The invention belongs to a double-
reflux denitrification membrane-
bioreactor (MBR) process for treating dry
acrylic fiber waste water, mainly aiming at treatment of high organic
nitrogen with
denitrification requirement and petrified dry
acrylic fiber waste water which is difficult to degrade. The process comprises the following steps: feeding petrified
dimethylformamide (DMF) dry
acrylic fiber waste water into a front anoxic
pool 2 from a water inlet 1, converting partial organic
nitrogen into
ammonia nitrogen under the anoxic condition, carrying out
denitrification on a
nitration liquid 10 refluxing to the front anoxic tank 2 by fully utilizing a waste water
carbon source, and simultaneously compensating basicity 3 to the waste water; and then feeding entering the waste water into an aerobic
pool 4, carrying out
organism aerobic oxidation, organic nitrogen aerobic oxidation and
ammonia nitrogen
nitration under the abundant basicity, wherein the
effluent contains a large amount of nitrates; refluxing the partial
effluent to the front anoxic
pool 2 for denitrification, and feeding the other
effluent into a membrane separation pool 7; carrying out denitrification by utilizing an additionally arranged
carbon source; and sucking with a micro-filter membrane
assembly 8 so as to generate effluent 9, and refluxing a
sludge concentrated liquid 11 to the front anoxic pool 2. The process is high in
nitrogen removal efficiency.