Chapter 9 Environmental physics

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Chapter 9 Environmental physics

• 9.1 Theory of environmental physics
• 9.2 Environmental atmosphere diffusion theory
• 9.3 The diffusion theory of pollutant in water
• 9.4 The diffusion discipline through other
  substances as media.
• 9.5 Pollution convection theory of environmental
  physics
• 9.6 Typical physical pollution analysis

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9.1 Theory of environmental physics




Law of Thermodynamics 
The first law of thermodynamics(law of
conservation of energy ) All the substances of
nature have energy, and energy has different
forms, it can transfer from one form to another
form, in the process of transference, the total
number of energy is constant.
The second law of thermodynamics (Law of Entropy
) It can not use any form to transfer heat from
object of lower temperature to object of high
temperature, and produce other effect.
law of conservation of matter
The substance can neither be generated, nor
perished, it can only transfer from one form to
another form, and this is law of conservation of
matter.
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We can see from law of conservation of matter

• The constituents of environment follow the famous
  law of conservation of matter and continually
  carrying out matter cycling
• Each input, output of environment is balanced
  with accumulation amount. In the environmental
  system or sub-system, the quality equation can be
  written as
• Accumulationinput-output
• When the input rate of one system is constant and
  equals to output rate, the accumulation ratio is
  zero. This state is regarded as steady state

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9.2 Environment atmosphere diffusion theory

• 9.2.1 The theory basis of atmosphere diffusion
• Definition the pollutant discharged into air
  is transferred, mixed, diluted by air level
  activity, turbulent flow diffusion activity as
  well as disturbance activity of different scale
  of atmosphere this is regarded as diffusion of
  atmosphere pollutant.

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Factors of atmosphere diffusion
It mainly indicates wind and turbulent flow, this
has decisive role for the dilution and diffusion
of pollutant. The weather condition favorable for
wind speed increase and turbulent flow increase
will facilitate the dilution and diffusion of
pollutant otherwise, it will aggravate
pollution.

• Power factor
• Thermal factors
• Meteorological conditions

It mainly indicates temperature lamination and
atmosphere stability of atmosphere. We can
usually find that the diffusion shape of smoke
plume discharged from chimney has close relations
to the temperature lamination

• Inversion
• Radiation and cloud

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Figure 9-1 smoke in different temperature (a)wave-
like (b)tapered spiral (c) loosely type
(d)climbing (e)smoke
Zheight Ttemperature ?(lapse rate of
air temperature )---------- ?d(dry adiabatic
lapse rate )
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Factors of atmosphere diffusion

• Geographical factors

underlying surface(The influence of terrain and
geophysics)
 mountain-valley breeze Due to the uneven heat
generated by the hillside and valley.
Figure 9-2 circulation of mountain-valley breeze
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Factors of atmosphere diffusion

• Sea and land breezeit is caused by the
• difference of land and sea heat nature.

landwind conditions in night
sea wind conditions in daytime
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9.2.2 Turbulent flow diffusion theory

• Gradient transference theory it is supposed
  the dispersion caused by air turbulent flow it
  is similar to molecule diffusion and can use the
  same molecule equation to describe.

Turbulent flow statics theory supposing
the particle in material is the same with
successive fluid, when particle is in
transference and diffusion, it will not happen
chemistry and biology reaction, seize and quality
of particle is not included, and regards particle
activity is happening relative certain space.
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9.2.3 The diffusion model of atmospheric
pollutants

• Nature and component of pollutant
• The pollutant discharged into air generally is
  composed of each air and solid particle their
  natures are determined by their chemical
  components.
• The geometry and discharge form of pollution
  source.

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• Diffusion model of atmospheric pollutant
• On the basis of plenty inspection date
  analysis, Gauss used the supposed turbulent flow
  statics get the diffusion model under normality
  distribution.

Figure 9-3 Coordinate system of gauss model
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Diffusion model

• Point source diffusion model
• Point source Gauss model in infinite space.
• Diffusion model of elevated continual points.
• Diffusion model of ground continual points.
• Line source diffusion model

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9.3 Environment atmospheric diffusion theory

• 9.3.1 Plug-flow transference
• It indicates the transference effect of
  pollutant under water flow effect. The plug-flow
  effect can only change the position of pollutant
  in water but not can decrease the density of
  pollutant.
• The transference gamma flux under effect of
  plug-flow, it can be calculated by the following
  formula

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• 9.3.2 Dispersion effect
• Molecule dispersion the dispersed phenomenon
  caused by the random movement of molecule. The
  molecule dispersion process follows the first law
  of Fick, which is the quality gamma flux of
  molecule dispersion is in direct ratio to the
  density and gradient of dispersed substance.

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• Dispersion of turbulent flow
• Dispersion of turbulent flow is a dispersed
  phenomenon that particle instantaneous value of
  each state in rivers relative to the random
  pulsation of its average value. When the
  turbulence, instant and pulsation speed of water
  particle is the random variable, turbulent flow
  diffusion speed can be expressed by the first law
  of Fick

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• The dispersion effect
• The dispersion effect can be defined as the
  separation phenomenon that hour average value of
  turbulent speed of space point(or other state)
  and space average value of flow speed hour
  average value system difference. The quality flux
  o dispersion effect can be described by the first
  law of Fick.

