Treatment plant of slurry from plastic strips washing

Place:

Veneto, Italy (IT)

Year of commissioning:

2016

Kind of application:

Treatment plant of wastewater

Capacity:

20 m³/h of slurry (water and solids)

Description

The Pozzato plant for the treatment of wastewater coming from plastic materials (such as films and hoses used in agriculture washing processes) has been designed and realized in order to recover the solids contained in the slurry and, at the same time, reuse the water in close cycle.

Rather than to dispose of 100% of water used in only one operating cycle, it is needed to replenish just the water volume that is, inevitably, held by the solids that are recovered and stocked on pile. The wastewater disposal is necessary only when the charge of the contaminants included in it (essentially fertilizers used in agriculture) doesn’t allow to properly wash the plastic materials treated in the specific washing plant.

Thanks to the Pozzato sand treatment unit, the fraction > 60 µ < 3 mm is recovered, dewatered and stocked on pile; whereas the solids < 60 µ included in the slurry are sent to the sludge and water treatment plant equipped with a thickener and a filter-press.

Here, a small amount of polyelectrolyte flocculant is added to the water via an automatic dosing station which forces fine particles to settle on the bottom of the thickener tank. The clean water on the top overflows the weir and is stored in a tank before being re-circulated around the plant.
The thickened solids are pumped into the filter-press enable to discharge, in the underneath bay, cakes easy to handle and transport; whereas, the removed water returns on cycle.

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