CN112520953A

CN112520953A - Aquaculture tail water treatment method and multistage ecological pond

Info

Publication number: CN112520953A
Application number: CN202011528013.8A
Authority: CN
Inventors: 戴雅奇; 王波杰; 孙一博; 叶骐; 丁亿凡; 朱淑媛; 陈渠成
Original assignee: Shanghai Water Engineering Design and Research Institute Co Ltd
Current assignee: Shanghai Water Engineering Design and Research Institute Co Ltd
Priority date: 2020-12-22
Filing date: 2020-12-22
Publication date: 2021-03-19

Abstract

The invention discloses an aquaculture tail water treatment method, which comprises the following steps: step S10, carrying out precipitation treatment on the culture tail water, and carrying out adsorption treatment and denitrification treatment on the precipitated culture tail water by using biological grid fillers so as to carry out primary denitrification treatment by using a soluble carbon source in the raw water of the culture tail water; step S20, purifying the aquaculture tail water obtained by the step S10 by using a compound microbial flora, and performing aeration treatment and biological grid filler treatment on the aquaculture tail water after purification treatment to improve the removal effect of organic matters and ammonia nitrogen; and step S30, carrying out adsorption treatment and secondary denitrification treatment on the culture tail water obtained by the treatment in the step S20 by using solid-phase carbon source fillers, and carrying out deep purification treatment on the culture tail water by using submerged plants to obtain a clean water body. Also discloses a multistage ecological pond for realizing the aquaculture tail water treatment method. The invention improves the denitrification efficiency and the effluent stability.

Description

Aquaculture tail water treatment method and multistage ecological pond

Technical Field

The invention relates to the technical field of ecological restoration engineering, in particular to an aquaculture tail water treatment method and a multistage ecological pond.

Background

With the rapid development of economy and the improvement of social living standard in China, the demand of aquatic products is gradually increased, and the aquaculture industry is continuously developed, but the pollution of the aquaculture tail water is more serious, a large amount of dead organisms, fish excrement and residual bait decomposition products exist in the tail water, the organic matters are decomposed to generate pollutants such as organic matters, ammonia nitrogen, nitrite, nitrate, phosphorus and the like, the environment of the aquaculture water area is deteriorated, the environment of the surrounding water area is polluted, and the water quality is deteriorated, so that the treatment of the aquaculture tail water is urgent.

The common aquaculture modes in China are pond low-density culture and facility high-density culture, and the common tail water treatment process comprises an ecological pond purification system, complete facility purification equipment and a wetland purification system. The ecological pond purification system is one of the main forms of the conventional culture tail water treatment, mainly comprises basic functions of precipitation, oxidation, adsorption, filtration and the like, has a purification function after part of ponds are transformed by combining the current situation of a culture farm, has the advantages of low cost and simplicity and convenience in operation, and is affected by irregular discharge of tail water and poor in water quality stability; the basic purification principle of the complete facility purification equipment is similar, but the specialty is higher, the operation technology is more detailed, and the purification equipment has the characteristics of stable purification effect and small occupied area; the wetland purification system is a comparatively complicated multi-functional ecosystem, and it utilizes the combined action of microorganism, filler and plant, carries out water purification through multiple modes such as biodegradable, chemisorption, physical filtration, and purifying effect is obvious, goes out water comparatively stably, especially has stronger removal effect to the nitrogen phosphorus element of breeding the tail water, but has the construction cost higher, and later stage operation management requires highly, appears blocking scheduling problem easily.

According to the popularization technical materials related to the agricultural department, the ecological pond purification technology is the main application technology at present, the use limit is small, the construction and operation cost is low, the field reconstruction is simple, the surrounding ditches, river channels and waste gas wasteland can be utilized, the construction period is short, and the ecological pond purification technology can be carried out in the culture gap. However, the ecological pond has poor water outlet stability due to unstable water discharge and unstable pollutant concentration of the culture tail water, and particularly, the total nitrogen index fluctuation is obvious, so that the key problem that how to improve the denitrification efficiency and the water outlet stability is to be solved urgently in the ecological pond of the culture tail water.

