The invention discloses a process for treating rural domestic
sewage by using an improved A2 / O + MBBR (
Moving Bed Biofilm Reactor), and relates to the technical field of
sewage treatment. The method comprises the steps of S1, initial-stage treatment, S2,
reflux treatment and S3,
tail-stage treatment. The rural domestic
sewage is treated by an improved A2 / O + MBBR
nitrogen and
phosphorus removal process, and the rural domestic sewage is distributed into each tank by adopting a sectional water inlet technology, so that an alternate multi-stage
facultative / aerobic environment is formed, and the biological
nitrogen and
phosphorus removal effect is enhanced; the improved A2 / O + MBBR process has the advantages of
high nitrogen and
phosphorus removal effect, low investment and operation cost, convenience in operation and management and the like; all returned
sludge enters the pre-denitration tank and enters the front-section anaerobic tank and the front-section anoxic tank, a
sludge concentration gradient from high to low is formed in each tank, and the average
sludge concentration in each tank is increased and the
hydraulic load of the
sedimentation tank is not changed under the condition that the
effluent sludge concentration is not increased, so that the proliferation speed of phosphorus-accumulating
bacteria and
nitrifying bacteria is accelerated; the proportion in the total amount of the
activated sludge is increased, so that the
nitrogen and phosphorus removal effect is improved.