Post on 28-Nov-2015
description
Controlling factors in water Chemistry
V.Subramanian
School of Envt.Sc,JNU
and
Institute of Envt.Sc,Amity university
subra42@gmail.com
Solar eruptions
Solar eclipse, gauhati. Sept
26,2012.
Human Body : Water NeedsHuman Body : Water Needs
80% 75% 70%
Fetus / Embryo New Born Adult
Brain 85%
Inactive
Adult
Active Adult
Loss
2 lit./day
Needs
2 lit./day
Needs
3 lit./day
Water Content
Water Distribution in Human Body
13%
15%
15%
16%
13%
15%
13%Brain
Lungs
Kidney
Blood
Heart
Liver
Muscles
Daily water loss
Human Body : Daily Water LossHuman Body : Daily Water Loss
Sole of Sole of
FeetFeetBreathingBreathing PerspirationPerspiration UrineUrine
250 ml250 ml 900 ml900 ml 450 ml450 ml 1300 ml1300 ml
Our personal water balance Water loss
Skin – 550 cc. Lungs – 440 cc. Urine – 1550 cc. Stool – 2650 cc. Total – 2650 cc.
Water Intake
Liquids – 1500 cc. Solid foods – 750 cc.
Produced in the body – 400 cc. Total – 2650 cc.
Water Chemistry
Weathering
Rock Type Hydro Factors
Climate
Rainfall
Regional Scale
Soil Cover
Local / Regional Variability
Episodic / Regular Events
Major Parameter
Nutrients
Metals
Secondary
Anthropogenic Land use Change
Urban inputs
Industrial
Resources Exploitation
Common Linkage
Fractionation
Estuary Ocean
River Behavior
Meanders
Delta Formation
Cut-offs
Flood and Sediments
First order impacts
• Sediment transport
• Water quality & temperature
• Transfer of energy
• Pollutants
Second order impacts
• Channel geomorphology
• Primary production
• Channel structure
Third order impacts
• Fish and invertebrate communities
• Spawning / scouring in water courses
Ecological Flow
River Behavior and Impacts
Factors Controlling dissolved parameters in water
1. Input = Output Steady state
Stable gradient Residence time Constant
Example: Cl-
2. Input > Output Non-steady state
Accumulation Residence time Higher,
Example: Hg+
3. Input < Output Non-steady state
Depletion/Erosion Residence time Lower,
Example: Rare gases?
4. Episodic Input/Output Prolonged non-equilibrium
Residual Dis-equilibrium in both Imbalance in residence time
Chemical (quality) and physical Example: Landslide/Volcanic
(quantity) processes Eruptions
Three phases of water
Water and Air interaction
• H2O(l) + CO2(g) = H2CO3(l)
• 1/[PCO2] k= 10(-3.5)
• H2CO3 = HCO3- + H+
• [HCO3-] [H+] / [H2CO3] k=5.(10-7)
• HCO3- = CO3-2 + H+
• [CO3-2] [H+] / [HCO3-] k=5.(10-11)
• HOH(l) + HOH(l) = H3O+ + OH-
• [H3O+] [OH-] k= 10(-1)
• HHO= H+ + OH-
• [H+]. [OH-] k=10 (-14)
Size-charge of elements
Radius-charge for ions in water( based on
Pauling)
Physical factors in Water Chemistry
• 1.Temperature
• 2.Pressure
• 3.Flocculation
• 4.Particle Size effect
• 5.Reaction Time
• 6.Turbulance/Flow velocity
• 7.Density
• 8.Dilution-concentration
Density-Temperature plot for
water
Unusual saline ground water in
Turkey
Float in Dead Sea !
•
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Chemical factors in water chemistry
• Dissolution
• Precipitation
• Complexation
• Colloids
• Oxidation-reduction
• Chelation
• Dilution
• Pollution
• Absorption-Desorption
Dissolved and solid carbon in
water
Basic rock-water reaction
2CO2 + 3H2O + CaSiO3 → Ca++ + 2HCO3- + H4SiO4,
Where, Ca++ might also be substituted by Mg++,
Fe+2,Zn+2 etc
CO2 + H2O + CaCO3 → Ca++ + 2HCO3-
or
2CO2 + 2H2O + CaMg(CO3)2 → Ca++ + Mg++ + 4HCO3-
Solubility factors
• Radical Soslubility
• Nitrates (NO3-),chlorides All nitrates and
chlorides are soluble
• Sulphates (SO4-2) Many sulphates are soluble.
• ------------------------------------------------------------------
• Carbonates (CO3-2) All carbonates are insoluble.
• Hydroxides (OH-) All hydroxides are insoluble.
• Sulphides (S-2, HS-1) All sulphides are insoluble.
