Size sorting
Size sorting
Type of treatment: Pretreatment
Description:Sorting of the sediments (and other waste) based on their size (fine sediment, sand, gravel, pebble, cobble, boulder).
Waste:
Polluted sand and pebbles/ stones
Situation/Possibilities in the country:
Use of public work/ construction work equipment easy to import and implement in any country.
Interest:
Some machinery applies to sand, other to gravel, others to pebble and cobble.
Most organic and inorganic contaminants tend to bind to the fine fraction of a soil (i.e. clay and silt). Thus, separating the fine clay and silt particles from the coarser sand and gravel soil particles concentrates the contaminants into a smaller volume of soil that can then be treated or disposed.
Entry criteria:
Any type of semi-solids and solid, polluted sand/ pebbles/ solid waste.
Operational constraints:
Requires personnel, specific sorting equipment, energy, and storage for the sorted sediment.
May not be carried out on sediment trapped in heavy / weathered / emulsified oil without fluidization (because oil fills in the pores of the sorting equipment).
Impacts:
Minimal if equipment is suitable, correctly operated and there are no oil leaks.
Legal constraints:
Refer to those applying to the transport, handling and storage of oil products.
Efficiency:
Depending on equipment, can allow sorting waste / various size of sand and pebbles (depending on the screen used in the machine).
The size of the installation ranges from simple sorting equipment (few 10’s of cubic metres per hour) to heavy of industrial equipment, e.g. Trommel screening type (screened cylinder used to separate materials by size, 200 to 300 cubic metres per hour).
Cost:
CAPEX and OPEX vary depending on the installation purchased/ rented.