Fate of enteric viruses and bacteriophages in sequencing batch reactor treating domestic wastewater : Luận văn ThS. Kỹ thuật hoá học, vật liệu, luyện kim và môi trường: 605203
Research purposes and significance Viruses cause harm to humans because they are very small in size and therefore move in water and can cause disease with very low dose. A group of viral pathogens, from within the human body, excrete through the feces, and overdisperse the drainage pipes. Current...
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Format: | Theses and Dissertations |
Language: | English |
Published: |
2019
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Online Access: | http://repository.vnu.edu.vn/handle/VNU_123/65743 |
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Institution: | Vietnam National University, Hanoi |
Language: | English |
Summary: | Research purposes and significance
Viruses cause harm to humans because they are very small in size and therefore
move in water and can cause disease with very low dose. A group of viral
pathogens, from within the human body, excrete through the feces, and overdisperse the drainage pipes. Currently, researchers have identified several types of
enteric viruses in the domestic effluent (Wong et al., 2012) mainly including
enteroviruses (EVs), rotaviruses (RVs), adenoviruses (AdVs), noroviruses (NVs)
hepatitis A virus (HAV) and astroviruses (AVs). The virus is responsible for some
infectious diseases such as gastroenteritis, conjunctivitis, and respiratory disease,
both developed and developing countries throughout the world. Therefore, studying
the behavioral characteristics, existence or inactivated of the viruses in the water
treatment stages of the plant is the most important.
It is complicated and expensive to analyze all types of virus. At present, many
previous studies have tried to identify suitable viral indicators of wastewater
treatment efficiency. Several studies have proposed F- specific coliphages can be a
good indicator monitoring the virus removal from wastewater (Tree et al., 2003;
Duran et al., 2003), because there have similar morphological characteristics with
many enteric viruses suggesting that they have the same single-stranded RNA,
icosahedral shape, less than 50nm, and they are more persistent than bacteria. FSpecific coliphages are bacteriophages that infect Escherichia coli cells. These
FRNA coliphages include MS-2 in group I, GA in group II, Qβ in group III and SP
in group IV.
GII and GIII F-RNA phage genotypes was found primarily from human feces, while
GI and GIV F-RNA phage genotype are involved in animal waste (Vinjé et al.,
2004). The use of F- specific coliphages as indicators of the presence and behavior
of enteric viruses and animal enteric viruses has always been attractive because of the easy of detection and low cost associated with plaque assay and for similarity to
enteric viruses in terms of transport and survival characteristics.
Scope and objective
This research studied the fate of enteric viruses and bacteriophages during the phase
of sequencing batch reactor treatment plant. Sequencing batch reactor (SBR) is a fill
and draws activated sludge system. In this system, each tank in the SBR system is
filled during a discrete period of time and then operated as a batch reactor. It means,
once the reactor is full, it behaves like a conventional activated sludge system, but
without a continuous influent or effluent flow. The aeration and mixing are
discontinued after the biological reactions are complete, the biomass settles, and the
treated supernatant is removed. The reason why this study chooses SBR system
because the hydraulic retention time is time-based so there is no short-circuiting.
The influent and effluent can be pair so it is easy to observe the treatment efficiency
using only a grab sample. In addition, almost no research data in sequencing batch
reactor for viruses’ removal. So SBR system is the good target for an assessment of
virus.
This study has three main objectives:
1.To investigate the removal of enteric viruses and F-RNA phages in SBR
system.
2.To evaluate the concentration of enteric viruses and F-RNA phages in
activated sludge.
3.To find out the relationship between FRNA phage specific group I, II, III, IV
and enteric viruses. |
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