Method for realizing advanced nitrogen removal of domestic sewage via two stage partial nitrification-anammox coupled with sulfur autotrophic denitrification

A method of treatment of municipal sewage by half partial nitrification-anammox coupled with sulfur autotrophic denitrification, comprising

• providing a device for treatment of municipal sewage by half partial nitrification-anammox coupled with sulfur autotrophic denitrification,
• providing the device with a raw water tank, a half partial nitrification reactor, an intermediate water tank and an upflow anammox coupled autotrophic denitrification granular sludge reactor;
• providing the raw water tank with a water inlet pump I;
• providing the half partial nitrification reactor with a pH meter, an aeration device, a dissolved oxygen (DO) meter, a gas flowmeter, an air pump, a stirring device, a drain valve and a sludge discharge valve;
• providing the intermediate water tank with a water inlet pump II;
• providing the upflow anammox coupled autotrophic denitrification granular sludge reactor with a temperature control device, a pH/DO meter, a U-shaped outlet pipe and a gas collecting port;
• the raw water tank connected with a water inlet of the half partial nitrification reactor via the water inlet pump I;
• a water outlet of the half partial nitrification reactor is connected with the intermediate water tank via the drain valve;
• a water inlet of the upflow anammox coupled autotrophic denitrification granular sludge reactor connected with the intermediate water tank via the water inlet pump II, and a water outlet of the upflow anammox coupled autotrophic denitrification granular sludge reactor connected to the U-shaped outlet pipe for water drainage;
• Step 1 commencing system startup:
• Step 11 commencing startup process of the half partial nitrification reactor:
• inoculating with partial nitrification floc sludge, and controlling the sludge concentration to be 2500-3000 mg/L, a hydraulic retention time to be 4-5 h, and a sludge age to be 10-15 d;
• and
• pumping sewage from the raw water tank into the half partial nitrification reactor by a inlet pump per cycle, stirring for 3-5 h under low-oxygen aeration, precipitating and draining water,
• wherein dissolved oxygen is controlled to be 0.5-2.0 mg/L, a drainage ratio is 50%, the start-up process of the half partial nitrification reactor is completed when a mass concentration ratio of NH4+—N to NO2−—N in effluent water of the half partial nitrification reactor is 1-1.3, and discharging the effluent water of the half partial nitrification reactor into the intermediate water tank;
• and
• Step 12, commencing startup of the upflow anammox coupled autotrophic denitrification granular sludge reactor;
• Step 121, inoculating with anammox granular sludge, wherein the sludge has an average particle size of 0.3-0.5 mm;
• not actively draining sludge during operation;
• and controlling the temperature inside the upflow anammox coupled autotrophic denitrification granular sludge reactor to be 30±1° C. by use of the temperature control device;
• Step 122, performing enrichment cultivation on autotrophic denitrifying bacteria in the upflow anammox coupled autotrophic denitrification granular sludge reactor using simulated wastewater prepared from 30-50 mg/L of Na2S2O3 and 20-40 mg/L of NaNO3 as inlet water, controlling the temperature inside the upflow anammox coupled autotrophic denitrification granular sludge reactor to be 301° C. by use of the temperature control device, and adjusting a pH to 7-8, and analyzing microbial abundance in the sludge after cultivating for 3 months or above,
• 1wherein when the flora abundance is greater than 10%, the cultivating is completed;
• and
• Step 123, mixing anammox sludge with denitrification sludge according to sludge concentration,
• wherein the concentration of the anammox sludge is greater than or equal to 5 times of the concentration of the denitrification sludge;
• adding FeS into the mixed sludge,
• wherein the mass concentration of FeS added in each 1L reactor is 10-20% of the mass concentration of ammonia nitrogen in inlet water in the upflow anammox coupled autotrophic denitrification granular sludge reactor;
• and
• controlling the concentration of sludge in the reactor after mixing to be 4000-5000 mg/L, a rising flow rate to be 0.5m/h, and the hydraulic retention time to be 150-160 min,
• wherein the upflow anammox coupled autotrophic denitrification granular sludge reactor startup is considered to be successful when both the concentration of NH4+—N and the concentration of NO2−−N in effluent water of the reactor are less than 5 mg/L;
• and
• Step 2, commencing operation after successful startup:
• Step 21, allowing domestic sewage to enter the half partial nitrification reactor via the water inlet pump I, starting anoxic/oxic (AO) operation, and allowing the half partial nitrification reactor to undergo five processes of water inlet, reaction, standing, precipitation, and water outlet, specifically performing anaerobic stirring after the water inlet, and carrying out a reaction for 30-60 min to remove organic matters in water;
• then, starting the air pump, performing aerobic stirring, controlling dissolved oxygen to be 0.3-2 mg/L by adjusting the gas flowmeter, and carrying out a half partial nitrification reaction for 3-4 h;
• and
• allowing the stirred material to stand for precipitation for 30-60 min after stirring is finished, opening the drain valve, and controlling the sludge age to be 10-15 d through regular sludge discharge,
• wherein a drainage ratio is 50%, and the mass concentration ratio of NH4+—N to NO2−—N in effluent water of the half partial nitrification reactor is 1-1.32;
• and
• Step 22, allowing the effluent water of the half partial nitrification reactor containing NH4+—N and NO2−—N to enter the intermediate water tank, and pumping sewage of the intermediate water tank into the upflow anammox coupled autotrophic denitrification granular sludge reactor by the water inlet pump II;
• controlling the hydraulic retention time of the upflow anammox coupled autotrophic denitrification granular sludge reactor to be 3-6 h, by controlling the flow rate to be 1 L/h-3 L/h;
• not actively draining sludge during operation;
• controlling the temperature inside the upflow anammox coupled autotrophic denitrification granular sludge reactor to 30±1 C by use of the temperature control device;
• converting NH4+—N and NO2−—N in inlet water to N2 under the action of anammox bacteria in the upflow anammox coupled autotrophic denitrification granular sludge reactor, while using FeS as an electron donor of autotrophic denitrifying bacteria to react with NO3−—N to produce NO2−—N, and draining the effluent water through overflow from the U-shaped outlet pipe.