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Do VM, Trinh VT, Le XTT, Nguyen DT. Evaluation of microplastic bioaccumulation capacity of mussel (Perna viridis) and surrounding environment in the North coast of Vietnam. Mar Pollut Bull 2024; 199:115987. [PMID: 38160603 DOI: 10.1016/j.marpolbul.2023.115987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 12/23/2023] [Accepted: 12/23/2023] [Indexed: 01/03/2024]
Abstract
This study aimed to identify the presence of microplastics in green mussels (Perna viridis), surface seawater, and beach sediment on the North Coast of Vietnam. The average concentration of MPs in mussels was 3.67 ± 1.20 MPs/g wet weight and 25.05 ± 5.36 MPs/individual. Regarding surface seawater and beach sediments, the MPs concentration was found at 88.00 ± 30.88 MPs/L and 4800 ± 1776 MPs/kg dry weight, respectively. The dominant microplastics shape was fragment with the fractions ranging from 69.86 to 82.41 %. In addition, the size distribution of MPs was mostly in the range of smaller than 50 μm and 1-150 μm (34.17 % and 45.62 % in mussels; 29.65 % and 43.20 % in surface seawater and 40.22 % and 39.40 % in beach sediment, respectively). Polyethylene terephthalate was the major polymer types 49.93-58.44 % of the detected MPs. The risk assessment results based on the polymer types indicated a warning level in several sites.
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Affiliation(s)
- Van Manh Do
- Institute of Science and Technology for Energy and Environment, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay District, Hanoi, Viet Nam; Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay District, Hanoi, Viet Nam
| | - Van Tuyen Trinh
- Institute of Science and Technology for Energy and Environment, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay District, Hanoi, Viet Nam; Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay District, Hanoi, Viet Nam
| | - Xuan Thanh Thao Le
- Institute of Science and Technology for Energy and Environment, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay District, Hanoi, Viet Nam; Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay District, Hanoi, Viet Nam
| | - Duy Thanh Nguyen
- Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay District, Hanoi, Viet Nam; Vietnam National Institute of Occupational Safety and Health, 99 Tran Quoc Toan Road, Hoan Kiem District, Hanoi, Viet Nam.
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Nguyen TH, Tran HN, Nguyen TV, Vigneswaran S, Trinh VT, Nguyen TD, Ha Nguyen TH, Mai TN, Chao HP. Single-step removal of arsenite ions from water through oxidation-coupled adsorption using Mn/Mg/Fe layered double hydroxide as catalyst and adsorbent. Chemosphere 2022; 295:133370. [PMID: 34973248 DOI: 10.1016/j.chemosphere.2021.133370] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 12/12/2021] [Accepted: 12/17/2021] [Indexed: 06/14/2023]
Abstract
This study developed a layered double hydroxides (Mn/Mg/Fe-LDH) material through a simple co-precipitation method. The Mn/Mg/Fe-LDH oxidized arsenite [As(III)] ions into arsenate [As(V)] anions. The As(III) and oxidized As(V) were then adsorbed onto Mn/Mg/Fe-LDH. The adsorption process of arseniate [As(V)] oxyanions by Mn/Mg/Fe-LDH was simultaneously conducted for comparison. Characterization results indicated that (i) the best Mg/Mn/Fe molar ratio was 1/1/1, (ii) Mn/Mg/Fe-LDH structure was similar to that of hydrotalcite, (iii) Mn/Mg/Fe-LDH possessed a positively charged surface (pHIEP of 10.15) and low Brunauer-Emmett-Teller surface area (SBET = 75.2 m2/g), and (iv) Fe2+/Fe3+ and Mn2+/Mn3+/Mn4+ coexisted in Mn/Mg/Fe-LDH. The As(III) adsorption process by Mn/Mg/Fe-LDH was similar to that of As(V) under different experimental conditions (initial solutions pH, coexisting foreign anions, contact times, initial As concentrations, temperatures, and desorbing agents). The Langmuir maximum adsorption capacity of Mn/Mg/Fe-LDH to As(III) (56.1 mg/g) was higher than that of As(V) (32.2 mg/g) at pH 7.0 and 25 °C. X-ray photoelectron spectroscopy was applied to identify the oxidation states of As in laden Mn/Mg/Fe-LDH. The key removal mechanism of As(III) by Mn/Mg/Fe-LDH was oxidation-coupled adsorption, and that of As(V) was reduction-coupled adsorption. The As(V) mechanism adsorption mainly involved: (1) the inner-sphere and outer-sphere complexation with OH groups of Mn/Mg/Fe-LDH and (2) anion exchange with host anions (NO3-) in its interlayer. The primary mechanism adsorption of As(III) was the inner-sphere complexation. The redox reactions made Mn/Mg/Fe-LDH lose its original layer structure after adsorbing As(V) or As(III). The adsorption process was highly irreversible. Mn/Mg/Fe-LDH can decontaminate As from real groundwater samples from 45-92 ppb to 0.35-7.9 ppb (using 1.0 g/L). Therefore, Mn/Mg/Fe-LDH has great potential as a material for removing As.
