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Disclosed are a membrane coupled activated sludge method and apparatus operating anoxic/anaerobic processes alternately for removal of nitrogen and phosporus, wherein nitrogen and phosphorous together with organics in the sewage, wastewater, filthy water etc. can be simultaneously removed with an ec

Disclosed are a membrane coupled activated sludge method and apparatus operating anoxic/anaerobic processes alternately for removal of nitrogen and phosporus, wherein nitrogen and phosphorous together with organics in the sewage, wastewater, filthy water etc. can be simultaneously removed with an economic and efficient manner, an operation thereof is easy and efficient, a capacity thereof is high and the method is economic due to the reduced operating costs with performing measurement and control of a recycle rate, a recycle time of alternate operation of the anoxic and anaerobic process, an amount of sludge, an amount of aeration and an operation of a blower for an intermittent membrane cleaning.

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What is claimed is: 1. A membrane coupled activated sludge method operating anoxic/anaerobic processes alternately for removal of nitrogen and phosphorous being a method for advanced treating of a sewage or wastewater or filthy water simultaneously treating nitrogen and phosphorous wherein an anoxi

What is claimed is: 1. A membrane coupled activated sludge method operating anoxic/anaerobic processes alternately for removal of nitrogen and phosphorous being a method for advanced treating of a sewage or wastewater or filthy water simultaneously treating nitrogen and phosphorous wherein an anoxic process, in which a denitrification reaction for removing nitrogen occurs, and an anaerobic process for discharging phosphorous are alternately carried out, the anoxic process comprising: (a) continuously flowing sewage or waste water or filthy water as an inflow water into an anoxic/anaerobic alternating-type reactor; (b) operating an internal recycle pump intermittently to internally recycle nitrate nitrogen occurring in an aerobic reactor continuously and thus to make the anoxic/anaerobic alternating-type reactor into anoxic condition; (c) converting and removing the nitrate nitrogen supplied through the internal recycle of (b) into nitrogen gas by using organics in the continuous inflow water as carbon source; (d) overflowing and moving the mixed solution denitrified in (c) into a continued aerobic reactor; (e) carrying out a nitrification process of converting organic nitrogen and ammonia nitrogen, which are supplied from the inflow water, into nitrate nitrogen with nitrification microbes and an organic oxidation process of decomposing remaining organics, under aerobic condition of the aerobic reactor in which continuous aeration is made by a blower; and (f) continuously discharging treated water by using a submerged-type separation membrane equipped in the aerobic reactor; the anaerobic process comprising: (a') continuously flowing sewage or waste water or filthy water as an inflow water into the anoxic/anaerobic alternating-type reactor; (b') stopping the internal recycle pump, which is intermittently operated, to discontinue the internal recycle of the nitrate nitrogen occurring in the aerobic reactor and thus to make the anoxic/anaerobic alternating-type reactor into anaerobic condition; (c') inducing phosphorous release with microbes for removing phosphorous by using organics of the continuous inflow water as carbon source, under anaerobic state that the nitrate nitrogen is denitrified and depleted due to the interruption of the internal recycle in (b'); (d') overflowing and moving the microbes having released the phosphorous in (c') into the continued aerobic reactor; (e') lowering a concentration of dissolved phosphorous in the aerobic reactor through an excess phosphorous uptake of the phosphorous releasing microbes in (d') and simultaneously carrying out the nitrification process of converting organic nitrogen and ammonia nitrogen, which are supplied from the inflow water, into nitrate nitrogen by nitrification microbes and the organic oxidation process of decomposing remaining organics, under aerobic condition of the aerobic reactor in which continuous aeration is made by the blower; (f') continuously discharging treated water of which phosphorous is removed by using the submerged-type separation membrane equipped in the aerobic reactor; and (g') wasting sludge, in which phosphorous is excessively uptook in (e'), to discharge the phosphorous; and wherein the anoxic and anaerobic processes in the anoxic/anaerobic alternating-type reactor are distinguished according to whether the internal recycle of the nitrate nitrogen by means of the internal recycle pump is performed, wherein the method further comprises: (S1) performing a recycle rate control for maintaining a ratio of an internal recycle flow rate of the nitrate nitrogen to an inflow rate of the inflow water to be constant; (S2) performing a recycle time control for continuously measuring an oxidation-reduction potential (ORP) in the anoxic/anaerobic alternating-type reactor and determining whether the internal recycle pump is operated or not, based on the measured value; (S3) performing a blower control for continuously measuring dissolved oxygen (DO) in the aerobic reactor if the internal recycle pump is operated and regulating a rotating speed of the blower so as to maintain the dissolved oxygen (DO) value to be a predetermined level; and (S4) performing a sludge waste amount control for determining a sludge waste amount according to the following equation and wasting the sludge, wherein, FR represents sludge waste amount (m3/day), Sanoxic/anaerobic alternating-type reactor represents sludge concentration in the anoxic/anaerobic alternating-type reactor (kg/m3), Saerobic reactor represents sludge concentration in the aerobic reactor (kg/m3), Vanoxic/aerobic alternating-type reactor represents a volume of the anoxic/anaerobic alternating-type reactor (m3), Vaerobic reactor represents a volume of the aerobic reactor (m3), and SRTd represents a set average SRT (Solids Retention Time)(day). 