air and noise pollution (salvato and intense)

Air pollution

Is the presence of solids, liquids, or gases in the outdoor air in amounts that are injurious or detrimental to humans, animal, plants, or property or that unreasonably interfere with the comfortable enjoyment of life and property.

35 lb

We breathe about _____ of air per day

78.09%

Composition of Clean Dry Air Near Sea Level of Nitrogen

20.94%

Composition of Clean Dry Air Near Sea Level of Oxygen

plants

___________ be used as indicators of harmful contaminants because of their greater sensitivity to certain specific contaminants.

Solar energy

__________ as light in the form of short-wavelength radiation

Acid Rain (Acidic Precipitation)

______________ releases nitrogen and sulfur oxides and carbon dioxide, as well as other pollutants, are carried into the atmosphere where they interact with sunlight and vapor

man made and natural

The sources of air pollution may be ____________, such as the internal combustion engine, or ______________, such as plants (pollens).

primary pollutant

is one that is found in the atmosphere in the same form as it exists

the stack; sulfur dioxide

nitrogen dioxide, and hydrocarbons are examples.

secondary pollutant

is one that is formed in the atmosphere as a result of reactions such as hydrolysis, oxidation, and photochemistry; photochemical smog is an example.

hydrocarbons

Most combustible materials are composed of ___________.

automobile catalytic converters

control carbon monoxide and hydrocarbon emissions causes some increase in sulfates and sulfuric acid emissions, but this is considered to be of minor significance.

Particulate Sampling—Ambient Air

Measurements needing much more development are in the area of particulates, where inhalable particles sizing (less than 10-3 m), identification, metals, sulfates, and nitrates are important.

High-volume (Hi-vol) samplers

pass a measured high rate of (40-60 cfm) through a special filter paper (or fiberglass), usually for a 24-hr period.

Sedimentation and settling devices

include fallout or dustfall jars, settling chambers or boxes, Petri dishes, coated metal sheets or trays, and gum-paper stands for the collection of particulates that settle out.

automatic (tape) smoke sampler

collects suspended material on a filter tape that is automatically exposed for predetermined intervals over an extended period of time.

Inertial or centrifugal collection equipment

operates on the cyclone collection principle.

Impingers

separate particles by causing the gas stream to make sudden changes in direction in passing through the equipment.

cascade impactor

the velocities of the gas stream vary, making possible the sorting and collection of different-sized particles on special microscopic slides.

Electrostatic precipitator

type sampling devices operate on the ionization principle using a platinum electrode.

Nuclei counters

measure the number of condensation nuclei in the atmosphere. They are a useful reference for weather commentators.

Pollen samplers

generally use petroleum-jelly-coated slides placed on a covered stand in a suitable area.

Gas sampling

requires separation of the gas or gases being sampled from other gases present.

Pulsed Fluorescent Analyzer

This instrument measures sulfur dioxide by means of absorption of UV light.

Atomic Spectrometry

a sample solution is atomized into a flame that produces a characteristic and measurable spectrum of light wavelengths.

Gas chromatography

separates compounds that can be volatilized

liquid chromatography

separates compounds that are not volatile.

Mass spectrometry

identifies a separated pure component by its characteristic mass spectrum.

Nitrogen Oxide Chemiluminescence Analyzer

Nitric oxide (NO) is measured by the gas-phase chemiluminescent reaction between nitric oxide and ozone.

Ozone Chemiluminescence Analyzer

Ozone is measured by the gas-phase chemiluminescence technique, which utilizes the reaction between ethylene and ozone (O3).

Carbon Monoxide Infrared (IR) Analyzer

This method utilizes dual beam photometers with detection accomplished by means of parallel absorption chambers or cells that are separated by a movable diaphragm.

The Ringelmann smoke chart

Historically, smoke and/or opacity was measured by ________________.

Tape Sampler—Coefficient of Haze (COH)

The _______________ can be designed to measure light transmittance rather than reflectance.