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• 9.3.3 Diffusion and dilution model of pollutant
  in water
• Diffusion and dilution of pollutant in river
• Diffusion model of pollutant discharged into
  lake
• Reaeration
• The diffusion model of pollutant entering from
  river to sea

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9.4 The diffusion discipline used other substance
as media

• 9.4.1 The depression discipline of sound wave
  transmission
• 9.4.2 Transference and diffusion theory of
  pollutant in soil
• 9.4.3 Transmission and depression discipline of
  electromagnetic wave

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9.5 Convection theory of environment physics
pollution

• urban heat island circulation

Because of urban heat island effect, the air in
the center of urban is heated and continually
ascending, the adjacent cold air will supplement
to the city suburb, this kind of convection
movement between urban and country is regarded as
urban breeze, it is most obvious in the evening
Figure 9-4 Schematic diagram of urban heat
island
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Radiative-convective equilibrium theroy
Due to causes of power and heat, the air is
always in the continual movement. On one aspect,
the greenhouse gases such as CO2 has certain
effect of increasing temperature, on the other
hand, air turbulent flow is favorable for the
transference of heat, so the overlapping of
these two effect is just the influence on
environment
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9.6 Analyses on typical physical pollution

• 9.6.1 Noise pollution
• The definition of noise we usually regard
  sound disturbing rest, study and work of human,
  that is also the sound that people need not to
  hear or harmful to human body, it is regarded as
  noise
• Harm of noise

affect the conversation and communication
damage to hearing structure
disturbance of sleep
impact on human physiology, psychology
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• 9.6.2 Electromagnetic radiation
• Electromagnetic wave radiation has been
  listed as the fourth biggest pollution source by
  World Health Organization, it is widely existed
  in the daily life, such as TV, computer, wireless
  telephone, microwave oven, mobile are the
  electromagnetism pollution source.
• Electromagnetic radiation pollution can be
  divided into natural electromagnetic radiation
  and artificial electromagnetic radiation
  pollution

Natural electromagnetic radiation pollution
resource
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Artificial electromagnetic radiation
pollution
Types of pollution source Types of pollution source  Equipment name of production pollution source Pollution source
Pollution source caused by discharg ng corona discharge Power lines (wires for distribution ) The electrostatic induction, electromagnetic induction and electric leakage caused by high voltage and large current
Pollution source caused by discharg ng glow discharge discharge tube White lamp, high-pressure mercury lamp and discharge tube
Pollution source caused by discharg ng arc discharge Switch, electric railways and discharge tube
Pollution source caused by discharg ng  spark discharge Electrical equipment, engine, refrigerator, automobile, etc Rectifier, generators, discharge tube, ignition system
Power frequency radiation field resource Power frequency radiation field resource High power transmission line, electric equipment, electric railway The pollution caused by high voltage, large current power lines, electrical equipment
 Radio-frequency radiation field resource  Radio-frequency radiation field resource High-frequency heating equipment, heat and machine, microwave drying machine, physical machine, instrument, etc circuits which use to industrial and medical rf equipment, oscillation system
 Radio-frequency radiation field resource  Radio-frequency radiation field resource Radio transmitters, household electric appliances, etc Radio, television, computers and wireless telephone, microwave oven, etc
Buildings reflection Buildings reflection High-rise buildings and large metal components Wall, steel, cranes, etc
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Green cardThe adverse effects and hazard on
human health by electromagnetic radiation
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9.6.3 Other physical pollution
Light pollution it is the phenomenon of
excessive radiation of each light source
(sunlight, lamplight, each reflected light as
well as infrared ray and ultraviolet rays and so
on) produces effect on surround environment,
human activity and production environment.
Heat pollution heat pollution is the resulted
environment pollution caused by each waste heat
discharged by the increasingly modern industrial
and agricultural production as well as human
production activity.
Radioactive pollution radioactive pollution is
the phenomenon that radioactive pollutant
discharged by human activity, it level exceeds
that of nature bottom value or exceeds the
standard regulated by the nation
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light pollution
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Figure 9-5 Radionuclide enter schemes
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Case studyIndoor physical pollution

• Radioactive pollution of decoration material
• Harm if the indoor ventilation is not good,
  human will subjected to radiation of high density
  radon, it can result in cancer, leukemia and air
  tube disease. It is predicted in China, indoor
  radon and its sub-body accounts for 3 to 20 in
  public cancer.
•  Prevention

People should carry out inspection of radioactive
body value before house decoration
When buying material, people should claim the
radioactivity inspection report.
When decoration, people should reasonable
allocate and use the decoration materials
After decoration is completed, people can invite
expert to do site inspection.
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• Pollution of household appliances (take
  microwave for example)

microwave have effects on cranial nerve
microwave have effects on the resistivity of body
the microwave food is not safe
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Thank you