To this end, the applicant has sought, through useful research and research, a solution to the above-mentioned problems, in the context of which the technical solutions to be described below have been made.

Disclosure of Invention

One of the technical problems to be solved by the present invention is: aiming at the defects of the prior art, the aquaculture tail water treatment method for improving the denitrification efficiency and the effluent stability is provided.

The second technical problem to be solved by the present invention is: provides a multi-stage ecological pond for realizing the aquaculture tail water treatment method.

An aquaculture tail water treatment method as a first aspect of the present invention comprises the steps of:

step S10, carrying out precipitation treatment on the culture tail water, and carrying out adsorption treatment and denitrification treatment on the precipitated culture tail water by using biological grid fillers so as to carry out primary denitrification treatment by using a soluble carbon source in the raw water of the culture tail water;

step S20, purifying the aquaculture tail water obtained by the step S10 by using a compound microbial flora, and performing aeration treatment and biological grid filler treatment on the aquaculture tail water after purification treatment to improve the removal effect of organic matters and ammonia nitrogen;

and step S30, carrying out adsorption treatment and secondary denitrification treatment on the culture tail water obtained by the treatment in the step S20 by using solid-phase carbon source fillers, and carrying out deep purification treatment on the culture tail water by using submerged plants to obtain a clean water body.

In a preferred embodiment of the present invention, the retention time of the cultivation tail water in the step S10 is 0.5 to 1 day, the retention time of the cultivation tail water in the step S20 is 0.8 to 1.4 days, and the retention time of the cultivation tail water in the step S30 is 5 to 7 days.

The multistage ecological pond for realizing the aquaculture tail water treatment method comprises a sedimentation pond, a contact oxidation pond and an ecological pond which are constructed at intervals along the water inlet direction, wherein the sedimentation pond is used for carrying out sedimentation treatment on aquaculture tail water and carrying out adsorption treatment and denitrification treatment on the settled aquaculture tail water by using biological grid fillers, the contact oxidation pond is used for carrying out purification treatment on the aquaculture tail water obtained by the sedimentation pond by using compound microbial flora and carrying out aeration treatment and biological grid filler treatment on the aquaculture tail water obtained by the purification treatment, and the ecological pond is used for carrying out adsorption treatment and secondary denitrification treatment on the aquaculture tail water obtained by the contact oxidation pond by using solid-phase carbon source fillers and carrying out deep purification treatment on the aquaculture tail water by using submerged plants to obtain a clean water body.

In a preferred embodiment of the invention, the settling pond comprises:

settling pond bodies;

a water inlet pipe laid on the ground on the front side of the sedimentation pond body and used for guiding the culture tail water into the sedimentation pond body;

at least one first ecological floating island structure floating on the water surface in the front end region of the settling pond body; and

a first biogate packing filled on the bottom of the pond in the rear end region of the sedimentation pond body.

In a preferred embodiment of the invention, the sedimentation pond body is in a deep-front and shallow-rear structure, and the depth of a deep water area is more than 3 m.

In a preferred embodiment of the invention, the contact oxidation pond comprises:

contacting the oxidized pond body;

the slow-release microorganism carrier structure is arranged on the pond bottom in the front end region of the contact oxidation pond body and is used for slowly releasing the compound microorganism flora into the water body;

a second bio-gate packing filled on the bottom of the middle region of the contact oxidation pond body;

a plurality of microporous aeration discs are arranged on the bottom of the middle area of the contact oxidation pond body at intervals along the water inlet direction;

the aerator is arranged on the ground at the side of the contact oxidation pond body; and

and one end of the air inlet pipe is connected with the air outlet of the aerator, and the other end of the air inlet pipe is respectively connected with the air inlet of each microporous aeration disc.

In a preferred embodiment of the invention, the ecological pond comprises:

an ecological pond body;

at least one second ecological floating island structure floating on the water surface of the front end area of the ecological pond body;

solid carbon source fillers suspended below each second ecological floating island structure;

submerged plants planted on the bottom of the middle area of the ecological pond body; and

and constructing a water outlet well on the bottom of the rear end region of the ecological pond body, wherein a drain pipe is arranged on the water outlet well.

