WO2016090810A1 - Method for determining discharge capacity of drainage basin fresh water aquaculture pollution - Google Patents

Abstract

A method for determining the discharge capacity of drainage basin fresh water aquaculture pollution. The method comprises the steps of: investigating and determining drainage basin aquaculture modes, aquaculture species and corresponding yields; carrying out investigation and survey according to the basic situation of aquaculture, and studying and determining basic calculation models of various pollutant discharge coefficients under the different aquaculture species and the different aquaculture modes on the basis of a field measurement method and a material balance method. On one hand, the basic investigation is carried out, the features of drainage basin aquaculture production are combined, and the effect of aquaculture on the water environment is reasonably evaluated; on the other hand, the basic calculation models of various pollutant discharge coefficients under the different aquaculture species and the different aquaculture modes are studied and determined on the basis of the field measurement method and the material balance method, and reducing of the production efficiency and increasing of aquaculture costs are avoided.

Description

Method for determining pollution discharge amount of freshwater aquaculture in river basin Technical field

The invention belongs to the field of calculation of pollution load of aquaculture, and in particular relates to a method for determining pollution discharge amount of freshwater aquaculture in a river basin.

Background technique

With the rapid development of freshwater aquaculture, traditional extensive aquaculture has continuously changed to modern intensive farming. The aquaculture area and production scale have been continuously expanded, and the types of culture and farming methods have changed greatly. As a result, the amount of residual bait and excrement left by the cultured organisms has also increased. The input of exogenous (bait) increased, and the dissolved and suspended matter also increased, which caused the aquaculture water to pollute itself and the surrounding water environment, directly affecting the development of China's aquaculture industry and the sustained growth of China's economy. More and more domestic and foreign scholars have begun to pay attention to and study the impact of freshwater aquaculture on the water environment. The analysis of the causes of aquaculture water pollution, the development and application of ecological farming techniques and treatment technologies have become the focus of attention. However, there are few quantitative studies on the extent to which various pollutants in aquaculture affect water bodies.

The research on the aquaculture discharge coefficient at home and abroad is in the initial stage, mainly focusing on the investigation of individual waters. In a study of cage cultured salmon in Europe in the 1980s, it was found that 80% of the nitrogen in the feed was directly ingested, 25% of the nitrogen in the feeding part was used for fish growth, and the remaining 65% was excreted. Funge-Smith et al. studied the sediment in aquaculture water and found that 24%, 84% and 93% of the total nitrogen, total phosphorus and particulate matter in the input water were deposited in the sediment.

Research on aquaculture systems is constantly deepening. For example, Chinese Patent Application No.: 201410199862.1, Application Date: May 13, 2014, the invention relates to an aquaculture water cycle ecosystem, including aquatic aquaculture ponds, organisms. The purification pool, the clean pool and the residue treatment ecological breeding ground, the environmental engineering of ecological breeding is constructed by the invention, the breeding environment is controlled and optimized, the ecological compatibility of microorganisms, plants and animals is utilized, the sewage of aquaculture is eliminated, and the ecological environment water body is achieved. Self-cleaning effect. In the form of circular economy, the self-purification of water bodies can be used at multiple levels to form an industrial chain of various products, resulting in a compound economic value-added effect. The ecological regulation of aquaculture by the production system can save more than 70% of the water used for aquaculture, and regulate and optimize the water quality to implement healthy aquaculture. However, the invention and the prior art literature rarely mention the effects of various aquaculture contaminants on water bodies.

Because freshwater basins often coexist with a variety of farming models and aquaculture water bodies, existing technologies generally use a single measurement method to measure the discharge coefficient of a cultured water body, culture mode and culture type. Therefore, the existing measurement of the pollutant discharge coefficient technology cannot accurately determine the amount of pollutants discharged from various cultured organisms in a watershed to a water body. In order to reasonably evaluate a watershed aquaculture water environment and comprehensively rectify the water environment of the river basin, there is an urgent need for a better solution for the aquaculture pollution discharge coefficient calculation.

