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Background: Tea is one of most frequently consumed beverages in the world. Only in Iran, around 12000 tons of tea is annually used. Besides, green tea, which is made from Camellia sinensis leaves and buds, is very popular among people. Although teas have health benefits, since they may be much drunk, they may pose a threat to consumers’ health because of absorbing various ions in their leaves. Unfortunately, there are a limited number of studies on the health effects of green teas.Methods: It was a cross-sectional study performed in 2021. In this research, the concentrations of ions: fluoride (F), chloride (Cl), nitrate (NO3), sulfate (SO4), and phosphate (PO4) in the six bestselling green tea brands, both loose and bag, in Iran were detected by means of ion chromatography.Results: The highest amounts of F, Cl, NO3, SO4, and PO4 in the brands were found to be, respectively, in 0.27310, 0.62103, 0.83533, 1.28067, and 1.1037 mg/L. The concentrations of the ions in the both loose and bag tea samples were different significantly. Also, the content of F in the all samples was lower than those acceptable levels suggested by different organizations.Conclusion: It was found that the concentration of the ions was by far lower than those have been introduced as the standard levels. Nonetheless, the water used for tea infusion may contain high levels of these compounds and its volume drunk every day is also very important.

Simple Summary: This study was carried out to examine how different diets with vitamin solutions/vitamin premixes and plant oils (algae and fungi oils) affect the reproduction of Pangasius catfish broodstock, growth performance, and survival rates of fish larvae and fingerling. The experiment was designed as a factorial setup, with Pangasius catfish broodstock fed six different diets in triplicate groups of ten fish (three males and seven females) cultured in separate hapa nets in an the earthen pond for about two months. Results showed significant differences among the six tested diets. Diets containing 35% CP, supplemented with 0.6% vitamin solutions and 1.26% algal oil, produced the best results in terms of the highest growth performance, reproductive indices, and fingerling survival rates. These findings provide valuable information for Pangasius catfish farmers and the fish production industries in the Mekong Delta, Vietnam. This study evaluates the effect of different diets supplemented with vitamin solutions on Pangasius catfish broodstock reproduction, growth performances, and the survival rates of fish larvae and fingerling. The growth and reproductive performances of breeders fed with different test diets showed significant differences among the six tested diets (p < 0.05). The highest final body weight (FBW), weight gain (WG), daily weight gain (DWG), specific growth rate (SGR) of broodstock, and survival rate of Pangasius fingerlings were found in Treatment 5, which contained 0.6% H-OVN mixed with 12.6% algal oil, and Treatment 3, which contained 0.6% vitamin premix H-OVN. The average gonadosomatic index (GSI), relative fecundity index (RFI), fertilized eggs, hatching rates of eggs, and survival rate of fingerlings was 9.1 ± 2.8 (6.7–12.8%), 133,224 ± 39,090 (104,267–199,512 eggs/kg), 77.9 ± 22.2 (62.2–93.6%), and 45.3 ± 17.4 (22.0–66.3%), respectively. The findings of this study showed that the diet containing 35% CP contents supplemented with 0.6% vitamin premix H-OVN mixed with algal oils showed the highest results in terms of growth, reproductive performance indices, and survival rates of Pangasius catfish fingerlings. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the possibility of eliminating cadmium (Cd) from contaminated agricultural soil using a combination of microbial inoculants of Penicillium chrysogenum fungus and Bacillus licheniformis with Limnocharis flava plants. Limnocharis flava (L. flava) and microbial inoculants with four Cd levels, including 2.05 (T1 control), 5 (T2), 10 (T3), and 20 mg/kg (T4), respectively, were tested in green house conditions. Cd accumulation was evaluated to assess the safety limit of the Cd concentration in the edible parts of L. flava. The results showed that the application of the microbial inoculants facilitated the stress tolerance of the plants caused by a Cd accumulation in the soil matrix. The use of Penicillium chrysogenum and Bacillus licheniform in combination with L. flava increased the Cd accumulation in plant biomass. The total Cd after the experiment varied between 4.86 and 18.44 mg/kg in dry, clean soil, equivalent to reduction rates of 2.80, 4.40, and 7.80%, respectively. Meanwhile, the availability of Cd in soil was significantly reduced by 12.50, 13.04, 13.33, and 13.93%, respectively. Consequently, the microbial inoculants helped the plants to grow healthily, increased the yield, and reduced the total and available Cd content of contaminated agricultural land up to a concentration level of 5 mg/kg. [ABSTRACT FROM AUTHOR]