Due to the adoption of the technical scheme, the invention has the beneficial effects that:

1. the construction cost is low, and the peripheral ditches, river channels and waste wastelands can be utilized, so that the peripheral space of the farm can be fully utilized;

2. the construction period is short, the construction period is about 1 month, and the construction can be carried out in the culture interval period;

3. the process is simple, the subsequent operation and maintenance operation is simple and convenient, part of aquatic plants can be harvested and returned to the field or used as fish feed for digestion treatment, and part of materials, such as the solid phase contrast nitrification filler, are agricultural wastes, so that local materials are convenient to obtain, the total running power consumption is saved, and the operation is green and energy-saving;

4. the water outlet effect is stable, and the buffer capacity is strong for the unstable conditions of the water inlet quantity and the water quality.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic structural view of a multistage ecological pond of the present invention.

Figure 2 is a schematic diagram of the structure of the settling pond of the present invention.

Fig. 3 is a schematic view of the structure of the contact oxidation pond of the present invention.

Fig. 4 is a schematic structural view of the ecological pond of the present invention.

Detailed Description

In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further explained below by combining the specific drawings.

The aquaculture tail water treatment method comprises the following steps:

and step S10, carrying out precipitation treatment on the culture tail water, and carrying out adsorption treatment and denitrification treatment on the precipitated culture tail water by using biological grid fillers so as to carry out primary denitrification treatment by using a soluble carbon source in the raw water of the culture tail water. The retention time of the culture tail water in the step S10 is 0.5-1 day.

And step S20, purifying the aquaculture tail water obtained by the step S10 by using a compound microbial flora, and performing aeration treatment and biological grid filler treatment on the aquaculture tail water after purification treatment to improve the removal effect of organic matters and ammonia nitrogen. The retention time of the culture tail water in the step S20 is 0.8-1.4 days.

And step S30, carrying out adsorption treatment and secondary denitrification treatment on the culture tail water obtained by the treatment in the step S20 by using solid-phase carbon source fillers, and carrying out deep purification treatment on the culture tail water by using submerged plants to obtain a clean water body. The retention time of the culture tail water in the step S30 is 5-7 days.

According to the invention, the denitrification treatment process is added in the steps S10 and S30, so that the denitrification efficiency is improved, meanwhile, the compound microorganism flora is used for purifying the culture tail water in the step S20, so that the purification efficiency is improved, and the advanced treatment is carried out in the step S30, so that the effluent stability is improved.

Referring to fig. 1, a multi-stage ecological pond for implementing the aquaculture tail water treatment method is shown, which comprises a sedimentation pond 100, a contact oxidation pond 200 and an ecological pond 300 which are constructed at intervals along the water inlet direction.

The sedimentation pond 100 is used for carrying out sedimentation treatment on the culture tail water, and carrying out adsorption treatment and denitrification treatment on the precipitated culture tail water by utilizing biological grid fillers. Specifically, referring to fig. 2, the settling pond 100 includes a settling pond body 110, a water inlet pipe 120, two ecological floating island structures 130, and a bio-grid packing 140. The sedimentation pond body 110 is of a structure with a deep front and a shallow back, the depth of a deep water area is more than 3m, and an anoxic environment is created. The water inlet pipe 120 is laid on the front ground of the settling pond body 110, and serves to guide the culture tail water into the settling pond body 110. The two ecological floating island structures 130 float on the water surface of the front end region of the sedimentation pond body 110 at intervals, play a certain role in root system adsorption and light shading, and adsorb a large amount of feed residues contained in the culture tail water. Of course, the ecological floating island structures 130 are not limited to the number in the present embodiment, and may be disposed according to adsorption and light shielding requirements. The bio-gate packing 140 is filled on the bottom of the pond in the rear end region of the settling pond body 110. The bio-grid filler 140 is preferably bio-rope filler, and is made of hydrophilic polypropylene fiber. On one hand, the biological grid filler 140 is used for adsorbing and enhancing the precipitation effect, on the other hand, the interface denitrification effect is used, the soluble carbon source in the raw water is used for primary denitrification, and the retention time of the precipitation pond 100 is 0.5-1 day.

