Research On The Volatile Fatty Acids (vfas) Production From Activated Sludge

Volatile Fatty Acids (VFAs), the preferred carbon for biological nutrient removal, is the important intermediate products of sludge anaerobic fermentation. PH is an important influencing of anaerobic fermentation. Surfactant and glucose are widely found in our lives. In this investigation the effect of pH, surfactant and glucose on VFAs production from waste activated sludge (WAS) was investigated to find out a technique for improving VFAs biological production from WAS.Experimental results of the effects of different pH, different kinds of surfactants and different consistency of glucose on WAS acidification showed that all of them could improve VFAs production from WAS. Under the same operational conditions, 10.0 is the best pH for VFAs production; different kinds of surfactants could promote VFAs production; the glucose could also improve VFAs production.Experimental results of the effects of different kinds of surfactants on WAS acidification showed that the VFAs production with amphoteric surfactant was the largest. The optimum conditions for the largest VFAs productions ware at a ratio of amphoteric surfactant dosage to dry sludge of 0.3g/g, cationic surfactant dosage to dry sludge of 0.1g/g and anion surfactant dosage to dry sludge of 0.02g/g. The concentrations of both PO43--P and NH4+-N in fermentation liquor increased in the presence of all kinds of surfactant. During the entire fermentation time pH values kept increasing no matter if the surfactants are.