A1-9
Parent material for soil formation
In North America, has be mostly deposited by glaciers
Best way to dispose of hazardous liquid waste
Incineration
Ways an operating plant can impact surrounding area
Incomplete Combustion. Vapor release, planned or unplanned. Hazardous or contaminated liquid release. airborne particulate matter. solid waste. noise generation. odour. surface disturbance.
How is Carbon Monoxide produced?
Incomplete combustion. Lack of Oxygen in furnace leads to CO vs CO2.
Describe electrostatic precipitator function
Intense electrostatic field is maintained. Particles become negatively charged and stick to positively charged collector.
Effects of acid rain on lakes and rivers
Interference in animal reproduction. Metals leached from soil can interfere with aquatic oxygen. Can produce dead lakes.
An operating crane strikes a diesel storage tank, resulting in a spill. Repairing the tank and cleaning up is an example of a
Interim action
Baffle type flyash collectors separate flyash from flue gases by
Introducing sudden changes in direction which protects particles out of gas stream. Best for larger, heavier particles.
Reduction of sound at source
Is typically featured in design phase. Vibration isolation mounts and vibration damping, and reducing operating speed and tip velocity in fans.
Why is carbon monoxide bad.
It is a serious pollutant. Deadly, toxic gas. It is explosive
Carbon dioxide from the combustion of fuels is considered a pollutant because
It is the main heat trapping gas responsible for the greenhouse effect
How are nitrogen oxides controlled in boiler operation
Reducing excess air. Staged combustion. Overfire air Tangential firing Gas recirculation
Nitrogen oxides in flue gases may be reduced by
Reducing the percentage of excess air
How are sulphur oxides produced
SO2 and SO3 are produced whenever a fuel containing sulphur is burned. Low sulphur fuels are much more to expensive. Some hot springs and volcanoes create sulphur oxides.
Describe operation of centrifugal flyash collector
1. Dirty gas enters and is whirled by vanes. 2. Centrifugal action separates dust. 3. Dust drops into hopper. 4. Clean gas rinses through center
3 effects of acid rain
1. Kill life in water. 2. When snow melts, high toxicity kills snails, clams, crayfish, and eggs. 3. Leeches nutrients from soil which kills plants.
What common conditions lead to carbon monoxide build up
1. Not enough air supplied to furnace. 2. Insufficient turbulence. 3. Overloading of boiler.
The NO x produced from nitrogen in a boiler fuel is dependent on
1. Percent of nitrogen in the fuel. 2. Reactivity of fuel nitrogen compounds. 3. Oxygen availability in the combustion zone
Methods to control noise at a given location include
1. Reducing the sound at the source. 2. Protecting the receiver with a barrier device. 3. Modifying the sound wave path to the location
What noise level reduction is noticeable
10 percent. 5 to ten fold is necessary to be worthwhile.
Flyash is normally less than
30 microns in diameter. Note 30 microns equals 0.03 mm
What is the range of permissible daytime sound levels
50 to 80 decibels
Electrostatic precipitator efficiency?
80-99%
What efficiency do precipitators run at
80-99%
A typical wet limestone scrubber, dealing with flue gas at 5000 ppm SO2, is how efficient
90- 95%
Fabric filters are capable of achieving particulate removal efficiencies up to
99% and more
What is a bag filters efficiency? When is it least efficient?
99% plus. Least efficient when freshly cleaned. Build up helps with trapping more debris.
The pollutant, carbon monoxide causes
A very poisonous gas
Studies have shown that systems to reduce SO2 also reduce SO3 by
About 50%
Mechanism of sound absorption by soundproofing materials
Absorb sound waves by trapping them in the material so only a very small wave leaves opposite side.
Thermal stratification
Differing temperature layers in a lake that can lead to oxygen starvation.
Effects of acid rain on plants
Acid deposition on leaves. Acid deposition on soil interferes with plant nutrition leading to death.
A transmitter is blown down to grade twice daily. Reducing the frequency of the blow down to as required would be an example of
Adaptive action
Advantages and disadvantages of Hydrogen as a fuel source.
Advantages. Yields 4.25 times energy over carbon Produces less CO2 Disadvantages. Even a small leak is a big explosion risk. Difficult to store due to high storage pressures.
Effect of acid rain on people
Affects our plant and animal food sources. Sulphur dioxide in air causes bronchitis. Acid water can leech heavy metals from soil and plumbing.