The contact oxidation pond 200 is used for purifying the culture tail water obtained by the treatment of the sedimentation pond 100 by using the complex microbial flora, and carrying out aeration treatment and biological grid filler treatment on the purified culture tail water. Specifically, referring to fig. 3, the contact oxidation pond 200 includes a contact oxidation pond body 210, a slow-release microorganism carrier structure 220, a bio-grid filler 230, four microporous aeration disks 240, an aerator 250, and an air inlet pipe 260. The slow-release microorganism carrier structure 220 is arranged on the bottom of the front end region of the contact oxidation pond body 210, and is used for slowly releasing the compound microorganism flora into the water body, so that the water body purification effect is improved, the microorganism culture period can be shortened, and the sewage load impact resistance is improved. The replacement cycle of the slow-release microorganism carrier structure 220 is about once a year. The bio-grid packing 230 is filled on the bottom of the pond contacting the middle region of the oxidation pond body 210. The bio-grid filler 140 is preferably bio-rope filler, and is made of hydrophilic polypropylene fiber. Four micro-porous aeration disks 240 are arranged at intervals along the water inlet direction on the bottom of the pond in the middle region of the contact oxidation pond body 210. Of course, the number of microporous aeration disks 240 is not limited to the number in this embodiment, and may be set according to actual contact oxidation requirements. The aerator 250 is disposed on the ground at the side contacting the oxidation pond body 210. One end of the air inlet pipe 260 is connected to the air outlet of the aerator 250, and the other end thereof is connected to the air inlet of each micro-porous aeration disk 240. The middle area of the contact oxidation pond 200 improves the removal effect of organic matters and ammonia nitrogen through the micropore aeration and the contact oxidation effect of the biological grid filler. The retention time of the contact oxidation pond 200 is 0.8-1.4 days.

The ecological pond 300 is used for performing adsorption treatment and secondary denitrification treatment on the culture tail water obtained by treatment of the contact oxidation pond 200 by using solid-phase carbon source fillers, and performing deep purification treatment on the culture tail water by using submerged plants to obtain a clean water body. Specifically, referring to fig. 4, the ecological pond 300 includes an ecological pond body 310, an ecological floating island structure 320, a solid carbon source filler 330, submerged plants 340, and an effluent well 350. The ecological floating island structure 320 floats on the water surface of the front end region of the ecological pond body 310. Of course, the ecological floating island structures 320 are not limited to the number in the present embodiment, and may be arranged according to specific design requirements. The solid carbon source filler 330 is suspended below the ecological floating island structure 320, and is used as a slow-release carbon source and a biological carrier to absorb suspended matters and perform secondary denitrification, and the solid carbon source filler 330 mainly adopts agricultural wastes, such as corn cobs, wood chips and the like, and can be processed by using local materials in rural areas. The replacement period of the solid carbon source filler 330 is about once a half year. The submerged plants 340 are planted on the bottom of the middle area of the ecological pond body 310, and the submerged plants 340 mainly adopt native species. The effluent well 350 is constructed on the bottom of the rear end region of the ecological pond body 310, and a drain pipe 351 is arranged on the effluent well 350. A submerged plant-based water ecological system is established to carry out advanced treatment on a water body, the water body enters the water outlet well 350 after the advanced treatment, and is discharged into a nearby river channel or an ecological ditch through the water discharge pipe 351, and the water body can also be used as a clean water source to be recycled into a farm. The retention time of the ecological pond 300 is 5-7 days.

The working process of the multistage ecological pond of the invention is as follows:

