ANAEROBIC TREATMENT METHOD AND EQUIPMENT FOR STARCH PARTICLE-CONTAINING LIQUID

摘要

PROBLEM TO BE SOLVED: To provide an anaerobic treatment method and equipment for a starch particle-containing liquid capable of efficiently subjecting the entire part of the starch particle-containing liquid to anaerobic treatment under a high load at a high speed. SOLUTION: The starch particle-containing liquid is separated to starch particles 10 and a starch separating liquid in a settling tank 1. The starch particle concentrate containing the starch particles 10 is introduced into an ozone treating vessel 2 where the concentrate is subjected to ozone treatment after regulation to a pH <=5 by hydrochloric acid. The treated liquid is introduced into an acid forming vessel 3 where the liquid is mixed with the starch separating liquid and its anaerobic property is maintained. After organic acid formation is effected by acid forming bacteria and the acid forming liquid is introduced into a methane fermenter 4 where the acid forming liquid is passed in upward current through a sludge blanket 27. The organic acids are anaerobically decomposed by methane forming bacteria and are converted to methane and carbon dioxide.