WasteServ Malta - Sant'Antnin Waste Treatment - Anaerobic Digestion
Sant Antnin Mechanical & Biological Treatment Plan

Sant' Antnin Waste Treatment Plant - Mechanical and Biological Treatment Plant

The original design of the Mechanical and Biological Treatment Plant was to treat Municipal Solid Waste. This facility is segmented into 2 different  sections:


An Organic Processing Plant (OPP)
The Aneorobic Digestion Plant (AD)


Organic Processing Plant

As from October 2018, SAWTP OPP started primarily receiving all the organic segregated waste (white bag) as its primary source of operations. The process is fundamentally simple whereby the organic matter is mixed with water and fed to the digesters within the Anaerobic Digestion Plant.

As the original plant was not specifically designed for organic source-segregated waste, the SAWTP OPP is presently undergoing a major refit with a technology that is designed to meet today’s requirements.



Anaerobic Digestion Plant

Anaerobic digestion can be defined as a series of processes in which micro-organisms break down biodegradable material in the absence of oxygen to produce digestate (a nitrogen rich soil improver) and biogas, with an average methane content of 55-60%.     

The organic waste from the OPP, now mixed with water and converted into pulp, passes into the anaerobic digestion tanks. Due to the various bio-kinetic processes which take place within the digesters, the pulp is broken down to further reduce the organic fraction and digestate is produced. The most important of these bio-kinetic processes is that of the methane forming bacteria. This bacteria converts the acids produced into methane and carbon dioxide. The methane is used as a fuel in a Combined Heat & Power (CHP) machine to produce heat and electricity. The heat is used to sustain the AD process itself whilst the electricity generated by the CHP’s is fed to the national grid.

The final process is the de-watering of the stabilized digestate, which may be used for landscaping and other projects, for example the rehabilitation of landfills.