CN106186321A - A kind of integrated energy-saving nitrogen rejection facility and method - Google Patents

Abstract

The invention discloses an integrated energy-saving denitrification device and method for treating domestic sewage, which comprises a water distribution pipe, an aerobic biological turntable, a turntable brush, double sedimentation areas, solid fillers, a permeable partition, a turntable brush and a turntable controller. The water inlet pump is connected to the water distribution pipe to control the water flow; the water distribution pipe is connected to the aerobic biological turntable with a speed control device, and the water is distributed from the middle of the turntable; the aerobic biological turntable is fixed on the upper part of the inner funnel-shaped sedimentation tank, and the inner sedimentation tank The body is connected to the external sedimentation tank body through the porous volcanic rock solid filler. The inner sedimentation tank and the outer sedimentation tank constitute a double sedimentation zone; the volcanic rock solid filler is placed on the upper part of the permeable barrier, which is an anaerobic zone; The mud port and the sludge return port are set at the bottom of the external sedimentation tank, and the return port is equipped with a sludge return pump to control the sludge return flow. The invention has high flexibility and low energy consumption, satisfies the secondary effluent of various sewage treatment plants, and can control the growth of the turntable biofilm.

Description

An integrated energy-saving denitrification device and method

technical field

The invention belongs to the field of sewage treatment, and in particular relates to a denitrification device suitable for operation in secondary effluent water of municipal sewage plants and an operation method thereof.

Background technique

my country's surface water is seriously polluted by ammonia nitrogen. According to statistics, in 2012, the total discharge of wastewater in the country was 68.46 billion tons, the total discharge of chemical oxygen demand was 24.237 million tons, a decrease of 3.05% compared with the previous year; the total discharge of ammonia nitrogen was 2.536 million tons. The annual average concentration of ammonia nitrogen in surface water exceeds the Class III water quality standard, becoming an important factor affecting the quality of water environment. A large amount of ammonia nitrogen discharge not only causes water environmental pollution, eutrophication of water bodies and red tides in water bodies, but also causes microorganisms in water equipment to multiply in industrial wastewater treatment and reuse projects, forming biofouling, blocking pipes and water equipment, and affecting heat exchange. At present, domestic and foreign scholars' research on nitrogen-containing sewage is mainly focused on the development of new denitrification technology to achieve the purpose of better treatment of ammonia nitrogen and the requirements of environmental protection.

At present, the traditional technology of domestic sewage denitrification (nitrification-denitrification), which is widely used in sewage treatment plants in my country, faces problems such as long process flow, many additional carbon sources, large aeration volume, and high energy consumption. The use of new biological denitrification technology (nitrosation-ANAMMOX) can solve some of the above problems, but most of the reaction devices still need to aerate the nitrosation part, which cannot minimize the energy consumption of the process. In addition, the traditional biological denitrification process that requires high carbon-to-nitrogen ratio sewage and the new biological denitrification process that requires low carbon-to-nitrogen ratio sewage have not been comprehensively applied at present, and the water quality that is between the water quality requirements of the two processes cannot be treated.

Contents of the invention

The technical problem to be solved by the present invention is to provide an integrated energy-saving biological denitrification device and method that does not require additional aeration, and can be freely switched between traditional biological denitrification processes and new biological denitrification processes according to influent water quality conditions. The energy consumption of the denitrification process can be reduced to the greatest extent, thereby providing a device and a method for solving the problem of denitrification of domestic sewage.

