Extraction of Silica and Iron Oxide from Municipal Solid Waste Incineration Ash and Biomass-fired Power Plant and It’s Application in the Production of Magnetic Mesoporous Silica for Tetracycline Adsorption

Master of Science (Environmental Management), 2023Municipal solid waste incinerator and biomass power plant byproducts, namely bottom ash (BA) and fly ash (FA), are rich in silica and represent a potential source for the synthesis of silica-based materials. This study investigated the optimal conditions for alkaline fusion to extract silica from BA and FA, resulting in a supernatant solution that served as the source of silica for Magnetic mesoporous silica synthesis. To separate Fe2O3 from the ash, a low-temperature hydrothermal reaction was conducted using acid leaching, followed by efficient separation and extraction with methyl alcohol. Before experimentation, the mineralogical composition of the ashes was determined using X-ray fluorescence. Fourier transform-infrared (FTIR), X-ray diffraction (XRD) pattern, and scanning electron microscopy (SEM) were utilized to analyze the extracted silica and iron oxide from the ashes. Sequential extraction under these conditions yielded 71% extraction efficiency and 81% silica purification. However, the efficiency and purity of iron oxide separation are both relatively low. Subsequently, the silica and magnetic ash derived from the bottom ash were used to synthesize magnetic mesoporous silica (MMS) with a high adsorption capacity TC of 276.74 mg/g. FTIR, XRD, and SEM were also employed to characterize the MMS. Optimal conditions for overnight incubation at 60 °C and a pH of 6-8 were determined. The Langmuir isotherm and pseudo-second-order kinetic models were the optimal fitting models based on isotherm and kinetic equations. The adsorption process was identified as physisorption and spontaneous, as evidenced by the low entropy changes (ΔS°), negative enthalpy changes (ΔH°) of -15.94 kJ/mol, and negative Gibbs free-energy changes (ΔG°).Thailand Science Research and Innovation (TSRI), grant number 652A01012; Graduate Research Development Grant of Prince of Songkla University

Ecolo-urbanistic conditions of territorial zoning of the settlement system in the Mekong Delta, Vietnam

The Mekong Delta is one of the four deltas of Vietnam that are deeply impacted by climate change and thus influencing heavily on the population distribution. This conference paper studies the scenarios of climate change, assesses the impacts of climate change, and on this basis, divides the Mekong Delta into three regions according to the ecolourbanistic conditions, while also introducing conceptions and solutions to restructuring the sustainable residential development system in response to climate change

Quality properties Of Vietnamese cocoa liquors

Vietnam (VN) is an emerging country targeting cocoa as a potential industrial domain. It is however still unclear how the quality of VN cocoa liquors can be positioned in the world cocoa supply. Three VN cocoa liquors exhibiting high to intermediate acidity (pH: 4.7 – 5.2) were selected to produce dark chocolate (48.0% sugar, 17.6% cocoa solids, 34.0% cocoa butter and 0.4% lecithin). A comparison study was conducted to investigate the difference between VN and Ghanaian (GH; pH: 5.6) dark chocolates in terms of Casson flow properties (yield stress sCA and viscosity hCA), hardness (F 20°C and F 30°C), water-soluble organic acid content, aroma profile and sensory evaluation. The impact of pre-treatments of cocoa liquor by ball-milling at different fat contents and conching (-C) was also examined

Control of Vibrio parahaemolyticus (AHPND strain) and improvement of water quality using nanobubble technology

Nanobubble technology is used in wastewater treatment, but its disinfectant properties in aquaculture have not been clearly demonstrated. This study investigated the ability of nanobubbles to reduce Vibrio parahaemolyticus (AHPND strain) and to improve water quality. Two laboratory experiments were conducted over a one‐week period, that is (a) assessing the effects of air and oxygen nanobubbles for 60 minutes per day and (b) comparing effects of ozone nanobubble treatments for 2, 4 and 6 minutes per day. Experiments were done in triplicate 100 L tanks with 15‰ saline water, inoculated with an initial bacterial concentration of 106 CFU/ml. At the end of experiment 1, the bacterial concentration of the air and oxygen nanobubble groups was counted for 69% and 46% of the control group respectively. At the end of experiment 2, the bacterial concentration of the 2‐, 4‐ and 6‐minute ozone nanobubble groups were counted for 23%, 2.2% and 0% of the control group respectively. Oxygen and ozone nanobubbles significantly increased oxygen reduction potential and oxygen values. Results indicate that under effective dosages nanobubbles can be used in the production farms to control V.parahaemolyticus and increase oxygen levels