The abundance of heat-trapping asphalt and concrete, smog, and heat emitted from buildings and vehicles is one of the major reasons for the prevailing high temperature, air and noise pollution in cities. Incorporation of green wall in buildings is considered to be an effective method to reduce temperature and mitigate environmental pollution. This study investigated and compared the performance of two types of climbing green wall (CGW) and paving green wall (PGW) vegetation for temperature and noise reduction. Besides, the biological characteristics of Parthenocissus tricuspidata and Sedum lineare Thunb were also analyzed to substantiate the temperature and noise reduction performance of these plants. The results revealed that, the average temperature reduction by CGW and PGW were 4.9% ± 1.3% and 16.6% ± 7.4%, respectively, under no irrigation condition, and 18.4% ± 9.4% and 23.8% ± 8.7%, respectively, under irrigation condition. The noise reduction by CGW in high (75–80 dB), medium (50–55 dB) and low (30–35 dB) sound pressure level was 12.4, 7.5 and 5.7 dB, respectively, and 15.6, 9.3 and 7.0 dB, respectively, by PGW. The results demonstrated that green wall has an excellent effect on buildings toward temperature and noise pollution reduction. [ABSTRACT FROM AUTHOR]

The large number of vehicles plying in roads is the main cause of traffic jam and air pollution in Hanoi. In this study, the vehicle density and shares of different vehicle types, the traffic flow velocity and roadside air pollutants concentrations were monitored in Chua Boc street, a typical arterial road in the city. The shares of the motorcycle, car and bus fleets in the total on-road traffic in the street were 78.4-87.3, 12.3-20.2 and 0.4-1.4%, respectively. The high density of vehicles caused traffic jam during rush hours and considerably reduced the vehicle speed. The traffic flow velocity during non-rush and rush hours was found to vary from 26.4-34.5 and 10.3-12.1 km/h, respectively. The average concentrations of PM10, PM2.5, SO2, NO2, CO and NMVOC during the rush hours were the following: 117.1 ± 8.5, 65.2 ± 10.6, 113.5 ± 10.9, 138.5 ± 16.0, 6792 ± 998 and 451 ± 71 µg/m3, respectively, which were about 1.9-2.6 times above the levels during non-rush hours. The decrease in vehicle speed during rush hours were strongly correlated with the increase in concentration of PM10 (R2 = 0.732), PM2.5 (R2 = 0.685), SO2 (R2 = 0.578), NO2 (R2 = 0.738), CO (R2 = 0.689) and NMVOC (R2 = 0.747). High levels of these toxic air pollutants in Hanoi city posed a high health risk to humans. Facemask use was more popular among the motorcycle commuters and pedestrians, especially during rush hours, than among the people working for extended time period alongside of the street. [ABSTRACT FROM AUTHOR]

The increasing intensification of aquaculture systems requires the development of strategies to reduce their environmental impacts such as pollution caused by the discharge of nutrient rich sediments into local water bodies. Recycling of fish pond sediments (FPS) as fertilizer has been proposed as a possible solution that may also reduce the reliance on synthetic fertilizers. With a case study in the Mekong Delta, Vietnam, we determined suitable mixtures of striped catfish (Pangasianodon hypophthalmus) pond sediment (PPS) and locally sourced organic amendments of rice straw (RS), or common water hyacinth (WH) to fertilize cucumber plants (Cucumis sativus L.) in an integrated cucumber–giant gourami fish (Osphronemus goramy) farming system. Highest nutrient concentrations were found when mixing 30% PPS with 70% RS or WH. When used in combination with chemical fertilizer, it was found that a 25% to 75% reduction in chemical fertilizer application could be achieved, while also increasing cucumber yields, with the highest yields found when RS was used in organic amendments. In combination with the additional income from fish production, integrated farming systems such as that demonstrated in this study, may increase both farm income and production diversity. [ABSTRACT FROM AUTHOR]

