Septic sludge smells like foul eggs and is highly corrosive. It contains grit and gravel as well as all kinds of debris that can pass through a latrine.
Septic sludge is supplied with tanker vehicles and directly discharged into a HUBER ROTAMAT® Complete Plant for complete mechanical pre-treatment. A Fine Screen and Grit Chamber are integrated in this unit. The fine screen simultaneously washes, dewaters and compresses the removed screening, which are disposed of as solid waste. Mineral solids are removed from the grit chamber and classified; then they are washed and dewatered in our Grit Washer. The well washed mineral product is reusable as construction material, e.g. for road bedding.
After all disturbing solids have been removed by pre-treatment, the septic sludge is dewatered in our ROTAMAT® Screw Press. The sludge cake is then composted for aerobic stabilisation and pathogen reduction.
Alternatively, thin septic sludge is concentrated in our ROTAMAT® Screw Thickener and then stabilized in an anaerobic digester. The generated digester gas is used for cogeneration of power and heat. Sludge dewatering occurs after digestion.
The produced compost or digested sludge is land applied as fertilizer and for soil improvement, or used as soil material for landscaping or land reclamation.
We treat the filtrate from sludge dewatering in a HUBER Membrane Bio-Rector. The effluent containing no solids and bacteria is recycled as process water (wash and spray water). Surplus effluent can be used for irrigation (it contains dissolved N and P nutrients).
All HUBER machines are completely enclosed to prevent odour nuisance, and the entire HUBER equipment is made of corrosion-resistant stainless steel.