240 t/h
of material treated
Quarries & Aggregates
Natural aggregates
Italy
Cava Nord
Water clarification and sludge treatment plant supporting closed-loop water recovery and site restoration.
300 m³/h
water flow rate
18 t/h
of solids to the filter press
Now part of the Heidelberg Group, Cava Nord is based in Paderno Dugnano and operates in Lombardy’s quarrying sector, supplying aggregates to the Milan construction market. The site is managed according to an integrated life-cycle approach: alongside aggregate extraction, excavated areas are progressively restored through controlled backfilling with certified materials, followed by agricultural or natural restoration. Groundwater protection and soil stability are managed through dedicated operating protocols, while closed-loop water management reduces freshwater abstraction and wastewater discharge.
The project challenges
Volume management
Up to 400 m³/h of highly turbid water had to be treated.
Footprint constraints
The new plant had to be integrated into the existing quarry layout within a limited footprint.
Immediate operation
The client required a fully tested turnkey plant ready for rapid on-site commissioning.
Tecnoidea’s process-engineering approach
Twin vertical clarifiers with load balancing
To reduce the footprint while keeping the overall plant height within the available limits, the turbid-water flow is split between two separate static vertical clarifiers. A flow splitter balances the hydraulic load using real-time level data from the LEM sludge-level monitoring system installed in the clarifiers
Filter press sized with reserve capacity
An overhead-beam filter press (model FPTA 1300/100/30) was selected, equipped with four pistons in a full-traction configuration. The machine was sized to handle up to twice the actual sludge flow rate from the aggregate-washing plant.
Sludge tank
A dedicated sludge tank was added to provide additional buffer capacity downstream of the static clarifiers, helping stabilise filter-press operation.
Results
Space optimisation
The water and sludge treatment plant uses a compact vertical layout, accommodating the complete treatment process within a footprint of just 260 m².
Closed loop
The plant recovers 3,000 m³ of treated water per day, all of which is reused in the aggregate-washing process.
High-volume sludge management
The plant produces 200 t/day of thickened sludge for subsequent filter-press dewatering.
Spadeable filter cakes
The dewatering process produces 120 m³/day of spadeable filter cakes.