Innovative integrated methodology for the use of decontaminated river
sediments in plant nursing and roadbuilding
Activity of partner UniFi
Activities done:
Dissemination – done
Sediment monitoring (BioTox) – done
Microbial diversity analysis (in progress)
Dissemination:
• SICA Winter School – Piacenza, Feb., 2014
• Workshop REMIDA – ARPA Umbria, Terni, Oct., 2013
• Proceedings of the REMIDA workshop Mar 2014
• Presentation at the UniFi institution – Mar., 2014
Sediment toxicity monitoring: BioTox test
The sediments toxicity analysis is assayed with the BioTox test (Aboatox Oy, Turku, Finland) according to the ISO standard method (ISO 11348e3, 1998). Bio-indicator: Vibrio fischeri, a luminescent marine bacterium.
_ Sensitivity to contaminants N sample bacteria_ Luminescence amount of contaminants
Advantages: _ Standardization _ Many kind of substances (soils and sediments; liquids or solids) _ Economical and rapid _ Correlation with the effects on higher organisms (Qureshi et Al., 1998)
BioTox test: analysis procedure
• Suspension of 2 g of sieved (<2 mm) sediments in 8 ml of 2% NaCl• Shake for 5min by hand and settling for 30min• Adjustment of pH and conductivity• Reconstituition freeze-dried V. fischeri cells• Addition of 300 ml of the bacterial suspension to 300 ml of samples (solid/supernatant)• Measure of bioluminescence• Calculation of the inhibition of bioluminescence index (INH%) after 15 or 30 minutes
< 20%
INH%
> 20%
BioTox test: preliminary results
Untreated sediments dredged in November, 2013: pore water (toxicity of lecheates) and sediment slurry
Legend 1: Incile 2: Sandy; low contamination3: Sandy-clay; middle contamination4: Clay-silty; middle contamination
1 2 3 40
10
20
30
40
50
60
Untreated sed-iments - slurry
Sediment
slurry1 2 3 4
Mean INH%
51.66 20.88 0 0
Pore water
1 2 3 4
Mean INH%
0 0 0 0
Toxic!
BioTox test: preliminary results
Untreated sediments dredged in November, 2013: dilituition series on 1 and 2 samples
Legend 1: Incile 2: Sandy; low contamination
1:1
1:2
1:4
1:8
1:1
61:3
21:6
41:1
28
1:1
1:2
1:4
1:8
1:1
61:3
21:6
41:1
28
1 2
0
5
10
15
20
25
30
35
Untreated sedi-ments: diluition
series
11:1 1:2 1:4 1:8 1:16 1:32 1:64
1:128
29 21 17 20 22 7 0 0
21:1 1:2 1:4 1:8 1:16 1:32 1:64
1:128
0 0 19 17 11 1 0 0
BioTox test: preliminary resultsTreated sediments sampled in November 28, 2013: torbid samples
None samples showed toxicity!
Legend
1: Paspalum vaginatum + Eisenia foetida
2: Tamarix gallica + Paspalum vaginatum + Eisenia foetida
3: Spartium junceum + Paspalum vaginatum + Eisenia foetida
4: Nerium oleander + Paspalum vaginatum + Eisenia foetida
5: Phragmites australis + Paspalum vaginatum + Eisenia foetida
6: No plants used as control area
1 2 3 4 5 6Mean INH%
0 0 0 0 0 0
BioTox test: preliminary results
Treated sediments sampled in January 28, 2014: pore water (toxicity of lecheates) and sediment slurry
The last sampling confirmed the non toxicity of the treated sediments!
Torbid samples1 (0-30cm) 2 (0-30cm) 3 (0-30cm) 4 (0-30cm) 5 (0-30cm) 6 (0-30cm)
0 0 0 0 0 01 (30-60cm) 2 (30-60cm) 3 (30-60cm) 4 (30-60cm) 5 (30-60cm) 6 (30-60cm)
0 0 1.90 7.75 0 0
Pore water1 (0-30cm) 2 (0-30cm) 3 (0-30cm) 4 (0-30cm) 5 (0-30cm) 6 (0-30cm)
0 0 0 0 0 01 (30-60cm) 2 (30-60cm) 3 (30-60cm) 4 (30-60cm) 5 (30-60cm) 6 (30-60cm)
0 0 0 0 0 0
Conclusions• The solid phase of untreated sediments (samples 1 and 2) is toxic
• The pore water is not toxic, indicating that contaminants are strongly retained by the solid phases
• Phytoremediated sediments are non toxic either the solid phase and the lecheates
• There is no difference between 0-30 cm (high plant root colonization) and 30-60 cm (low plant root colonization)
• Microbial activity seems the main factor in de-toxification of treated sediments
Microbial diversity analysis… in progress
Two aims:
1) Understanding the progress of microbial diversity
2) Amend phytoremediated sediments with plant growth promoting rhizobacteria (PGPR)
Additional activities
Test the performance of phytoremediated sediments as a suitable substrate in real plant nursery companies
Thanks for your attention!
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