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

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