Summary of the invention

1. The problem to be solved

The present invention provides a method for determining the pollution discharge amount of freshwater aquaculture in a river basin, which is capable of accurately calculating and storing the pollution discharge amount of freshwater aquaculture in a river basin of different culture modes and culture types. Starting from the basic investigation, combined with the characteristics of the aquaculture production in the basin, the impact of aquaculture on the water environment is evaluated reasonably by measuring the typical typical breeding mode and the parameters of the cultured species. On the other hand, the invention is based on the field measurement method and materials. On the basis of the balance algorithm, the basic calculation model for determining the pollutant discharge coefficient of various types of culture and different culture modes is determined, and the pollution discharge amount of freshwater aquaculture in the basin is calculated accurately, which avoids the decrease of production efficiency and the increase of aquaculture cost. .

2. Technical solutions

In order to solve the above problems, the technical solution adopted by the present invention is as follows:

A method for determining pollution discharge amount of freshwater aquaculture in a river basin, the steps of which are:

(1) Select the watershed for the aquaculture pollution discharge to be determined, and investigate and determine the aquaculture model, culture type and corresponding yield of the basin;

(2) According to the basic situation of aquaculture surveyed in step (1), the on-site measurement method and material balance algorithm are used to determine the basic calculation model of the pollutant discharge coefficient corresponding to the culture type and culture mode; the determined calculation model includes :

(A) Calculation model for pond culture or factory farming:

Where: M _i is the environmental discharge (kg/t) of a certain pollutant in pond culture or factory culture, and Q _{row j} is the amount of wastewater discharged by the jth drainage in the culture process (m ³ ), C _{Row j, i} is the concentration (mg/L) of a certain pollutant in the jth discharge water body, Q _{complement j} is the water amount (m ³ ) of the jth hydration in the breeding process, C _{complement j, i} is the jth The concentration of a certain pollutant in the secondary hydration water (mg/L); ΔW ₁ is the net production or weight gain (t) of the pond culture or factory farming; i is the pollutant production index TN, TP; The first few drainages and hydration; p is the total number of times the water is drained;

(B) Calculation model for cage culture or purse seine culture:

K _{dissolve i} = K _{total i} × X _i (III)

Where: K _{total i} is the total emission coefficient (kg/t) of certain pollutants in cage culture or purse seine culture; W _{feed r} is the determination of the amount of certain feed (kg) in the culture process, C _{feed r, i} is the content of a certain component in a certain feed (mg/kg), W _{seedling r} is the amount of a certain seed in the breeding process (kg), C _{seedling r, i} is a certain component of a certain seed Content (mg/kg), W _{into r} is the catch (kg) of certain adult fish (crab) in the breeding process, C is _{r, i} is the content of a certain component in a certain adult fish (crab) (mg/ Kg), ΔW ₂ is the net net production or weight gain (t) of cage culture or purse seine culture; K _{dissolve i} is the discharge coefficient (kg/t) of a certain pollutant dissolved state; X _i is a certain pollutant The solubility coefficient; i is the pollutant index TN, TP produced by aquaculture organisms; r is the first feeding, fish (crab) seedling and catching adult fish (crab); q is the total number of measurements.

(3) Determination of the discharge coefficient: According to the measurement data under the typical breeding mode of the cultured species in step (2), the discharge coefficient is calculated;

(4) Calculation of pollutant discharge from aquaculture in the basin: According to different farming modes, the discharge coefficient under the cultured species, the different production modes of the cultured species, and the annual output of the cultured species, the annual discharge of aquaculture pollutants in the whole river basin is obtained. The summation formula is as follows:

S _{total i} = M _i × ΔW ₁ + K _{total i} × ΔW ₂ (IV)

Where: S _{total i} is the environmental discharge (kg/t) of a certain pollutant in the whole river basin; M _i is the environmental discharge (kg/t) of a certain pollutant in pond culture or factory farming; ΔW ₁ is the pond Net production or weight gain of farmed or factory aquaculture (t); K _{total i} is the total emission factor (kg/t) of certain pollutants in cage culture or purse seine culture; ΔW ₂ is cage culture or purse seine Net production or weight gain of farmed organisms (t); i is the pollutant index TN, TP produced by aquaculture organisms.

Preferably, the method for determining and determining the aquaculture mode and culture type in the step (1) is as follows:

(a) Determine typical farming patterns based on the size of the cultured area as found in fishery culture materials;

(b) Determine the dominant aquaculture species in the basin based on the size of the aquaculture production.

