APPLICATION OF NITROSOMONAS AND ANAMMOX COMBINATION IN A REACTOR FOR AMMONIUM REMOVAL IN SWINE WASTEWATER

This study investigated the combination of two kinds of autotrophic bacteria, named Anammox and Nitrosomonas in a reactor to remove ammonium existed in swine wastewater. The reactor which was operated with swine wastewater taken from Dong A pig breeding enterprise (Di An, Binh Duong) had 15 liters volume. The biomass carrier used in this model was made from the synthetic acrylic with attached capacity of 0.5-0.6g-SS/g-material. The sludge was taken from a reactor using partial nitritation/Anammox processes of a previous study at Vietnam Academy of Science and Technology. In 118 days of operation, average influent ammonium was 350mg/l, feeding to three loading rates (LR) 0.47, 0.70, 0.93 kg N-NH4+/m3/day with flow rate 20, 30, 40 liters, respectively. The highest efficiency was found at the first loading rate 0.47 kg N-NH4+/m3/day with 91.55 %. The other loading rates 0.70 and 0.93 kg N-NH4+/m3/day gave lower efficiency, 78.08 and 70.5 %, respectively. VSS at the beginning and the end of the operation were 4g/l and 9.4 g/l, respectively. The optimum pH for the reactor was in range of 7.8 - 8.0

Simulation of Ballast Water Dispersion in the Gulf of Tonkin and Offshore Waters of Hai Phong Port, Vietnam

Transfer of invasive alien organisms and their negative impacts have been recorded around the world. It is estimated that approximately 7,000 species of marine creatures are silently moved around the world by ballast water every hour. Recently, discharge of ballast water in the coastal area has become a serious concern. The movement of discharged ballast water and accompanying alien organisms largely depends on the preveiling hydrodynamics of the receiving water body. Dynamics simulation models for marine environment provide sound prediction of dispersion of ballast water. The study was undertaken in the seas of the Gulf of Tonkin and in the offshore area of Hai Phong Port using the MIKE 21 model – a two-dimensional hydrodynamics model. The yearly-mean wind field was used in the model to generate the circulation. Ballast water discharged to the three sites in the study area was simulated by using dispersal-advection model. The outputs showed that ballast water discharged near the coast tends to move along the coastline. Ballast water discharged at 200 NM seaward from the coast is still able to influence the coastal zone of Vietnam

Awareness And Risk Behaviors Towards Zoonotic Disease Among Ethnic Minority In Mountainous Area Of Central Vietnam

Background: As a result of the population explosion and rapid urbanization, human activities have been causing negative impacts on the environment. The changing patterns of transmissible diseases among wild animals, livestock and human have been getting more and more complicated in the context of climate change. Ethnic community from mountainous and isolated areas undoubtedly are the most vulnerable, with the high risk of emerging and re-emerging zoonosis. Objectives: To explore the awareness and risk behaviors of the residents in Nham commune, A Luoi district towards zoonosis transmission. To determine the factors related to the risk behaviors of the residents. Methods: A sectional-cross study was conducted among 230 residents whose ages range from 18 – 85, currently living in Nham commune, A Luoi district, adjacent to the Vietnam – Laos border. All participants were interviewed directly with a questionnaire including the following categories: demographics, household wealth, awareness of zoonosis, livestock management and behaviors related to wildlife animals. Descriptive analysis and multivariable logistic regression analysis were conducted to determine factors associated with risk behaviors. Results: The proportion of respondents who have heard about zoonotic diseases was 40%. The majority of subjects raise free-range livestock (83,4%), especially on poultry and cow. The percentage of participants who consumed culled sick and dead animals accounted for 26%, over 30% of villagers slept in forest and more than 50% consumed bushmeat. Risk behaviors related to management livestock and wildlife were statistically significantly associated with gender, age of subjects, educational background, household wealth, information approach on zoonosis, and the number of livestocks. Conclusions: The proportion of respondents who have heard about zoonotic diseases was 40%. The high-risk group falls on those who consume dead domestic animals, wildlife animals and sleep in the forest. Behaviors of human-wildlife contact and zoonosis are quite common with the Nham locals, which emphasizes the necessity for intervention programs in zoonotic disease control.

