Vietnam Journal of Science and Technology最新文献_第6页

The effects of ammonium loading rates and salinity on ammonium treatment of wastewater from super-intensive shrimp farming 氨负荷率和盐度对超集约化对虾养殖废水氨处理的影响

Vietnam Journal of Science and Technology Pub Date : 2023-10-20 DOI: 10.15625/2525-2518/16427

Tran Manh, Nguyen Thanh, Tung, Nguyen Trieu Duong, Nguyen Cam Tu, Nguyen Truong Quan, Nguyen Hoai Chau

{"title":"The effects of ammonium loading rates and salinity on ammonium treatment of wastewater from super-intensive shrimp farming","authors":"Tran Manh, Nguyen Thanh, Tung, Nguyen Trieu Duong, Nguyen Cam Tu, Nguyen Truong Quan, Nguyen Hoai Chau","doi":"10.15625/2525-2518/16427","DOIUrl":"https://doi.org/10.15625/2525-2518/16427","url":null,"abstract":"Treatment of wastewater from super-intensive shrimp farming (SISF) for discharge or recirculation purposes is currently attracting the attention of managers and researchers. The fixed bed biofilm reactor (FBBR) has been successfully used for biological treatment of drinking water as well as for wastewater treatment in aquaculture farm. Ammonium and salinity are important factors affecting the efficiency of pollutants treatment. This paper presents the results of research on ammonium treatment in super-intensive shrimp wastewater by aerobic microbiological process using FBBRs. The results showed that at ammonium loading rates of 0.014; 0.028; 0.049 and 0.070 kg/m3/d, at salinity of 10‰, the ammonium removal efficiencies were 98 - 99; 97.7 - 98.8; 96.8 – 98.7 and 95.7 – 98.0 percent respectively (ammonium concentrations in effluent were 0.05 – 0.1; 0.12 – 0.23; 0.23 – 0.56 and 0.51 – 1.07 mgN/l, respectively), at salinity of 15‰, the ammonium removal efficiencies were 95.8-96.0, 94.5-92.0, 93.1-92.3 and 66.8-68.8 percent respectively (ammonium in effluent were 0.20 – 0.21; 0.55 – 0.8; 1.20 – 1.35 and 7.8 – 8.3 mgN/l, respectively), at salinity of 20‰, the ammonium removal efficiencies were 92.0-96.0, 87.0-89.0, 69.1-70.9 and 59.6-66.0 percent respectively (ammonium in effluent were 0.2 – 0.4; 1.1 – 1.3; 5.1 – 5.4 and 8.5 – 10.1 mgN/l, respectively). This result showed that the influence of ammonium loading and salinity on ammonium treatment efficiency was very significant.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"234 1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139316105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Follow effect of low cost glass fibre reinforced polymer (GFRP) on the performance of concentrically loaded concrete column 关注低成本玻璃纤维增强聚合物（GFRP）对同心加载混凝土柱性能的影响

Vietnam Journal of Science and Technology Pub Date : 2023-10-20 DOI: 10.15625/2525-2518/18079

Pannirselvam N, Sudarsan J S, Nithiyanantham S

引用次数: 0

Synthesis of intermediate derivatives from Schweinfurthin G using chiral ionic liquid 使用手性离子液体合成 Schweinfurthin G 的中间衍生物

Vietnam Journal of Science and Technology Pub Date : 2023-10-20 DOI: 10.15625/2525-2518/17560

Nguyen Thuy Linh, Bui Thi Minh, Anh, T. Hiếu, Phi Thi Dao, Tran Thu Huong, Doan Thi Mai, Huong, P. Cuong

{"title":"Synthesis of intermediate derivatives from Schweinfurthin G using chiral ionic liquid","authors":"Nguyen Thuy Linh, Bui Thi Minh, Anh, T. Hiếu, Phi Thi Dao, Tran Thu Huong, Doan Thi Mai, Huong, P. Cuong","doi":"10.15625/2525-2518/17560","DOIUrl":"https://doi.org/10.15625/2525-2518/17560","url":null,"abstract":"Schweinfurthins possess a wide diversity of important biological and pharmacological activities. To date, more than fifty schweinfurthins and their analogues have been prepared for the investigation of structure-function relationships. Schweinfurthin G, one of the most representative of schweinfurthins containing the hexahydroxanthene moiety, was found to strongly inhibit the growth of cancer cell lines when evaluated on the U87 cell line (EC50 of 0.04 µM), and on the KB cell line (IC50 of 0.06 µM). Ionic liquids have been regarded as “solvents of the future” and applied in various fields. They have been utilized most widely in modern organic synthesis as an environmentally friendly alternative to conventional organic solvents and catalysts due to their flexible, nonvolatile, noncorrosive, low viscous properties and they still maintain similar and sometimes enhanced chemical selectivity and reactivity of organic reactions. In this paper, we present the synthesis of intermediate compounds 2 and 3, which are the key compounds for synthesizing the derivatives of schweinfurthin G using chiral ionic liquid. These compounds are the key blocks to further synthesize schweinfurthin G derivatives for biological activity tests.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139316064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Polycyclic Aromatic Hydrocarbons (PAHs) in paddy soil around Nam Son landfill area, Ha Noi, Viet Nam 越南河内南山垃圾填埋场周围稻田土壤中的多环芳烃 (PAHs)

