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 4Mean 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

1:16

1:32

1:64

1:12

81:

11:

21:

41:

81:

161:

321:

641:

128

1 2

0

5

10

15

20

25

30

35

Untreated sedi-ments: diluition

series

1 1:1 1:2 1:4 1:8 1:16 1:32 1:64 1:128

29 21 17 20 22 7 0 0

2 1:1 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 foetida2: Tamarix gallica + Paspalum vaginatum + Eisenia foetida3: Spartium junceum + Paspalum vaginatum + Eisenia foetida4: Nerium oleander + Paspalum vaginatum + Eisenia foetida5: 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 resultsTreated 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!