MicroMétha^®for WWTPs

Wastewater treatment is carried out into several stages in WWTP's (WasteWater Treatment Plant). After having being screened (trapping of bulky matter) and sieved (finer filtration), the wastewater is decanted in order to extract the sands (grit removal) and fatty substances (de-oiling). The water is then sent into an aeration basin in which the polluting organic matter is degraded by microbial oxidation. After clarification, an ultimate waste persists, a thickened sludge (after having being pressed through a screw press) to be spread on agricultural field. To sanitize it and stabilize its fermentation, the operator needs often to add lime (operation called liming).

The grease retained during de-oiling, the organic matter that is oxidized and the spreading sludge are all carbonaceous materials that can produce energy. The MicroMétha^® process consists in methanizing this organic material. The biogas produced can then generate heat and electricity by cogeneration. This biogas can also be purified into fuel or natural gas.

The MicroMétha^® methanization unit degrades organic matter into methane under thermophilic (high temperature) and anaerobic (without the presence of oxygen or air) conditions. The fermentation temperature (50-55°C) allows faster degradation than in mesophilic conditions (35°C) and has the great advantage of sterilizing the sludge thus avoiding the need for liming. The residence time of the sludge is shortened by half to release their methanogenic potential (20 days in thermophilic versus 40 in mesophilic). The result is an energy production unit twice as compact. A patented heat recovery exchanger heats the incoming sludge with the outgoing sludge and considerably reduces the thermal energy input.

MicroMétha^® units process scheme for WWTP's

The MicroMétha^® unit advantages