CN-122003386-A - Method for operating water treatment device and water treatment device

Abstract

The invention provides an operation method of a water treatment device, which can reduce the operation burden of operators and is beneficial to energy saving. The water treatment apparatus includes a biological treatment tank including at least an aerobic tank in which a membrane separation device is immersed, wherein in the operation method of the water treatment apparatus, a suction coefficient K (K < 1) is set as a control factor so that a sludge suction amount Qwas satisfies a sludge suction amount Qwas =raw water inflow amount Qraw ×K, and the membrane separation device is operated so that a filtration amount Qtrt from the membrane separation device satisfies a filtration amount Qtrt =raw water inflow amount Qraw × (1-K), and surplus sludge naturally overflows from an overflow path provided in the biological treatment tank.

Inventors

• OKAJIMA YASUNOBU
• Ishihara tokako
• FUJINO KOTA
• MATSUMOTO SAYAKA

Assignees

• 株式会社久保田

Dates

Publication Date

20260508

Application Date

20241114

Priority Date

20231121

Claims (6)

1. 1. A method for operating a water treatment apparatus, characterized in that the water treatment apparatus has a biological treatment tank comprising at least an aerobic tank impregnated with a membrane separation device, In the operation method of the water treatment apparatus, The extraction coefficient K is set as a control factor such that the sludge extraction amount Qwas satisfies the sludge extraction amount Qwas =raw water inflow amount Qraw ×K, where K <1, The membrane separation device is operated such that the filtration amount Qtrt from the membrane separation device satisfies that the filtration amount Qtrt =raw water inflow amount Qraw × (1-K), And naturally overflowing the excess sludge from an overflow path of the biological treatment tank.
2. 2. The method of operating a water treatment apparatus according to claim 1, wherein, The filtration amount Qtrt is updated and set at predetermined time intervals based on the raw water inflow amount Qraw measured at the predetermined time intervals.
3. 3.A method of operating a water treatment apparatus according to claim 2, wherein, The mixed liquor suspended solids of the biological treatment tank are measured periodically or aperiodically, and the extraction coefficient K is adjusted to be increased or decreased based on the measured mixed liquor suspended solids.
4. 4. A method of operating a water treatment apparatus according to claim 3, wherein, And measuring the water level of the biological treatment tank, and increasing or decreasing the extraction coefficient K when the measured water level deviates from a specified allowable range.
5. 5. A method of operating a water treatment device according to claim 3 or 4, wherein, The water level of the biological treatment tank is measured, and when the measured water level deviates from a predetermined allowable range, an abnormal state is notified via a notification means.
6. 6. A water treatment apparatus, comprising: A biological treatment tank at least comprising an aerobic tank immersed in the membrane separation device, and The control device is used for controlling the control device, The control device sets the extraction coefficient K as a control factor so that the sludge extraction amount Qwas satisfies the sludge extraction amount Qwas =raw water inflow amount Qraw ×K, wherein K <1, The control device operates the membrane separation device such that the filtration amount Qtrt from the membrane separation device satisfies that the filtration amount Qtrt =the raw water inflow amount Qraw × (1-K), The control device naturally overflows excess sludge from an overflow path provided in the biological treatment tank.

Description

Method for operating water treatment device and water treatment device Technical Field The present invention relates to a method for operating a water treatment apparatus and a water treatment apparatus. Background As shown in FIG. 5, a water treatment apparatus 1 using a membrane separation activated sludge method (Membrane Bio Reactor) for purifying water to be treated such as organic wastewater as raw water has a biological treatment tank 8 including at least an anoxic tank 2 and an aerobic tank 3 in which a membrane separation device 4 is immersed, and a sludge circulation path 7 for circulating sludge from the aerobic tank 3 to the anoxic tank 2. Raw water flowing into the anoxic tank 2 is mixed with activated sludge in the tank by the stirring mechanism 2a, and then flows into the aerobic tank 3. In the aerobic tank 3, organic matter is decomposed by aerobic microorganisms under an aerobic environment of the auxiliary air diffusing device 6, and ammonia components are nitrified, and a part of the purified water to be treated is extracted as treated water through the membrane separation device 4. The water to be treated in the aerobic tank 3 is circulated and conveyed to the anoxic tank 2 together with the sludge via the sludge pump P1 and the sludge circulation path 7, and is denitrified by the anaerobic microorganisms in the anaerobic environment in the anoxic tank 2. In the above membrane separation activated sludge process, it is necessary to perform an operation such that the amount of microorganisms present in the biological treatment system and the viscosity of the circulated activated sludge are controlled within the target management value. At this time, the MLSS (Mixed Liquor Suspended Solids: mixed liquor suspended solid) concentration is used as a management index. Since the MLSS concentration in the system increases depending on the proliferation of SS and microorganisms contained in the raw water flowing in, it is necessary to continuously or intermittently pump out an appropriate amount of sludge to the outside of the system. Accordingly, a sludge discharge pipe 11 having a discharge valve 10 is branched and connected to the sludge circulation path 7. Since it is difficult to accurately predict the increase amount of the MLSS concentration, the operator measures and monitors the MLSS concentration in the system, and at the same time, determines the sludge extraction amount according to personal experience and a recipe and performs sludge extraction in order to keep the MLSS concentration continuously within the range of the management value. In general, the sludge extraction amount is often set and controlled according to a standard of several percent with respect to the inflow amount of raw water. The related art related to such extraction of excess sludge is disclosed in patent document 1 and patent document 2. Prior art literature Patent literature Patent document 1 Japanese patent application laid-open No. 2010-194482 Patent document 2 Japanese patent application laid-open No. 2013-17670 Disclosure of Invention Problems to be solved by the invention However, in the water treatment apparatus using the membrane separation activated sludge method, unlike the above-described sludge extraction process, an operator monitors the water level in the system and performs operation control for adjusting the filtration amount of the membrane separation apparatus according to the inflow amount of raw water. That is, the operator is required to monitor the amount of raw water flowing in, and to perform two troublesome operations, namely, an operation of adjusting the amount of treated water to be extracted through the membrane separation device and an operation of adjusting the amount of excess sludge to be extracted through the sludge extraction pipe, independently of each other. Further, the amount of electric power consumption required for a pump driven for the purpose of water extraction or excess sludge extraction increases, and from the viewpoint of energy saving, an operation method acceptable to a decarbonizing society is also demanded. The invention aims to provide an operation method of a water treatment device and a water treatment device, which can reduce the operation burden of operators and contribute to energy saving. Technical means for solving the problems In order to achieve the above object, a first feature of the operation method of the water treatment apparatus of the present invention is an operation method of a water treatment apparatus having a biological treatment tank including at least an aerobic tank in which a membrane separation device is immersed, wherein in the operation method of the water treatment apparatus, a suction coefficient K (K < 1) is set as a control factor so that a sludge suction amount Qwas satisfies a sludge suction amount Qwas =a raw water inflow amount Qraw ×k, and the membrane separation device is operated so that a filtration amount Qtrt from the