Nowadays West Germany produces 50 million cubic metres of liquid sludge per year. This tendency is still on the increase, whereas traditional means of utilisation, such as in agriculture, show a sharp decline. For this reason, about 60 - 70 % of the sludge has to be deposited at waste tips with a limited capacity. Therefore it is highly desirable to reduce the sludge volume as much as possible. By enzymatic hydrolsis it is possible to modify the hydrophilic, water-retaining organic compounds of the sludge in order to reduce its water content. Enzymes improve mechanical dewatering in common belt-type filter presses or decanters in combination with flocculation by means of special flocculating aids.
- Sewage sludge
- hydrolytic enzymes
- © International Association on Water Quality 1993