Preferably, the culture mode in the step (1) comprises pond culture, factory culture, cage culture and purse seine culture; the cultured species include filter-feeding fish, crabs, shellfish;

Preferably, said step (2) X _i means aquatic pollutant emissions indicators TN, TP Dissolved coefficients, respectively, 0.55,0.40;

Preferably, in the step (2), the formula (I) p ≥ 1 is determined according to the number of water changes in the pond culture or the factory culture; in the formula (II), q ≥ 1, when the seed is put into the fish, Each time the crab is caught, it is guaranteed to be sampled once every quarter during the breeding process, but in June-September, at the peak of the growth of the organism, the number of monitoring is increased under the condition that the feed amount is greatly increased, and monitoring is performed every month. 2 times;

Preferably, in the step (3), the measurement data needs to be determined as an unknown parameter in the formulas (I) and (II);

Preferably, the methods for collecting water samples, sediments, and feed-level organisms when the unknown parameters in the formulas (I) and (II) are determined are as follows:

(1) Pond culture or factory farming: water samples include three aspects: hydration water source, aquaculture water body and drainage;

(a) Sampling method for hydration water source: At least one sampling point is set at the water filling port. When the water body depth is ≤ 5m, the water sample at 0.3~0.5m below the water surface is collected; when the water source water depth is greater than 5m, and the water source water depth is ≤ At 10m, samples of water samples from 0.3 to 0.5m and above 0.5m below the surface are mixed and analyzed. When the water source depth is >10m and less than or equal to 50m, the water surface is 0.3~0.5m, the middle layer and the bottom are 0.5. The water samples at m are mixed in equal proportions for monitoring and analysis;

(b) Sampling method for aquaculture water sampling: Five sampling points are set around the pond culture area and in the central area for each sampling, and water samples at 0.5 m below the water surface are collected at each sampling point, and the samples are analyzed in equal proportions;

(c) Drainage measurement sampling method: When the displacement exceeds half of the aquaculture water, the actual drainage water sample is collected at the initial, middle and end of the drainage, and the mixture is analyzed in equal proportion; when the displacement is less than half of the aquaculture water, the drainage is The actual drainage water samples were collected at the initial and final stages, and an equal proportion mixed sample analysis was performed;

(2) cage culture or purse seine culture: water samples include two types of water bodies in the enclosure (net) and water bodies outside the net (box);

The sampling method for the water body in the net circumference is as follows: five sampling points are set around the circumference and the central area of the net culture area, and water samples at 0.5 m below the water surface are collected at each sampling point, and the samples are analyzed in equal proportions;

The sampling method for measuring the outer water body of the net is: selecting a sampling point in the area away from the net circumference, and collecting the water sample at 0.5 m below the water surface at the point;

(3) Collection method of sediment: The sediment is collected by direct excavation of the surface sediment; in the aquaculture water, including the pond and the net, the mud collection site is set in the central area of the culture area; , including the hydration water source of the pond and the water body outside the net, and the location of the collection of the same water sample;

(4) Method for collecting feed: During the feeding period of the culture process, various feeds used at each monitoring point are collected, and the same feed used at different monitoring points does not have to be collected repeatedly; each feed is analyzed in parallel. ;

(5) Method for collecting organisms: During the feeding period of fry or crab seedlings, different juvenile samples, including crab seedlings and different fry samples, are collected; when the organisms are harvested, different commercial fish or crabs are collected;

Preferably, the sampling frequency of the water sample, the sediment, and the feed-level organism described in the formula (I), (II) is as follows:

(1) Sampling frequency of water sample and sediment: sampled once each time the seed is placed and caught in adult fish and crabs, and sampled once every quarter during the breeding process, but in June-September, in the organism During the peak period of growth, the number of monitoring is increased under the condition that the feed amount is greatly increased, and it is monitored twice a month;

(2) Frequency of sampling of organisms: Generally, when seedlings are put into production and when fish and crabs are caught, the corresponding seedlings and adult fish and crabs are collected for monitoring, and each breeding species is collected;

(3) Frequency of sampling of feed: During the feeding period of the feed, various feeds fed are fed;

Preferably, the parameters of the unknown parameters in the formulas (I) and (II) are as follows for the water sample, the sediment, and the feed-grade organism:

(1) Water body: total nitrogen, total phosphorus and water intake and discharge;

(2) sediment: total nitrogen and total phosphorus content;

(3) Feed: type, dosage, total nitrogen and total phosphorus in the feed;

(4) Culture organisms: species, seedling volume, commodity quantity, total nitrogen and total phosphorus content in organisms.

