromide and the E-beam/H(2)O(2) system increased the removal efficiency by an amount of OH· generation. In the presence of OH scavengers (10 mM sulfite ion), the required dose for 90% removal of 100 µM iopromide was only 0.9 kGy. This greatly enhanced removal was achieved in the presence of OH· scavengers, which was rather unexpected and unlike the results obtained from most advanced oxidation process (AOP) experiments. The reasons for this enhancement can be explained by a kinetic study using the bimolecular rate constants of each reaction species. To explore the reaction scheme of iopromide with OH· or e(aq)(-) and the percent of mineralization for the two reaction paths, the total organic carbon (TOC), released iodide, and intermediates were analyzed.