Module 5 Flashcards
Airport operators need to pay attention to their wide range of fluid discharges. These particularly includes:
de-icing fluids, handling fuels, stormwater runoffs
melt existing and inhibit the further formation of snow and ice
antiicing/de-icing fluids (ADF)
can pollute groundwater
de-icing fluid
has been the cause of multiple accidents
accumulated snow and ice
can severely damage the environment, particularly groundwater and wildlife
leaks and spills
these chemicals used on the airport property can also have major adverse environmental impacts if leaks and spills occur
aircraft servicing and maintenance fluids, firefighting fluids, pesticides and herbicides
The large quantities of water can create ______ that can cause runway or taxiway closures if the airport drainage system is not designed properly.
flash floods
It is the act of reducing the severity of an impact.
mitigation
What does EPA stand for?
Environment Protection Agency
What does the EPA do?
- reduction of the amounts used
- collection and disposal of fluids
- recycling
Centralized De-icing Facilities
Denver/International, Montreal/Trudeau, Toronto/Pearson
Big reduce to ADFs, but demands very high power
Infrared Heaters
De-Icing na mga bagay
special vehicles, settling pools, infrared heaters
solutions for fuel and other chemical leaks and spills
reliable fuel storage, distributed fuel system, effective cleanup procedures, secondary containment, zoned leak detection systems
protection against accidental spills or deliberate sabotage
secondary containment
built around the tanks to contain massive spills
berms
used to identify volumetric changes of the product
zoned leak detection systems
solution for stormwater runoffs
drainage system
permit to allow discharge on surface water
Discharge Permit (US)
permit required by the National Pollution Discharge Elimination System (NPDES)
Discharge Permit (US)
grabs monthly sample to be tested against allowable EPA limits
National Pollution Discharge Elimination System (NPDES)
What does NPDES stand for?
National Pollution Discharge Elimination System
Water treatment methods depend on the ______
characteristics of raw water
depends on the characteristics of raw water
water treatment (methods)
serve multiple purposes, including drinking water, industrial use, and firefighting
public water systems
The treatment method is primarily determined by the need to produce ______ for human consumption.
potable water
It is a crucial step in conventional water treatment
rapid mixing
it’s all about getting chemicals and raw water to know each other very quickly
rapid mixing
the water is gently mixed to allow the clumps to grow larger and heavier
flocculation
also called sedimentation
settling
it is a natural process used in water treatment
settling or sedimentation
it’s like letting dirt settle out of a glass of muddy water
settling or sedimentation
it is a physical process used in water treatment to remove particles suspended in water
filtration
a process widely used in water treatment to disinfect water
chlorination
is a large tank that stores treated water
clear well
are a key part of delivering clean water after it’s treated at a water treatment plant
pumping stations
process of neutralizing or manipulating the electrostatic charges of the particles suspended in the water
coagulation
characteristics of silt particles
small size, colloidal nature, negative charges
when suspended in water, they are hard to eliminate since they are incapable of clumping together to create larger particles that could be more easily cleared out
silt particles
is negatively charged and attracts positively charged ions
solid particle
What do negative ions form given that they are so strongly attracted that they are virtually attached to the particle and travel with it?
slippage or slipping plane
The charge on the particle as it moves through the fluid is the negative charge, diminished in part by the positive ions in the inner layer called the ______
zeta potential
negative charge is considered as a ________
repulsive charge
attractive electrostatic charge
van der Waals force
prevents the particles from coming together
energy hill
objective of coagulation
reduce energy barrier to 0
one way to reduce the energy barrier
adding trivalent cations
with charges opposite those of the suspended solids are added to the water
coagulant chemicals
forms when the small, suspended, neutralized particles stick together
flocs
The building of larger flocs from the smaller particles suspended in the water.
flocculation
Flocculation is typically achieved through the addition of specialized chemicals known as ______.
flocculants
serve to promote particle clumping and aid in the collision and attachment of particles
flocculants
often used together to remove contaminants and impurities
flocculation and coagulation
more easily separated from soluble components (often water) through sedimentation or filtration
aggregates
Larger aggregates. Coagulation or Flocculation?