Describe a closed natural draft tower
Air comes in at bottom, absorbs heat and moisture, which leads it up and out chimney.
Open natural draft cooling tower
Air enters tower via slats in a downward direction to reduce spray being carried out top of tower.
A settling pond is used for
Allow particulate to settle from effluent. Colloidal matter is handled by adding coagulants.
Adaptive action
Allows plant to function with the problem indefinitely.
Interim action
Allows you to live with the effects of a problem, while making definite plans to address the cause.
High frequency noise is perceived as more
Annoying and louder than low frequency noise
CO2 is produced by
Any fossil fuel being burnt. If fuel has any carbon, CO2 will be part of combustion process
Last resort for sound protection is
Direct protection of workers ears.
Most beneficial and effective action in reduction of environmental impacts is
Attitude. Always look for best way of doing things.
Most proficient principle of hazardous waste
Avoid generation in the first place.
The test used to determine how much the natural oxygen content of water is taxed by incoming organic contamination is the
Biochemical oxygen demand test
List 6 tests conducted on water to determine contamination
Biochemical oxygen demand. Chemical oxygen demand. ph. Turbidity. Colour testing. Nitrates. Phosphates.
What is done with collected flyash
Buried under landfill or sold to concrete industry
How are Sulphur dioxides produced in a boiler?
Burning, or oxidation, of sulphur, a common element in almost all industrial coal and fuels.
In a pneumatic fly ash removal system, - is conveyed to a storage bin
Buy a high velocity air stream
The pH of industrial effluents can be controlled
By the addition of acid or alkali as required.
Short term effects of an oil spill
Fire or explosion Toxicity to humans Fumes, vapors, or clouds carried from the spill Reactivity problems where hazardous byproducts can be formed
Samples taken within facility must be
Collected in appropriate containers, and properly disposed of
What is a cooling pond for
Cool the hot waste water to combat thermal pollution. Sprays are used for both temperature reduction and oxygen enrichment.
Where a plant is surrounded by a large flat land area and water can be supplied in unlimited quantities, a commonly used method to reduce the cooling water temperature employs
Cooling ponds
Gas solubility in a liquid will ______ when liquid temperature increases
Decrease.
The ability of water to dissolve oxygen
Decreases with the increase of water temperature
Chlorofluorocarbons
Destroy ozone after they reach the stratosphere
Chlorofluorocarbons in the environment cause
Destruction to ozone after rising to the stratosphere
Biochemical oxygen demand, BOD test
Determine level of organic contamination such as domestic sewage effluent. Tells how much natural oxygen content of water is taxed by incoming pollution.
Turbidity testing
Determines how much suspended material is being carried in water.
What bonus does a wet scrubber remove?
Dust + gaseous pollutants.
After design phase, modification of sound path is often achieved by
Enclosures. Soundproofing materials such as lead, loose sand, brick, most best insulants (glass, wool, polyurethane, cork.)
Carbon monoxide production
Extremely poisonous gas produced primarily by internal combustion engine due to incomplete combustion
In dealing with an operating problem, interaction is the most desirable since it deals with and eliminate the root cause. True or false
False
True or false. Gaseous pollutants do not affect the operating life of a power plant
False
True or false. Testing in destroying hazardous material should take precedence over recovering and reducing the amount of hazardous material
False
Dry tower uses
Finned tubes. For places where water is limited
Henry's law
Gas solubility in a solution decreases as gas partial pressure above the solution decreases.
As a pollutant, methane causes
Greenhouse gas
Ozone in lower atmosphere is
Hazardous to health and corrosive to many materials in the lower atmosphere.
Ozone is produced by
High intensity sunlight in the upper atmosphere
What frequency is perceived as louder and more annoying.
Higher pitch frequencies
Chemical oxygen demand, COD test
How much natural oxygen is consumed by nonorganic pollution.
Some sulfur dioxide flu gas subscribing system produce a readily usable by product called
Hydrated calcium sulfate aka gypsum
What caution for wet scrubber
If gas contains Sulphur Dioxide, SO2, water plus SO2 forms a weak acid that is corrosive to steel and is a pollutant. Will need proper means of disposal.
Key to limiting effects of uncontrolled release of liquid is
Immobilize material, or neutralize/ lower its hazard potential.
Questions for how to handle something going wrong.