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Affiliation(s)
- Thi Hai Nguyen
- Faculty of Engineering and IT, University of Technology Sydney (UTS), Sydney, Australia
| | - Hai Nguyen Tran
- Institute of Fundamental and Applied Sciences, Duy Tan University, Ho Chi Minh, 700000, Viet Nam; Faculty of Environmental and Chemical Engineering, Duy Tan University, Da Nang, 550000, Viet Nam.
| | - Tien Vinh Nguyen
- Faculty of Engineering and IT, University of Technology Sydney (UTS), Sydney, Australia.
| | | | - Van Tuyen Trinh
- Institute of Environmental Technology, Vietnam Academy of Science and Technology, Hanoi, Viet Nam
| | - Thanh Dong Nguyen
- Institute of Environmental Technology, Vietnam Academy of Science and Technology, Hanoi, Viet Nam
| | | | - Trong Nhuan Mai
- VNU University of Science, Vietnam National University, Hanoi, Viet Nam
| | - Huan-Ping Chao
- Department of Environmental Engineering and R&D Center for Membrane Technology, Chung Yuan Christian University, Taoyuan, 32023, Taiwan
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Duong TT, Le PT, Nguyen TNH, Hoang TQ, Ngo HM, Doan TO, Le TPQ, Bui HT, Bui MH, Trinh VT, Nguyen TL, Da Le N, Vu TM, Tran TKC, Ho TC, Phuong NN, Strady E. Selection of a density separation solution to study microplastics in tropical riverine sediment. Environ Monit Assess 2022; 194:65. [PMID: 34993616 DOI: 10.1007/s10661-021-09664-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 11/27/2021] [Indexed: 06/14/2023]
Abstract
Microplastics (MPs) are small (< 5 mm) plastic particles that are widely found in marine, freshwater, terrestrial and atmospheric environments. Due to their prevalence and persistence, MPs are considered an emerging contaminant of environmental concern. The separation and quantitation of MPs from freshwater sediments is a challenging and critical issue. It is necessary to identify the fate and sources of MPs in the environment, minimise their release and adverse effects. Compared to marine sediments, standardised methods for extracting and estimating the amount of MPs in freshwater sediments are relatively limited. The present study focuses on MP recovery efficiency of four commonly used salt solutions (NaCl, NaI, CaCl2 and ZnCl2) for isolating MPs during the density separation step from freshwater sediment. Known combinations of artificial MP particles (PS, PE, PVC, PET, PP and HDPE) were spiked into standard river sediment. Extraction using NaI, ZnCl2 and NaCl solutions resulted in higher recovery rates from 37 to 97% compared to the CaCl2 solution (28-83%) and varied between polymer types. Low-density MPs (PE, HDPE, PP and PS) were more effectively recovered (> 87%) than the denser polymers (PET and PVC: 37 to 88.8%) using NaCl, NaI and ZnCl2 solutions. However, the effective flotation of ZnCl2 and NaI solutions is relatively expensive and unsafe to the environment, especially in the context of developing countries. Therefore, considering the efficiency, cost and environmental criteria, NaCl solution was selected. The protocol was then tested by extracting MPs from nine riverine sediment samples from the Red River Delta. Sediments collected from urban rivers were highly polluted by MPs (26,000 MPs items·kg-1 DW) compared to sediments located downstream. Using a NaCl solution was found to be effective in this case study and might also be used in long-term and large-scale MP monitoring programmes in Vietnam.