the culture tail water is collected through an ecological ditch and a pipeline and is lifted into the sedimentation pond 100 through the water inlet pipe 120 for one time, the granular pollutants are settled at the front end of the sedimentation pond 100 through the action of gravity, the sedimentation effect is enhanced through the adsorption of the biological grid filler 140 arranged at the rear end area of the sedimentation pond 100, and meanwhile, the effect of interface denitrification is achieved, and the carbon source of the raw water is utilized for primary denitrification; effluent of the sedimentation pond 100 automatically flows into the contact oxidation pond 200, the front end region of the contact oxidation pond 200 purifies culture tail water through a composite microbial flora released by a slow-release microbial carrier structure 220, the purification effect is improved, and the removal effect of organic matters and ammonia nitrogen is improved through the contact oxidation effect of a microporous aeration disc 240 and a biological grid filler 230; effluent of the contact oxidation pond 200 automatically flows into the ecological pond 300, solid carbon source fillers 330 arranged in the front end region of the ecological pond 300 are used as slow-release carbon sources and biological carriers to play roles in adsorbing suspended matters and performing secondary denitrification, a clear water type plant pond is constructed in the middle region of the ecological pond 300, a submerged plant-based water ecological system is established, the effluent is deeply treated and then discharged into a nearby ditch or an ecological ditch, and the effluent can also be used as a clean water source to be recycled into a culture farm.

The following is a specific application example of the invention:

selecting an aquaculture farm in a chongming area of Shanghai city to construct a multistage ecological pond for tail water treatment, wherein the pond clearing period of the aquaculture farm is from 11 months in the current year to 1 month in the next year, and the water drainage is not more than 10cm at ordinary times; the pond cleaning period of the crab pond is 12 months to 2 months in the next year, and the drainage is not more than 10cm at ordinary times; the drainage concentration CODmn is 8-35 mg/L, the total phosphorus is 0.2-0.9 mg/L, the total nitrogen is 0.9-7 mg/L, the drainage concentration at the initial stage of cultivation is low, and the drainage concentration at the later stage of cultivation and the pond cleaning stage is high.

According to the drainage rule, the treatment capacity of tail water is designed to be 3000m³Design water standard CODmn of 15mg/L, total phosphorus of 0.5mg/L and total nitrogen of 3 mg/L. The tail water of the farm is collected through an ecological ditch and a pipeline, the water pump is lifted once, the sedimentation pond occupies 3 mu, the retention time is 1 day, the contact oxidation pond occupies 4 mu, the retention time is 1.3 days, the ecological pond occupies 22 mu, the retention time is 6 days, and the total retention time is 8.3 days. The trial operation is started from 11 months in 2019, the trial operation is carried out till now, the fluctuation of the water inflow is large, and the fluctuation range is 500-2500 m³And d, the water quality is greatly changed, particularly the total nitrogen is changed to the maximum extent, the change range is from 0.7 to 6.8mg/L, and the final effluent is stable and basically reaches the design standard.

The foregoing shows and describes the general principles and broad features of the present invention and advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. An aquaculture tail water treatment method is characterized by comprising the following steps:

2. The aquaculture tail water treatment method of claim 1, wherein the retention time of aquaculture tail water in the step S10 is 0.5 to 1 day, the retention time of aquaculture tail water in the step S20 is 0.8 to 1.4 days, and the retention time of aquaculture tail water in the step S30 is 5 to 7 days.

3. A multi-stage ecological pond for implementing the aquaculture tail water treatment method according to claim 1 or 2, it is characterized by comprising a sedimentation pond, a contact oxidation pond and an ecological pond which are constructed at intervals along the water inlet direction, wherein the sedimentation pond is used for carrying out sedimentation treatment on the culture tail water, and the biological grid filler is used for carrying out adsorption treatment and denitrification treatment on the settled culture tail water, the contact oxidation pond is used for carrying out purification treatment on the culture tail water obtained by the settlement pond through the compound microbial flora, and carrying out aeration treatment and biological grid filler treatment on the purified culture tail water, wherein the ecological pond is used for carrying out adsorption treatment and secondary denitrification treatment on the culture tail water obtained by the contact oxidation pond by using solid-phase carbon source fillers, and carrying out deep purification treatment on the culture tail water by using submerged plants to obtain a clean water body.

4. The multi-stage ecological pond according to claim 3, characterized in that said sedimentation pond comprises:

settling pond bodies;

5. The multi-stage ecological pond according to claim 4, wherein the sedimentation pond bodies are of a deep-front shallow structure, and the depth of a deep water area is more than 3 m.

6. The multi-stage ecological pond according to claim 3, characterized in that said contact oxidation pond comprises:

contacting the oxidized pond body;

7. The multi-stage ecological pond according to claim 3, characterized in that it comprises:

an ecological pond body;