Stack Sampling

The collection of stack samples, such as fly ash and dust emissions, requires special filters of known weight and a measure of the volume of gases sampled.

Meteorology

involves the physics, chemistry, and dynamics of the atmosphere and includes many direct effects of the atmosphere on the earth's surface, ocean, and life.

Topography

refers to both the natural and man-made features of the earth's surface.

wind, speed and direction, solar radiation, stability, precipitation

The meteorological elements that have the most direct and significant effects on the distribution of air pollutants are __________, _______________, __________ and __________

Wind

is the motion of the air relative to the earth's surface.

wind speed

The higher the ______________, the greater the separation of the particles or molecules of the pollutant as they are emitted, and vice versa.

TURBULANCE

air motions are rapid and random and constitute the wind characteristic

Radiational inversion

is a phenomenon that develops at night under conditions of relatively clear skies and very light winds.

Subsidence inversion

develops in high-pressure systems (generally associated with fair weather) within a layer of air aloft when the air layer sinks to replace air that has spread out at the surface.

Frontal inversion

forms when air masses of different temperature characteristics meet and interact so that warm air overruns cold air.

Precipitation

constitutes an effective cleansing process of pollutants in the atmosphere

Settling chambers

cause velocity reduction, usually to slower than 10 fps, and the settling of particles larger than 40 m in diameter in trays that can be removed for cleaning.

Cyclones

impose a downward spiraling movement on the tangentially directed incoming dust-laden gas, causing separation of particles by centrifugal force and collection at the bottom of the cone.

Sonic collectors

can be used to facilitate separation of liquid or solid particles in settling chambers or cyclones.

Filters

are of two general types: the baghouse and cloth screen. The filter medium governs the temperature of the gas to be filtered, particle size removed, capacity and loading, and durability of the ______.

Cloth-screen filters

are used in the smaller grinding, tumbling, and abrasive cleaning operations.

Electrostatic precipitators

have application in power plants, cement plants, and incinerators as well as in metallurgical, refining, and heavy chemical industries for the collection of fumes, dusts, and acid mists.

Scrubbers

are of different types, selected for specific applications. They include spray towers, ejector venturis, venturi scrubbers, and packed-bed, plate, moving-bed, centrifugal, impingement, and entrainment types.

Wet collectors

are generally used to remove gases such as hydrogen chloride, nitrous oxides, and sulfur dioxide and particles that form as a dust, fog, or mist.

Thermal afterburners

are used to complete the combustion of unburned fuel, such as smoke and particulate matter, and to burn gaseous hydrocarbons and odorous combustible gases.

Catalytic afterburners

may be used for the burning of lean mixtures of combustible gaseous air contaminants. They are also used to reduce nitrous oxides, with ammonia injection.

Condensers

are best used to remove vapors by condensation, generally prior to passage to other air pollution control equipment, thus reducing the load on this equipment.

Adsorbers

are of the fixed-bed stationary or rotating type, in horizontal or vertical cylinders, usually with activated-carbon beds or supported screens, through which the gas stream passes.

absorption

the gaseous emission to be treated is passed through a packed tower, spray or plate tower, and venturi absorbers, where it comes in contact with a liquid absorbing medium or spray that selectively dissolves or reacts with the air contaminants to be removed.

fumigation

With the discharge of a plume below an inversion, the plume will be dispersed rapidly downward to the ground surface, causing ''_______________''

planning and zoning

The implementation of ________________ controls requires professional analysis and the cooperation of the state and regional planning agencies and the local county, city, village, and town units of government.

Air Quality Modeling

it is possible to calculate and predict, within limits, the approximate effects of existing and proposed air pollution sources on the ambient air quality. A wide variety of models are used to estimate the air quality impacts of sources on receptors, to prepare or review new industrial and other source applications, and to develop air quality management

Gaussian

Numerical

Statistical

Physical

Air quality models can be categorized into four classes.

Gaussian

Most often used for estimating the ground-level impact of nonreactive pollutants from stationary sources in a smooth terrain.