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Affiliation(s)
- Thi Thuy Duong
- Institute of Environmental Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay, Hanoi, Vietnam.
- Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay, Hanoi, Vietnam.
| | - Phuong Thu Le
- University of Science and Technology of Hanoi, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam
| | - Thi Nhu Huong Nguyen
- Institute of Environmental Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay, Hanoi, Vietnam
| | - Thi Quynh Hoang
- Institute of Environmental Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay, Hanoi, Vietnam
| | - Ha My Ngo
- University of Science and Technology of Hanoi, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam
| | - Thi Oanh Doan
- Faculty of Environment, Hanoi University of Natural Resources and Environment, No 41A, Phu Dien Street, Bac Tu Liem, Hanoi, Vietnam
| | - Thi Phuong Quynh Le
- Institute of Natural Product Chemistry, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay, Hanoi, Vietnam
| | - Huyen Thuong Bui
- University of Science and Technology of Hanoi, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam
| | - Manh Ha Bui
- Department of Environmental Sciences, Saigon University, 273 An Duong Vuong Street, District 5, Ho Chi Minh City, Vietnam
| | - Van Tuyen Trinh
- Institute of Environmental Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay, Hanoi, Vietnam
| | - Thuy Lien Nguyen
- VNU University of Science, Vietnam National University, Thanh Xuan, 334 Nguyen Trai street, Hanoi, Vietnam
| | - Nhu Da Le
- Institute of Natural Product Chemistry, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay, Hanoi, Vietnam
| | - Thanh Mai Vu
- Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam
| | - Thi Kim Chi Tran
- Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam
| | - Tu Cuong Ho
- Institute of Environmental Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay, Hanoi, Vietnam
| | - Ngoc Nam Phuong
- PhuTho College of Medicine and Pharmacy, Hung Vuong Boulevard, 2201, Viet Tri City, Phu Tho Province, Vietnam
| | - Emilie Strady
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO, Marseille, France
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Trinh VT, Nguyen TMP, Van HT, Hoang LP, Nguyen TV, Ha LT, Vu XH, Pham TT, Nguyen TN, Quang NV, Nguyen XC. Phosphate Adsorption by Silver Nanoparticles-Loaded Activated Carbon derived from Tea Residue. Sci Rep 2020; 10:3634. [PMID: 32107469 PMCID: PMC7046672 DOI: 10.1038/s41598-020-60542-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Accepted: 02/11/2020] [Indexed: 11/24/2022] Open
Abstract
This study presents the removal of phosphate from aqueous solution using a new silver nanoparticles-loaded tea activated carbon (AgNPs-TAC) material. In order to reduce costs, the tea activated carbon was produced from tea residue. Batch adsorption experiments were conducted to evaluate the effects of impregnation ratio of AgNPs and TAC, pH solution, contact time, initial phosphate concentration and dose of AgNPs-AC on removing phosphate from aqueous solution. Results show that the best conditions for phosphate adsorption occurred at the impregnation ratio AgNPs/TAC of 3% w/w, pH 3, and contact time lasting 150 min. The maximum adsorption capacity of phosphate on AgNPs-TAC determined by the Langmuir model was 13.62 mg/g at an initial phosphate concentration of 30 mg/L. The adsorption isotherm of phosphate on AgNPs-TAC fits well with both the Langmuir and Sips models. The adsorption kinetics data were also described well by the pseudo-first-order and pseudo-second-order models with high correlation coefficients of 0.978 and 0.966, respectively. The adsorption process was controlled by chemisorption through complexes and ligand exchange mechanisms. This study suggests that AgNPs-TAC is a promising, low cost adsorbent for phosphate removal from aqueous solution.
