HJ 521-2009Codes for wastewater discharging (English PDF)

3.1 Wastewater discharge rules

The relationship between the various discharge states of the wastewater during the inspection period (one year). Monitoring of wastewater discharge status indicators by relevant state Test technical specifications are implemented. The inspection period is not included in the inspection period.

3.2 (with) regular it refers to the repeated connection between the various discharge states (flows) of wastewater, and its changing situation has certain inevitability.

3.3 Irregular

It means that the change state of each discharge state (flow rate) of wastewater is not inevitable, and the next state cannot be foreseen.

3.4 Continuous

It means that the wastewater flow rate is always greater than zero.

3.5 Intermittent Intermittent

Refers to the conversion of wastewater flow between 0 and non-zero.

3.6 Stable

Refers to the discharge state where the flow has a relative standard deviation of no more than 20%.

The relative standard deviation calculation formula is.

1RSD 100%

Where. 1

Xi--Check the ith flow monitoring value during the period;

n--The number of inspections during the inspection period shall be no less than the number of times reported in the Declaration Report on Emission of Pollutants.

3.7 Unstable

Refers to the discharge state where the flow has a relative standard deviation of more than 20%.

3.8 Periodic periodical

Change from any emission state, after a period of time (cycle) or an integral multiple of this time, always return to the beginning State and repeat the original changes.

3.9 Impact type impactive

Wastewater discharge caused by unexpected events is unpredictable, such as heavy rain or sudden accidents.

4.1 Scientific principles

According to the key indicator of wastewater discharge status--flow, the classification of wastewater discharge law is divided, and the time dimension of wastewater discharge law is taken into account.

4.2 Systematic principles

The wastewater discharge law will be systematically arranged in a certain order to form a reasonable scientific classification system.

4.3 The principle of scalability Taking into account the business development of wastewater discharge, water pollution prevention and management, the wastewater discharge law category sets the containment category and reserves space to Ensure that the classification system has certain flexibility, and at the same time create conditions for the extension and refinement of the classification system.

4.4 Compatibility Principle

It is consistent with existing relevant national and industry standards.

4.5 Comprehensive practical principles

The classification of wastewater discharge laws is based on the overall requirements for classification of wastewater discharge laws, and it is recommended to meet pollution source supervision and sewage.

The business management needs of emission control are in line with the actual needs of environmental statistics, pollution declaration and registration, and total emission reduction control.

5.1 Basic methods

The basic classification method of this standard follows the requirements and requirements of GB/T 7027-2002.

5.2 Classification method of wastewater discharge law

The classification of wastewater discharge is classified by mixed classification. Combined with the actual business work of water pollution prevention and management, from the perspective of wastewater discharge flow the wastewater discharge law is described, and then the surface classification method is adopted according to the needs of the sub-divisions; the line classification method is used to classify the next layer under each surface.

Example.

Classified by wastewater discharge flow Classification by stability according to continuity classification Continuously stable Intermittent Unstable Regular Irregular

6.1 Coding principle

6.1.1 Normative

In the wastewater discharge law code system, the type, structure and writing format of the code must be uniform.

6.1.2 Uniqueness

There is only one code for each wastewater discharge law category, and one code indicates the only one type of wastewater discharge law.

6.1.3 Rationality

The code structure of the wastewater discharge law should be adapted to its classification system.

6.1.4 Extensibility

The code for wastewater discharge should be coded with appropriate backup capacity to accommodate expansion needs.

6.1.5 Simplicity

The code structure should be as simple as possible, convenient for users to fill in, while saving computer storage space, reducing code error rate and improving processing efficiency.

rate.

6.1.6 Stability

Once the wastewater discharge law code is determined, it should remain unchanged.

6.2 Coding method

The coding method for the classification of wastewater discharge law uses a juxtaposition code. There is no encoding for each attribute face. The category of the line classification method under each attribute face the code is primarily coded in hierarchical order, but the following categories use special code.

a) The category code with negative meaning is 0. These categories include "intermittent" (discontinuous), "unstable", "irregular";

b) the code for the containment category "other" is 9;

c) The code length of the wastewater discharge law is consistent. Insufficient code length due to thicker classification, supplemented by the English lowercase letter "x".

6.3 Code Structure

In the category code, the category codes classified by the line classification method under each attribute face are arranged in a layer-by-layer order. The code is segmented by different main attribute faces and Set. The code structure of the wastewater discharge law is shown in Figure 1.

Flow stability law code (3 digits) Flow continuity code (1 bit)

Figure 1 code structure diagram

The meaning of each code is shown in Table 1.

Table 1 Wastewater discharge law code meaning table

Code location meaning Whether the first digit is continuous is the second bit stable?

Is the third position regular?

4th place

flow

Special law

Example. A wastewater A has a periodic pattern for flow interruption, the code is 0011; a wastewater B is continuously stable for flow, and its code is 11xx.

7.1 Wastewater Discharge Flow Category Code Table

7.1.1 Wastewater Discharge Flow Continuity Rule Code Table

Table 2 Wastewater Discharge Rule Code Table 1st Bit Code (Flow Continuity)

1st meaning

1 continuous

0 break

7.1.2 Wastewater discharge flow stability law code table

Table 3 Wastewater discharge law code table 2 to 4 bit code (flow stability)

2nd, 3rd, 4th

Code meaning code meaning code meaning 1 stable x - x -1 periodicity 1 regular