Many chemical substances rejected into the natural environment accumulate in the vases or muds constituting the sediments. Nowadays, in order to reduce human health and ecological risks, also to prevent the blockage of drainage channels and manage flood risks, operations of dredging are accomplished everywhere across the world. In European countries dredged sediments are used sometimes as manure to fertilizer agricultural soils. In Port-au-Prince, operations of dredging are usually realized on “Bois-de-Chêne” river or channel. The Channel sediments are exposed to wastewater from the Urban Community of Port-au-Prince. After the operations of dredging, the polluted sediments, including solid wastes, are deposited on a site very close to the bay of Port-au-Prince. This discharge allows to a transfer of pollutants to ocean. Indeed, these sediments mixed with solid and liquid wastes can contribute to an eutrophication hazard for the marine ecosystem of Port-au-Prince. Terrestrial ecohydrology approaches, based on phytotechnology, are mostly used to reduce and manage hazards or risks linked to contaminated sediments. In order to eliminate pollutants containing in the polluted dredged sediments from drainage channel of Port-au-Prince. Zea mays L. has been used, as ecohydrological agent, in this study to reduce the toxicity of sediments chemical compounds on natural ecosystems. The analysis of pore water of the sediments taken at three (3) points along the channel has allowed showing the Toxicity of the experimental material in nitrogen and phosphorus compounds. The nitrogen (nitrates, ammonia) and phosphorus (phosphate) pollutants were determined according to the french standards. The phosphate values, in particular, are higher of more than 7 times than the maximum limit (2 mg/L). The latter consisted in trapping the mineral compounds by the vegetable material. The measured physical parameters reveal that corn samples raised in the sediments had a better growth than those in the pilot ground from Damien farm. The analysis of collected plants samples shows the potentialities of Zea mays L in the phytoremediation of nitrogen and phosphorus.

1. Evens Emmanuel, Martine E Mathieu, Pierre M. Samson, Elmyre Clervil
Université Quisqueya
BP 796, Port-au-Prince, HAITI
e-mail: evens.emmanuel@gmail.com
62th Annual Meeting of the Southeastern GSA
20 – 21 March 2013 – San Juan, Puerto Rico
Efficiency of Zea mays L. in the retention
of nutrients in the interstitial water
from Port-au-Prince dredged sediments

2. Wastewater management in Haiti
Human health
Jeopardise the bilogical
equilibrium of ecosystems : loss
of aquatic biodiversity
ecological
Economical umbalance
Direct discharge in
Aquatic ecosystems
R
I
S
K
S

3. 2
Port-au-Prince Urban wastewater
1 2 3
4 5

4. 3
Urban Wastewater characterization
P1
P2
P3
P4
P5
P6
P7
P8
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
P1 P2 P4 P5 P6 P7 P8
Sampling points
ConcentrationsofPhosphate(mg/L)
Dry season Reany season Treshold values

5. Dredged sediments from
drainage channel of Port-au-
Prince
The bay ecosystems
of Port-au-Prince
Dredged sediments disposal

6. Ecotoxicological approach for management of
dredging sediments
Daphnia magna Pseudokirchneriella
subcapitata
Phyto toxicity testBrachydanio rerioEcotoxicity tests

7. Ecohydrological approach
The ecohydrology of an area or region is determined by
climate, geomorphology, plant cover/biota dynamics and
anthropogenic modifications. By understanding these
factors, the potential exists for the application of
Phytotechnologies to increase plant biomass and to
regulate nutrients and water dynamics, thereby
increasing ecosystem carrying capacity, resilience and
functionality. This can lead to significant improvements in
water quality, enhanced biodiversity, improved
agricultural production, potential bioenergy generation,
and remediation of degraded ecosystems (SANTIAGO-
FANDINO and NEATE, 2002)

8. Ecohydrological approach for management of
dredging sediments
Phytotechnology
Terrestrial ecohydrology approaches, based on
phytotechnology, are mostly used to reduce and
manage hazards or risks linked to contaminated
sediments.

9. Materials and methods
• 3 samples of
sediments from the
drainage channel
• 1 sample of pilot soil
from an agricutural
farm
• Use of Zea mays L.,
(gramineae family)
A3
A1
A2

10. Experimental implementation
• Chemical characterization
of the interstitial water of
dredged sediments
(Nitrates, phosphate, NH3..
• Chemical analysis of pilot
soil,
•Physical characterization of
plants (diameter and H cm)
• Chemical characterization
of plants (N and P)

11. 0
2
4
6
8
10
12
14
16
18
A2 A3 A4
Stations de prélèvement
Teneurenphosphates(mg/L)
PO4
Valeur limite
Phosphate values in interstitial water of dredged sediments

12. Physical parameters of plants
Stations
Parameters
A1 A2 A3 A4
Body diameter
(cm)
0.3 0.4 0.6 0.5
H of the body
(cm)
11.5 15.7 19.6 16.0
Roots diameter
(mm)
0.2 0.2 1.5 2.0
H of roots. pr.
(cm)
4.8 5.9 5.9 5.1
A.- After one month

13. Stations
Parameters
A1 A2 A3 A4
H (cm) 42.75 53.65 55.60 55.00
Presence of
fruits
yes yes yes yes
B.- Observations at the end of experimentation

14. N and P in Zea mays L.
Parts Body Roots
Parameters
Stations
N
(g/100g)
P
(g/100g)
N
(g/100g)
P
(g/100g)
A0 1.36 0.013 1.32 0.020
A1 0.67 0.023 0.14 0.016
A2 0.97 0.0357 0.68 0.023
A3 0.95 0.0244 0.80 0.0154

15. Conclusion
The measured physical parameters reveal that
corn samples raised in the sediments had a
better growth than those in the pilot soil from
agricultural farm.
The analysis of collected plants samples shows
the potentialities of Zea mays L in the
phytoremediation of nitrogen and phosphorus

16. UNESCO Chair on Ecohydrology
Humanities: Social Representation of Water in the
population - Assessment of behavioral risk
Social sciences (economics):
(i) Management of shared water resources
(ii) Environmental accounting of water
resources
Environmental Sciences: Ecotoxicology
tropical and process engineering.

17. Muchas gracias
Thank you
Merci beaucoup