The first successful bone marrow transplantation in Vietnam for a young Vietnamese boy with chronic granulomatous disease: a case report

BackgroundChronic granulomatous disease (CGD) is an inborn error of immunity (IEI) disorder that results from defects in the respiratory burst activity in phagocytes, leading to the inability to kill bacterial and fungal microorganisms. CGD patients usually have a high incidence of morbidity such as infections and autoinflammatory diseases and a high mortality rate. Allogeneic bone marrow transplantation (BMT) is the only definitive cure for patients who suffer from CGD.Case presentationWe report the first transplant case of chronic granulomatous disease in Vietnam. A 25-month-old boy with X-linked CGD underwent bone marrow transplantation from his 5-year-old, full-matched human leukocyte antigen (HLA)-carrier sibling after myeloablative conditioning regimen with busulfan 5.1 mg/kg/day for 4 days, fludarabine 30 mg/m2/day for 5 days, and rATG (Grafalon-Fresenius) 10 mg/kg/day for 4 days. Neutrophil was engrafted on day 13 posttransplant, donor chimerism was 100% on day 30 with the dihydrorhodamine-1,2,3 (DHR 123) flow cytometric assay test that reached 38% of the normal 45 days posttransplant. Five months after transplant, the patient was free of infection with stable DHR 123 assay at 37%, and donor chimerism remained 100%. No sign of a graft-versus-host disease had been observed posttransplant.ConclusionWe suggest that bone marrow transplantation is a safe and effectual cure for CGD patients, especially for patients with HLA-identical siblings

A Clinically Oriented antimicrobial Resistance surveillance Network (ACORN): pilot implementation in three countries in Southeast Asia, 2019-2020

Background: Case-based surveillance of antimicrobial resistance (AMR) provides more actionable data than isolate- or sample-based surveillance. We developed A Clinically Oriented antimicrobial Resistance surveillance Network (ACORN) as a lightweight but comprehensive platform, in which we combine clinical data collection with diagnostic stewardship, microbiological data collection and visualisation of the linked clinical-microbiology dataset. Data are compatible with WHO GLASS surveillance and can be stratified by syndrome and other metadata. Summary metrics can be visualised and fed back directly for clinical decision-making and to inform local treatment guidelines and national policy. Methods: An ACORN pilot was implemented in three hospitals in Southeast Asia (1 paediatric, 2 general) to collect clinical and microbiological data from patients with community- or hospital-acquired pneumonia, sepsis, or meningitis. The implementation package included tools to capture site and laboratory capacity information, guidelines on diagnostic stewardship, and a web-based data visualisation and analysis platform. Results: Between December 2019 and October 2020, 2294 patients were enrolled with 2464 discrete infection episodes (1786 community-acquired, 518 healthcare-associated and 160 hospital-acquired). Overall, 28-day mortality was 8.7%. Third generation cephalosporin resistance was identified in 54.2% (39/72) of E. coli and 38.7% (12/31) of K. pneumoniae isolates. Almost a quarter of S. aureus isolates were methicillin resistant (23.0%, 14/61). 290/2464 episodes could be linked to a pathogen, highlighting the level of enrolment required to achieve an acceptable volume of isolate data. However, the combination with clinical metadata allowed for more nuanced interpretation and immediate feedback of results. Conclusions: ACORN was technically feasible to implement and acceptable at site level. With minor changes from lessons learned during the pilot ACORN is now being scaled up and implemented in 15 hospitals in 9 low- and middle-income countries to generate sufficient case-based data to determine incidence, outcomes, and susceptibility of target pathogens among patients with infectious syndromes

Surface-Plasma-Induced One-Pot Synthesis of N,S-Carbon Dot Intercalated MoS₂/Graphene Nanosheets for Highly Efficient Hydrogen Evolution Reaction

