Matakuliah : S0372 – Kimia Teknik Sipil
Tahun
: Ganjil 2007/2008
ENVIRONMENTAL CHEMISTRY
Pertemuan 03
ENVIRONMENTAL CHEMISTRY
1.Sour Rain
2.Degradation Materials
3.Relation with building.
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NATURE OF WATER
1. Dissolve very good.
2. Highest dielectric konstanta.
3. High surface tension.
4. Transparent look and longer wavelength faction of light of
ultraviolet.
5. Maximum Density 4oC
6. Higher heat of evaporation of other materials.
7. Heat of Latent bigger than other dilution fusion except
ammonia.
8. Bigger capacities heat.
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ACIDITY OF WATER AND OF CARBONDIOSIDA IN WATER.
Acidity as application for natural water and waste water [is] capacities
irrigate for menetralisasi OH- ; and this matter of analogue with alkalinitas,
capacities for the menetralisasi of H+.
Acidity generally result of from existence of acid weak, especially CO2,
sometime the including other like H2PO4-, H2S, protein, and fat acids.
Acidity of metal ion, especially Fe3+ , also give acidity contribution.
From contamination, sour of strength is very important contribution for the
acidity of. Free acid mineral like H2SO4 and of HCl in water. Sour of water
mine is acidulous common polutan of free mineral. Total acidity determined
with titration with basa use fenolftalein as final dot ( pH=8,2), free acid
mineral determined with titration of basa metally orange as final dot ( pH
4,3).
Nature of acidity some metal ion of hydration giving acidity contribution:
Al (H2O)63+ ==== Al(H2O)5OH2++ + H+
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Sour Rain (SOx , NOX)
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Materials of York Minster is especially two rock type: crystalline a,
dolomite granular, MgCO3.CaCO3, porous more a and, calcite of largely
made limestone oolithic granular, CaCO3.
As construction materials, the dolomite stone is much more resistant to
erosion than the limestone (Mills 2000), lasting up to four times longer.
With existence of water, dioxide sulphur react with the following
limestone dolomite :
CaCO3.MgCO3 (s) + 2SO2(g) + O2(g) —> CaSO4.2H2O(s) +
MgS04.7H20(s) + C02(g)
Oolithic limestone Dry react with oxygen and dioxide sulphur for :
CaC02(s) + S02(g) + 1/2 O2(g) ——> CaSO4(s) + CO2(g)
With existence of water for the forming of hydration sulphate calcium.
SO 2(g) + NO2(g) + H2O(/) = H2SO4(aq) + NO(g)
nitrogen of Oxides (NOX) form nitrate acid with water to react with
limestone to form dissolve easier Calcium nitrate salt in water.,
Ca(NO3)2.
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RELATION WITH BUILDING
• Concrete building will caused by brittle of sour rain,
and so do other materialss able to be dissolve by
sour rain.
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FACTORS INFLUENCING CONCRETE STRENGTH
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CORROSION PROTECTION
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Proper cover of at least 2”
lower w/c = weight of water / weight of cement
denser concrete
avoid using chlorides
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