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Affiliation(s)
- Van Tuyen Trinh
- Institute of Environmental Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet road, Ha Noi city, Vietnam
| | - Thi Minh Phuong Nguyen
- Faculty of Environment and Chemical Engineering, Duy Tan University (DTU), 254 Nguyen Van Linh road, Da Nang, Vietnam
| | - Huu Tap Van
- Faculty of Natural Resources and Environment, TNU-University of Sciences (TNUS), Tan Thinh Ward, Thai Nguyen City, Vietnam
| | - Le Phuong Hoang
- Faculty of Civil and Environmental Engineering, Thai Nguyen University of Technology (TNUT), Tich Luong Ward, Thai Nguyen City, Vietnam
| | - Tien Vinh Nguyen
- Faculty of Engineering and IT, University of Technology Sydney (UTS), Box 123, Broadway, Sydney, PO, Australia
| | - L T Ha
- Faculty of Physics and Technology, TNU-University of Sciences (TNUS), Tan Thinh Ward, Thai Nguyen City, Vietnam
| | - Xuan Hoa Vu
- Faculty of Physics and Technology, TNU-University of Sciences (TNUS), Tan Thinh Ward, Thai Nguyen City, Vietnam
| | - T T Pham
- Institute of Research and Development, Duy Tan University, Da Nang, 550000, Vietnam
| | - Thi Nu Nguyen
- Cao Bang Teacher's Training College, De Tham road, Cao Bang town, Cao Bang Province, Vietnam
| | - N V Quang
- Faculty of Chemistry, Ha Noi Pedagogical University 2, Vinh Phuc, Vietnam
| | - X C Nguyen
- Laboratory of Advanced Materials Chemistry, Advanced Institute of Materials Science, Ton Duc Thang University, Ho Chi Minh City, Vietnam.
- Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam.
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Nguyen TH, Tran HN, Vu HA, Trinh MV, Nguyen TV, Loganathan P, Vigneswaran S, Nguyen TM, Trinh VT, Vu DL, Nguyen THH. Laterite as a low-cost adsorbent in a sustainable decentralized filtration system to remove arsenic from groundwater in Vietnam. Sci Total Environ 2020; 699:134267. [PMID: 31677468 DOI: 10.1016/j.scitotenv.2019.134267] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 09/01/2019] [Accepted: 09/02/2019] [Indexed: 06/10/2023]
Abstract
In the Red River Delta, Vietnam, arsenic (As) contamination of groundwater is a serious problem where more than seventeen million people are affected. Millions of people in this area are unable to access clean water from the existing centralized water treatment systems. They also cannot afford to buy expensive household water filters. Similar dangerous situations exist in many other countries and for this reason there is an urgent need to develop a cost-effective decentralized filtration system using new low-cost adsorbents for removing arsenic. In this study, seven locally available low-cost materials were tested for arsenic removal by conducting batch adsorption experiments. Of these materials, a natural laterite (48.7% Fe2O3 and 18.2% Al2O3) from Thach That (NLTT) was deemed the most suitable adsorbent based on arsenic removal performance, local availability, stability/low risk and cost (US$ 0.10/kg). Results demonstrated that the adsorption process was less dependent on the solution pH from 2.0 to 10. The coexisting anions competed with As(III) and As(V) in the order, phosphate > silicate > bicarbonate > sulphate > chloride. The adsorption process reached a fast equilibrium at approximately 120-360 min, depending on the initial arsenic concentrations. The Langmuir maximum adsorption capacities of NLTT at 30 °C were 512 μg/g for As(III) and 580 μg/g for As(V), respectively. Thermodynamic study conducted at 10 °C, 30 °C, and 50 °C suggested that the adsorption process of As(III) and As(V) was spontaneous and endothermic in nature. A water filtration system packed with NLTT was tested in a childcare centre in the most disadvantaged community in Ha Nam province, Vietnam, to determine arsenic removal performance in an operation lasting six months. Findings showed that the system reduced total arsenic concentration in groundwater from 122 to 237 μg/L to below the Vietnam drinking water standard of 10 μg/L.
