SOLIA™ Solar Drying

Greenhouse solar sludge drying

Process Priniciple

Veolia Water Technologies has enhanced the efficiency of greenhouse solar sludge drying by coupling two well-known processes: air drying and aerobic fermentation.

• Under the effect of solar radiation and the action of an automated windrow turner (Soliamix™), water evaporates from the sludge for subsequent removal from the greenhouse by a powerful air draft.
• The fermentation step is promoted by regular turning of the sludge windrows ; the energy released by the oxidation of organic matter in the sludge accelerates the evaporation process.

A unique windrow turning system

Once unloaded in the greenhouse, the dewatered sludge is piled in the form of windrows with the automated Soliamix™ system. In order to renew the exchange surface and for aeration, the windrows are turned at regular intervals.

The Soliamix™ range of windrow turners is available in 3 sizes and their operation may be automated.

Smart storage

Triangular windrow shaping offers a larger exchange surface area than sludge drying beds for the same amount of greenhouse space, resulting in a faster drying process.
Furthermore, a higher quantity of sludge can be stored.

Class A End Product

The exothermal reactions occurring during the fermentation process generate a high temperature increase (50 to 60°C), thereby promoting sludge sanitisation in parallel with drying.