The depletion of the world water resources is a fact that must not be disregarded and the LIFE MCUBO team is highly aware of the cause. For this reason, it continues to seek lines of action and LIFE projects are a highly interesting option for networking. Among them, we can find LIFE ANADRY, a project equally aware of the water cause with which we have decided to collaborate . Led by the company Depuración de Aguas del Mediterráneo (DAM), this initiative, launched in September 2015, deals with the dry anaerobic digestion of sludge from medium-sized wastewater treatment plants (WWTP) and is applied on a pre-industrial scale at the WWTP of Alguazas (Murcia).
Anaerobic digestion is a biological process in which organic matter, highly present in WWTP sludge, is transformed in the absence of oxygen by the action of a group of specific bacteria. The sludge decomposes into a gaseous product or «biogas», which can be used as an energy source. Also, a treated sludge (digestate) is obtained with a degree of stabilization and sanitization more suitable for use in agriculture. Anaerobic digestion is a very efficient process to reduce greenhouse gas emissions, take advantage of the energy present in organic waste and improve the fertilizing value of treated products. Specifically, dry anaerobic digestion is a compact form of technology, suitable for working at higher concentrations of organic matter that allows for a considerable reduction in the size of installations and, therefore, leads to a reduction in investment and operating costs, as well as an increase in energy efficiency.
The project, already at a very advanced stage, has achieved important results. It has succeeded in demonstrating that the treatment of 1 t/d of dehydrated sludge under mesophilic conditions can result in 25 m3 of biogas with a methane richness of around 65 %, which can be used as a source of energy or heat. In addition, it has also been proven that, from this, it is possible to obtain a sanitized sludge free of E. coli and Salmonella spp.
LIFE ANADRY (ENV/ES/000524) has the support of the Wastewater Sanitation and Treatment Entity of the Region of Murcia (ESAMUR), the Ceit-IK4 Technology Centre, the company «Ingeniería y Desarrollos Renovables» (INDEREN) and the Euro-Mediterranean information System on Know-how in the Water Sector (SEMIDE).The sewage sludge generated in the WWTPs is a complex and heterogeneous mixture of microorganisms and inorganic and organic substances, which is classified as non-hazardous waste. Sludge treatment can represent up to 50 % of WWTPs’ management costs, so the project, apart from its eco-friendliness, promotes the reduction of expenses in medium-small WWTPs associated with the treatment and transport of them. It is vitally important to lay the foundations for sustainable and environmentally friendly management of sewage sludge in urban WWTPs in the EU.