Preferably, the method for determining the amount of water in the measurement index (1) is as follows: the product of the water volume of the pond and the water exchange ratio, or the difference between the total water volume of the aquaculture water before drainage and the total water volume of the aquaculture water after drainage, or Flow meter measurement.

The water samples and feed and biological samples of each monitoring point need to collect corresponding parallel samples, and the sediment samples are collected. Not less than 10% of the sample number of parallel samples.

3. Beneficial effects

Compared with the existing estimation methods, the beneficial effects of the present invention are:

(1) The invention comprehensively considers a plurality of factors such as aquaculture water type, culture mode, culture type, feeding amount, grass yield, harvest amount, etc., and considers the system and comprehensive factors affecting the pollution load;

(2) According to the method of the present invention, the parameters of the typical breeding mode of the dominant breeding species in the key production areas are combined with the field measurement method and the material balance algorithm, which is more accurate than the single estimation method, and can effectively coexist different cultures. Determination of aquaculture discharges in freshwater basins of species and culture mode;

(3) In the case of aquaculture planning for a freshwater basin, the present invention predicts the annual aquaculture discharge amount according to the basic calculation model of various pollutant discharge coefficient under different culture types and culture modes, and pre-evaluates the influence of aquaculture on the water environment. To avoid the reduction of production efficiency and the increase of aquaculture cost, so as to reasonably plan a number of factors such as aquaculture mode, aquaculture species and feeding amount according to the estimated results;

(4) The invention aims at estimating the pollution discharge amount of aquaculture at home and abroad at the level of individual waters. Through the implementation of the invention, the pollution discharge of freshwater aquaculture in the whole river basin can be estimated, and the scientific and accuracy of the results can be Better serve the results and conclusions of the national aquaculture pollution survey, provide a scientific basis for the development of aquaculture industry development plans and industrial policies, and rationally evaluate the impact of aquaculture on the water environment, which is sustainable for fisheries and waters. Ecological environment protection is of great significance;

DRAWINGS

Figure 1 is a flow chart of the estimation method of the present invention.

detailed description

The invention is further described below in conjunction with the specific embodiments, but is not intended to limit the scope of the invention. The meanings of the tables used in the examples are:

Table 1 shows the inland aquaculture area of Changzhou;

Table 2 shows the basic situation of the farm;

Table 3 is the 1# monitoring point bait and crab seeding scale;

Table 4 shows the annual dosage of river crab and bait and their respective TN and TP content tables;

Table 5 is the result table of water quality monitoring results of 2# monitoring points;

Table 6 is the 2# monitoring point feed and writing crab seedlings scale;

Table 7 shows the discharge coefficient of pond farming under two calculation methods.

Table 8 shows the annual total discharge scales of the two farms in the Wuhu Basin under different methods.

Example 1

The following is an example of a freshwater aquaculture farm under different farming modes in the Wuhu small watershed, using a single material balance algorithm and the method provided by the present invention.

1. Determine the aquaculture model, aquaculture species and corresponding yields in the basin: According to the China Fishery Statistical Yearbook and local fishery statistics, Table 1 shows that the inland aquaculture area of Changzhou City in the Penghu Basin is in a breeding mode in a certain year. It can be divided into pond culture, lake culture (net and cage) culture, reservoir culture, river ditch and paddy field culture. According to the size of the culture area, it can be determined that pond culture and lake culture in the lake are the main breeding modes in the Penghu Basin. The annual emissions of aquaculture pollutants from two farms in the Wuhu Basin are estimated. The basic conditions are shown in Table 2. In both farming modes, river crabs are the main breeding species, and the annual output of 1# river crabs in the fence farms is 1387.5kg, the annual production of 2# river crab in pond farm is 7005kg.