1:1
0.1
1
10
0.1 1.0 10.0
Alkalinity meq/L
(Ca
+M
g)
me
q/L
Himalyan Rivers
Peninsular Rivers
Correlation of Alkalinity against total Ca
+ Mg
100 1000 10000 Alkalinity micro.eq/l
Kerala Rivers
Other Rivers
G-B river system
Saturation line 10000
1000
100
Carbonate saturation in river water
Tota
l dis
solv
ed s
olid
s
Na / (Na + Ca)
Gibbs diagram of water chemistry
Godavari river- CO2 plot
MB- Main branch; TR– Tributaries; CW- CO2 consumption rate due to
chemical weathering; SW- CO2 consumption rate due to silicate weathering
Atm and Soil derived alkalinity in
rivers
Basin Area vs pCO2
0
500000
1000000
1500000
2000000
G-B-M
I (P)G (I)
B I (L)G K M N C T W
FRs
River Basins
Bas
in A
rea
(km
2)
-4.00
-3.00
-2.00
-1.00
0.00
1.00
pC
O2 (
mE
q/L
)
Basin Area
pCO2
CO2 consumption rates (106 mol km-2 y-1) in
Silicate weathering for major world rivers
0.00
0.50
1.00
1.50
2.00
2.50
Narmada
TaptiMeckong
Ganges
Brahmaputra
Mississippi
Amazon
Mackenzie
St Lawrence
Lena
River Basins
CO
2 (
sil)
r water chemistry of India
Ganges river water
Average ground water chemistry in
India ( mg/l)
Lake water in India
Calculated HCO3 for various pCO2
scenario
y = 1.0029x - 1.6215
R2 = 0.9949
-4.5
-4
-3.5
-3
-2.5
-2
-1.5
-1
-0.5
0
-3 -2 -1 0 1 2
Log m HCO3,m/l
Lo
g p
CO
2,a
tm
Long term impact on water quality?
pCO2 and Deforestation
?
CO
2 c
on
sum
ed
in W
eat
he
rin
g
Deforestationincreasing
increa
sing
Model indicating the inter
Water,Society and Global change and Socirty and health and healthynergies between the concerns
Quality depends on quantity
also
Now, let us look into some
issues on water quantitatively
since quality and quantity are
inseparable!
Framework for Analysis of the Fresh
Water Environment
Drivers for monsoon rain
• El Nino is an oscillation of the ocean-
atmosphere system in the tropical Pacific
having important consequences for weather
around the globe.
• La Nina is the name for the cold phase of
ENSO, during which the cold pool in the
eastern Pacific intensifies and the trade winds
strength.
0
200
400
600
800
1000
1200
1400
1600
Delhi Kolkata Shillong Chennai Trivandrum Mumbai
Delhi
Kolkata
Shillong
Chennai
Trivandrum
Mumbai
Tota
l R
F (
mm
)
Monsoon, 2012 ( 1 June- 30 September)
The unpredictable rain!
•
Monsoon rainfall
Monsoon 2013 till sept 10
•
•
Virtual water demand
• 1 kg wheat 1500 litres
• Daily drinking water we need 2.5 litres
• 1 Kg rice 3000-5000 litres
• 1 Kg banana 2000 litres
1Kg of meat 15000 litres
Example of virtual water
Product Unit of measurement water consumption in liter
tomato 1 piece 13
Al metal can 1 piece 25
tea 1 cup 35
potato chips 1 bag (200 g) 185
paper 1 kg 750
bananas 1 kg 2000
cotton shirt 1 piece 2000
egg 1 kg 4500
rice 1 kg 5000
jeans 1 piece 8000
computer 1 piece 30000
car 1 piece 380000
Source of ganges waterSource of
Source of Ganges waterGanges
water
Water use through centuries
0
50
100
150
200
250
300
1900 1940 1950 1960 1970 1980 1990 1995 2000
(Year)
Irri
ga
ted
Are
a (
Millio
n H
a)
0
200
400
600
800
1000
1200
1400
1600
1800
2000
Wa
ter
us
e (
Km
3/y
r)
Irrigated Area Water Use
Water for agriculture
Water use for Major Crops in Asia
(Average production rates)
0
200
400
600
800
1000
1200
Cott
on
Pea
nut
Bar
ley
Bea
ns
Whea
t
Corn
Pota
to
Gra
in S
org
hum
Sunfl
ow
er
Tom
atoes
Sugar
bee
ts
Sugar
cane
Ric
e
Crop
Wat
er U
se(m
m)
Water for irrigation- from where?
Urban water demand
Per Capita Water Supply in Selected Metros
208
258
227
76
114
242
200
307
207
170156
262253
274
0
50
100
150
200
250
300
350
Mu
mb
ai
De
lhi
Ca
lcu
tta
Ch
en
na
i
Ba
ng
alo
re
Hy
de
rad
ab
ad
Ah
me
da
ba
d
Ka
np
ur
Na
gp
ur
Pu
ne
Ja
ipu
r
Lu
ck
no
w
Ka
rac
hi
Ba
ng
ko
k
City
Lit
re/ d
ay
Mumbai 2005: 2000 mm in 24 hrs
Endowments of water infrastructure…..
US and Australia have ~5000 m3/cap;
China has 2,400;
India has 130 m3/cap
India
130
Water and energy
Water for Energy Generation and
industry
Petroleum extraction. 10-40 litre/Mwh
Gas power plant 30000-75000
Coal gasification 900
Coal power plant 23000 litre/Mwh
Nuclear power plant 94600-227100
Biofuel power plant upto 27900000 litre/Mwh
Dams in Tibet
Water in air
Water from air !
Water droplets on mars lander
Artificial recharge of water
Artificial Recharge of water
Achankoil
Pamba
150x106 m3 Tunnel - 9 km
Vaipar River Basin LINK PROJECT
MICRO SCALE
Ken-Betwa Link?
Water resources development-
case from M.P.
Super Link!
Parameter units Bramaputra
Cauvery
Area (mill.ha) 53 2
Cultivated,(mil.km2) 18 10
Water needed( mill.ha.m) 3.6 2
Man and animal :all need water in
some form- virtual or real !