This novel study on cement paste material was conducted with the aim of keeping up with the rapid development of urban construction and contributing to the continuous improvement of building materials to overcome environmental issues. In this study, several kinds of industrial waste were used to enhance the properties of cement paste for application in a marine environment with a tropical climate, such as in Vietnam. This study focuses on evaluating the properties of cement paste containing cement replacement combining 0–30% fly ash, 0–10% silica fume, and plasticizer accounting for 0.3% and 0.4% of the binder by mass. Water demand, chloride ion and sulfate ion permeability, and microstructural properties of the cement paste were determined by thermogravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscope (SEM) and they were investigated after 28 and 56 days. The test results show that an optimum mixture could be obtained with the use of 20% fly ash, 10% silica fume (replacing Portland cement), and 0.4% plasticizer. The application of such materials to sea dikes affected by a tropical climate (characterized by heat, humidity, salty seawater, many big storms, large waves, and strong tides) was investigated for four years on the Vietnamese coast. The test results indicate that fly ash and silica fume can improve the corrosion and abrasion resistance of concrete in coastal areas with a tropical climate, such as in Vietnam. [ABSTRACT FROM AUTHOR]

The current study was performed with an aim to investigate the performance of ecological revetments implemented on the bank of the Cuatien River in Vinh city, Vietnam. Based on the ecological, topographical, and hydrological conditions of the Cuatien River, the gabion and riprap models were introduced to investigate the effect of ecological revetment on the slope stability and ecological restoration characteristics. The effect of prevailing climatic indicators, such as temperature, precipitation, sunlight hours, and humidity were investigated to ascertain the characteristics of weather conditions on the subtropical area. On the surface soil layer of the gabion and riprap, the nutrient indicators of soil organic matter (SOM) and available nitrogen (AN) increased in the spring, summer, and winter, but decreased in autumn, and available phosphorus (AP) did not show an obvious change in the four seasons. The biomass growth rate of Vetiver grass on the gabion and riprap revetments was found to be the highest during the summer, at 15.11 and 17.32 g/month, respectively. The root system of Vetiver and other native plants could increase the cohesion of soil. After 6 and 12 months, the shear strength of the soil behind the gabion revetment increased by 59.6% and 162.9%, while the shear strength of the soil under the riprap also increased by 115.6% and 239.1%, respectively. The results also indicated that the gabion and riprap revetments could improve the river water purification effect and increase the ecological diversity in the region. In the current study, 26 floral and 9 faunal species were detected in the riprap revetment, whereas 14 floral and 5 faunal species were detected in the gabion revetment, respectively. Through high sequencing technology, the number of bacterial species in the present study was found to be 198, 332, and 351 in the water, gabion, and riprap samples, respectively. [ABSTRACT FROM AUTHOR]

The non-treated wastewater from residential areas contains high concentrations of ammonium-nitrogen (NH 4 + -N). When discharged into the drainage water system, it deteriorates the water quality in urban rivers. This study used two types of materials to form eco-bags, using activated zeolite bead (AZB) and alkaline pretreated straw (APS), in geotextile bags for easy recovery and reuse. The AZB and APS provided the breeding habitat for the microorganisms that promoted biofilm formation on their surface. The immobilization of engineered denitrification microorganisms facilitated the removal of NH 4 + -N from the urban river water. The NH 4 + -N removal in the AZB and APS bags were in the range of 64-73%, and 56-61%, respectively, while the chemical oxygen demand (COD) removal in the AZB and APS bags ranged from 33-36%, and 30-31%, respectively. In addition, as evident from DNA and microbial community analysis, the microorganisms demonstrated a greater proclivity to grow and proliferate on the surface of AZB and APS and improved the water quality of urban rivers.

Common porous concrete templates (CPCT) and advanced porous concrete templates (APCT) were employed in this study to construct wetlands for their applications in pollutant removal from storm runoff. The planting ability of the concrete was investigated by growing Festuca elata plants in them. Strength of the porous concrete (7.21 ± 0.19 Mpa) decreased by 1.8 and 4.9% over a period of six and 12 months, respectively, due to its immersion in lake water. The height and weight of Festuca elata grass growth on the porous concrete were observed to be 12.6-16.9 mm and 63.4-95.4 mg, respectively, after a duration of one month. Advanced porous concrete template based constructed wetland (APCT-CW) showed better removal of chemical oxygen demand (COD) (49.6%), total suspended solids (TSS) (58.9), NH 3 -N (52.4%), total nitrogen (TN) (47.7%) and total phosphorus (TP) (45.5%) in storm water, when compared with the common porous concrete template based constructed wetland (CPCT-CW) with 20.6, 29.8, 30.1, 35.4 and 26.9%, respectively. The removal of Pb, Ni, Zn by the CPCT-CW unit were 28.9, 33.3 and 42.3%, respectively, whereas these were 51.1, 62.5 and 53.8%, respectively, with the APCT-CW unit. These results demonstrate that the advanced porous concrete template in constructed wetland could be employed successfully for the removal of pollutants from urban storm water runoff.