Table 1: Changzhou Inland Aquaculture Area Table: hectare

Table 2: Basic table of farms

2. According to the basic situation of aquaculture surveyed in step (1), the on-site measurement method and material balance algorithm are used to determine the basic calculation model of the pollutant discharge coefficient corresponding to the species and culture mode:

(A) Changzhou pond culture calculation model:

Where: M _i is the environmental discharge (kg/t) of a certain pollutant in pond culture, and Q _{row j} is the amount of wastewater discharged by the jth drainage in the culture process (m ³ ), C _{row j, i} The concentration (mg/L) of a certain pollutant in the jth discharge water body, Q _{complement j} is the water amount (m ³ ) of the jth hydration in the breeding process, and C _{complement j, i} is the jth hydration water body Concentration of a certain pollutant (mg/L); ΔW ₁ is the net production or weight gain (t) of pond culture or factory farming; i is the pollutant index TN, TP of the cultured organism; j is the first drainage , hydration; p=1;

(B) Yixing City's purse culture calculation model:

K _{dissolve i} = K _{total i} × X _i (III)

Where: K _{total i} is the total emission coefficient (kg/t) of certain pollutants in the purse seine culture; W _{feeding r} is the determination of the amount of certain feed (kg) in the breeding process, and C _{feeding r, i} is some kind The content of a certain component in the feed (mg/kg), W _{seedling r} is the amount of a certain seed in the breeding process (kg), and the _{seedling r, i} is the content of a certain component in a certain seed (mg/ Kg), W _{into r} is the catch (kg) of certain adult fish (crab) in the breeding process, C is _{r, i} is the content of certain components (mg/kg), ΔW in some adult fish (crab) ₂ is the net net production or weight gain (t) of cage culture or purse seine culture; K _{dissolve i} is the discharge coefficient of dissolved state of certain pollutants (kg/t); X _i is the solubility coefficient of certain pollutants ;i is the pollutant index TN, TP produced by aquaculture organisms; r is the first feeding, fish (crab) seedling and catching adult fish (crab); q=9.

3. Determination of the discharge coefficient: According to the measurement data under the typical breeding mode of the culture type, the discharge coefficient is calculated. Freshwater nets around the farm 1 ^# generally in mid-late February, seedlings, mid-November - next February, listed, feeding corn seeds, snails and small fish and other bait, planting water plants, but not fishing drugs. The feed intake in a certain year is shown in Table 3. The TN and TP contents of river crab and bait are shown in Table 4. According to the above parameters, bring into the Yixing City purse network breeding calculation model:

It can be concluded that the water production and discharge coefficient TN of the purse seine farm is 20.89kg/t, and the TP is 2.75kg/t.

Table 3: ^# 1 monitoring point scale delivery of food and Crab

Note: The snail is divided into shell and meat. The meat is eaten by crab or fish. The shell is still in the water or sediment. This part can not be used as a pollutant. Therefore, only the snail meat can be counted when calculating the amount of snail. The amount of snail meat accounts for about 25% of the entire snail.

Table 4 Annual dosage of river crab and bait and their respective TN and TP contents

sample name	TN (g/kg)	TP (g/kg)
			River crab	22.40	1.45
Water grass	2.60	0.39
			Small fish	27.50	4.10
corn	15.36	2.70
			Screw	110	0.98

Changzhou freshwater pond farms ^# 2 in accordance with the requirements for water, and water culture was sampled and monitored drainage, drainage Count is 1, the intake displacement are 12826.4m ^3, mean monitoring results are shown in Table 5. According to the Changzhou pond culture calculation model:

It is concluded that the fish production and discharge coefficient TN of the pond farm is 1.062kg/t and the TP is 0.0018kg/t.

Table 5: 2 ^# Monitoring point water body water quality monitoring results table

4. Calculation of pollutant discharge from aquaculture in the basin: According to different farming modes, the discharge coefficient under the cultured species, the different production modes, and the annual production of the cultured species, the aquaculture pollution of the two farms in the whole river basin is obtained by re-summation. The annual emissions, the summation formula is as follows:

S _{total i} = M _i × ΔW ₁ + K _{total i} × ΔW ₂

Bring M _TN = 1.062kg / t, M _TP = 0.0018kg / t, ΔW ₁ = 7.005t, K _{total TN} = 20.89kg / t, K _{total TP} = 2.75kg / t, ΔW ₂ = 1.387t, Wuhu The two annual aquaculture pollution emissions in Yixing and Changzhou are 36.41kg and TP is 3.83kg.