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Affiliation(s)
- Thi Hai Nguyen
- Faculty of Engineering and IT, University of Technology Sydney (UTS), Sydney, Australia; Institute of Environmental Technology, Vietnam Academy of Science and Technology, Hanoi, Viet Nam
| | - Hai Nguyen Tran
- Institute of Fundamental and Applied Sciences, Duy Tan University, Ho Chi Minh City, Viet Nam
| | - Hai Anh Vu
- Institute of Chemistry, Vietnam Academy of Science and Technology, Hanoi, Viet Nam
| | - Minh Viet Trinh
- Institute of Environmental Technology, Vietnam Academy of Science and Technology, Hanoi, Viet Nam
| | - Tien Vinh Nguyen
- Faculty of Engineering and IT, University of Technology Sydney (UTS), Sydney, Australia.
| | | | | | - Tuan Minh Nguyen
- Institute of Environmental Technology, Vietnam Academy of Science and Technology, Hanoi, Viet Nam
| | - Van Tuyen Trinh
- Institute of Environmental Technology, Vietnam Academy of Science and Technology, Hanoi, Viet Nam
| | - Duc Loi Vu
- Institute of Chemistry, Vietnam Academy of Science and Technology, Hanoi, Viet Nam
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Nguyen LH, Vu TM, Le TT, Trinh VT, Tran TP, Van HT. Ammonium removal from aqueous solutions by fixed-bed column using corncob-based modified biochar. Environ Technol 2019; 40:683-692. [PMID: 29161983 DOI: 10.1080/09593330.2017.1404134] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 10/26/2017] [Indexed: 06/07/2023]
Abstract
This study investigated the potential of removing ammonium ([Formula: see text]) from aqueous solutions using corncob based on modified biochar (MBCC) in the fixed-bed column. Corncob biochar was soaked in a mixture of HNO3 6.0 M and NaOH 0.3 M to prepare active binding sites for ammonium removal. The effect of initial ammonium concentrations (10-40 mg/L), flow rates (1-9 mL/min) and MBCC fixed-bed heights (8-24 cm) on the breakthrough characteristics of the adsorption system were studied. The results showed that the highest adsorption capacity of fix-bed column, the breakthrough time and value of Ct/Co were 12.83 mg/g, 480 min and 0.862 ± 0.025 at 10 mg/L of initial ammonium concentration, 8 cm of MBCC fixed-bed height and 3 mL/min of flow rate, respectively. The breakthrough curve model in this study also indicated that all Yoon-Nelson, Thomas and Adam-Bohart models well fit with the experimental data with a high R2. The results also proved that MBCC can be used as a potential adsorbent for eliminating [Formula: see text] in the fixed-bed column. The saturated MBCC was also regenerated and reused consecutively for four cycles. The usage of mixture of NaOH and NaCl in recovering MBCC was better than NaCl only.