Know the material. Know the isolation points. Identify what is required to contain a release and protect yourself. Identify problems to environment or process that an upset may cause. Inform others in your area. Discuss "what ifs" of an occurrence with others to gain their experience.
Mercury presents a unique clean up problem
Lack of capillary action makes clean up using a drawing action impossible.
Good sound absorbers include
Led, loose sand and most heat insulants.
Advantages of induced draft fan type vs forced draft tower
Less chance of icing since fan is in path of warm air discharge. Noise from fan is less due to location.
Advantages of wet limestone scrubbing
Less limestone used per SO2 removed, greater efficiency in removal, and less interference with boiler operation.
As a pollutant, carbon dioxide cause
Main best trapping gas responsible for the greenhouse effect.
Methane production
Main component of natural gas. Product of decomposed organic matter and from digestion processes of animals.
Why are nitrogen oxides undesirable in the atmosphere
Main constituent of photochemical smog. Combine with water to form nitric acid in acid rain.
Steps you would follow in decommissioning and abandoning a facility
Make a plan to address. Closure. Dismantling. Site evaluation. reclamation procedure.
Chlorofluorocarbons are produced in
Man-made products used in refrigerants, foaming agent for some plastics, aerosol propellants, cleaning agents, and in halon fire suppression.
Mechanical draft cooling tower. Induced draft
Most commonly used. Hot water is sprayed from upper aspect. ID fan is at top. Pulls atmospheric air in as water drifts and drips down.
A liquid spill must be handled using info from
Msds
Acid rain is formed by
NOx and SOx plus sunlight and vapor in the atmosphere and make sulphuric and nitric acid.
The environment consist of
Natural and man-made elements
What two growth nutrients are found in sewage
Nitrates and phosphates
Mechanical centrifugal collectors
Removal via centrifugal, inertial, and gravitational forces. Also better for coarse particles. Not suitable for high efficiency collection of fine particles. It has added disadvantage of relatively high pressure drop which results in excessive horsepower consumption of ID fan motor.
Lime and limestone scrubbing, double alkali systems and dilute sulfuric acid method are classified as
Non regenerable processes
Decibel levels from multiple sources are
Not linear. Cannot be simply added together.
State 2 reasons a centrifugal flyash collector would not be used in a large coal fired boiler.
Not suitable for high efficiency collection of fine particles. High pressure drop results in excessive horse power consumption of ID fan motor
Hazards presented due to a liquid spill in a plant include
One. Reactive formation of hazardous by-products. 2. Fire or explosion hazard. 3. Vapor clouds carried from the spill
Most effective means of recognition of a problem in an operating plant
Operating and maintenance personnel performing frequent and comprehensive checks.
Effluent
Out flow. Usually carries connotation of something undesirable. Water itself may be OK, but carries material dissolved or suspended and is now a pollutant.
The gas that is released during the process of photosynthesis is
Oxygen
Nitrogen oxides are produced by
Oxygen and nitrogen can react to form several forms of NOx. High temps and excess oxygen increase production of NOx. NO is primarily formed in the furnace. Some combines in stack with oxygen and makes NO2. When water is added, HNO3 accounts for roughly 30% of acidity in most acid rain.
As a pollutant, Nitrous oxide causes
Responsible for about 30% of acid rain, produces smog and trap heat causing greenhouse effect
As a pollutant, Sulphur oxides cause
Responsible for about 70% of acid rain
Wet scrubbers operate by
Passing gas stream through a sprayed mist. Deflectors may be added to provide an impinging surface.
How do wet scrubbers operate
Passing gas stream through a wet mist. A deflector may be used as an impinging surface.
A chemical treatment vessel is normally empty to the storm train. Redirecting the outlet to the sewage drain would be an example of
Permanent actions
Cooling towers and cooling ponds
Prevent thermal pollution of rivers and lakes
What are the two practical means of controlling emissions of nitrogen oxides?
Preventing formation by lowering temp or decreasing oxygen, and by removing oxides from flue gas.
Other than pipelines, liquid spills are limited to
Process leaks, storage leaks, and transportation leaks.
The major components of an ecosystem are
Producers, consumers, inactive organic matter
Solid pollutants such as fly ash are produced when burning
Pulverized coal
Greenhouse effect
Radiation from the sun hits the earth and a lower level is reflected back through the atmosphere. Green house gases trap some of that radiation, leading to drought, melting polar ice caps.
