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REVATECH / Processes / Biological treatments

CONCEPT

In the early 1980s REVATECH began operating a biological treatment unit using sludge activated by forced aeration (submerged and surface aerators).
Twenty years later, this has become a unit with an authorised BOD capacity of 4,200 kg/day, operated by injecting pure oxygen.
This unit treats biodegradable waste water from various sources, most of it with a very high biological load (BOD greater than 100,000 mg/l).

METHODOLOGY

Before being accepted in the treatment plant, the waste water is first assayed for biodegradability by monitoring the BOD (biological oxygen demand) in the presence of oxygen and biomass from the purification station. Only water with biodegradability of 75% is processed this way.

After acceptance, the waste water is stored and its BOD is brought down to less than 100,000 mg/l, in order to prevent poisoning of the bacteria in the reactors. The water is then led to various aeration ponds where the biomass and dissolved oxygen content are strictly controlled. The excess biomass is purged and treated by physico-chemical methods. After decantation, the purified water is discharged into the environment, in accordance with the strictest standards for ground water.

MAIN TYPES OF WASTE TREATED

• Process water, mainly from the pharmaceutical and chemical industries (mother liquors);

• Beverages that have passed their sell by date, or that have been downgraded or seized by the authorities;

• Waste water from the agro-food sector;

• Landfill effluent.