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Affiliation(s)
- Lan Huong Nguyen
- a Faculty of Biotechnology and Environmental Engineering , Ho Chi Minh City University of Food Industry (HUFI) , Ho Chi Minh City , Viet Nam
| | - Thi Mai Vu
- b Hanoi University of Natural Resources and Environment , Ha Noi , Viet Nam
| | - Thi Trinh Le
- b Hanoi University of Natural Resources and Environment , Ha Noi , Viet Nam
| | - Van Tuyen Trinh
- c Institute of Environmental Technology (IET) , Vietnam Academy of Science and Technology , Ha Noi , Viet Nam
| | - Thi Pha Tran
- d Faculty of Environment , Thai Nguyen University of Agriculture and Forestry , Thai Nguyen city , Viet Nam
| | - Huu Tap Van
- e Faculty of Environment and Earth Science , Thai Nguyen University of Sciences (TNUS) , Thai Nguyen city , Viet Nam
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Trinh TT, Hoang TS, Tran DA, Trinh VT, Göhler A, Nguyen TT, Hoang SN, Krumkamp R, Nguyen LTN, May J, Doan PM, Do CD, Que TA, Steinmetz I. A simple laboratory algorithm for diagnosis of melioidosis in resource-constrained areas: a study from north-central Vietnam. Clin Microbiol Infect 2017; 24:84.e1-84.e4. [PMID: 28780059 DOI: 10.1016/j.cmi.2017.07.029] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 06/26/2017] [Accepted: 07/26/2017] [Indexed: 01/25/2023]
Abstract
OBJECTIVES Melioidosis may be endemic in many tropical developing countries, but diagnosis of the disease is currently unreliable in resource-limited areas. We aimed to validate a simple and cheap laboratory algorithm for the identification of Burkholderia pseudomallei from clinical specimens in parts of Vietnam where the disease has not previously been reported. METHODS In June 2015, we conducted training courses at five general hospitals in north-central provinces in order to raise awareness of the disease and to introduce a simple and cheap laboratory identification algorithm for B. pseudomallei including the three-antibiotic disc test. RESULTS Until the end of the year (7 months later), 94 suspected B. pseudomallei strains resistant to gentamicin and colistin but sensitive to amoxicillin/clavulanic acid were detected in clinical specimens from 70 patients. All strains were further confirmed as B. pseudomallei by using a specific TTSS1 real-time PCR assay and recA sequencing analysis. Among positive blood cultures, positive rates with B. pseudomallei ranged from 3.4% (5/147) to 10.2% (32/312) in the various clinics. A total of 82.8% (58/70) patients were bacteraemic, with a mortality of 50% (18/36) among patients with known outcome. No death occurred in nonbacteraemic patients. CONCLUSIONS Our results demonstrate that the introduction of a simple and easy-to-perform laboratory algorithm for the identification of B. pseudomallei from clinical samples, together with clinical awareness raising, can lead to the diagnosis of a significant number of melioidosis cases in resource-limited clinical laboratories which previously did not identify the pathogen.
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Affiliation(s)
- T T Trinh
- Institute of Microbiology and Biotechnology, Vietnam National University, Hanoi, Viet Nam.
| | - T S Hoang
- Institute of Microbiology and Biotechnology, Vietnam National University, Hanoi, Viet Nam
| | - D A Tran
- General Hospital of Nghe An Province, Viet Nam
| | - V T Trinh
- General Hospital of Ha Tinh Province, Viet Nam
| | - A Göhler
- Friedrich Loeffler Institute for Medical Microbiology, Greifswald, Germany
| | - T T Nguyen
- General Hospital of Quang Binh Province, Viet Nam
| | - S N Hoang
- General Hospital of Quang Tri Province, Viet Nam
| | - R Krumkamp
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany; German Centre for Infection Research (DZIF), Hamburg-Borstel-Lübeck, Germany
| | | | - J May
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany; German Centre for Infection Research (DZIF), Hamburg-Borstel-Lübeck, Germany
| | - P M Doan
- Bach Mai Hospital, Hanoi, Viet Nam
| | - C D Do
- Bach Mai Hospital, Hanoi, Viet Nam
| | - T A Que
- General Hospital of Nghe An Province, Viet Nam
| | - I Steinmetz
- Friedrich Loeffler Institute for Medical Microbiology, Greifswald, Germany; Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Graz, Austria
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Vu TM, Trinh VT, Doan DP, Van HT, Nguyen TV, Vigneswaran S, Ngo HH. Removing ammonium from water using modified corncob-biochar. Sci Total Environ 2017; 579:612-619. [PMID: 27890415 DOI: 10.1016/j.scitotenv.2016.11.050] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 11/07/2016] [Accepted: 11/08/2016] [Indexed: 05/14/2023]
Abstract
Ammonium pollution in groundwater and surface water is of major concern in many parts of the world due to the danger it poses to the environment and people's health. This study focuses on the development of a low cost adsorbent, specifically a modified biochar prepared from corncob. Evaluated here is the efficiency of this new material for removing ammonium from synthetic water (ammonium concentration from 10 to 100mg/L). The characteristics of the modified biochar were determined by Brunauer-Emmett-Teller (BET) test, Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM). It was found that ammonium adsorption on modified biochar strongly depended on pH. Adsorption kinetics of NH4+-N using modified biochar followed the pseudo-second order kinetic model. Both Langmuir and Sips adsorption isotherm models could simulate well the adsorption behavior of ammonium on modificated biochar. The highest adsorption capacity of 22.6mg NH4+-N/g modified biochar was obtained when the biochar was modified by soaking it in HNO3 6M and NaOH 0.3M for 8h and 24h, respectively. The high adsorption capacity of the modified biochar suggested that it is a promising adsorbent for NH4+-N remediation from water.
