Combined effect of sodium dodecyl sulfate and enzyme on waste activated sludge hydrolysis and acidification

► The SDS + enzyme has better effect on WAS hydrolysis and acidification compared with SDS or enzyme. ► The SDS + ME is more effective on WAS hydrolysis compared with SDS + single enzyme. ► More hydrolysate was correspondence with higher NH4+-N release and SCFAs accumulation. ► Acetic, propionic and iso-valeric acids are the main products in WAS hydrolysis liquid. ► The SDS + enzyme treatment of WAS seems to be a new strategy in this field.