A Constructed Wetland Technology Based
Pilot Plant For Treating Municipal Wastewaters
Of Indian Agricultural Research Institute
Ravinder Kaur, Project Director
Water Technology Centre, Indian Agricultural Research Institute
Other Team Members: Gaurav Dhir, Paritosh Kumar, Gitla
Laishram, Deepa Ningthoujam and Praveen Sachdeva
Second Regional Workshop ‘Safe Use of Wastewater in Agriculture’ , 16-18 May 2012, New Delhi, India
NEED ASSESSMENT
IARI Watershed
(1030 ha)
Total area- 466 ha
Farm area- 290 ha
Total irrigation Demand: 7.8 MLD
Ground Water demand: 4.47 MLD
(57 %)
Canal Water
Demand: 0.55 MLD (7 %)
Deficit: 2.78 MLD
Available Sewage:
22 MLD
COSTLY
UNSUSTAINABLE
GENERATE HAZARDOUS SLUDGE
CONSTRUCTED WETLANDS
Experimental Wetland Site
A PILOT PLANT FOR TREATING MUNICIPAL WASTEWATERS OF IARI
18 Experimental wetlands
3 wetland vegetations such as
Reed grass (Phragmytis karka),
Achorous calamus (Vacch)
Typha latifolia (cattail)
SW
CW
PW
TW
VW
GW
SW: Sewage Water
CW: Non –Veg. Wetland water
PW: Phragmites Water
TW: Typha Water
VW: Acorous (Vacch) Water
GW: Ground Water
SYSTEM LAYOUT
Sewage Channel
Main influent pipe
Pump
house
Inlet Valve
S
u
m
p
Influent pipe
Control
Screen
Effluent pipe
Outlet Valve
Main effluent pipe
SYSTEM MONITORING
Influent
pH
EC
TDS
DO
ORP
Temperature
Salinity
Turbidity
Carbonate & Waste
Bicarbonate water
Ca & Mg
Na
K
ClFSO4-2
NO3-
Plant
PO
-3
4
Soil Organic CarbonTreated
Soil
waterHeavy Metals
Soil moisture content
Effluent
(Zn, Cu, Cd, Cr, Co, Mn, Fe, Ni, Pb)
VOLUMETRIC EFFICIENCY
100
Percentage
80
60
81.8
98.4
80.1
78.48
40
20
0
Typha
Phragmites
Acorus
Treatments
Unplanted
HYDRAULIC RETENTION TIME
HRT (Hours)
60
50
40
Less than 1 day
30
20
10
0
Typha
Phragmites
Acorus
Wetland Systems
Unplanted
POLLUTANT MASS REDUCTION EFFICIENCY
350
250
100.8 %
86%
Percent
150
57%
68%
40%
53%
50
-50
Redox
Potential
Turbidity
Nitrate
Phosphate Potassium
Sulphate
-150
-250
Typha (T1)
Phragmites (T2)
Acorus (T3)
Unplanted (T4)
METAL MASS REDUCTION EFFICIENCY
90
39 %
50 %
44 %
70
50
30
Percent
10
-10
-30
IRON
Typha (T1)
NICKEL
Phragmites (T2)
Acorus (T3)
COBALT
Unplanted (T4)
60
50
40
43 %
17 %
30
20
10
0
Chromium
Lead
IMPACT OF TREATED & UNTREATED SEWAGE WATERS ON FOOD GRAIN CONTAMINATION IN WHEAT & PADDY
90
80
Metal Concentration (ppm)
Wheat var. HD
2329
70
60
50
80.21
Food grain
contamination
in Wheat
73.95
-59%
-54%
MAL - 1 ppm
MAL - 0.8 ppm
40
30
20
10
0
Pb
Paddy var.
Pusa Basmati 4
Metal Concentration (ppm)
140
120
100
80
Food grain
contamination
in Paddy
Cr
125.88
120.85
MAL - 1 ppm
-60%
MAL - 1 ppm
60
40
-84%
28.99
21.61
20
0
Pb
Cr
The impact of the untreated and treated sewage water irrigations on the quality of produce from wheat and paddy
fields was also assessed to show significantly (2-3 times) lower metal concentrations in the food grains produced
from wetland treated sewage waters.
TEMPORAL PROFILE OF SOIL METAL CONCENTRATIONS at SEWAGE PLOT SITE
EMERGY BUDGET:
Experimental Wetland Vs. Conventional STP
Inputs
Local renewable resources
Solar Emergy (sej/yr)
Experimental
Wetlands
Conventional
STP
1.14 X 1016
1.82 X 1016
Purchased renewable
Conventional
STP had 143.27
times
X 1015
resources
More
Resource
Use than
Purchased
non
renewable
3.97 X 1016
resources
Experimental Wetlands
0.00
7.68 X 1017
Purchased resources
4.30 X 1016
7.68 X 1017
Total resource use
5.44 X
5.44
X 10
101616
17
7.87 X 10
7.87
1017
Emergy Based Sustainability Indices
Emergy Yield Ratio (EYR)
EYR = Y/F
Y: Emergy yield ; F: Purchased emergy
Environmental Load Ratio (ELR)
ELR= (F + N) / R
N: Non renewable resource emergy
R: Local Renewable resource emergy
Emergy Sustainability Index (ESI)
ESI = EYR/ELR
Percent Renewable Index (PR)
PR = (R + Fr)/U
Fr : Purchased renewable resource emergy
U: Total resource use emergy
Emergy Analysis of
Experimental Wetland Vs. Conventional STP
Emergy Indices
Experimental
Wetland
Conventional
Treatment Plant
Environment Load Ratio
1.37
42.19
Emergy Yield Ratio
0.70
0.01
Experimental Wetlands exerts 33 times lesser Stress on
STP
RenewableEnvironment
Percentage than Conventional
0.51
0.02
Experimental Wetlands were 70 times more Efficient in utilizing
Emergy
Sustainability
0.54
0.00034
purchased
resources Index
& Consumed 25
times more Renewable
resources than Conventional STP
Experimental Wetlands 1500 times more
Sustainable than Conventional STP
Salient Findings
Overall Volumetric Efficiency of Experimental Wetland System: 84%
Seasonal Nutrient & Metal Removal Efficiencies: 40 to 90%
Planted Wetlands Performed Better than the Unplanted ones
Typha Out-performed Phragmites and Acorus
Wetlands: Smaller Ecological Footprint & OPEX,
as consumed 100 times lesser non-renewable energy than STP
Wetland based Wastewater treatment cost ½ of STP
Eco-friendly Technology for Mitigating Global Environmental Pollution &
Health Problems due to Improper Sewage Treatment
Attractive Solution for Developing Countries with Scarce Resources for
Investment in Expensive Centralized Sewage Infrastructure
Outcome
Technology Being Up-scaled for
Treating Krishi Kunj Sewage Water
&
Augmenting IARI Irrigation Water Supplies
Thank you