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Affiliation(s)
- Thi Mai Vu
- Hanoi University of Natural Resources and Environment, Ministry of Natural Resources and Environment, 44 Phu Dien, Tu Niem, Ha Noi, Viet Nam
| | - Van Tuyen Trinh
- Institute of Environmental Technology, Vietnam Academy of Science and Technology, A30, 18 Hoang Quoc Viet Street, Ha Noi, Viet Nam
| | - Dinh Phuong Doan
- Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Street, Ha Noi, Viet Nam
| | - Huu Tap Van
- Faculty of Environment and Earth Science, Thai Nguyen University of Sciences, Tan Thinh ward, Thai Nguyen city, Viet Nam
| | - Tien Vinh Nguyen
- Faculty of Engineering and IT, University of Technology, Sydney (UTS), PO Box 123, Broadway, Sydney, Australia.
| | - Saravanamuthu Vigneswaran
- Faculty of Engineering and IT, University of Technology, Sydney (UTS), PO Box 123, Broadway, Sydney, Australia
| | - Huu Hao Ngo
- Faculty of Engineering and IT, University of Technology, Sydney (UTS), PO Box 123, Broadway, Sydney, Australia.
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Abstract
Adenovirus serotype 5 remains one of the most promising vectors for delivering genetic material to cancer cells for imaging or therapy, but optimization of these agents to selectively promote tumor cell infection is needed to further their clinical development. Peptide sequences that bind to specific cell surface receptors have been inserted into adenoviral capsid proteins to improve tumor targeting, often in the background of mutations designed to ablate normal ligand:receptor interactions and thereby reduce off target effects and toxicities in non-target tissues. Different tumor types also express highly variable complements of cell surface receptors, so a customized targeting strategy using a particular peptide in the context of specific adenoviral mutations may be needed to achieve optimal efficacy. To further investigate peptide targeting strategies in adenoviral vectors, we used a set of peptide motifs originally isolated using phage display technology that evince tumor specificity in vivo. To demonstrate their abilities as targeting motifs, we genetically incorporated these peptides into a surface loop of the fiber capsid protein to construct targeted adenovirus vectors. We then systematically evaluated the ability of these peptide targeted vectors to infect several tumor cell types, both in vitro and in vivo, in a variety of mutational backgrounds designed to reduce CAR and/or HSG-mediated binding. Results from this study support previous observations that peptide insertions in the HI loop of the fiber knob domain are generally ineffective when used in combination with HSG detargeting mutations. The evidence also suggests that this strategy can attenuate other fiber knob interactions, such as CAR-mediated binding, and reduce overall viral infectivity. The insertion of peptides into fiber proved more effective for targeting tumor cell types expressing low levels of CAR receptor, as this strategy can partially compensate for the very low infectivity of wild-type adenovirus in those cells. Nevertheless, the incorporation of relatively low affinity peptide ligands into the fiber knob, while effective in vitro, has only minimal targeting efficacy in vivo and highlights the importance of high affinity ligand:receptor interactions to achieve tumor targeting.
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Affiliation(s)
- E N Ballard
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390-8573, USA
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