Sludge digestion and energy recovery
One concern modern society has is protection of the environment. Reduction in energy consumption, preservation of the sources of raw materials and the waste reduction are main factors to ensure this.
Waste produced must be stabilised and made inert and, if possible, must be turned into the object of clean technology development by reuse or recycling.
The stabilisation methods now used vary according to the technical and economic conditioning factors, which may be summarised as follows: aerobic or anaerobic digestion, lime treatment, composting, drying and incineration.
Due to the importance of energy recovery and the possibility to obtain products that allow beneficial use of sludge from sewage, anaerobic digestion continues to be the most widespread process.
The organic matter in sludge is converted biologically, under anaerobic conditions (in the absence of oxygen), into methane and carbon dioxide. That biogas produced may be used to generate power so the need for the plant to consume external power is significantly reduced.
Cadagua, being aware of the environmental importance of this process, encourages research work by its R&D team on such projects as “Gassification Process of Biosolids from sewage plants for energy use". That project was distinguished with the European Environmental Award - Basque Section and that has provided Cadagua recognition in the sector beyond our borders.
- List of wastewater treatment plants with anaerobic sludge digestion
- Energy Recovery and Cogeneration References