CN1314605C

CN1314605C - Domestic sewage denitrifying-dephosphorizing method and apparatus

Info

Publication number: CN1314605C
Application number: CNB2005100187911A
Authority: CN
Inventors: 胡细全; 钟春敏; 李兆华; 李海波; 蔡鹤生
Original assignee: Hubei University
Current assignee: Hubei University
Priority date: 2005-05-27
Filing date: 2005-05-27
Publication date: 2007-05-09
Anticipated expiration: 2025-05-27
Also published as: CN1709810A

Abstract

The present invention relates to a method for removing phosphorus and nitrogen from domestic waste water and a device thereof, which belongs to the field of water treatment. The method is characterized in that the phosphorus of sewage is removed through an anaerobic sludge layer and an iron dust filler layer of an anaerobic deflecting plate reactor; organic pollutants are removed through anaerobic microorganisms; under the action of a biological membrane of an aerobic immersion type biological filtering tank, unconverted organic pollutants are degraded; ammoniacal nitrogen is converted into nitrate nitrogen, and the nitrate nitrogen is removed by denitrifying bacteria in an anaerobic area of the biological membrane; the treated sewage is deposited and discharged. The device is composed of the anaerobic deflecting plate reactor, the aerobic immersion type biological filtering tank and a deposition tank which are mutually communicated; the anaerobic deflecting plate reactor is composed of three to four compartments, and a deflecting plate, a partition plate and anaerobic sludge are arranged in each compartment; the first compartment is provided with the iron dust filler layer, and the lower part of the first compartment is provided with a back flushing pipe; a filler layer is arranged in the aerobic immersion type filtering tank. The present invention adopts anaerobic biological treatment and has the advantages of high-efficiency nitrogen and phosphorus removal capability, no blockage, strong impact load resistance, small occupation of land, low running investment cost, small energy consumption and simple and convenient operation management.

Description

A kind of method of domestic sewage denitrifying-dephosphorizing and device

Technical field

The invention belongs to water treatment field, be applicable to domestic sewage treating.

Background technology

The city domestic sewage treatment technology of China more than 80% adopts aerobic activated sludge process at present, owing to need a large amount of aerations, thereby investment is big, the energy consumption height.In recent years, the anaerobic treatment city domestic sewage becomes a research focus.Yet anaerobic biological treatment does not have the denitrogenation dephosphorizing ability, has limited it greatly in Application of Sewage.For domestic sewage treating, employing anaerobic biological treatment+oxidation pond technology is abroad arranged, remove a part of nitrogen, phosphorus by oxidation pond, but the oxidation pond floor space is big, be not suitable for the national conditions that China has a large population and a few land.Domestic existing dephosphorization process is mainly biological phosphate-eliminating, but need set up sludge reflux pump and pipeline etc., and investment is increased, and flow process is complicated, is unfavorable for daily operation management.Some developed countries of Europe extensively adopt the chemical precipitation method dephosphorization, and the precipitation agent of employing has ferric sulfate, ferric oxide, ferrous sulfate etc., its cost height usually.Existing " a kind of alternative expression internal recycle aerobe reactor " (number of patent application 200410009048) comprises that communicating aperture, each reaction tank between aerobe reaction tank, each reaction tank is provided with water inlet pipe and the dual-side pond is provided with effluent weir and rising pipe.The aerobe reaction tank is 4, and 4 reaction tanks are arranged side by side; The reaction tank that is positioned at both sides is provided with water inlet pipe, effluent weir and rising pipe, is positioned at the intermediary reaction tank and only is provided with water inlet pipe; Between each reaction tank to be provided with communicating aperture and reflux pump; The reaction tank of both sides alternately uses as aeration tank and settling tank, and middle two reaction tanks use as the aeration tank all the time.

Anaerobic baffled reactor is a kind of new and effective anaerobic reactor of studying and being applied gradually, with the research of aerobic process and usefulness relevant report is arranged also abroad, but this method has only the COD of removal and denitrogenation ability, does not have the dephosphorization ability.In the water body too high levels of phosphorus will cause environment many unfavorable, as lake eutrophication, the ornamental value that reduces water body, harm humans and biological existence etc., studies show that phosphorus is the restricted factor of body eutrophication, whenever can cause 950g (dry weight) algae grows to water body discharging 1g phosphorus.Therefore, waste water dephosphorization is particularly crucial to preventing body eutrophication.

Summary of the invention

The objective of the invention is at above-mentioned present situation, aim to provide a kind of high-efficient denitrification and dephosphorization ability that has, do not stop up, capacity of resisting impact load is strong, take up an area of less, the cost that puts into operation is low, energy consumption is little, the operational management method and the device of domestic sewage denitrifying-dephosphorizing simply and easily.

