African swine fever (ASF) is a highly contagious virus and classified as a notifiable disease by the World Organization for Animal health (OIE) (Tulman, Delhon, Ku, & Rock, 2009). It is a double-stranded DNA virus of the Asfarviridae family, genus Asfivirus (Dixon et al., 2005). The disease causes acute haemorrhagic fever with mortality of up to 100% depending on the virulence of the isolate, dose and route of exposure to the virus (Costard, Mur, Lubroth, Sanchez-Vizcaino, & Pfeiffer, 2013). Pigs are infected via contact

In this study, three good biofilm-forming yeast strains, including Candida viswanathii TH1, Candida tropicalis TH4 and Trichosporon asahii B1, were isolated from oil-contaminated water and sediment samples collected in coastal zones of Vietnam. These strains were registered in the GenBank database with the accession numbers JX129175, JX129176 and KC139404 for strain TH1, TH4 and B1, respectively. The biofilm formed by a mixture of these organisms degraded 90, 85, 82 and 67% of phenol, naphthalene, anthracene and pyrene, respectively, after a 7-day incubation period using an initial concentration of 600 ppm phenol and 200 ppm of each of the other compounds. In addition, this biofilm completely degraded these aromatic compounds, which were from wastewater collected from petroleum tanks in Do Xa, Hanoi after 14 days of incubation based on gas chromatography mass spectrometry analysis. To the best of our knowledge, reports on polycyclic aromatic hydrocarbon and phenol degradation by biofilm-forming yeasts are limited. The results obtained indicate that the biofilm formed by multiple yeast strains may considerably increase the degradation efficiency of aromatic hydrocarbon compounds, and may lead to a new approach for eliminating petroleum oil-contaminated water in Vietnam.

Competing interestsNo potential conflict of interest relevant to this article was reported. Funding sourcesState funding sources (grants, funding sources, equipment, and supplies). Include name and number of grant if available.

ZnSe nanoparticles (NPs) were prepared by combining both hydrothermal and mechanical milling methods. Transmission electron microscopy images show that fabricated ZnSe NPs with a sphere-like shape have an average size (d) in the range of 20–100 nm, affected by changing the milling time from 10 to 60 min. All the samples crystalize in zincblende-type structure without impurities, as confirmed by analyzing X-ray diffraction patterns, Raman spectra, and energy-dispersive X-ray spectroscopy. Carefully checking Raman spectra, we have observed the broadening and redshift of vibration modes as decreasing NP size, which are ascribed to extra appearance of disorder and defects. The photoluminescence study has found a blue emission at 462 nm attributed to the excitonic near-band edge and a broad defect-related emission around 520–555 nm. Increasing milling time leads to the decrease in the exciton-emission intensity, while the defect-related emissions increase gradually. Interestingly, as decreasing d, we have observed an improved photodegradation of Rhodamine B under UV irradiation, proving application potentials of ZnSe NPs in photocatalytic activity.

Wastewater treatment plants (WWTPs) generate significant amount of sewage sludge (SS). Besides, faecal sludge (FS) generated from popularly existing septic tanks in cities need also adequate treatment. Selection of appropriate sludge treatment options is among most challenging wastewater management issues for fast growing cities. The case study has selected the central part of Hanoi city, with expected population of 2,145,437 persons by 2030, total design capacity of WWTPs 588,300 m3/day, whereas different options of SS and FS management were analysed. The calculation results shown that an energy required for operation of sludge treatment processes in scenarios 2, 3 and 4 could be fully self-sufficient. Besides, with total energy demand for operation of WWTPs was of 311,799 kWh/day, 21.3% (scenario 2), 99.3% (scenario 3) or 71.3% (scenario 4) of demand could be covered by remaining biogas produced from anaerobic co-digestion of SS and FS. A conventional SS treatment process, dewatering by centrifuge and dumping dewatered sludge to the landfill (scenario 1) did not generate any energy but required an energy of 17,371 kWh/day for SS treatment and dumping. Anaerobic co-digestion of SS, FS, other organic fractions, can be a promising sludge management solution aiming at energy efficiency and resource recovery.