The denitrification device provided by the present invention is a continuous operation device aiming at the secondary effluent of the sewage treatment plant as the inflow water, and has the function of the secondary sedimentation tank at the same time, saving the occupied area of the equipment to the greatest extent. It is characterized in that it includes a water distribution pipe connected to the aerobic biological turntable, a turntable brush that can control the lifting, an internal funnel-shaped sedimentation tank, an external porous volcanic rock solid filler, an outlet overflow tank, a sludge return pump, an inlet solenoid valve and Turntable speed control device. The water inlet pump is connected to the water distribution pipe to control the water flow; the water distribution pipe is connected to the aerobic biological turntable with a speed control device, and the water is distributed from the middle of the turntable; the aerobic biological turntable is fixed on the upper part of the inner funnel-shaped sedimentation tank for attachment Aerobic nitrifying bacteria (nitroso bacteria and nitrifying bacteria) that remove ammonia nitrogen and COD aerobic heterotrophic bacteria are removed. This part is the aerobic area of the device; the internal sedimentation tank body is connected to the external sedimentation tank through a permeable partition with porous volcanic rock solid filler. The tanks are connected, and the inner sedimentation tank and the outer sedimentation tank constitute the double sedimentation area of the device; the porous volcanic rock solid filler is placed on the upper part of the permeable partition to attach and remove anaerobic denitrification bacteria for nitrate nitrogen and nitrite nitrogen ( Anaerobic ammonia oxidizing bacteria and denitrifying bacteria), this part is the anaerobic area of the device; the outlet overflow weir is on the upper part of the external tank body, and the overflow height is lower than the height of the water distribution pipe; the sludge discharge port and the sludge return port are in the external sedimentation tank Bottom setting, the return port is equipped with a sludge return pump to control the return flow of sludge.

Among them, the water distribution pipe has the function of supporting the aerobic biological turntable while distributing water evenly.

Among them, the upper part of the biological turntable is equipped with a turntable brush that can be raised and lowered, and the height is adjusted by the turntable brush controller to regularly remove the aging biofilm and overgrown microbial biomass on the outer surface of the turntable.

Among them, the biological turntable has a grid-shaped surface, which provides a larger specific surface area and can retain an appropriate amount of microbial biomass when brushing off the aging biofilm on the turntable, which is convenient for re-hanging the film later.

Among them, the reactor has two sedimentation areas inside and outside, which have the function of sedimentation tank.

Among them, the particle size of the porous volcanic rock solid filler needs to be relatively large (12mm≤d≤15mm), otherwise the height of the outlet water head will be affected.

Among them, the permeable partition is fixed on the external pool body, and the permeable holes should be smaller than the particle size of the solid filler.

The operation method of the integrated energy-saving denitrification device is characterized in that it includes the following steps:

1) The secondary outlet water (mud-water mixture) enters the water distribution pipe (2) from the water inlet pipe through the water inlet pump (1) into the aerobic biological turntable (3), and the aerobic biological turntable adjusts the speed through the turntable controller (13). The rotation speed of the oxygen biological turntable should be controlled at 2.0-4.0r/min, and the hydraulic retention time HRT in the _aerobic zone should be controlled at 1.0-2.0h;

2) The mud-water mixture is followed by the double sedimentation area (5). After the mud-water separation, the sludge settles into the sludge discharge pipe (8) or the sludge return pipe (9), and the return sludge flows back to the biochemical tank of the municipal sewage plant. The mud return ratio is 20% to 50%;

3) Sewage upstream passes through the permeable partition (7) and enters the porous volcanic rock solid filler to control the hydraulic retention time HRT _anaerobic in the anaerobic zone at 4.0-6.0h;

4) The sewage enters the upper clear water overflow area after passing through the porous volcanic rock solid filler (6), and enters the outlet pipe (11) through the outlet overflow baffle (10);

Regularly remove redundant and aging microorganisms, control it at 10-20d/time when the COD value is greater than 50mg/L, and control it at 20-30d/time when the COD value is less than 50mg/L.

The domestic sewage denitrification device and method of the present invention have high process flexibility and low operating energy consumption, and can meet the secondary water discharge requirements of various sewage treatment plants. At the same time, they are equipped with biological turntable brushes, which can control the growth of biofilm on the turntable, and provide a solution for the denitrification of domestic sewage. Nitrogen treatment provides a new approach with high applicability and low cost.