Vietnam Journal of Science and Technology Pub Date : 2023-10-20 DOI: 10.15625/2525-2518/18427

Nguyen Thuy Ngoc, Truong Thi Kim, Nguyen Thi Quynh, Phung Thi Vi, Pham Hung Viet, Duong Hong Anh

{"title":"Polycyclic Aromatic Hydrocarbons (PAHs) in paddy soil around Nam Son landfill area, Ha Noi, Viet Nam","authors":"Nguyen Thuy Ngoc, Truong Thi Kim, Nguyen Thi Quynh, Phung Thi Vi, Pham Hung Viet, Duong Hong Anh","doi":"10.15625/2525-2518/18427","DOIUrl":"https://doi.org/10.15625/2525-2518/18427","url":null,"abstract":"The paddy soils were collected in the rice growing fields and the uncultivated lands around the Nam Son domestic waste landfill in Hanoi. The average concentration of 16 US EPA priority PAHs in dry soil was 61.61 ng/g, with a range of 22.15-115.1 ng/g. The higher levels of PAHs in soil samples were observed in cultivated paddy fields near the landfill in comparison with the fields far from the landfill. On the other hand, there was no difference in PAHs levels in cultivated paddy fields near the landfill and along the irrigation water canal. Concentrations of 16 PAHs in paddy soils decreased in the order: 5 rings > 3 rings > 4 rings > 2 rings > 6 rings in this area. The PAH isomeric diagnostic ratios including Fluth/(Fluth+Pyr) ratio (Ave 0.43, a range of 0.17-0.61), BaA/(BaA+Chr) ratio (Ave 0.51, a range of 0.26-0.63), IcdP/(IcdP+BghiP) ratio (Ave 0.71, a range of 0.51-0.90) indicated that the potential main sources emitted PAHs in paddy soils from pyrogenic biomass combustion and coal burning. Compared with the risk threshold causing adverse impacts on the ecological environment from different countries in the world, concentrations of PAHs in the soil surrounding the Nam Son landfill area were still below the affected limit. However, environmental quality around the landfill area still needs to be regularly monitored to take timely measures to protect the environment in this area.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139316152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

High gravity enzymatic hydrolysis of non–gelatinized starch from black - purple rice 高重力酶水解黑紫色大米中的非胶化淀粉

Vietnam Journal of Science and Technology Pub Date : 2023-08-22 DOI: 10.15625/2525-2518/17252

Huong Do, Thi Thanh, Tien Thanh Nguyen

{"title":"High gravity enzymatic hydrolysis of non–gelatinized starch from black - purple rice","authors":"Huong Do, Thi Thanh, Tien Thanh Nguyen","doi":"10.15625/2525-2518/17252","DOIUrl":"https://doi.org/10.15625/2525-2518/17252","url":null,"abstract":"Thanks to novel recombinant starch degrading enzymes which can directly hydrolyze raw starch at ambient temperature, the technology of hydrolysis of uncooked starch has recently been developed andproven to be effective. In combination with high substrate concentration (high gravity) approach, this technology not only saves the thermal energy for starch gelatinization but also reduces the impact of heat on valuable components in starch–containing raw materials. Black–purple rice is a specialty of Northwest Viet Nam, which contains high level of anthocyanin, a biologically active ingredient. In this study, commercial enzymes were applied to hydrolyze non–gelatinized black–purple rice to obtain anthocyanin–containing sugar solution. Factors affecting the starch conversion such as enzyme/substrate ratio, hydrolysis duration, temperature, and the presence of supporting enzymes in the hydrolysis process were investigated. The results showed that in the presence of Stargen 002, Viscozyme L, and Cellulast 1.5 L, more than 86 % of starch in a total of 320 g/L black-purple rice were converted into glucose after 72 hours at 50 °C. From black-purple rice, two products were received, including a glucose–rich hydrolysate (245.92 g/L) containing anthocyanin (30 mg/L) and a solid by–product rich in protein, which were very potential for food application.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"2015 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139349647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Controlling near-field coupling for switchable metamaterial between absorption and polarization-conversion functions 在吸收和偏振转换功能之间控制可切换超材料的近场耦合