The implementation of the object of the invention is, a kind of method of domestic sewage denitrifying-dephosphorizing, city domestic sewage is regulated after distributing trough 1 enters anaerobic baffled reactor 4 through grid filtration, guide functions through traverse baffle 2, zig-zag was streamed about current were, at first the flow through anaerobic sludge layer of the 1st compartment, again through the iron filings packing layer, the H in iron filings and the water ⁺Reaction generates Fe ²⁺And then with water in phosphorus reaction, generation ferrous phosphate precipitation, waste water flows through the 2nd successively then, 3, the anaerobic sludge layer of 4 compartments, utilizing anaerobion that organic pollutant is converted into methane gas discharges, the organic pollutant that fully transforms further degraded under the microbial film effect of aerobic submerged bio-filter 6 not yet, ammonia nitrogen is converted into nitric nitrogen under the effect of aerobic nitrification bacterium, being converted into nitrogen by the denitrifying bacteria effect again in biomembranous anaerobic zone discharges, last waste water flows into settling tank 9, the microbial film fragment that comes off precipitates in this compartment, discharges through rising pipe 10 through the water outlet of post precipitation.

A kind of device of domestic sewage denitrifying-dephosphorizing, anaerobic baffled reactor 4, aerobic submerged bio-filter 6 and settling tank 9 connect successively mutually, anaerobic baffled reactor 4 is made up of 3-4 compartment, each compartment is by traverse baffle 2, dividing plate 14 is divided into the upward flow chamber, down to the stream chamber, all be added with anaerobic sludge in each compartment, form more thick anaerobic sludge layer in the compartment bottom, the 1st compartment connects distributing trough 1, the top, upward flow chamber of the 1st compartment is provided with iron filings packing layer 3, iron filings packing layer 3 bottoms are furnished with recoil tube 13, be provided with elasticity or semi soft packing 7 in the aerobic submerged bio-filter 6, lower disposed has aeration tube 12, settling tank 9 is a back taper, and there is baffle plate 8 centre, settling tank 9 be connected to shore pipe 11 and rising pipe 10 '.

The following advantage that the present invention has:

1, anaerobic baffled reactor has extremely strong capacity of resisting impact load, submerged bio-filter has the advantage of activated sludge process and biomembrance process concurrently, add iron filings filler 3 in the anaerobic baffled reactor 4 again, both organic assembling have high-efficient denitrification and dephosphorization ability and higher organic pollutant removal rate;

2, the agent set current are run by gravity, except that regular recoil needs one determined power of aerobic submerged bio-filter 6 aerations and iron filings packing layer 3, need not other energy, and power consumption is few;

3, the integrated device of agent set, have occupation of land less, the cost that puts into operation is low;

4, stronger to organic loading fluctuation adaptive faculty, so this device is less demanding to equalizing tank;

5, process structure is simple, is difficult for stopping up;

6, no reflux pump and return line, energy consumption is little, operational management is simple and convenient.

Description of drawings

Accompanying drawing is an apparatus structure synoptic diagram of the present invention

Embodiment

With reference to accompanying drawing, this device is made up of the anaerobic baffled reactor 4, aerobic submerged bio-filter 6 and the settling tank 9 that connect mutually successively.Anaerobic baffled reactor is made up of the compartment of traverse baffle, dividing plate, anaerobic sludge in 3-4, each compartment is divided into upward flow chamber, following to the stream chamber by traverse baffle 2, dividing plate 14, all be added with anaerobic sludge in each compartment, form more thick anaerobic sludge layer in the compartment bottom, the 1st compartment connects distributing trough 1, the top, upward flow chamber of the 1st compartment is provided with iron filings packing layer 3, and iron filings packing layer 3 bottoms are furnished with recoil tube 13.Be provided with flow deflector 5, elasticity or semi soft packing 7 in the aerobic submerged bio-filter 6, lower disposed has aeration tube 12, and settling tank 9 is a back taper, and there is baffle plate 8 centre, and settling tank 9 is connected to shore pipe 11 and rising pipe 10.

The present invention is provided with the iron filings packing layer in the 1st compartment of anaerobic baffled reactor, the H in iron filings and the water ⁺Reaction generates Fe ²⁺, and and then generate the ferrous phosphate precipitation with phosphorus reaction in the water; The unreacted Fe of part ²⁺In aerobic submerged bio-filter 6, be oxidized to Fe ³⁺, generate the tertiary iron phosphate precipitation with phosphorus reaction again, thereby reach the dephosphorization purpose; The issuable polyacid of crossing that neutralized simultaneously makes methanogen avoid the reactor acidifying in its optimal ph scope (6.8-7.2).Meanwhile, ferrous ion is a kind of ionogen, makes to be difficult for the effect of settled colloidal organic matter particle generation coagulation in the sanitary sewage, thereby removes from waste water; The existence of the ferrous ion of reductibility in the waste water simultaneously makes redox potential ORP reduce, and for methanogen provides a good environment, has improved activity; On the other hand, under the precipitation capture effect of the ferrous phosphate precipitation that generates and tertiary iron phosphate precipitation that in aerobic submerged bio-filter 6, generates and ironic hydroxide flocks, particulate organic matter in the sewage is also precipitated, and sludge settling property improves, thereby has improved the clearance of COD greatly.

