A flow of 900 m3/day of waste sludge (1% SS of which is 70% organic matter) is thickened to an SS-concentration of 60 gSS/L by gravity. The thickened sludge is pumped to a digester. In the digester 50% of the organic matter is degraded to biogas. The digested sludge is dewatered to 25% SS (no chemicals are needed for dewatering).
1a: If 1,075 litre of biogas is produced per kg SS that was degraded, what is the daily biogas production in m³/day? You can assume a desity of the sludg of 1000 kg/m³. This is because sludge mainly consist of water and 1 litre of water is approximately 1 kg of water.
1b: How much dewatered sludge is produced per day in ton/day? Be carefull with the units, this question asks for ton/day!
1c: How many trucks with a capacity of 30 tons are needed per week to transport the dewatered sludge to the central incineration plant?
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