Herein, a facile and rapid surface-plasma-induced method was adopted for the one-pot synthesis of a 2D/0D/2D hybrid nanostructure consisting of N,S co-doped carbon dots (NSCD) intercalated few-layer MoS2/graphene nanosheets (MoS2/G) as an excellent catalyst for the hydrogen evolution reaction (HER). In this process, bulk MoS2 and graphite foil served as the sources of MoS2 and graphene nanosheets, respectively, while glucose and thiourea served as the source of NSCD. The sturdy integration of 0D NSCD and 2D MoS2/G in a well-constructed ternary composite provided a huge number of edge active sites with tunable and extraordinary physicochemical properties for electron transport, facilitating HER performance. The optimal NSCD@MoS2/G exhibited a superior catalytic activity toward HER with a low onset potential (37 mV), an overpotential of 98 mV at 10 mA cm–2, and a Tafel slope as small as 53 mV dec–1, which were better than other 2D electrocatalysts. The increase in double-layer capacitance for NSCD@MoS2/G (12.2 mF cm–2), which was 2-fold of the MoS2/G sample, is strong evidence of the large catalytic edge sites and electrical coupling in the NSCD@MoS2/G ternary system. Moreover, the strong bonding and interaction between NSCD and MoS2/G nanosheets enabled outstanding long-term stability and structural integrity, displaying 95 and 90% activity retention at 10 and 50 mA cm–2 after 48 h i–t test, respectively. This approach paves the way to efficient syntheses of 2D/0D/2D heterostructures with great potential for various energy-related applications

Surface-Plasma-Induced One-Pot Synthesis of N,S-Carbon Dot Intercalated MoS₂/Graphene Nanosheets for Highly Efficient Hydrogen Evolution Reaction

Herein, a facile and rapid surface-plasma-induced method was adopted for the one-pot synthesis of a 2D/0D/2D hybrid nanostructure consisting of N,S co-doped carbon dots (NSCD) intercalated few-layer MoS2/graphene nanosheets (MoS2/G) as an excellent catalyst for the hydrogen evolution reaction (HER). In this process, bulk MoS2 and graphite foil served as the sources of MoS2 and graphene nanosheets, respectively, while glucose and thiourea served as the source of NSCD. The sturdy integration of 0D NSCD and 2D MoS2/G in a well-constructed ternary composite provided a huge number of edge active sites with tunable and extraordinary physicochemical properties for electron transport, facilitating HER performance. The optimal NSCD@MoS2/G exhibited a superior catalytic activity toward HER with a low onset potential (37 mV), an overpotential of 98 mV at 10 mA cm–2, and a Tafel slope as small as 53 mV dec–1, which were better than other 2D electrocatalysts. The increase in double-layer capacitance for NSCD@MoS2/G (12.2 mF cm–2), which was 2-fold of the MoS2/G sample, is strong evidence of the large catalytic edge sites and electrical coupling in the NSCD@MoS2/G ternary system. Moreover, the strong bonding and interaction between NSCD and MoS2/G nanosheets enabled outstanding long-term stability and structural integrity, displaying 95 and 90% activity retention at 10 and 50 mA cm–2 after 48 h i–t test, respectively. This approach paves the way to efficient syntheses of 2D/0D/2D heterostructures with great potential for various energy-related applications

Surface-Plasma-Induced One-Pot Synthesis of N,S-Carbon Dot Intercalated MoS₂/Graphene Nanosheets for Highly Efficient Hydrogen Evolution Reaction

