Hue University Journal of Science: Natural Science

Activated peat for application of Cd2+ ion treatment in aqueous solution

2023-09-30T03:05:16+07:00

In this study, peat was activated with H₃PO₄ at a concentration of 2.0 M. The synthesized samples were characterized by several methods such as EDX, XRD, SEM, BET and FTIR. The adsorption properties of the materials were evaluated through their ability to remove Cd²⁺ ions in aqueous solution. Material characteristics show that the peat sample after activation has a higher specific surface area and porosity than the raw peat sample. The study shows that experimental data of Cd²⁺ ion adsorption on activated peat is well described simultaneously by both Langmuir and Freundlich isotherm models, however the Langmuir isotherm model appears to be more suitable. The activated peat material reached the maximum adsorption capacity q_m 29.07 mg/g. In addition, the study also shows that the adsorption of Cd²⁺ ions on activated peat follows the apparent second-order kinetic model. From the above research results, it shows that adsorbent materials from peat have great potential in remove heavy metal ions in aqueous solution.

Flavanoids and diarylheptanoids from Conamomum rubidum Lamxay & N.S.Lý

2023-08-29T06:35:16+07:00

Five compounds included two dihydrochalcones, 2’,6’-dihydroxy-4’-methoxydihydrochalcone (1), dihydroflavokawin B (2), one flavanone, pinocembrin (3) and two diarylheptanoids, dihydroyashabushiketol (4), 5-methoxy-1,7-diphenyl-3-heptanone (5) were isolated for the first time from the whole plants of Conamomum rubidum. The structure of isolates were determined by a combination of spectroscopic analyses as well as by comparison with the reported spectroscopic data. Biological evaluations revealed that compounds 2, 4, and 5 inhibited NO production in RAW 264.7 cells with IC₅₀ values ranging from 58.16 ± 3.02 to 81.95 ± 2.87 µM. Compound 1 exhibited moderate cytotoxicity against the SK-LU-1 cells with IC₅₀ value of 58.45 ± 2.26 µM.

Simultaneous determination of lead and cadmium in aqueous sources by anodic stripping voltammetry method using BiF/ErGO-GCE modified electrode

2023-10-21T09:26:45+07:00

At present, the differential pulse anodic stripping voltammetry (DP-ASV) method using modified electrodes is considered as a robust method with high selectivity, sensitivity and low cost. In this study, the glassy carbon electrode was modified with reduced graphene oxide combined with a film bismuth in-situ (BiF/ErGO-GCE) to simultaneously determine Cd(II) and Pb(II) in aqueous source. Several parameters were studied including the amount of graphene oxide material, the concentration of Bi(III) and the parameters of the DP-ASV method. The detection limits of Cd(II) and Pb(II) were determined to be 1.50 ppb and 1.39 ppb. In addition, BiF/ErGO-GCE modified electrode was also applied to simultaneously determine Cd(II) and Pb(II) in two water samples of Huong and An Cuu rivers. The results were compared to those of inductively coupled plasma mass spectrometry method with sactifaction.

Optimization of culture conditions and study on naphthalene and dibenzofuran degradation abilities of Paenibacillus naphthalenovorans 4B1

2024-02-01T01:21:44+07:00

The pollution of polycyclic aromatic hydrocarbon compounds caused by herbicide residues contaminated with dioxin from the war and other wastes from industrial activities has left severe consequences to human health and the environment. Bioremediation using microorganisms capable of decomposing pollutant compounds exhibits more advantages than physicochemical treatment methods as it is highly efficient, economically feasible, sustainable, and eco-friendly. In this study, Paenibacillus naphthalenovorans strain 4B1, isolated from dioxin-contaminated soil in Vietnam, was optimized the culture conditions and evaluated its abilities to degrade dibenzofuran and naphthalene. The results revealed that strain 4B1 showed the best growth on mineral salts medium supplemented with dibenzofuran 1250 mg/L or naphthalene 750 mg/L, pH 7.0, incubated at 45°C and 180 rpm with a cell density of 9,42 × 10⁷ và 5,6 × 10⁷ CFU/mL, respectively. Gas chromatography analysis of the substrate concentrations indicated that strain 4B1 could degrade 79.76% of 1250 mg/L dibenzofuran and 83.03% of 750 mg/L naphthalene after 72 hours of incubation at optimal conditions. These results make Paenibacillus naphthalenovorans 4B1 a potential candidate for application in bioremediation of environments contaminated with polycyclic aromatic hydrocarbon compounds.

Preliminary data of the zoogeography of inland freshwater snails in Thua Thien Hue

2023-04-03T14:37:29+07:00

The survey and sampling were conducted in Thua Thien Hue Province from May 2018 to July 2020. Initial remarks are made on the zoogeography of inland freshwater snails in Thua Thien Hue. In which, species with Indian-Malaysian characteristics are dominant (8 species; 40%), followed by widespread species (6 species; 30%), species with Chinese characteristics are less diverse (4 species; 20%) and Vietnamese endemic species are the least diverse (2 species; 10%).

Removal of Pb from industrial wastewater by using Muc weed (Eclipta alba)

2023-11-13T12:15:10+07:00

One of the major ongoing environmental problems is the contamination of water and soil by toxic metals. Hence, this study aimed to evaluate the potential use of Muc weed (Eclipta alba) to remove lead (Pb) from contaminated water by phytoremediation and to investigate the effects of some parameters (Pb concentration, contact time and pH value) on the Pb removal efficiency of E. alba. The results showed that at a concentration of 50 ppm, E. alba presented the highest removal efficiency of Pb²⁺ (99.34%) after 7 days. In addition, the results also showed that pH= 7 is the optimal pH for Pb removal by the E. alba (98.95% efficiency). The analysis results showed that after 7 days of treatment at pH=7, the Pb accumulation capacity of roots, shoots, and leaves were 2861.2 mg/kg, 2497.1 mg/kg, and 503.2 mg/kg, respectively. Furthermore, the results also indicated that E. alba had a translocation factor (TF) >1 and a bioconcentration factor (BCF) of shoot >1 for Pb, so it is suitable for the extraction of Pb from industrial wastewater.

Evaluation of the potential of the naturally growing Leptocarpus disjunctus Mast. in Central Vietnam as feed for ruminants

2023-12-04T02:39:23+07:00

Leptocarpus disjunctus Mast., is a species of grass that grows naturally in the sandy coastal areas of central Vietnam. This species has strong vitality, growing singly in clumps or growing together, covering the surface of the sand. Adaptability and ability to withstand flooding and drought are very high. The study aimed to evaluate the potential of naturally growing L. disjunctus as food for ruminants through the assessment criteria of the highest plant height, canopy height, green matter yield, dry matter yield, protein yield, and chemical composition. The experiment was conducted in the sandy soils of Le Thuy District, Quang Binh Province, and Quang Thai District, Thua Thien Hue Province. At each location, five plots were selected to implement experiments and conducted over two seasons, dry season and rainy season. The highest plant height ranged from 102.58 - 104.82cm, and canopy height ranged from 80.26 - 81.57cm. Green matter yield, dry matter yield, and protein yield were from 10.3 - 12.4 tons/ha/batch, 4.1 - 4.8 tons/ha/batch, and 0.6 - 0.7 tons/ha/batch, respectively. Chemical composition including dry matter (DM) 43.55%, CP 5.70%, EE 1.72%, CF 43.23%, ADF 43.64%, NDF 69.09%, and total minerals 2.14%, calculated as a percent of DM. In conclusion, the results showed that L. disjunctus growing naturally in poor sandy soils and harsh weather in Quang Binh and Thua Thien Hue provinces could be used as food for ruminants.