2. The method according to claim 1, wherein, in the step S1, the ratio of an internal recycle flow rate of the nitrate nitrogen to an inflow rate of the inflow water is controlled through a proportional controller. 3. The method according to claim 1, wherein, in the step S2, under state that the internal recycle pump is being operated, the oxidation-reduction potential (ORP) value in the anoxic/anaerobic alternating-type reactor is continuously measured to operate the internal recycle pump continuously when the oxidation-reduction potential (ORP) value is-100 mV or less and to stop the operation of the internal recycle pump when the oxidation-reduction potential (ORP) value is more than-100 mV, and under state that the internal recycle pump is not operated, the oxidation-reduction potential (ORP) value in the anoxic/anaerobic alternating-type reactor is continuously measured to operate the internal recycle pump when the oxidation-reduction potential (ORP) value is less than-400 mV. 4. The method according to claim 1, wherein, in the step S3, when the internal recycle pump is not operated, the rotating speed of the blower is maximized to clean the membrane for a predetermined time. 5. The method according to claim 1, wherein, in the step S3, under state that the internal recycle pump is operated, the rotating speed of the blower is regulated so that the dissolved oxygen (DO) in the aerobic reactor is not to be less than 2.0 mg/l, and under state that the internal recycle pump is not operated, the operation interruption time of the internal recycle pump is measured and then the rotating speed of the blower is maximized to clean the membrane when the operation interruption time is more than 1 minute and less than 10 minutes. 6. The method according to claim 1, wherein, in the step S4, the SRTd of the equation is set to be 20 days when determining the sludge waste amount. 7. A membrane coupled activated sludge apparatus operating anoxic/anaerobic processes alternately for removal of nitrogen and phosphorous being an apparatus for advanced treating of a sewage or wastewater or filthy water simultaneous treating nitrogen and phosphorous, wherein an anoxic process, in which a denitrification reaction for removing nitrogen occurs, and an anaerobic process for discharging phosphorous are alternately carried out, the apparatus comprising: an anoxic/anaerobic alternating-type reactor having an agitator and into which inflow water of sewage or filthy water or wastewater is continuously flown; an aerobic reactor having a blower and allowing an organic oxidation reaction, a nitrification reaction and an excessive uptake of phosphorous to occur under an aerobic condition; an internal recycle pump recycling nitrate nitrogen occurring from the aerobic reactor to the anoxic/anaerobic alternating-type reactor; and a submerged-type separation membrane equipped in the aerobic reactor and discharging treated water continuously through membrane filtration, wherein the anoxic and anaerobic processes in the anoxic/anaerobic alternating-type reactor are distinguished according to whether the internal recycle of the nitrate nitrogen by means of the internal recycle pump is performed, wherein the apparatus further comprises: an oxidation-reduction potential (ORP) measuring sensor for measuring an oxidation-reduction potential (ORP) in the anoxic/anaerobic alternating-type reactor; a dissolved oxygen (DO) measuring sensor for measuring a dissolved oxygen (DO) in the aerobic reactor; an inflow flowmeter for measuring and controlling a flow rate of the inflow water; a recycle flowmeter for measuring and controlling an internal recycle flow rate; a surplus sludge flowmeter for measuring and controlling an amount of waste sludge discharged from the aerobic reactor; and a processor for controlling the internal recycle pump, the blower and each of the flowmeters, corresponding to the information of the measured values inputted from the sensors and flowmeters, wherein the processor performs a recycle rate control, a recycle time control, a blower control and a sludge waster amount control, the recycle rate control comprising maintaining a ratio of an internal recycle flow rate of the nitrate nitrogen to an inflow rate of the inflow water to be constant; the recycle time control comprising continuously measuring an oxidation-reduction potential (ORP) in the anoxic/anaerobic alternating-type reactor and determining whether the internal recycle pump is operated or not, based on the measured value; the blower control comprising continuously measuring dissolved oxygen (DO) in the aerobic reactor if the internal recycle pump is operated and regulating a rotating speed of the blower so as to maintain the dissolved oxygen (DO) value to be a predetermined level; and the sludge waste amount control comprising determining a sludge waste amount according to a following equation and wasting the sludge, wherein, FR represents sludge waste amount (m3/day), Sanoxic/anaerobic alternating-type reactor represents sludge concentration in the anoxic/anaerobic alternating-type reactor (kg/m3), Saerobic reactor represents sludge concentration in the aerobic reactor (kg/m3), Vaerobic/anaerobic alternating-type reactor represents a volume of the anoxic/anaerobic alternating-type reactor (m3), Vaerobic reactor represents a volume of the aerobic reactor (m3), and SRTd represents a set average SRT (Solids Retention Time)(day). 8. The apparatus according to claim 7, wherein the processor comprises a digital input/output computer and an analog/digital (A/D) converter converting a digital signal outputted into an analog signal for outputting the analog signal and converting the analog signal inputted into a digital signal for inputting the digital signal.