Herein, a facile and rapid surface-plasma-induced method was adopted for the one-pot synthesis of a 2D/0D/2D hybrid nanostructure consisting of N,S co-doped carbon dots (NSCD) intercalated few-layer MoS2/graphene nanosheets (MoS2/G) as an excellent catalyst for the hydrogen evolution reaction (HER). In this process, bulk MoS2 and graphite foil served as the sources of MoS2 and graphene nanosheets, respectively, while glucose and thiourea served as the source of NSCD. The sturdy integration of 0D NSCD and 2D MoS2/G in a well-constructed ternary composite provided a huge number of edge active sites with tunable and extraordinary physicochemical properties for electron transport, facilitating HER performance. The optimal NSCD@MoS2/G exhibited a superior catalytic activity toward HER with a low onset potential (37 mV), an overpotential of 98 mV at 10 mA cm–2, and a Tafel slope as small as 53 mV dec–1, which were better than other 2D electrocatalysts. The increase in double-layer capacitance for NSCD@MoS2/G (12.2 mF cm–2), which was 2-fold of the MoS2/G sample, is strong evidence of the large catalytic edge sites and electrical coupling in the NSCD@MoS2/G ternary system. Moreover, the strong bonding and interaction between NSCD and MoS2/G nanosheets enabled outstanding long-term stability and structural integrity, displaying 95 and 90% activity retention at 10 and 50 mA cm–2 after 48 h i–t test, respectively. This approach paves the way to efficient syntheses of 2D/0D/2D heterostructures with great potential for various energy-related applications

S-scheme N-doped carbon dots anchored g-C3N4/Fe2O3 shell/core composite for photoelectrocatalytic trimethoprim degradation and water splitting

Photoelectrocatalysis is a promising technique for energy conversion and environmental treatment. This study describes the photoelectrochemical (PEC) degradation of trimethoprim and hydrogen evolution using a photoanode prepared by N-doped carbon dots (NCD) incorporated g-C3N4/α-Fe2O3 (CNFO) shell/core nanocomposite. The electrochemical analysis reveals that the photocurrent density of NCD@CNFO photoanode reached 3.07 mA cm−2 at 1.6 V vs. NHE, which is 4 and 15 times greater than that of CNFO and intact α-Fe2O3, respectively. In the presence of peroxymonosulfate (PMS), the NCD@CNFO photoanode enabled 95 % and 90 % of trimethoprim (TMP) degradation in aqueous solution and lake water, respectively. Hydrogen generation coupled with TMP degradation was also observed in the PEC system, where the H2 generation rate was 550 µmol cm−2 h−1. Both superoxide (•O2−) and hydroxyl (•OH) radicals played a significant role in the degradation of TMP. The achievements could be assigned to the excellent photoabsorption and electron transfer properties of NCD, which enhanced the PEC activity of CNFO by enabling the S-scheme heterojunction to reduce electron-hole recombination. Moreover, PMS served as a cathodic electron acceptor to improve the catalytic properties of NCD@CNFO photoanode, demonstrating its contribution to both water treatment and hydrogen production. Such superior efficiency offers great potential to develop a PEC system using carbon dots/semiconductor hybrid catalysts for antibiotic degradation and synchronous photocatalytic H2 evolution from wastewater, providing an alternative solution to environmental pollution and energy crisis issues.The authors thank the National Science and Technology Council (NSTC), Taiwan, for financial support under grant No 111-2223-E-007-008.Publicad

Effect of Lauric Acid on the Thermal and Mechanical Properties of Polyhydroxybutyrate (PHB)/Starch Composite Biofilms

Polyhydroxybutyrate (PHB) is a biopolymer of natural origin, one of the suitable alternatives for synthetic plastics. However, pure PHB has a high production cost, is relatively brittle, and has poor processability, hence its limited application. Combining PHB with biomass fillers and plasticizers can significantly improve the properties of the polymer, leading to its commercial usage. In this study, PHB was incorporated with starch (S) as a cheap biomass filler and lauric acid (LA) as a potential plasticizer. The PHB/S/LA composites were prepared using a modified solvent casting method with the incremental addition of LA. The PHB/S ratio was maintained at a ratio of 80/20 (w/w). Physicochemical characterization via EDS, XRD, and FTIR proved that the composite components have blended through nucleation and plasticization processes. The morphology of the PHB/S blends was found to be a heterogeneous matrix, with decreased inhomogeneity upon the addition of LA in the composite. Thermal characterization done by TGA and DSC showed that the thermal properties of PHB/S films improved with the addition of LA. Mechanical tests (UTM) proved that the elastic strain of the films also increased with the addition of LA, although the tensile strength decreased slightly compared to pure PHB/S. Overall, the results of this study provide baseline information on the improvement of PHB-based bioplastics