Have only aerobic submerged bio-filter 6 need carry out certain aeration in this device, because organism is significantly eliminated (having removed 50-60%) in anaerobic baffled reactor 4 before, therefore organic loading is low, and aeration rate greatly reduces, and energy expenditure can reduce to the utmost point low.Elastic solid filler or semi soft packing organic loading are low, and consumption is few, thereby reduces cost of investment greatly.

Particular content of the present invention is described in detail in detail below: city domestic sewage is regulated after distributing trough 1 flows into anaerobic baffled reactor 4 through grid filtration, and through the guide functions of traverse baffle 2, current are in the upward flow chamber, stream up and down between the stream chamber down.At first the flow through anaerobic sludge layer of the 1st compartment, the organic pollutant in the waste water decomposes under the effect of anaerobic hydrolysis-acidification flora, is converted into low molecular solvability organic acid etc., thereby waste water ph descends; Iron filings in the iron filings packing layer and the H in the water ⁺Reaction generates Fe ²⁺, and then with water in phosphorus reaction, generate the ferrous phosphate precipitation, from waste water, remove.The waste water anaerobic sludge layer of the 2nd, 3,4 compartments of flowing through successively makes full use of anaerobion and removes organic ability then, organic pollutant is converted into methane gas discharges.Waste water flow to aerobic submerged bio-filter 6 through flow deflector 5, the organic pollutant that fully transforms further degraded under the microbial film effect of adhering on the elastic solid filler of aerobic submerged bio-filter 6 or the semi soft packing yet.Ammonia nitrogen is converted into nitric nitrogen under the effect of aerobic nitrification bacterium in this compartment, is converted into the nitrogen discharge by the denitrifying bacteria effect again in biomembranous anaerobic zone, thereby reaches the purpose of denitrogenation.Last waste water flows into settling tank 9, and current slow down, and the microbial film fragment that comes off precipitates at this, discharges through rising pipe 10 through the water outlet of post precipitation.

Excess sludge in each compartment, the pond is regularly got rid of through shore pipe 11.The recoil tube 13 of iron filings packing layer 3 bottoms regularly recoils, and iron filings is washed away, to upgrade the iron filings surface.

Carried out handling the test of sanitary sewage with the present invention: the experiment water inlet is community life sewage, and water inlet TP (total phosphorus) mean value is 4.45mg/L.The result is as follows: the average removal rate of TP is 76.5%, is up to 81%, and TP mean value is 1.04mg/L in the water outlet, is low to moderate 0.87mg/L most, reaches " urban wastewater treatment firm pollutant emission standard " GB18918-2002 primary standard substantially.

To the removal effect of organic pollutant, when water inlet COD concentration was 353mg/L, clearance reached 86.8%, and water outlet COD is low to moderate 46.6mg/L; When water inlet COD was 172mg/L, the water outlet COD of device was low to moderate 27.2mg/L, reaches primary standard A standard.

Water inlet TN (total nitrogen) is between 19-28mg/L, and clearance has also reached primary standard about 50%.

Claims

1, a kind of method of domestic sewage denitrifying-dephosphorizing, it is characterized in that city domestic sewage regulates after distributing trough (1) enters anaerobic baffled reactor (4) through grid filtration, guide functions through traverse baffle (2), zig-zag was streamed about current were, at first the flow through anaerobic sludge layer of the 1st compartment, again through the iron filings packing layer, the H in iron filings and the water ⁺Reaction generates Fe ²⁺And then with water in phosphorus reaction, generation ferrous phosphate precipitation, waste water flows through the 2nd successively then, 3, the anaerobic sludge layer of 4 compartments, utilizing anaerobion that organic pollutant is converted into methane gas discharges, the organic pollutant that fully transforms further degraded under the microbial film effect of aerobic submerged bio-filter (6) not yet, ammonia nitrogen is converted into nitric nitrogen under the effect of aerobic nitrification bacterium, being converted into nitrogen by the denitrifying bacteria effect again in biomembranous anaerobic zone discharges, last waste water flows into settling tank (9), the microbial film fragment that comes off precipitates at this, discharges through rising pipe (10) through the water outlet of post precipitation.