Leachate treatment plant – Catania

In the authorized treatment plant the leachate coming from the landfill is processed as
follows:

• equalization and preliminary sedimentation of rough materials of coarse solids;
• ultrafiltration;
• 3-stage reverse osmosis;
• reverse osmosis at high pressure (for concentrate).

The leachate is temporarily stored inside the storage units and it is pumped inside an
equalization tank which has buffer function to homogenize the wastewater to be treated
inside this tank, moreover, the sedimentation of the suspended solids of larger dimensions
takes place.
From the tank, the leachate is pumped into the filtration section, for the separation of
the remaining suspended solids; the permeate from this treatment step is pumped into
a feed tank for the subsequent reverse osmosis phases, while the UF concentrate is sent
back into the accumulation tank.
The UF permeate then undergoes reverse osmosis treatment divided into three distinct
phases; in each of them, in any case, the pressure applied to the fluid allows the separation
of dissolved solids in the passage through the membranes.

Finally, from the third reverse osmosis stage, the permeate, which is purified from all
the polluting components of the untreated leachate, is discharged into the underground
storage tank. The treatment plant is completely automatic and also provides the possibility
of remote control and telediagnosis; the plant is equipped with one MMI interface and
SCADA system.