Stabilisation using binding agent, (e.g. quicklime)

Stabilisation using binding agent, (e.g. quicklime)

Type of treatment: Treatment

Description:
This process comprises two steps:
- Solidification: transforms the waste into a granular solid with limited porosity and interesting mechanical characteristics,
- Stabilisation: transforms soluble compounds into stable less soluble compounds.
The oxydo-reduction reaction of the quicklime with the oil (on the sediments) stabilises the thickest oil compounds and (partially) degrades the lightest compounds of the oil.

Stabilisation may be carried out on the working site or in specialized units.


Waste:

Semi-solids and solid
Polluted sands
Note. Liquid waste should not be treated if oil content is too high.


Situation/Possibilities in the country:

Quicklime is easily available and cheap.
Other proprietary Hydraulic Binding Materials are also available.


Interest:

- Stabilizing the leachate of oil and toxic compounds.
- Produces a granular hydrophobic material, physically and chemically suitable for use as a filling material, as raw material in civil works (quality of the material must be tested prior to any use), or to be left in-situ in a stabilised condition.


Entry criteria:

Avoid polluted waste, polluted sorbent and pebbles.


Operational constraints:

Requires easily available equipment (e.g. earth moving equipment to mix the quicklime with the polluted material), little personnel, and binding agent (e.g. quicklime).
In case of oil content too high or high temperature, there is a risk of fire.
The grain size of the bulk quicklime has to be adapted to the grain size of the oiled sediment to treat (the smaller the sediment, the coarser the quicklime, e.g. quicklime grain of 20 to 40mm to treat silt and sand mix).


Impacts:

The oxydo-reduction reaction is followed by atmospheric releases of dust, gases and fumes.
Leachate of stabilised material has less than 1% of oil (in the worst case).
The stabilized material is limited in time, the gradual degradation of the stabilisation process and the release of the remaining contaminants in the environment must be anticipated, when considering the final disposal environment.


Legal constraints:

Refer to atmospheric releases legislation (however, special authorisation should be delivered for such work).
May require THC and leachate testing, and EIA or legal authorisation.


Efficiency:

80 m3/ day of waste treated with one mechanical shovel and one experienced driver.


Cost:

CAPEX/ OPEX: the price for the stabilisation of 1 m3 of waste is approx. 150 to 200 euros per m3 of waste to treat (depending on the local availability of binding agent).

published on 2019/12/10 14:45:51 GMT+0 last modified 2019-12-10T14:45:51+00:00