Description of drawings

Figure 1 - Side view of the invention.

In the figure: 1- water inlet pump; 2- water distribution pipe; 3- aerobic biological turntable; 4- turntable brush; 5- double sedimentation area; 6- porous volcanic rock solid filler; ; 9-sludge return pipe; 10-outlet overflow baffle; 11-outlet pipe; 12-turntable brush controller; 13-turntable controller.

specific implementation plan

The present invention will be described in further detail below in conjunction with the accompanying drawings.

Referring to the figure, the integrated energy-saving denitrification device of the present invention includes a water distribution pipe 2, an aerobic biological turntable 3, a turntable brush 4, a double sedimentation area 5, a solid filler 6, a water-permeable partition 7, a turntable brush controller 12, and a turntable controller 13 .

1) The secondary outlet water (mud-water mixture) enters the water distribution pipe (2) from the water inlet pipe through the water inlet pump (1) and enters the aerobic biological turntable (3). The speed of the aerobic biological turntable is adjusted by the turntable controller (13). The residual COD contacts with the aerobic heterotrophic bacteria attached to the aerobic biological turntable, and the dissolved oxygen content is increased while the turntable rotates to consume COD. At the same time, the ammonia nitrogen in the water contacts with the aerobic nitrifying bacteria attached to the aerobic biological turntable, and part of the ammonia nitrogen is converted into For nitrous nitrogen, the rotation speed of the aerobic biological turntable should be controlled at 2.0-4.0r/min, and the hydraulic retention time HRT in the _aerobic zone should be controlled at 1.0-2.0h;

2) The mud-water mixture is followed by the double sedimentation zone (5). After the mud-water separation, the sludge settles into the sludge discharge pipe (8) or the sludge return pipe (9), and the return sludge flows back to the biochemical tank of the municipal sewage plant to ensure There is sufficient biomass in the biochemical tank, and the sludge return ratio is 20% to 50%;

3) The sewage flows upwards through the permeable partition (7) and enters the solid packing (6). The solid packing part is an anoxic anaerobic area, and denitrifying bacteria and anammox bacteria are attached to the packing. The residual ammonia nitrogen and ammonia nitrogen in the sewage Nitrogen denitrification process occurs in the presence of COD, denitrification occurs in the anaerobic ammonium oxidation process in the absence of COD, and the hydraulic retention time HRT _anaerobic in the anaerobic zone is controlled at 4.0-6.0h;

4) The sewage enters the upper clear water overflow area after passing through the porous volcanic rock solid filler (6), and enters the outlet pipe (11) through the outlet overflow baffle (10);

The biomass of the aerobic biological turntable (3) is controlled by the turntable brush (4) and the turntable controller (12), which regularly removes excess and aging microorganisms, and is controlled at 10-20d/time when the COD value is greater than 50mg/L. When the value is less than 50mg/L, it is controlled at 20-30d/time.

During actual installation and operation, first determine the volume ratio of the aerobic zone to the anaerobic zone according to the average value of various indicators of water quality to be treated, so as to determine the height of the porous volcanic rock solid filler, and at the same time control the filler diameter not less than 12mm, so as to affect the water discharge head height. The solid filler can be made of porous volcanic rock or other porous fillers with a similar density (1.2-1.5g/cm ³ ), which must ensure that it does not float when it encounters water and that microorganisms can attach.

The biological turntable 3 is evenly fixed on the water distribution pipe 2 at an interval of 5 mm, and is installed as a whole above the sedimentation tank inside the tank body. This can ensure that the biological turntable can be in contact with the air and the liquid surface with half the surface of the turntable, so that the microorganisms on the turntable can also contact the air with half the turntable area, so as to achieve the purpose of "aeration".

During operation, the rotation speed of the biological turntable can be adjusted through the turntable controller 13 according to the actual water intake load.