Numerical

Most often used for estimating the impact of reactive and nonreactive pollutants in complex terrain.

Statistical

Employed in situations where physical or chemical processes are not well understood.

Physical

Involves experimental investigation of source impact in a wind tunnel facility.

Source Emission Data Sources

___________of pollutants can generally be classified as point, line, or area sources.

Point sources

are individual stacks and are identified by location, type and rate of emission, and stack parameters

Meteorological Data

The data needed to represent the meteorological characteristics of a given area consist of (as a minimum) wind direction, windspeed, atmospheric stability, and mixing height.

Pollutant Concentration Data

In order to assess the accuracy of a model for a particular application, predicted concentrations must be compared against observed values.

NOISE CONTROL

One of the most important tasks of architects, builders, acoustic engineers,

urban planners

industrial hygiene engineers, equipment manufacturers, and public health personnel is to ensure that noise and vibration are kept to an acceptable level in the general environment, in the workplace, and inside dwellings.

Noise

is of special concern in occupational health where hearing loss has been documented.Sound, and therefore all _____, is physically a rapid alteration of air pressure above and below atmospheric pressure.

pure tone

A sound that contains only one frequency is a ______________

pitch

The___________ of a sound is determined primarily by frequency: vibrations per second.

sound pressure

amplitude or magnitude of sound is the ___________

molecular heating and geometric spreading

As sound travels through a medium, it loses energy or amplitude in two ways:

Noise

is unwanted sound.

Noise pollution

is the condition in which noise has characteristics and duration injurious to public health and welfare or unreasonably interferes with the comfortable enjoyment of life and property in such areas as are affected by the noise.

Ambient noise

the total noise in a given situation or environment.

Noise level

is the weighted sound pressure level in dBA* obtained by the use of an approved type [American National Standards Institute(ANSI)] sound-level meter.

Frequency

____________of sound is the number of times a complete cycle of pressure variation

pitch

The frequency of a sound determines its ____________.

30

sounds with a frequency of _____ Hz are considered very low pitch

15000

sounds with a frequency of ______ Hz are very high pitch.

20 and 20000Hz

1000 and 6000 Hz

A young healthy ear can detect frequencies over a range of about ____ to ______

most common sensitive hearing range is between __________ and ____________Hz.

Intensity

______________of a sound wave is the energy transferred per unit time (in seconds) through a unit area normal to the direction of propagation.

Loudness

_______________or amplitude, of sound is the sound level or sound pressure level as perceived by an observer.

Noys

is a measure of the perceived noise level (PNL) (in decibel) in relation to the noisiness or acceptability of a sound level.

The day-night average sound level

is the 24-hr average sound level, expressed in decibels, obtained after the addition of a 10-dB penalty for sound levels that occur at night between 10 p.m. and 7 a.m.

A sound-level meter

is used to measure the sound pressure level; it is the basic instrument for noise measurement. Meters are available to cover the range of 20 to 180 dB.

The noise dosimeter

will measure the amount of potentially injurious noise to which an individual is exposed over a period of time.

A frequency analyzer

may be necessary to measure complex sound and sound pressure according to frequency distribution.

Cathode-Ray Oscillograph

This makes possible observing the wave form of a noise and pattern.

Octave-Band Analyzer

This has filters that usually divide a noise into eight possible frequency categories. Each category is called an octave band, with frequency ranges of 45 to 90, 90 to 180, 180 to 355, 355 to 710, 710 to 1400, 1400 to 2800, 2800 to 5600, and 5600 to 11,200 Hz (or cps).

Background noise

is noise in the absence of the sound being measured that may contribute to and obscure the sound being measured.

Sound Absorption

The amount of sound energy a material can absorb

Sound transmission loss (TL)

is the ratio of the energy passing through a wall, floor, or ceiling to the energy striking it—that is, how effective a material is in stopping the passage of sound.

Troposphere Stratosphere Mesosphere Thermosphere

Layes of the Atmosphere

Air pollution

any alteration of the physical, chemical and biological properties of the atmospheric air