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Bioremediation
This is enhanced bio-degradation of large organic molecules in
less toxic materials such as CO2 and water, using turning equipment with
treatment stockpiles (windrows). May Gurney undertake this work under the
mobile plant licence regime.
Treatable materials
Contaminated soils:
Clays. Granular soils (sands & gravels), Loam-based, Tar Lagoons, Contaminated sludges, Contaminated Made Ground (less than 120mm particle size)
Pre-treatment Requirements
Pre-treatment typically involves soil screening (greater than 120mm and untreatable materials), stockpiling, de-watering/hydrating and mixing/blending of additives.
Contaminants that are treatable
Contaminated wastes with the following Hazard Codes, as defined in Part II of Schedule 2 of the Special Waste Regulations (1996), can be treated using bio technology:-
- H2 Oxidising
- H3-A Highly Flammable
- H3-B Flammable
- H4 Irritant
- H14 Ecotoxic
- H5 Harmful
- H7 Carcinogenic
- H6 Toxic
- H8 Corrosive
- H12 Substances or preparations which release toxic or very toxic gases in contact with water, air or an acid.
- H13 Substances and preparations capable by any means, after disposal, of yielding another substance, e.g. a leachate, which possess any of the characteristics listed above.
Bio treatment technology can be used to treat degradable organic compounds such as TPH up to 60,000 mg/kg to 100mg/kg, BTEX up to 20,000mg/kg to less than 1mg/kg and PAH up to 30,000mg/kg down to 10mg/kg. However, higher concentrations could be treated depending on time constraints, additives used and the application of consortium bacteria and nutrients. Cohesive materials take longer to treat than more granular soils.
Contaminants that are not treatable
Contaminated wastes with the following Hazard Codes, as defined in Part II of Schedule 2 of the Special Waste Regulations (1996), cannot be treated using Bio remediation technology:-
- H1 Explosive
- H9 Infectious
- H10 Teratogenic
- H11 Mutagenic
- Also non-treatable are dioxins/furans, PCBs, PCTs, pesticides/herbicides, inorganics, asbestos, cyanides, and clinical waste.
Geotechnical properties
The geotechnical properties of the treated materials vary depending on the source soils. It is possible to produce a useable fill material.
However, compaction can be difficult due to the presence of additive bulking agents used in the treatment.
Requirements
Typical footprint:
Minimum treatment/mixing area 12mx8m.
Windrow turning plant allow approx.2.5-3m between windrows.
1.5m3 soil treated per m2 area at any time.
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