Taking the secondary effluent of a municipal sewage treatment plant as the treatment object, the influent water quality during the test period is as follows:

Test conditions: the volume ratio of the aerobic zone to the anaerobic zone of the device is 1:4, the influent flow rate is 5L/h, the HRT is 6.3h, the sludge return ratio is 20%, and the rotation speed of the aerobic biological turntable is 3.0r·min ^{- 1} or so, the DO in the aerobic zone is 2.5-4.0mg/L, the DO in the anaerobic zone is 0.4-0.5mg/L, the hydraulic retention time HRT in the aerobic zone is _aerobic =1.5h, and the hydraulic retention time in the _anaerobic zone is HRTanaerobic = 4.8h.

Test results: After the system is stabilized, the effluent average COD, NH ₄ ⁺ -N, NO ₂ ^- -N, NO ₃ ^- -N, TN, TP, etc. are 25.26, 0.88, 0.05, 9.36, 10.29, respectively It has reached the first-level A standard stably.

The above descriptions are only specific embodiments of the present invention, and are not intended to limit the scope of the present invention. All equivalent changes or modifications made according to the structures, features and principles described in the scope of the present invention shall be included in the scope of the present invention .

Claims (5)

1. integrated energy-saving nitrogen rejection facility, it is characterised in that: include the water distributor with aerobe rotating disk UNICOM, lifting can be controlled Rotating disk brush, internal funnel-form sedimentation tank, outside cellular volcanic rock solid packing, water outlet overflow launder, sludge reflux pump and turn Dish revolution speed control device；Intake pump is connected with water distributor, controls flow of inlet water；Aerobic with revolution speed control device of water distributor Biological rotating disk is connected, water distribution in the middle part of rotating disk；Aerobe rotating disk is fixed on internal funnel-form sedimentation tank body top, this part For aerobic zone；Internal precipitate cell body is by placing the permeable dividing plate of cellular volcanic rock solid packing and outside sedimentation tank body phase Even, internal precipitate pond constitutes double settling zone with outside sedimentation tank；Cellular volcanic rock solid packing is placed on permeable dividing plate Portion, this part is anaerobic zone；Effluent overflow weir water is less than water distributor height in outside cell body top, overflow height；Mud discharging mouth with Sludge reflux mouth is being arranged at the bottom of outside sedimentation tank, and refluxing opening is furnished with sludge reflux pump in order to control sludge reflux amount.

The most according to claim 1, device, wherein, biological rotating disk is grid like surface.

The most according to claim 1, device, wherein, cellular volcanic rock solid packing particle diameter d is 12mm≤d≤15mm.

The most according to claim 1, device, wherein, permeable dividing plate permeable hole should be less than solid packing particle diameter.

5. application method of device as described in claim 1 or 4 any one, it is characterised in that comprise the following steps:

1) secondary effluent is entered water distributor (2) by water inlet pipe through intake pump (1) and is passed through aerobe rotating disk (3), and aerobe turns Dish regulates rotating speed by wheel controller (13), and aerobe rotary speed controls 2.0～4.0r/min, controls aerobic zone water Power time of staying HRT_Aerobic1.0～2.0h；

2) the most double settling zone of muddy water mixed solution (5), after mud-water separation, sludge settling enters discharge pipeline (8) or mud returns Flow tube (9), returned sludge is back to the biochemistry pool of municipal sewage plant, and return sludge ratio is 20%～50%；

3) sewage is upper is passed through cellular volcanic rock solid packing through permeable dividing plate (7), controls anaerobic zone hydraulic detention time HRT_Anaerobism4.0～6.0h；

4) sewage enters clean water overflow district, upper strata, through water outlet overflow baffle afterwards by cellular volcanic rock solid packing (6) (10) outlet pipe (11) is entered；

Aerobe rotating disk (3) needs periodically to remove unnecessary and aging microorganism, specific as follows: the COD value bar more than 50mg/L Controlling 10～20d/ time under part, COD value is less than controlling in the case of 50mg/L 20～30d/ time.