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Chapter 9 Chapter 9 Environmental physicsEnvironmental 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
9.1 Theory of environmental physics Law of Thermodynamics
law of conservation of matter
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 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.
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.
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. 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.
We can see from law of conservation of
matter : The constituents of environment follow the famo
us 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:
Accumulation=input-output When the input rate of one system is constant and equal
s to output rate, the accumulation ratio is zero. This state is regarded as steady state
9.2 Environment atmosphere diffusion theory
9.2.1 The theory basis of atmosphere diffusion
Definition: the pollutant discharged into air is tran
sferred, mixed, diluted by air level activity, turbule
nt flow diffusion activity as well as disturbance act
ivity of different scale of atmosphere; this is regar
ded as diffusion of atmosphere pollutant.
Factors of atmosphere diffusion
Power factor
Thermal factors
Meteorological conditions
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.
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.
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 re
lations to the temperature lamination
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 re
lations to the temperature lamination
Inversion Radiation and cloud
Inversion Radiation and cloud
Figure 9-1 smoke in different temperature
( a ) wave-like ( b ) tapered spiral ( c ) loosely type ( d ) climbing ( e ) smoke
Z——height T——temperature
——γ( lapse rate of air temperature ); ---------- γd ( dry adiabatic lapse rate )
Factors of atmosphere diffusion
Geographical factors
underlying surface ( The influence of terrain and geophysics)
underlying surface ( The influence of terrain and geophysics)
mountain-valley breeze : Due to the uneven heat g
enerated by the hillside and valley. mountain-valley breeze : Due to the uneven heat g
enerated by the hillside and valley.
冷
暖
谷
风暖
山
风冷
暖
冷
Figure 9-2 circulation of mountain-valley breeze
Factors of atmosphere diffusion
Sea and land breeze : it is caused by thedifference of land and sea heat nature.
Sea and land breeze : it is caused by thedifference of land and sea heat nature.
sea wind conditions in daytime landwind conditions in night
9.2.2 Turbulent flow diffusion theory
Gradient transference theory: it is supposed the dispersion caused by air t
urbulent flow; it is similar to molecule diffusion and can use the same m
olecule equation to describe.
Gradient transference theory: it is supposed the dispersion caused by air t
urbulent flow; it is similar to molecule diffusion and can use the same m
olecule equation to describe.
Turbulent flow statics theory: supposing the particle in material is the
same with successive fluid, when particle is in transference and diffusi
on, it will not happen chemistry and biology reaction, seize and quality
of particle is not included, and regards particle activity is happening re
lative certain space.
Turbulent flow statics theory: supposing the particle in material is the
same with successive fluid, when particle is in transference and diffusi
on, it will not happen chemistry and biology reaction, seize and quality
of particle is not included, and regards particle activity is happening re
lative certain space.
9.2.3 The diffusion model of atmospheric poll
utants 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.
The diffusion model of
pollution source
According to the geometry of pollution source, it can be divided into
following: point source, line source, surface source
According to the duration of pollution discharge, it can be divided
into instant source, continual source.
According to the height of discharge source, it can be divided into
ground source, elevated source and so on.
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
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
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:
xx uf yy uf zz uf
9.3.2 Dispersion effect
Molecule dispersion: the dispersed phenomenon caused by the random
movement of molecule. The molecule dispersion process follows the fi
rst law of Fick, which is the quality gamma flux of molecule dispersio
n is in direct ratio to the density and gradient of dispersed substance.
yEI Mx
1
yEI My
1
zEI Mz
1
Dispersion of turbulent flow : Dispersion of turbulent flow is a dispersed phenomenon th
at 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 e
xpressed by the first law of Fick
xEI xx
2
yEI yy
2
zEI zz
2
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.
xDI xx
3
yDI yy
3
zDI zz
3
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
9.49.4 The diffusion discipline used other substance as mediaThe 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 electromag
netic wave
9.5 Convection theory ofConvection theory of environment physics pollutenvironment physics pollut
ionion 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
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
9.6 Analyses onAnalyses on typicaltypical physical pollutionphysical 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
9.6.2 Electromagnetic radiation Electromagnetic wave radiation has been listed as the fourth biggest pollu
tion 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:
天然电磁辐射污染源
大气与空气污染源
宇宙电磁场源
太阳电磁场源
自然界的火花放电、雷电台风、高寒地区飘雪、火山喷发
太阳的黑子活动与黑体放射等
银河系恒星的爆发、宇宙间电子移动
Natural electromagnetic
radiation pollution resource
Natural electromagnetic
radiation pollution resource
Artificial electromagnetic radiation pollution Artificial electromagnetic radiation pollution
Types of pollution source Equipment name of production pollutio
n source Pollution source
Pollution
sourcecausedbydischargng
corona discharge Power lines (wires for distribution )
The electrostatic induction, electromagneticinduction and electric leakage caused by high voltageand large current
glow discharge discharge tubeWhite lamp, high-pressure mercury lamp and dischar
ge tube
arc discharge Switch, electric railways and dischargetube
spark discharge Electrical equipment, engine,refrigerator, automobile, etc
Rectifier, generators, discharge tube, ignition system
Power frequency radiation field resource
High power transmission line, electricequipment, electric railway
The pollution caused by high voltage, largecurrent power lines, electrical equipment
Radio-frequency radiation fieldresource
High-frequency heatingequipment, heat and machine,microwave drying machine,physical machine, instrument, etc
circuits which use to industrial and medical rf equipment, oscillation system
Radio transmitters, household electricappliances, etc
Radio, television, computers and wireless telephone, microwave oven, etc
Buildings reflectionHigh-rise buildings and large metal
components Wall, steel, cranes, etc
Green card : The adverse effects and hazard on human
health by electromagnetic radiation
The influence
of the central system
Cause Cardio
ascular disease
Cause Cardio
ascular disease
The harm to the
immune function
of body
The harm to the
immune function
of body
The influence of
the blood system
The influence of
the blood system
The influence of
the visual system
The influence of
the visual system
The influence of
human health
The influence of
human health
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.
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.
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
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
light pollution
放射性废物
水体
大气
土壤 水生生物陆生生物
吸附
沉积
沉降
摄入
Figure 9-5 Radionuclide enter schemes
Case study : Indoor physical pollution
Radioactive pollution of decoration material Harm: if the indoor ventilation is not good, human will subjected t
o 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.
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
Thank you