Abstract In this study, a nanocomposite, Fe 3 O 4 /Fe‐Mn binary oxide/bentonite (FFMB), was synthesized, characterized and evaluated its adsorption behavior of azo Reactive Red 195 dye (RR‐195) in ...aqueous solution. The results of characterization (X‐ray diffraction, Fourier transform infrared spectroscopy, field emission scanning and transmission electron microscopies, vibration‐sample magnetometer, etc.) demonstrate that FFMB consists of Fe 3 O 4 core and Fe 2 O 3 ‐MnO 2 binary oxide shell, which are distributed relatively uniformly on the exfoliated bentonite support with BET surface area of about 188 m 2 g −1 . It exhibits superparamagnetic properties with saturation magnetization of 39.6 emu g −1 . The results of batch adsorption experiments show that the material has high ability of RR‐195 adsorption in terms of both adsorption rate and capacity. The adsorption efficiency was highest at pH 2–3. The adsorption process followed the pseudo‐second‐order kinetics and Langmuir isotherm models with a rather high maximum adsorption capacity of 163.4 mg g −1 . Besides, Weber–Morris kinetic and Temkin isotherm models also provide useful insight into the adsorption mechanism. The material shows a good reusability. After 5 adsorption–desorption cycles the adsorption efficiency reached about 75% of the first cycle and the saturation magnetization decreased insignificantly. These results reveal that FFMB can become an alternative adsorbent for azo dye removal from wastewaters.
Abstract Due to the growing pollution of the environment, water purification methods have to be improved. One of the most effective solutions is the removal of heavy metal ions by porous materials, ...including hydroxyapatite. Lao Cai Province in Vietnam has a tremendous reservoir of apatite ore that can be a precursor for nanostructural materials. In this paper, we refer to the recent studies on removing heavy metal salts, including the cobalt and chromium ions, from the wastewater by the nanostructural hydroxyapatite obtained from the apatite ore gained in the Lao Cai Province. The measurements were performed according to the pH, mass of the adsorbent addition into the real wastewater solution, and time exposition onto the adsorbent; and the suitable condition is a dose of modified apatite of 1 g/L; contacting time of 60 minutes and 6 g/L and 15 minutes in the pH range from pH 0 (3.76 and 6.57) to neutral pH corresponding to Cr 3+ and Co 2+ . We show that just a small amount of the nanostructural hydroxyapatite can work efficiently to remove the chromium and cobalt ions from the solution with maximum adsorption capacity is 70.37 mg/g and 13.52 mg/g, respectively.
Background: Nursing students do scientific research at the university level not only contributing to the development of the nursing profession but also helping themselves to practice more useful ...skills for future work. A positive attitude toward scientific research has been shown to motivate students to practice research. Objective: to assess attitudes toward scientific research and explore associated factors of nursing students in Vietnam. Methods: A cross-sectional study design was adopted and conducted on 238 nursing undergraduate students. Study samples were collected from October to November 2021 through a face-to-face meeting with study subjects and an accidental sampling technique. The attitudes Toward Research Scale was used in this study. Results: The study showed that 76.1% of nursing students had a positive attitude toward scientific research. Through simple linear regression analysis, it showed that having been or participating in scientific research projects (p=0.019), scientific research activities (p=0.028); intending to pursue a postgraduate degree (p=0.016); being introduced/invited to participate in scientific research projects (p=0.021) and having contact with people who can guide scientific research (p=0.033) was the factors that affect nursing students' attitudes toward scientific research. Conclusions: Many associated factors influence the attitude toward scientific research of nursing students. Further effective interventions are needed to address this issue
Diplospora siamica is newly recorded for the flora of Vietnam. It was found in Muong La Nature Reserve, Son La Province, northern Vietnam. A description and colour photos of the species are provided. ...A key to Diplospora species in Vietnam is also given.
Hanoi is known as the City of Lakes because there are some one hundred natural or manmade watercourses within its territory. However, in common with all of Vietnam, more than 60% of the city’s water ...resources derive from beyond the country’s borders. Much of that water is polluted, both within Hanoi and downstream because wastewater is discharged directly into the Nhue and Day rivers via the Nhat Tuu and Ba sewers, among other channels. International attempts to revive the To Lich River in the city, notorious for its black color and unwholesome smell, have proved to have only limited success. There is some scope for new materials to improve filtration effects and experiments in this area continue. Rapid urbanization in Hanoi has been intensified by the sudden decision to increase the city’s size so that it became comparable to the southern capital of Ho Chi Minh City. This has led to large areas of industrial land being incorporated into municipal water management systems. One possible means of relieving the pressure on these systems would be to employ approaches derived from the soft path of water management. To date, most scientific investigation of these issues depends almost entirely on technocratic approaches to water management issues and the attempt to force technical solutions to deal with social issues. Consequently, this paper investigates the possibility of understanding how Hanoi residents interact with current wastewater management approaches and how their needs might be better met in the future.
Four new acyclic diterpenes, siegetalises A-D (1-4), were isolated from the aerial parts of Siegesbeckia orientalis. Their chemical structures were elucidated by extensive analysis of high-resolution ...electrospray ionization mass spectrometry and nuclear magnetic resonance spectral data. The effects of the isolated compounds on the activity of xanthine oxidase were evaluated by the oxidative reaction with xanthine as a substrate. At a concentration of 50 µM, compounds 1-4 exhibited xanthine oxidase inhibitory activity at levels of 13.59% ± 0.51%, 19.64% ± 1.54%, 17.45% ± 1.26%, and 21.36% ± 1.40%, respectively.
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