An undesirable by-product of the wastewater treatment process is sludge, the microbiological mass that is created as a result of the decomposition of organic material in wastewater. Sludge is a nuisance to the environment since, barring expensive treatment, it contains active bacteria and pathogens, and its foul odor repels humans but attracts insects.

Shtang has designed and constructed a multitude of sludge treatment facilities, both aerobic and anaerobic.


Depending on the needs of our customers, we construct simple sludge-treatment modules to generate class B sludge or highly sophisticated facilities to turn a mix of sanitary and industrial sludge to class A biosolids, which, after treatment and processing, can be recycled and applied as fertilizer to improve and maintain productive soils and stimulate plant growth, all while generating heat and electricity to provide the grid.

Shtang has installed ATAD systems for sludge treatment - a method based on auto-thermophilic, aerobic digestion, which uses bacteria to digest the sludge automatically with zero chemicals and zero energy for heating as well as the largest anaerobic digesters in the world, with a volume of 13,200 cubic meters each, for treating the sludge of Israel's largest wastewater treatment plant.