Regional Conference on Advancing Non Conventional Water Resources Management in the Mediterranean, 14-15 September 2011, Athens, Greece

1. SUSTAINABLE USE OF
TREATED URBAN
WASTEWATER IN
AGRICULTURE
(BARI INSTITUTE EXPERIENCE)
Prof. Atef Hamdy
CIHEAM – Mediterranean
Agronomic Institute of Bari

2. Water Scarcity in Arid and Semi Arid Countries
of the Mediterranean and Arab World : The
Dilemma
• Nowadays, many countries in the region are approaching
the limit of water resources development and others reeling
under sever supply shortage; the problem of water scarcity
is turning into crisis. The dilemma those countries already
are facing is how to balance the increasing water demand
with the limited fragile water supply?; how to avoid water
crisis?; and what are the alternative options to ease the
situation?. there are potential ways to ease the burden
of water scarcity by trapping non conventional water
resources like sewage and industrial effluents, which
have traditionally been neglected.

3. Why Non-Conventional Waters?

4. Renewable Fresh Water Availability Per Person in the
Southern Mediterranean Countries, 1990 to 2050
Annual renewable fresh water
Annual renewable fresh water per capita
per meters)
(cubic
capita
(cubic meters)
4000
1990
2025
3500
2050
3000
2500
2000
1700-Periodic
Water Stress
1500
1000 - Chronic
Water Stress
1000
500-Absolute
Water Stress
500
0
Algeria Cyprus Egypt Israel Jordan Lebanon Libya Morocco Syria Tunisia Turkey

5. The Mediterranean Region:
Water Demand in 1990 and Foreseen
Demand for the years 2010 and 2025 [in km3/year]
Waa te rD ee man dd [in km 33 /ye a r]
W te r D m an [in km /ye a r] 4411 4.5
4 .5
33 566 .9
5 .9
44 5 0
50
44 0 0
00 22 788
7
33 5 0
50
33 0 0
00
22 5 0
50
+49%
related
+28%
22 0 0
00 to 1990
11 5 0
50
11 0 0
00
55 0
0
00
11 999 0
9 0 2200 100
1 22 022 5
0 5

6. A more rational management of water resources can permit
considerable savings, of the order of at least 30%, but it is not
easy to achieve, nor is it sufficient to solve the problems of
water scarcity
Therefore the use of non-conventional water resources is
mandatory
In particular, reusing non-conventional water resources is a
win-win solution because it is possible to solve two problems
simultaneously: safe wastewater disposal and more water to
irrigation

7. The Challenges
Can agriculture make use of non-conventional water
resources in a way which is technically sound,
economically viable and environmentally non
degrading?
What are the applicable techniques and management
practices required for the sustainable use of the
non-conventional water resources in agriculture?

8. Tha main non-conventional water resources

9. Non Conventional water resources and its use in
the region : Main Obstacles
• The efficient reuse of this vital water source is still
facing many technical, economical, environmental
and social constrains which are still seeking
sustainable solutions.
• Most countries of the region don’t have national
policies and strategies related to waste water
management in general and waste water for
agriculture in particular.
• Health fears and hazard due to the absence of well
defined waste water treatment technology to be
adapted.

10. URBAN
WASTEWATERS

12. The problems and The Risks

13. Bari Institute Program : Focusing elements

14. Intensive vs. Extensive Treatments

15. Intensive vs. Extensive Treatments
(e.g. lagooning, constructed wetlands and Soil
Infilteration)

16. Extensive treatments
Extensive treatments Looking for a reasonable
trade-off between cost and
Risk risk
?
There’s no point in pushing
treatment beyond reasonable limits
even in wealthy communities: you
pay more to have less and damage
Cost the environment (it is the Italian
case)
Intensive treatments
Intensive treatments

18. Constructed wetlands
Stabilization ponds and constructed wetlands are a low-cost
alternative for the treatment of domestic wastewater. They
provide water for irrigation in urban agriculture and for
watering green spaces.
Detention and retention ponds, lined up with reeds and
other wetland plants, perform well in purifying run-off
rainwater from quite streets. More polluted water requires
constructed wetlands designed for horizontal or vertical
flow, filtering, adsorption and uptake of nutrients. Good
design and maintenance are vital.

19. poplar plantation for depuration of domestic wastewater

20. Reed beds

22. monitoring water in a constructed wetland

23. inlet outlet tap water
Visual comparison of water depurated in a
constructed wetland
Outlet water is not intended for domestic uses, but can be used –and
further depurated- in irrigation

24. Standards for the Use
It is not true that standards are more advanced when more
stringent
Exceedingly stringent standards –like those adopted in most
industrialized countries- imply a waste of resources (organic
matter, nutrients) precious for the agriculture and the
environment, a waste of energy, and release CO2 to the
atmosphere
The only solution is to find out a way for taking advantage of
such resources instead of spending money to eliminate them
The challenge is: how to determine the correct level of
treatment? which is the permissible load of pollutants in
irrigation water under any specific condition?

25. Which Solution can We Suggest ?
Abandon unreasonably restrictive, universal standards
Look for a trade-off between costs and benefits
But never abandon the bottom-line level of safety

26. USING TREATED WASTEWATER AS
SUPPLEMENTAL IRRIGATION FOR
STABILIZING RAIN FED WHEAT YIELD

27. Impact of Treated Wastewater as
Supplemental Irrigation
• Using 2410 m3 per hectare for wheat
production can save 30 – 35 % of the
nitrogen fertilizer, 10 % of P fertilizer, and 70
– 82 % of K fertilizer, of the whole plant
exported nutrients and increase the farmer
income.

28. Impact of Treated Wastewater as
Supplemental Irrigation
• Equal amount of supplemental irrigation (125
mm) at flowering and grain filling stages
produced satisfactory yield (41.4 q/ha)
• Maximum yield (48.1 q/ ha) were obtained
when 70 % of supplementary irrigation ( 175
mm) is applied at the flowering stage.
• Less than 50 mm at flowering stage recorded
a drastic reduction in the grain yields.
• Flowering stage is the most critical growth
stage

29. Wheat Production Under supplementary
irrigation
• Wheat production in arid regions of Morocco
depends on rainfall.
• Drought periods took place during the spring,
which corresponds to flowering or gain filling
stage according to the planting date.
• Supplementary irrigation is widely practiced
in several mediterranean countries to
stabilize and improve the crop yield

30. Sustainable Safe Use : Major Needs

31. THANK YOU FOR YOUR
ATTENTION