Vietnam Journal of Science and Technology Pub Date : 2023-08-22 DOI: 10.15625/2525-2518/16900

Nguyen Van Ngoc, Le Van Long, Dinh Ngoc Dzung, T. Huynh, Nguyen Thi Mai, B. Tung, B. Khuyen, Vu Dinh Lam

引用次数: 0

A colorimetric assay with leuco crystal violet for the detection of inorganic phosphate in water 用无色结晶紫比色法测定水中无机磷酸盐

Vietnam Journal of Science and Technology Pub Date : 2023-08-21 DOI: 10.15625/2525-2518/18063

M. Ahmed, Fareeha Arshad

{"title":"A colorimetric assay with leuco crystal violet for the detection of inorganic phosphate in water","authors":"M. Ahmed, Fareeha Arshad","doi":"10.15625/2525-2518/18063","DOIUrl":"https://doi.org/10.15625/2525-2518/18063","url":null,"abstract":"Phosphate enters the aquatic system through runoff from pastures, croplands, urban areas, and sewage treatment systems and fosters algal bloom causing eutrophication at higher concentrations in water. Therefore, controlling its concentration through routine monitoring of water quality in aquatic ecosystems is essential. Using a smartphone camera and colour analysis app, a simple colourimetric technique was developed to quantitatively detect inorganic phosphate in natural and treated drinking water samples using colourless leuco crystal violet (LCV). Upon reaction with phosphate (PO43−), LCV forms leuco crystal violet phosphate (LCV-P) complex with a violet colour and shows maximum absorbance at 583 nm. A light-sensitive colourimetric box with in-built LED light was constructed to maintain the consistency of the image quality for precise and accurate measurement. The Red, Green and Blue (RGB) analyses of the digital images were done to determine the linear response of the intensity of G against the concentration of the LCV-P complex. A microplate reader was also used to analyse the UV-Vis absorbance of the samples to validate the results further. Under optimum conditions, the colourimetric assay achieved a detection limit of 0.25 μM with a linear range between 0.1 and 1 μM. Thus, the proposed colourimetric assay was highly sensitive and selective towards phosphate in natural and drinking water samples.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87574447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Correlation between heavy metals and polyaromatic hydrocarbons of particulate matter in the flue gas of municipal solid waste incinerators in north Vietnam 越南北部城市固体废物焚烧炉烟气中重金属与颗粒物质多芳烃的相关性

Vietnam Journal of Science and Technology Pub Date : 2023-08-02 DOI: 10.15625/2525-2518/17343

Phạm Quốc Việt, N. T. Hue, Nguyen Thi Truc Phuong, Mai, Le Phuong Thu

{"title":"Correlation between heavy metals and polyaromatic hydrocarbons of particulate matter in the flue gas of municipal solid waste incinerators in north Vietnam","authors":"Phạm Quốc Việt, N. T. Hue, Nguyen Thi Truc Phuong, Mai, Le Phuong Thu","doi":"10.15625/2525-2518/17343","DOIUrl":"https://doi.org/10.15625/2525-2518/17343","url":null,"abstract":"This study aimed to determine the content of heavy metals (Cu, Ni, Pb, Zn, Cd, Cr, and As) and polyaromatic hydrocarbon (PAHs), and focus on their relationship in particulate matter (<10μm) contained in the flue gas of the incinerators. Samples were collected in the exhausted gas of 5 municipal solid waste incinerators located in Bac Giang, Bac Ninh, Hai Duong, Hanoi, and Hai Phong. Heavy metals and PAHs were analyzed by ICP-MS and GC-MS, respectively. The heavy metal content shows a significant difference between incinerators, varying from 0.822 to 6.13 × 103 µg/Nm3. In which, the predominant element in the PM10 samples was zinc, accounting for 80% of the total content of studied elements, it was mixed with Pb and Cu (10 to 20%). The contribution of Cd was stable at roughly 5% of the total heavy metal content. Meanwhile, total polyaromatic hydrocarbon exhibited a fairly low concentration, varying from 21.9 to 994 µg/Nm3, of which PAHs have the carcinogenic potential ranging from 21.3 to 73.2% of total PAHs. These results hypothesized the correlation between Zn and Pb to the formation of PAHs during the combustion and discharge to the environment through waste dust. However, the low molecular PAH content decreased when heavy metal concentration increased.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"52 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85883967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Occurrence and human exposure risk assessment of brominated and organophosphate flame retardants in indoor dust in Ha Noi, Viet Nam 越南河内室内粉尘中溴化和有机磷阻燃剂的发生和人体暴露风险评估

