Solar greenhouses for sewage sludge drying

15% reduction of sewage sludge

Drying of sludge from purification processes in solar greenhouses to reduce the amount of sludge to be disposed of

Technological scouting and feasibility study on the possibility of using particular greenhouses to dry sewage sludge have recently been completed. The pilot solar greenhouse installed at the purification plant in Ca' Nordio (Padua) in 2018 gave excellent results allowing a saving of 335 tons of mud in the first 15 months. Thanks to the effectiveness and simplicity of this system and the low operating costs, it has been decided to continue with the construction of the final greenhouse with size 4 times larger (900 square meters) of the current prototypal drying chamber.

The new solar greenhouse will allow to dry about 200 tons of inlet mud dehydrated to 30% for each treatment cycle. After treatment, it will have a dry matter content ranging from 50 to 80% according to management needs and seasonal climatic conditions. The start of the new greenhouse took place in April 2020 and it is expected to reduce 900 tons of mud per year, equal to about 15% of the sludge annually produced by the Ca' Nordio sewage treatment plant.

Area: province of Padua