A single material balance algorithm is used to estimate the amount of farm discharge in the two different farming modes in the small watershed:

In step 3, the 1 ^# aquatic product discharge coefficient TN of Yixing City Weiwang Farm is 20.89kg/t, and TP is 2.75kg/t. Changzhou pond farm 2 ^# Farmers have farmed crabs for more than 10 years, listed every year from November to December, and invested in new crops in February. Feed pelletized feed, cornseed, snails and small fish in your own processing; the pond is rich in water and grass, and no additional planting is required. The feed amount for a certain year is shown in Table 6.

Table 6: ^# 2 feed monitoring sites and put in writing Crab Scale

Bring the parameters into the purse farming calculation model:

It can be concluded that the 2 ^# aquatic product discharge coefficient TN of Changzhou Weiwang Farm is 23.99kg/t, and the TP is 3.20kg/t. The production and discharge coefficient is very different from the field measurement method in the method of the present invention, as shown in Table 7.

Table 7: Production and discharge coefficient of pond culture under two calculation methods

Method type	TN (kg/t)	TP (kg/t)
			Material balance algorithm	23.99	3.20
Method of the invention	1.062	0.0018

In step 4, the calculation of pollutant discharge from aquaculture in the basin: according to different farming modes, the discharge coefficient under the culture type, the different production mode, and the annual output of the cultured species, the annual sum of the aquaculture pollutants in the whole river basin is obtained by re-summation. According to the summation formula:

S _{total i} = M _i × ΔW ₁ + K _{total i} × ΔW ₂

Bring M _TN = 23.99kg / t, M _TP = 3.20kg / t, ΔW ₁ = 7.005t,

K _{total TN} = 20.89kg / t, K _{total TP} = 2.75kg / t, ΔW ₂ = 1.387t, the two annual aquaculture pollution emissions of Yixing and Changzhou in the Wuhu Basin are 197.02kg, and the TP is 26.23kg.

Two different methods for estimating the total annual discharge of farms under the two farming modes in the Wuhu Basin are shown in Table 8.

Table 8: Total annual sewage discharge table of two breeding mode farms in Wuhu Basin under different methods

Method type	TN (kg)	TP (kg)
			Single material balance algorithm	197.02	26.23
Method of the invention	36.41	3.83

It can be seen from Table 8 that the results of the calculation method of the present invention are one order of magnitude smaller than the single material balance algorithm, mainly because the pond culture mode adopts different methods, and the calculation result of the physical scale algorithm is larger than the scene. The result of the measured method. The material balance method follows the material balance theory of the mass of each substance in the feed of the fish pond as the sum of the content of each substance in the living body and the mass of the unabsorbed substance in the living body. The pollution load calculated by this method is more in line with the actual situation. . However, this method neglects the self-purification ability of the water body, the adsorption and decomposition of the sediment, and the absorption and utilization of other organisms in the water body, so the value obtained is too large. When analyzing the amount of TN and TP discharged from the river crab culture in the Penghu Basin to the environment, it is calculated according to the actual field measurement method.

Claims (10)

1. A method for determining pollution discharge amount of freshwater aquaculture in a river basin, the steps of which are:

   (1) Select the watershed for the aquaculture pollution discharge to be determined, and investigate and determine the aquaculture model, culture type and corresponding yield of the basin;

   (2) According to the basic situation of aquaculture surveyed in step (1), the on-site measurement method and material balance algorithm are used to determine the basic calculation model of the pollutant discharge coefficient corresponding to the culture type and culture mode; the determined calculation model includes :

   (A) Calculation model for pond culture or factory farming:

   