Flocculation
the initial step in particle aggregation
coagulation
a subsequent step that creates larger and more easily removable agglomerated flocs
flocculation
introduces velocity gradients into the water so that the particles in a fast-moving stream can catch up and collide with slow-moving particles
flocculator
A flocculator introduces ______ into the water so that the particles in a fast-moving stream can catch up and collide with slow-moving particles.
velocity gradients
introduces velocity gradients
rotating paddles
also an important variable in flocculation
time
term often used in design
Gt
t in Gt
hydraulic retention time
the length of time it takes for the water on top to leave the flocculation basin
hydraulic retention time
refers to the process of allowing suspended particles in a fluid, usually water, to settle out of the fluid by gravity, aiding in water treatment and purification
settling
facilitate the removal of suspended solids from liquids through gravitational settling
settling tanks
integral components of water and wastewater treatment systems
settling tanks
aids in the clarification of water by allowing heavier particles to settle to the bottom
settling tanks
4 major zones of a settling tank
inlet zone, outlet zone, settling zone, sludge zone
Types of settling tanks
based on methods of operation, based on location, based on shape
Types of settling tanks based on methods of operation
fill and draw type, continuous flow type
Types of settling tanks based on location
primary tank, secondary tank
Types of settling tanks based on shape
circular tank, rectangular tank, hopper bottom tank
These tanks are designed to ensure uniform flow and minimize turbulence, with entrance and exit configurations being key elements
gravity settling tanks
requires periodic removal via a mud valve, as it does not decompose easily
alum sludge
what does an alum sludge require for removal?
mud valve
produces odoriferous gases and float solids within hours
wastewater treatment sludges
The clarified water leaving settling tanks undergoes further polishing with a ______ to achieve optimal purity
rapid sand filter
2 processes of separating impurities
filtration, backwashing
step-by-step process of cleaning a rapid sand filter
- shut off flow of water
- allow wash water to enter below the filter bed
- allow the wash water to flow
- shut off the wash water
- resume filtration
process of removing the solid impurities in the water
straining, sedimentation, interception, diffusion
most effective process of removing solid impurities in the water for larger particles
straining, sedimentation, interception
this process of removing the solid impurities in the water can occur only for colloidal particles
diffusion
possibly the most important mechanism, takes place exclusively in the first few centimeters of the filter medium, removing only the particles in the water large enough to get caught in the pores
straining
A process where larger and heavier particles do not follow the fluid streamline around the sand grain, and settle on the grain.
sedimentation
A process that occurs with particles that do follow the streamline, but are too large and are caught because they brush up against the sand grain.
interception
A process where larger and heavier particles do not follow the fluid streamline around the sand grain, and settle on the grain.
diffusion
random motion of particles suspended in a medium (a liquid or a gas)
Brownian motion
classifications of filter beds
single medium, dual media, trimedia
filter beds often utilized by wastewater treatment
dual media, trimedia
spread head loss buildup and permit longer filter runs
multimedia filters
a primary condition in filter design
head loss
refers to the pressure loss that occurs due to resistance as water passes through the filter media
head loss
As sand gets progressively dirtier the head loss _____.
increases
proponents of the Cannan-Kozeny Equation
scientists Erich H. von Cannan and J. Kozeny
one of the oldest and most widely used methods; helps us understand how fluids move through materials that have tiny holes or gaps in them
Cannan-Kozeny Equation
proponents of Darcy-Weisbach Equation
Henry Darcy and Julius Weisbach
In scenarios where the head loss of a dirty filter exceeds the total head available, a _________ may form within the filter bed.
negative pressure region
Alternatively, some filters allow water to flow based on the head loss, resulting in ________.
variable flow rate
Process of a typical water treatment facility
- rapid mixing
- flocculation
- settling
- filtration
- chlorination
- clear well storage
- pumping to distribution system
After filtration, _____ is added to kill remaining germs.
chlorine
Chlorine reacts with _____ to kill them.
organic matter
Chlorine may react with other things in water to create new substances. To avoid this, some plants use alternative methods like _______.
ozonation
It is added to drinking water in a number of municipalities since it has been shown to prevent tooth decay in children and young adults.
fluorine
