Turning sewage sludge into fertilizer

MAYEN, Germany, Sept. 4, 2008 -- Autoheated Thermophilic Aerobic Digestion (ATAD) is for more than 30 years the sludge treatment process of choice for mid-sized wastewater treatment plants, especially under the aspect of the future regulations, as for example in Europe.

FUCHS-ATAD is a process providing for simultaneous stabilization and disinfection. With the ATAD organic solids are biologically degraded. This natural aerobic process releases energy, mainly in the form of heat, leading to thermophilic temperatures. At temperatures > 50°C the thermophilic aerobic microorganisms grow rapidly, overwhelming other bacteria and even pathogens. The rapid growth of the bacteria and the usage of two stages result in short detention times (6-9 days), allowing a small footprint of the plant. The final product is well stabilized and disinfected sludge, classified as Class A Biosolids.

The FUCHS-ATAD is equipped with sturdy and reliable aeration equipment which has proven its performance in more than 80 plants worldwide.

The experience of many years and the positive feedback from numerous ATAD plants led to a new design concept. The Advanced Integrated Concept (ATAD AIC™) is patented in Germany with several patents pending in further countries.

Others propagandize new generations featuring long detention times. In contrast FUCHS-ATAD AIC™ is an economic concept considering the whole sludge treatment line by including advanced peripherals. Focussing on excellent dewaterability of the treated sludge, a new reactor configuration for optimum operation, sludge thickening without polymers and odour control with a Photo-Catalytic Oxidation are integrated. As a result of all these improvements, plants, designed according to the new FUCHS ATAD Advanced Integrated Concept, convert sewage sludge into highest quality Class A fertilizer at minimum costs.

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