Carbon Source for Denitrification from Pre-Precipitated Sludge
The organic matter not removed by gravity in a pre-sedimentation tank is in a stable suspension consisting of particles smaller than 0.1 mm. This stable suspension may be destabilized by using low molecular, positively charged metal salts such as polyaluminium sulphate or polyaluminum chloride. These salts are also able to form fluffy hydroxide flocs that can arrest the destabilized particles through general sweep coagulation. Large aggregates capable of being sedimentated are formed. Dissolved compounds like phosphorus are precipitated at the same time. Figure 1 shows that with an effective flocculant and with good initial mixing and floc formation, particles down to 0.1 µ may be destabilized, coagulated and removed from the wastewater (Levine et. al., 1985).
KeywordsHydrolysis Fermentation Phosphorus Hydrate Carbohydrate
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