The plant has a capacity that varies depending on the size of the particles of the soil to be treated; in particular, it has a capacity of 25 t/h in the case of soil with a silt content of around 36% and a capacity of 50 t/h in the case of soil with a silt content of around 20%.


The washing section of contaminated soil involves a washing process with water and the possible addition of specific detergents (surfactants and soda), or of an organic de emulsifier (in case there are oily emulsions in the soil) or sodium hypochlorite (in case of malodorous soil) in order to obtain materials that are suitable for subsequent direct recovery or inerting treatment.


The washing process removes heavy metals, linear chain and aromatic hydrocarbons (BTEX, PAH), organochlorine solvents.


The waste may then pass through an off line crusher if necessary and is subsequently fed into the loading hopper of the coarse screening system. From here, by means of a conveyor belt equipped with a magnetic separator, the waste is further screened with a roughing sieve. Material with a size > 60 mm is washed separately. The finest fraction, between 2 and 60 mm, is sent to the following washing phase. The soil passes through three hydrocyclones, it is washed, the water and sand suspension is vibration dried and then the sand is removed.
At the end of the cycle, the washing water is sent for chemical physical treatment in the same soil washing plant.
The following fractions are obtained from soil washing: Pebbles, gravel and coarse sand (fraction with a larger particle size) are recovered and intended for reuse; Fine sand, silt, clay (fraction with a smaller particle size) either undergoes further treatment or is sent for disposal or it is reused. The particle sizes of the above mentioned recoverable inert materials are as follows: Pebbles > 150 mm; Pebbles > 60 mm; Gravel 2 60 mm; Sand 0.06 2 mm. In accordance with Ministerial Decree 471/99, materials with a particle size of less than 2 mm are analysed as they are, while materials with a particle size of more than 2 mm undergo a leaching test with water saturated with CO2. The test results are compared with the limit values specified in the above mentioned Ministerial Decree.
In the event that the aggregates coming out of the washing plant do not have the expected characteristics, the possibility of carrying out a further washing cycle or inerting treatment or of sending them to other treatment or disposal plants is considered.
The following types of waste also originate from washing operations: Sludge from the chemical physical treatment of washing water; Sludge with light fraction originating from soil washing; Removed ferrous and coarse material. Sottotitolo: Waste approval
Specific waste control procedures are applied both when contracts are drawn up with customers (the approval phase) and as disposals are received at the plant.
Correspondence between the quality of the incoming waste and the respective approval is verified by means of visual and analytical checks carried out, immediately, periodically and spot sampling the waste.
After the control phase, the waste is sent for the type of treatment defined in the approval phase. MODULO ACCORDION Titolo: Waste reception and storage
Testo: In the area in front of the warehouse housing the soil washing and inerting plant, an area is designated for the storage of the remediated soil to be washed and the aggregates resulting from the treatment. The area is paved in industrial type concrete sloping towards the centre to allow for the collection of surface water. MODULO ACCORDION
Titolo: Soil washing section
Testo: This section treats contaminated soil with water and washing aids, separating the soil into its constituent fractions to obtain material suitable for recovery, such as clean sand and gravel. The process also produces waste that is sent for recovery/disposal in third party facilities. The process involves a soil washing phase with water and the possible addition of specific detergents (surfactants and soda), or of an organic de emulsifier (in case there are oily emulsions in the soil) or sodium hypochlorite (in case of malodorous soil) in order to obtain materials that are suitable for subsequent direct recovery or inerting treatment, removing heavy metals, linear chain and aromatic hydrocarbons (BTEX, PAH), organochlorine solvents. The water used for washing, loaded with contaminants and with materials finer than soil (very fine sand and silt), is sent to a special chemical physical treatment section next to the washing plant to be subsequently reused for soil washing.
The fractions obtained from washing are:
a fraction with a larger particle size (pebbles, gravel, fine gravel and coarse sand), which can be reused; a fine fraction (fine sand, silt, clay), which, depending on its characteristics, may either undergo inerting treatment or be sent for disposal or, if not contaminated, be sent for reuse at external plants. The particle sizes of the aggregates recovered are as follows: pebbles > 150 mm; pebbles > 60 mm; gravel 2 60 mm; sand 0.063 2 mm. The materials listed above (recovered aggregates) complying with the Ministerial Decree of 5/02/1998 and current End of waste regulations can be used in civil engineering for operations such as: • Filling and environmental reclamation; • Beach nourishment, embankments and river works. • Laying of roadbeds; • Reuse in the production of cement or asphalt In the event that the aggregates coming out of the washing plant do not have the expected characteristics, the possibility of carrying out a further washing cycle or inerting treatment or of sending them to other treatment or disposal plants is considered. The following types of waste also originate from washing operations: 1. Sludge from the chemical physical treatment of washing water; 2. Sludge with light fraction originating from soil washing; 3. Removed ferrous and coarse material.