How are bag filters cleaned.
Rapper system shakes bags and debris Falls to a hopper.
If hazardous waste is unavoidable, then
Recover and reduce. What is produced must be securely contained and monitored.
3 ways to reduce sound
Reduce at source. Modify pathway. Protect receiver
3 ways to reduce noise at a given location
Reduce source. Modify sound wave path to location. Protect receiver with barrier device
What firing modifications do large coal fired plants use to decrease NOx production
Reduced excess air percentage, stage combustion, use of Overfire air, tangential firing, and gas recirculation
A potential negative side effect of SO2 and wet scrubber
SO2 and water forms a weak acid that corrodes steel and is an environmental pollutant. Requires safe disposal or lime/dolomite treatment
Particulate matter may be removed from a plant's effluent by
Settling ponds
Pressurized tanks carrying liquid chlorine, anhydrous ammonia, pose a ______ term threat
Short term since they turn to vapor quickly. This is from a liquid spill perspective.
How is oil or grease removed from water
Simple skimming process in a grease trap with surface skimming, or by centrifugal separation.
A vacuum filter functions by
Sucking water through a fine mesh media filter partially submerged in effluent. As it slowly rotates out of water, filter dries and is blown or scraped off.
Basic construction of induced draft cooling tower
Suitable enclosure that contains spray nozzles, baffles, and an induced draft fan at the top
The atmospheric contaminant responsible for the formation of about 70% of acid rain is
Sulfur oxides
Describe how sunlight can be converted to beef
Sun evaporates water. Rain goes to ground. Plants draw water. Cow eats plant and we eat cow.
Describe water cycle
Sun evaporates water. Water comes to soil in form of rain. filters back to water.
When an area is contaminated,
boundaries must be defined. Core sampling, area removed for destruction, fresh fill to replace.
How might cooling towers contribute to pollution
Thermal pollution by increasing atmospheric pressure and thus decrease amount of oxygen that can be dissolved in water. Deaeration. Vapor contacts effluent carrying pollution to town or into nature.
Advantage of wet scrubber
They remove solids and liquid pollutants.
When an outside contractor is used for hazardous waste disposal, key points are
Transportation conforms with TDG. Periodic assessments of disposal company to ensure all methods used comply with required legislation.
Bag filters operate by
Trapping or impinging dust on fine fabric filters.
The pattern of feeding relationships in an ecosystem is called food webs. True or false.
True
True or false. Pressurized tank scaring liquefied gases pose a short term problem as hazardous liquids because they quickly turn the vapor when released from the tank
True
When an existing facility is shut down in decommissioned, the site must be left and conditions suitable for alternative uses. True or false
True
The most effective method of controlling the formation of nitrogen oxide in the boilers combustion process is
Two-stage combustion
Hyperbolic tower
Type of natural draft tower made of concrete. Used in large central electricity generating stations.
Ph control
Using a dilution tank, effluent is monitored and corrected if an alkaline or acidic surge is detected
Organic matter is primarily deposited from
Vegetation
Flyash
Very fine powdery material. Typically manor portion is less than 30 microns diameter.
In order for acid rain to be formed
Water vapor and sunlight must be present
Is truck traffic sound impact included in permissible sound level regulation?
Yes
When a facility is shut down and decommissioned, it must be left in
a suitable condition for alternate uses, and pose no further threat to public health or the environment. A reclamation plan is part of the pan pre-construction.
Bag filters clean by
catching dust on fine filters made of fabric.
Acceptable sound levels mean that
indoor sound levels for residents are not adversely affected.
Baffle and mechanical collectors work best on
larger particles. Advantage is no moving parts. Inexpensive initial and operating cost.
Describe electrostatic precipitator function
produce an electric charge on the particles to be collected, and then propel particles by electrostatic forces to collecting electrodes. Later, particles are rapped into storage hoppers.
Baffle-type flyash collectors function by
projecting particles out of the gas stream when gases make abrupt changes in direction.
Mechanical Centrifugal collectors
remove particulate via centrifugal, inertial, and gravitational forces. Tangentially or axially whirl over vanes to create high velocity.
Permanent action
solution that addresses the root cause.
Noise impact statement
specify the design sound level at the nearest or most impacted permanently or seasonally occupied dwelling.
For drilling and servicing rigs, responsibility for sound control belongs to
well licensee. Compliance is enforced on a complaint basis only.