The invention belongs to the
treatment field of waste water, and provides a method for converting active
sludge into autotrophic denitrified
sludge based on a
mixed type continuous flow reactor. The method which is used for converting the common active
sludge into the autotrophic denitrified sludge by the
continuous flow reactor specifically comprises two stages. The first stage comprises the steps of: converting anaerobic or anoxic sludge into a
nitrosation status by the condition which controls the
organic matter concentration (COD (
chemical oxygen demand) is less than 20mg / L), the water dissolved
oxygen concentration (1-0.5mg / L), and the inflowing
ammonia nitrogen concentration (50-450mg / L), and restraining the growth of the other microorganisms step by step by the running condition and the washing characteristic of the
continuous flow reactor. When the cumulative percentage of the
nitrite is more than 60%, the second stage is started. The second stage comprises the step of: promoting the
nitrosation status to be converted into the autotrophic
denitrification status by the condition which improves the
ammonia nitrogen concentration (450-550mg / L), reduces the dissolved
oxygen (0.5mg / L), and keeps a certain PH value (7.5-8.0) to form a
system which is coupled nitrosified
microorganism to
anammox microorganism. The practice proves that the
system can stably run for a long term. After entering into the practical running stage of the waste
water treatment, the method leads the
ammonia nitrogen removing rate and the
total nitrogen removing rate to be respectively more than 80% and 70% by the reaction which is remained only by the natural reoxygenation or a small quantity of
aeration without
aeration.