Environmental engineering

1. Hazardous
Waste Treatment
Technologies
Treatment (Biological),
Disposal and Reuse
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2. Report Objectives
Explore biological treatment technologies in managing hazardous
wastes.
Understand hazardous waste disposal and recycling requirements
within local context.
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3. Biological Treatment
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4. Biological Treatment
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5. Biological
Treatment
Conventional organic treatments use
natural organisms to break down or
remove hazardous ingredients. In contrast,
biotechnology uses bacteria that have
been selected from nature, colonize
specific substrates, and induce mutations
using methods such as UV exposure to
attach suitable traits. Many hazardous
substances cannot be biodegraded,
although they can be effectively removed
from the waste stream in this way.
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6. Biological
Treatment
These techniques have been widely used
to treat municipal and industrial waste to
prevent odor gas formation, kill infectious
microorganisms, remove nutrients for
aquatic flora and remove or destroy
certain toxic compounds. Several
biological techniques can be used as a
series of steps for waste treatment.
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7. Activated
Sludge
Activated sludge (AS) is an industrial wastewater
and wastewater treatment process and was
developed around 1912-1914. There are many
designs, however, in principle, all ASs consist of
three components. main part: aeration in the tank,
acting as a bioreactor; a settling tank ("final
clarifier") to separate AS solids and treated
wastewater; activated sludge return (ARS) device
to transfer the settled AS from the sump to the
aeration tank inlet. Air in the air or, in rare cases,
pure oxygen, introduced into a mixture of treated
or primary screened wastewater (or industrial
wastewater) combines with organisms to grow a
biological floc (“Activated Sludge” AS). The mixture
of raw wastewater (or industrial wastewater) and
biological mass is often referred to as Mixed Liquor.
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8. Activated
Sludge
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9. Aerated
Lagoon
In a wastewater treatment
plant, an aerated lagoon is a
suspended-growth process.
The aerated lagoon water
treatment system is made up of
a large earthen lagoon or basin
with mechanical aerators to
maintain an aerobic
environment and prevent
suspended biomass from
settling.
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10. Types of
Aerated
Lagoons
Suspended Growth Aerated lagoons
Suspended growth aerated lagoons are
shallow earthen basins with mechanical
aerators on floats or fixed platforms, with
a depth ranging from 2 to 5 meters.
Mechanical aerators offer oxygen for
biological wastewater treatment while
also keeping biological materials
suspended.
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11. Types of
Aerated
Lagoons
Facultative Aerated Lagoon
Aeration is sufficient for oxygenation
but not for keeping solids in
suspension in facultative aerated
lagoon water treatment, some solids
escape with the effluent stream and
others settle down in the lagoon. The
word facultative is applied to aerated
lagoons because the lowest levels may
be anaerobic while the upper layers
are aerobic. Because of their ease of
operation and lack of machinery,
facultative aerated lagoons have
become more popular around the
world.
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12. Trickling Filter
Trickling filters are a unique type of fixed film biological
treatment. In a trickling filter, the microorganisms used to
treat the wastewater are attached, or fixed, to a medium
as they contact the wastewater. These microorganisms
form a slim growth on the medium known as zoogleal
film. Wastewater applied to a trickling filter has already
passed through a mechanical bar screen and/or primary
clarifiers where the majority of settleable and floatable
solids are removed.
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13. Trickling Filter
Wastewater is distributed over the top of the medium and
slowly trickles through it. The biological growth is attached to
the media. Trickling filter effluent always passes through a
secondary clarifier or sand filter to allow for capture of solids
generated as a result of treating the wastewater. The sludge
(solids) from a final clarifier should be pumped back to the
primary clarifier or to a sludge thickener for further treatment.
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14. Biocontactors
Rotating biological contactors (RBC), also called
rotating biological filters, are fixed-bed reactors
consisting of stacks of rotating disks mounted on a
horizontal shaft. They are partially submerged and
rotated as wastewater flows through. They are used
in conventional wastewater treatment plants as
secondary treatment after primary sedimentation of
domestic grey- or blackwater, or any other
biodegradable effluent. The microbial community is
alternately exposed to the atmosphere and the
wastewater, allowing both aeration and assimilation
of dissolved organic pollutants and nutrients for
their degradation.
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15. Biocontactors
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16. Packed Bed Reactors
Packed bed reactors are very versatile and
are used in many chemical processing
applications such as absorption, distillation,
stripping, separation processes, and
catalytic reactions. Across the diverse
applications in which they are used, the
physical dimensions of the beds can vary
greatly. Typical reactors consist of a
chamber, such as a tube or channel that
contains catalyst particles or pellets, and a
liquid that flows through the catalyst. The
liquid interacts with the catalyst across the
length of the tube, altering the chemical
composition of the substance.
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17. Stabilization
Ponds
Is a relatively shallow body of
wastewater contained in an
earthen man-made basin into
which wastewater flows and
from which, after a certain
retention time (time that takes
the effluent to flow from the inlet
to the outlet), a well-treated
effluent is discharged.
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18. Anaerobic Digestion
Anaerobic digestion is a process through which bacteria break down organic
matter—such as animal manure, wastewater biosolids, and food wastes—in
the absence of oxygen. Anaerobic digestion for biogas production takes
place in a sealed vessel called a reactor, which is designed and constructed
in various shapes and sizes specific to the site and feedstock conditions.
These reactors contain complex microbial communities that break down (or
digest) the waste and produce resultant biogas and digestate (the solid and
liquid material end-products of the AD process) which is discharged from the
digester.
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19. Anaerobic
Digestion
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20. Disposal and Recycling
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22. References
• https://www.princeton.edu/~ota/disk3/1983/8323/832307.PDF
• https://www.iwapublishing.com/news/activated-sludge-process
• https://www.thewatertreatments.com/wastewater-sewage-treatment/aerated-lagoon/
• https://water.mecc.edu/courses/ENV110/lesson15b.htm
• https://sswm.info/water-nutrient-cycle/wastewater-treatment/hardwares/semi-centralised-
wastewater-treatments/rotating-biological-contactors
• https://www.climate-policy-watcher.org/wastewater-treatment/stabilization-ponds.html
• https://www.epa.gov/agstar/how-does-anaerobic-digestion-work
• https://www.epa.gov/anaerobic-digestion/basic-information-about-anaerobic-digestion-ad
• Google Images
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23. References
• https://emb.gov.ph/hazardouswastemanagementsection/
• https://www.env.go.jp/en/recycle/asian_net/Country_Information/Law_N_Regulati
on/Philippines/DAO%201992-29.pdf
• https://emb.gov.ph/wp-content/uploads/2016/06/dao20041.pdf
• https://emb.gov.ph/wp-content/uploads/2018/06/dao-2013-22.pdf
• https://emb.gov.ph/wp-content/uploads/2020/11/proposed-revisions-to-DAO-
2013-22_-October-22-2020.pdf
• http://www.eolss.net/sample-chapters/c09/e4-13-05-03.pdf
• file:///C:/Users/LOUIE/Downloads/Classification-of-Hazardous-Waste-new.pdf
• file:///C:/Users/LOUIE/Downloads/Hazardous_Waste_Disposal_Flow_Chart.pdf
• Google Images
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