Présentation Mambilo RPIC 3 février 2016 Version Anglaise (1)€¦ · Présentation Mambilo RPIC...

Applicability of solidifica0on/stabiliza0on for the direct treatment of hydraulic dredging sludges in geotex0le tubes Marine Infrastructure Na/onal Workshop, Quebec, February 2-‐3, 2016 16

III. Work completed

Phase 1 : S/S treatment of «se3led» sediments

o  Phase 1B : Formula;on and prepara;on of mixtures

Material Mixing of addi0ves

Physical and chemical tes0ng

Characterisa0on of sediments


III. Work completed

Phase 1 : S/S treatment of « se3led » sediments o  Phase 1C : Assessment of performance

Control tests Comparative values (MDDELCC guidelines to apply S/S treatment for contaminated soils)

Physical tests — Flexural strength ( to 28 days) -‐

— Compression strength (to 28 days) > 3,5 MPa

— Hydraulic conduc0vity < 10-‐7 cm/s

— Physical altera0on (freeze/thaw or drying/weTng)

< 10 % loss aVer 12 cycles

Chemical tests — Leaching SPLP < potability criteria

— Water leaching < potability criteria

— Diffusivity (leachability index) > 9


III. Work completed

Phase 2 : S/S treatment of «liquid» sediments

o  Phase 2A : Performance assessment program

o  Solidified material : same program as for Phase 1

(physical and chemical tests)

o  Filtrate: Addi0onal performance assessment program —  Total and dissolved metals —  pH and redox poten0al —  Electrical conduc0vity —  Turbidity and suspended solids —  Chemical oxygen demand (COD) —  Anions —  Ammonia —  Total and dissolved organic carbon (TOC and DOC)


III. Work completed


o  Phase 2B : Determining flocculant dosage o  Jar tests :

—  Concentra0on of polymer solu0ons : 0.1%, 0.2%, 0.3% et 0.4% —  Polymer type (ca0on, anion) —  Compa0bility with S/S treatment


III. Work completed


o  Phase 2B : Determining flocculant dosage o  Selected polymer (AQ 8539) based on the best floccula0on charateris0cs :

—  Floc size —  Sedling rate —  Supernatant clearness

Before addi*on A-er addi*on

Clear supernatant

Flocculated solids


III. Work completed


o  Phase 2C : Se3ling/filtra;on column test

Geotex*le membrane


III. Work completed


o  Phase 2C : Se3ling/filtra;on column test o  Small scale column tests:

•  Sediment + S/S treatment + polymer •  Sediment + polymer

Before treatment A-er treatment

Solidified material retained on the filter (geotex*le)


III. Work completed


o  Phase 2D : Geotex;le tube injec;on test o  Laboratory prototypical treatment unit to simulate a direct coupled S/S and

polymer treatment during the pumping of hydraulically dredged sediments into a geotex0le tube

Hydraulically dredged

sediments to be treated

S/S sludge Flocculant

Geotex*le tube

Floccula*on

General illustra;on of the pumping system

Homogeniza*on


III. Work completed


o  Phase 2D : Geotex;le tube injec;on test o  Conduct compara0ve injec0on tests (with and without S/S treatment)

o  «Liquid» sediments : dry-‐solids content of approx. 15% (dilu0on of same sediments as for Phase 1)

Material before treatment Material aVer treatment Water (filtrate) aVer treatment

Solidified material extracted from the geotex*le tube


IV. Results

Phase 1 : Performance assessment of S/S treatment on «se3led» sediments

Control tests

Comparative values (MDDELCC guidelines to apply S/S treatment for contaminated soils)

Results

Physical tests — Flexural strength (at 28 days) -‐ 0,6 -‐ 1,6 MPa

— Compression strength (at 28 days) > 3,5 MPa 2,0 -‐ 5,0 MPa

— Hydraulic conduc0vity < 10-‐7 cm/s 10-‐8 -‐ 10-‐9 cm/s

— Physical altera0on < 10 % loss aVer 12 cycles (freeze/thaw or drying/weTng)

< 1% aWer 56 cycles (drying/weTng)

Chemical tests — Leaching SPLP < potability criteria < potability criteria

— Water Leaching < potability criteria < potability criteria

— Diffusivity (leachability index) > 9 > 10


IV. Results

Phase 2 : Assessment of treatment performance on «liquid» sediments

o Results being processed for

–  Filtrate

–  Solidified sediments

Solidified material extracted from the geotex*le tube


Conclusions

Summary

o  Development of a new treatment process for contaminated hydraulically dredged sediments:

— Coupling of solidifica0on/stabiliza0on with dewatering in geotex0le tubes

o  S/S treatment of contamined material : — Decrease in contaminant mobility — Encapsula0on of contaminants in a monolithic matrix — Improvement of mechanical proprie0es of materials

o  Dewatering in geotex0le tubes: — Control of suspended solids during dewatering of hydraulically dredged sediments


Conclusions

o  Suitability and benefits of this innova;ve process

o  Recovery and reuse of fine –grained sediments, which are commonly regarded as waste (e.g. without geotechnical applicability), for construc0on/civil engineering applica0ons

o  Stabiliza0on and encapsula0on of contamina0on in a cemen00ous matrix

o  Strengthening of sediments allowing the integra0on of the treated material in structural works (dike cores, plamorm, embankments)


Thank you for your a3en;on!

Ques0ons …

JEAN-PHILIPPE BOUDREAULT, ing. [email protected]

VALERI MAMBILO [email protected]

JEAN-SÉBASTIEN DUBÉ, ing., Ph.D. [email protected]

Présentation Mambilo RPIC 3 février 2016 Version Anglaise (1)€¦ · Présentation Mambilo RPIC...

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