The invention is a divisional application of a Chinese invention
patent application with an application number of 202510145545. X, an application date of February 10, 2025, and an invention name of a
sewage treatment method based on
sulfate reduction and endogenous
sulfur autotrophic
denitrification. The method comprises the following steps: feeding
sewage into an anoxic tank, and adding
sodium sulfate and
sulfate reducing
bacteria;
effluent of the anoxic tank enters a primary
sedimentation tank to realize mud-water separation,
effluent containing
sulfur anions and
nitrate ions is discharged into a
sulfur autotrophic
denitrification filter tank, and
phosphorus-containing
sludge is discharged into an anaerobic
phosphorus discharge tank; elutriating the anaerobic
phosphorus discharge tank to remove residual sulfate ions in the phosphorus-containing
sludge, discharging supernate containing
phosphate ions into a secondary
sedimentation tank, and refluxing the phosphorus-released
sludge into the anoxic tank;
lime is added into the secondary
sedimentation tank, and
phosphate ions in the
sewage are converted into hydroxyl
calcium phosphate precipitates to form a
fertilizer. The
sewage treatment method disclosed by the invention is low in
oxygen consumption and less in residual sludge, and the
sewage treatment cost is greatly reduced; meanwhile, heavy
metal in the sewage is effectively removed, phosphorus in the sewage is converted into
fertilizer, and
effective treatment of phosphorus is achieved.