Vietnam Journal of Science and Technology Pub Date : 2023-08-02 DOI: 10.15625/2525-2518/16449

H. Thi, T. Minh, D. Thi, Hanh, Phan Quang Thang, T. T. Hà

{"title":"Occurrence and human exposure risk assessment of brominated and organophosphate flame retardants in indoor dust in Ha Noi, Viet Nam","authors":"H. Thi, T. Minh, D. Thi, Hanh, Phan Quang Thang, T. T. Hà","doi":"10.15625/2525-2518/16449","DOIUrl":"https://doi.org/10.15625/2525-2518/16449","url":null,"abstract":"The widespread use of flame retardants in commercial and industrial products has led to their increased presence in the environment. Recently, indoor dust has been identified as a major human exposure route for flame retardants. In the present study, brominated flame retardants (BFRs) and organophosphate flame retardants (OPFRs) were examined in indoor dust samples collected from apartments in Hanoi, Vietnam. OPFRs were detected at the highest concentrations with the mean concentration of ∑OPFRs was 8700 ng/g (ranged from 1400 to 18000 ng/g). Tris(1-chloro-2-propyl) phosphate (TCPP) and tris(2-butoxyethyl) phosphate (TBOEP) were the most abundant OPFRs in all indoor dust samples, accounting for 50 % (ranged 22 – 69 %) and 33 % (ranged 16 – 63 %) of the total OPFRs levels, respectively. The mean concentrations of total polybrominated diphenyl ethers (PBDEs) and total novel brominated flame retardants (NBFRs) in these samples were 200 ng/g (ranged 67 - 480 ng/g) and 310 ng/g (ranged 56 - 1500 ng/g), respectively. Polybrominated diphenyl ether congener 209 (BDE 209) and decabromodiphenyl ethane (DBDPE) were the most predominant components in PBDEs and NBFRs, respectively. Other BFRs were only found in some samples at very low levels. The estimated daily intake doses (IDs) of FRs via dust ingestion were calculated for both adults and children. The results revealed that the estimated levels of compound exposure through dust ingestion, even under the high-exposure scenario were also below their reference dose (RfD) values, indicating that human health risks from exposure to flame retardants (FRs) via indoor dust ingestion are not significant.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"65 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91070786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Genetic diversity and some biological characteristics of antibacterial yeasts isolated from natural honey and beeswax in Son La province 从 Son La 省天然蜂蜜和蜂蜡中分离的抗菌酵母菌的遗传多样性和一些生物学特征

Vietnam Journal of Science and Technology Pub Date : 2023-08-02 DOI: 10.15625/2525-2518/17260

Anh Ngoc Pham, Anh Kieu Ha, Thuy Thi Tran

{"title":"Genetic diversity and some biological characteristics of antibacterial yeasts isolated from natural honey and beeswax in Son La province","authors":"Anh Ngoc Pham, Anh Kieu Ha, Thuy Thi Tran","doi":"10.15625/2525-2518/17260","DOIUrl":"https://doi.org/10.15625/2525-2518/17260","url":null,"abstract":"Yeast living in honey, an environment with high sugar content (up to 70 %, w/v), normally shows good resistance to the high level of osmotic pressure; they are of high potential for application in many fields. There were not many studies on the genetic diversity and biological characteristics of yeast from honey in Vietnam. This study aims to (1) evaluate the genetic diversity of antibacterial yeast isolated from natural honey and beeswax in Son La province by RAPD (Random Amplified Polymorphic DNA) and (2) study some biological characteristics of them. The research results may contribute to the scientific basis for screening yeast strains applied in different fields such as bioethanol and probiotic production. Sixty-eight yeast strains were isolated from natural honey and beeswax collected in Son La. Among them, twenty-one strains showed antibacterial activity against at least a tested bacterium including Escherichia coli, Bacillus subtilis, and Serratia marcescens. These yeast strains were genetically distinct in the RAPD analysis using M13 and (GTG)5 primers. Evaluation of yeast growing in the medium containing high glucose concentration (30 - 40 %, w/v) or high ethanol concentration (5 - 10 %, v/v) has shown some yeast strains that can tolerate high osmotic pressure and high ethanol concentration for different applications. YC.8 and YC.61 strains exhibited relatively good survival rates in two phases of digestion and have a wide pH range (2 - 7). YC.8 strain expressed the most potential for human or animal probiotics.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"74 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139352096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0