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Ch2 Water, Air and Their Impurities2.A Water and the Hydrosphere

• 水及水圈• 空氣及大氣圈• 環境介質中之污染物

– 酸、鹼、– 無機物、– 有機物、– 臭味、顏色、– 顆粒物質、– 微生物

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Water and hydrosphere

• Hydrologic cycle– Characteristic residence times

• Physicochemical properties– Density (1g/cm3, 55.6 M, Temp., Composition)– Density of ice 0.92 g/cm3

– Viscosity (0.6-1.8 g/m.s in 0-40 oC)– Water and Life

• O2 → H2O

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• 水密度隨溫度而異，湖泊溫層逆轉。• 水比熱較高，穩定氣溫。• 微生物細胞含水率 75%(w/w) 以上。

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•Density of freshwater, as a function of temperature

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•Density of seawater (a) as a function of salinity (mass percentage of total salts in water)

for various temperatures and (b) as a function of temperature for various salinities.

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•Dynamic viscosity, μ, of freshwater as a function of temperature.

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2.B Air and the Atmosphere• Five major gases

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Physicochemical properties of air

• Ideal gas– n/V = P/RT (1 atm, 293 K, gas conc.=41.6

mol/m3)– Partial pressure = Mole fraction– Molecular weight (dry, moist)– Density (Temp., Pressure)

• Atmosphere

• 空氣分子量計算• 空氣分子量隨含水量 ( 濕度 ) 而異。• 理想氣體公式之使用。• 空氣之比熱明顯較水低。

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• PV=nRT PM=ρRT

•Density of dry air versus temperature at several pressures (P)

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Ci = MW ． ni / V

↓

Ci = YiMW ． ni / V ( PV = nRT )

↓

Ci = YiMW ． P / RT

And ρair= MW ． n / V = MW ． P / RT

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•Typical dependence of temperature, pressure, and air density on height through the

lower portion of the troposphere. The given altitudes range from sea level to near that

of the tallest mountains on earth.

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2.C Impurities in Environmental Media– 2.C.1 Gases Dissolved in water

– 2.C.2 Water in Air

– 2.C.3 Acids,Bases,and the Hydrogen Ion

– 2.C.4 Inorganic Impurities

– 2.C.5 Organic Impurities

– 2.C.6 Radio nuclides

– 2.C.7 Compounds Causing Odor,Taste,or Color

– 2.C.8 Particulate Matter

– 2.C.9 Microorganisms

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• 2.C.1 Gases Dissolved in water– O2, CO2, SO2, HNO3, NH3, CH4

• 2.C.2 Water in Air

• 2.C.3 Acids, Bases, and the Hydrogen Ion– pH = -log [H+]– pH = 1 -14, pH = 0 (?)

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• 2.C.4 Inorganic Impurities– Ions in water

• Electroneutrality,• Ionic strength, • Hardness, • Alkalinity, A=[OH- ]+[HCO3

-]+2[CO32- ]- [H+ ]

– Inorganic gaseous pollutants • CO, NOx, SOx, O3

– Toxic metals• Cadmium (Cd), Chromium (Cr), Lead (Pb),

Mercury (Hg)

i

iiCz 0

i

ii zCI )(2

1 2

i

ii zCTH )(

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• 水中正負離子呈電價中性狀態，陽離子當量數等於陰離子當量數。

• TDS 代表總溶解固體物，含非離子成分。• 離子強度：用以表示溶液中離子間靜電

作用力強度。• 硬度：多價陽離子當量數總和。硬度種

類• 硬水定義、硬度單位。• 硬水軟化技術。

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• 鹼度：中和酸之能力，與鹼性 (pH>7) 不同，重要參數。

• 鹼度單位。• 無機氣態污染物： CO, NO2, SO2, O3.

• 毒性重金屬 ……

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Conductivity

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

11000

0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000

Dosage(mgL-1 as NaCl)

Con

d. (µ

Scm

-1)

NaCl 之電導度

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Conductivity

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

11000

0 5000 10000 15000 20000 25000 30000 35000 40000 45000 50000 55000 60000

Dosage(mgL-1 as MgSO4)

Con

d. (

µScm

-1)

MgSO4 之電導度

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• 2.C.5 Organic Impurities

– Specific organic impurities• HCHO, CFCs, Benzene, PCE, Dioxin,

PAHs

– Aggregate measurement of organic compounds• OD, TOD (ThOD), BOD, COD, TOC• NMHC

• 特定有機污染物• 非特定有機污染物，總合性有機污染物

之必要性及限制。• 氧需要量之意義。• 氧需要量與有機碳之轉換。• BOD 之定義、實驗、特性。• COD 之定義、實驗、特性。• BOD < COD (?)

• NMHC – ppmC, ppbC

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• 2.C.6 Radio nuclides

• 2.C.7 Compounds Causing Odor,Taste,or Color

• 2.C.8 Particulate Matter

– Aerosol and Hydrosol

– Small Colloids (10-3 μm)

– Particles in Air: fine and coarse

– Particles in Water: settleable, suspended and colloidal solid

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• 2.C.9 Microorganisms

• 微生物：細菌、真菌、藻類、原生動物 、病毒。

• 細菌之角色、分類、應用特性。– 好氧、厭氧、兼性– 異營、自營– 光合、化合

• 原生動物、後生動物 – 水質指標微生物。• 真菌、藻類 – 明日之星。• 病毒 – 疾病、研究用途。

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•Prokaryotic

•Eukaryotic

•Bacteria

•Archaea

•Viruses

•Algae

•Fungi

•Protozoa

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Problem assignments #2In textbook:• 2.3 Volume occupied by air• 2.14 Electroneutrality• 2.15 River water quality• READING:

Chapter 2: Section 2.C (pp. 41-69)Chapter 3: Sections 3.A and 3.B (pp. 76-106)Appendix C (pp. 613-619