STUDY ON CAUSE-EFFECT RELATIONS AND OPTIMIZATION OF TABLETS CONTAINING AQUILARIA CRASSNA SPRAY-DRIED EXTRACT

Objective: The aim of this study was to develop and optimize the formulation of tablets containing Aquilaria crassna extract using the direct compression method.Methods: D-optimal design based on three independent variables was applied to evaluate the cause-effect relations and optimize the A. crassna tablet formulation. The weight variation (Y1), disintegration time (Y2), hardness (Y3) and friability (Y4) were investigated with respect to three independent variables including % dicalcium phosphate anhydrous (DCPA) in filler (X1), % filler (X2) and % croscarmellose sodium (CCNa) (X3). The dissolution study of the optimized A. crassna tablets were investigated in simulated gastric fluid (SGF) (pH 1.2) using a validated high-performance liquid chromatography (HPLC) method for mangiferin analysis.Results: All investigation factors were found to have significant effects on the physical properties of A. crassna tablet. The tablet hardness and the disintegration time increased in positive relations with the ratios of DCPA. The results exhibited the negative relations between disintegration time and the percentages of CCNa. The optimized A. crassna tablet formulation which included 35 % (w/w) DCPA in filler, 60 % (w/w) filler and 7% (w/w) CCNa possessed the weight variation of 1.38 % (w/w), the disintegration time of 6.29 min, the hardness of 85.63 N and the friability of 0.41 % (w/w). The optimized A. crassna tablet formulation was experimentally examined which demonstrated a good agreement between the experimental and predicted values. Mangiferin was found to release completely from the optimized A. crassna tablets within 30 min.Conclusion: The cause-effect relations and optimization of A. crassna tablet formulation were investigated and reported for the first time. The A. crassna spray-dried extract could be formulated into tablet by direct compression method with good mechanical properties and acceptable release profile

Saponins isolated from the Vietnamese sea cucumber Stichopus chloronotus.

Using various chromatographic methods, three triterpene saponins neothyonidioside (1), stichoposide D (2), and holothurin B (3), were isolated from the methanol extract of the sea cucumber Stichopus chloronotus. Their structures were elucidated by 1D and 2D-NMR experiments and comparison of their NMR data with reported values. Compound 1 was isolated from S. chloronotus for the first time

Effectiveness of training programme on nurses wound care competencies after one year of implementation

This study aims to review the impacts of the nursing training programme on the knowledge, skills and attitude among nurses working in seven clinical departments at Viet Duc University Hospital one year after the interventional programme has been conducted. It was carried out in 2014 and 2015 with a sample size of 145 nurses. The data collection tool included a wound care observation checklist to measure two indicators - the mean score and effects of training on wound care competencies. Data was analysed with SPSS 18.0. The study results showed that the post training rate of nurses with adequate practice competencies increased from the pre-training survey (p < 0.001). The effectiveness indicators relating to the competencies of identification, planning, plan implementation and evaluation were 31.9%; 43.3%; 71.3% and 28.3% (p < 0.001). Wound care training programme based on nursing competencies standards has proved to be effective

A new species of the Cyrtodactylus chauquangensis species group (Squamata, Gekkonidae) from Lao Cai Province, Vietnam

We describe a new species of the genus Cyrtodactylus based on five adult specimens from Bac Ha District, Lao Cai Province, northern Vietnam. Cyrtodactylus luci sp. nov. is distinguished from the remaining Indochinese bent-toed geckos by a combination of the following morphological characteristics: medium size (SVL up to 89.5 mm); dorsal tubercles in 17–19 irregular transverse rows; ventral scales in 32–34 longitudinal rows at midbody; precloacal pores present in both sexes, 9 or 10 in males, 8 or 9 in females; 12–15 enlarged femoral scales on each thigh; femoral pores 9–12 in males, 5–10 in females; postcloacal tubercles 2–4; lamellae under toe IV 21–23; dorsal pattern consisting of 5 or 6 irregular dark bands, a thin neckband without V-shape or triangle shape in the middle, top of head with dark brown blotches; subcaudal scales transversely enlarged. Molecular phylogenetic analyses recovered the new species as the sister taxon to C. gulinqingensis from Yunnan Province, China, with strong support from all analyses and the two taxa are separated by approximately 8.87–9.22% genetic divergence based on a fragment of the mitochondrial ND2 gene. This is the first representative of Cyrtodactylus known from Lao Cai Province

Steroids from the blood cockle Anadara granosa

Using various chromatographic experiments, four sterols as 5α,8α-epidioxy-24(S)-ethylcholest-6-en-3β-ol (1), (22E,24S)-5α,8α-epidioxy-24-ethyl-cholesta-6,22-dien-3β-ol (2), 7-oxocholesterol (3), and (22E)-3β-hydroxycholesta-5,22-dien-7-one (4) were isolated from the methanol extract of the blood cockle Anadara granosa. The structures of isolated compounds were elucidated by 1D and 2D-NMR experiments in comparison with reported data. This is the first report of these compounds from A. granosa

CHOLESTANE-TYPE STEROIDS FROM THE OCTOCORAL Verrucella corona

Using various chromatographic separations, three cholestane-type steroids were isolated from the methanol extract of the octocoral Verrucella corona. Their structures were elucidated to be (22E)-cholesta-5,22-dien-3β-ol-7-one (1), trans-liagosterol (2), and guggulsterol-II (3), by detailed analysis of the 1D and 2D-NMR data as well as comparison with those reported. Among them, compound 2 showed significant cytotoxicity against eight human cancer cell lines as HepG2, HL-60, KB, LNCaP, LU-1, MCF7, SK-Mel2, and SW480