   Where: M _i is the environmental discharge (kg/t) of a certain pollutant in pond culture or factory culture, and Q _{row j} is the amount of wastewater discharged by the jth drainage in the culture process (m ³ ), C _{Row j, i} is the concentration (mg/L) of a certain pollutant in the jth discharge water body, Q _{complement j} is the water amount (m ³ ) of the jth hydration in the breeding process, C _{complement j, i} is the jth The concentration of a certain pollutant in the secondary hydration water (mg/L); ΔW ₁ is the net production or weight gain (t) of the pond culture or factory farming; i is the pollutant production index TN, TP; The first few drainages and hydration; p is the total number of times the water is drained;

   (B) Calculation model for cage culture or purse seine culture:

   

   K _{dissolve i} = K _{total i} × X _i (III)

   Where: K _{total i} is the total emission coefficient (kg/t) of certain pollutants in cage culture or purse seine culture; W _{feed r} is the determination of the amount of certain feed (kg) in the culture process, C _{feed r, i} is the content of a certain component in a certain feed (mg/kg), W _{seedling r} is the amount of a certain seed in the breeding process (kg), C _{seedling r, i} is a certain component of a certain seed Content (mg/kg), W _{into r} is the catch (kg) of certain adult fish (crab) in the breeding process, C is _{r, i} is the content of a certain component in a certain adult fish (crab) (mg/ Kg), ΔW ₂ is the net net production or weight gain (t) of cage culture or purse seine culture; K _{dissolve i} is the discharge coefficient (kg/t) of a certain pollutant dissolved state; X _i is a certain pollutant The solubility coefficient; i is the pollutant index TN, TP produced by aquaculture organisms; r is the first feeding, fish (crab) seedling and catching adult fish (crab); q is the total number of measurements.

   (3) Determination of the discharge coefficient: According to the measurement data under the typical breeding mode of the cultured species in step (2), the discharge coefficient is calculated;

   (4) Calculation of pollutant discharge from aquaculture in the basin: According to different farming modes, the discharge coefficient under the cultured species, the different production modes of the cultured species, and the annual output of the cultured species, the annual discharge of aquaculture pollutants in the whole river basin is obtained. The summation formula is as follows:

   S _{total i} = M _i × ΔW ₁ + K _{total i} × ΔW ₂ (IV)

   Where: S _{total i} is the environmental discharge (kg/t) of a certain pollutant in the whole river basin; M _i is the environmental discharge (kg/t) of a certain pollutant in pond culture or factory farming; ΔW ₁ is the pond Net production or weight gain of farmed or factory aquaculture (t); K _{total i} is the total emission factor (kg/t) of certain pollutants in cage culture or purse seine culture; ΔW ₂ is cage culture or purse seine Net production or weight gain of farmed organisms (t); i is the pollutant index TN, TP produced by aquaculture organisms.
2. The method for determining pollution discharge amount of freshwater aquaculture in a river basin according to claim 1, wherein the method for determining and determining aquaculture mode and culture type in the step (1) is as follows:

   (a) Determine typical farming patterns based on the size of the cultured area as found in fishery culture materials;

   (b) Determine the dominant aquaculture species in the basin based on the size of the aquaculture production.
3. The method for determining pollution discharge amount of freshwater aquaculture in a river basin according to claim 1, wherein the culture mode in the step (1) comprises pond culture, factory culture, cage culture and purse seine culture. The cultured species include filter-feeding fish, crabs, and shellfish;
4. The method for determining contamination of freshwater aquatic breeding of watershed emissions according to claim 1, wherein: said step (2) X _i means aquatic pollutant emissions indicators TN, TP Dissolved coefficient, 0.55, 0.40 respectively;
5. The method for determining pollution discharge amount of freshwater aquaculture in a river basin according to claim 1, wherein: in the step (2), formula (I) p ≥ 1, according to the number of water exchanges in pond culture or factory farming In the formula (II), q≥1, once in the seedlings and once in the adult fish and crabs, it is guaranteed to be sampled once every quarter during the breeding process, but in the organism from June to September. During the peak period, the number of monitoring is increased under the condition that the feed amount is greatly increased, and it is monitored twice a month;
6. The method for determining pollution discharge amount of freshwater aquaculture in a river basin according to claim 1, wherein in the step (3), the measurement data needs to be determined as an unknown parameter in the formulas (I) and (II);
7. The method for determining the pollution discharge amount of freshwater aquaculture in a river basin according to claim 6, wherein the water sample, the sediment, the feed-level organism are determined when the unknown parameters in the formula (I) and (II) are determined. The collection method is as follows:

   (1) Pond culture or factory farming: water samples include three aspects: hydration water source, aquaculture water body and drainage;

   (a) Sampling method for hydration water source: At least one sampling point is set at the water filling port. When the water body depth is ≤ 5m, the water sample at 0.3~0.5m below the water surface is collected; when the water source water depth is greater than 5m, and the water source water depth is ≤ At 10m, samples of water samples from 0.3 to 0.5m and above 0.5m below the surface are mixed and analyzed. When the water source depth is >10m and less than or equal to 50m, the water surface is 0.3~0.5m, the middle layer and the bottom are 0.5. The water samples at m are mixed in equal proportions for monitoring and analysis;

   (b) Sampling method for aquaculture water sampling: Five sampling points are set around the pond culture area and in the central area for each sampling, and water samples at 0.5 m below the water surface are collected at each sampling point, and the samples are analyzed in equal proportions;

   (c) Drainage measurement sampling method: When the displacement exceeds half of the aquaculture water, the actual drainage water sample is collected at the initial, middle and end of the drainage, and the mixture is analyzed in equal proportion; when the displacement is less than half of the aquaculture water, the drainage is The actual drainage water samples were collected at the initial and final stages, and an equal proportion mixed sample analysis was performed;

   (2) cage culture or purse seine culture: water samples include two types of water bodies in the enclosure (net) and water bodies outside the net (box);

   (a) The sampling method for the water body in the net circumference is as follows: five sampling points are set around the circumference and the central area of the net culture area, and each sample point collects the water sample at 0.5 m below the water surface, and the sample is analyzed in equal proportion;

   (b) The sampling method for measuring the outer water body of the net is: selecting a sampling point in the area away from the net circumference, and collecting the water sample at 0.5 m below the water surface at the point;

   (3) Collection method of sediment: The sediment is collected by direct excavation of the surface sediment; in the aquaculture water, including the pond and the net, the mud collection site is set in the central area of the culture area; , including the hydration water source of the pond and the water body outside the net, and the location of the collection of the same water sample;

   (4) Method for collecting feed: During the feeding period of the culture process, various feeds used at each monitoring point are collected, and the same feed used at different monitoring points does not have to be collected repeatedly; each feed is analyzed in parallel. ;

   (5) Method for collecting organisms: During the feeding period of fry or crab seedlings, different juvenile samples, including crab seedlings and different fry samples, are collected; when the organisms are harvested, different commercial fish or crabs are collected;
8. The method for determining the pollution discharge amount of freshwater aquaculture in a river basin according to claim 6, wherein the water sample, the sediment and the feed are determined when the unknown parameters in the formula (I) and (II) are determined. The frequency of collection of organisms is as follows:

   (1) Sampling frequency of water sample and sediment: sampled once each time the seedlings are put into production and adult fish and crabs, and sampled once every quarter during the breeding process;

   (2) Frequency of sampling of organisms: Generally, when seedlings are put into production and when fish and crabs are caught, the corresponding seedlings and adult fish and crabs are collected for monitoring, and each breeding species is collected;

   (3) Frequency of sampling of feed: During the feeding period of the feed, various feeds fed are fed;
9. The method for determining pollution discharge amount of freshwater aquaculture in a river basin according to claim 6, wherein the unknown parameters in the formula (I) and (II) are used for determining water samples, sediments, and feed-grade organisms. The indicators are as follows:

   (1) Water body: total nitrogen, total phosphorus and water intake and discharge;

   (2) sediment: total nitrogen and total phosphorus content;

   (3) Feed: type, dosage, total nitrogen and total phosphorus in the feed;

   (4) Culture organisms: species, seedling volume, commodity quantity, total nitrogen and total phosphorus content in organisms.
10. The method for determining the pollution discharge amount of freshwater aquaculture in a river basin according to claim 9, wherein the method for measuring the amount of water in the measurement index (1) is as follows: a product of a water volume of the pond and a water exchange ratio, or The difference between the total water volume of the aquaculture water before drainage and the total water volume of the aquaculture water after drainage is measured by a flow meter.

Images