As one of the main parameters to judge water pollution, COD has been used in environmental protection, sewage treatment and other industries. Especially in the monitoring of river pollution, the change of organic pollutants in water can be learned in real time through the online COD monitoring system, and corresponding treatment measures can be taken. However, if we want to do a good job in online monitoring of water quality, we should not only ensure the normal operation of instruments and equipment, but also do a good job in supporting construction.
Generally, the online COD water quality detector needs to be transported to the detection point for installation after debugging by the manufacturer, and these works are completed by the manufacturer's technicians. After installation, the most important step is to carry out the corresponding acceptance work. The acceptance mainly includes two types, one is the acceptance of online COD water quality detector, and the other is the acceptance of related supporting construction.
The acceptance of instruments and equipment is mainly about error, accuracy, stability, safety, etc., while the acceptance of related supporting construction is mainly about sampling unit, discharge outlet, station building, flow monitoring, etc.
Today we will introduce the acceptance requirements for sampling units, discharge outlets, station buildings and flow monitoring.
1. Requirements for acceptance of pollution source discharge outlet
The layout of pollution source discharge outlet shall meet the requirements of HJ 91.1.The pollution source discharge outlet shall be provided with environmental protection graphic signboards meeting the requirements of GB/T15562.1.
The pollution source discharge outlet shall be equipped with a sampling port that is convenient for the installation of automatic water quality sampling unit and flow monitoring unit.
The discharge outlet of pollution source shall be set with manual sampling port.
2. Acceptance requirements for flow monitoring unit
The back end of triangular weir and rectangular weir is provided with a dredging platform, which can facilitate the cleaning of the deposits at the back end of the weir slot.The installation place of flowmeter is equipped with a working platform for ultrasonic probe maintenance and comparison, which can facilitate the maintenance and comparison of flowmeter.
All scattered edges of the working platform shall be provided with protective railings, and the empty and high parts of the water intake shall be provided with protective railings and steel platforms,
Each platform edge shall be provided with a device to prevent debris from falling into the water intake.
The installation and construction of maintenance and sampling platforms shall all meet the requirements.
The installation of protective railings shall meet the requirements.
3. Acceptance requirements for monitoring station building
Special room for monitoring station building.The monitoring station is closed, equipped with cooling and heating air conditioners and exhaust fans, and the air conditioners have the function of power on self starting.
The area of the new monitoring station building shall not be less than 15 ㎡, and the height of the station building shall not be less than 2.8m. All instruments and equipment shall be placed reasonably to facilitate maintenance and repair.
The distance between the monitoring station building and the sampling point shall not be greater than 50.
The foundation load strength, area, space height and ground elevation of the monitoring station building meet the requirements.
The monitoring station building is equipped with safe and qualified power distribution equipment, the power load provided is not less than 5kW, and a regulated power supply is provided.
The lighting power supply is used for the power incoming line of the monitoring station: the power incoming line is equipped with surge protector; the power supply should have obvious signs: the grounding wire should be firmly around and have obvious signs.
The power supply of the monitoring station is equipped with a master switch, and each instrument is equipped with an independent control switch.
There are qualified water supply and drainage facilities in the monitoring station building, which can clean the instruments and related devices with self meter water.
The monitoring station building shall be equipped with complete and standardized grounding devices, lightning protection measures, anti-theft, anti vandalism and fire-fighting facilities.
The monitoring station building is not located in the communication blind area, and shall be able to realize data transmission.
Video monitoring shall be provided in the monitoring station building, sampling port and other areas.
4. Acceptance requirements for water quality automatic sampling unit
It realizes the functions of collecting instantaneous water samples and mixed water samples, mixing and temporary storage of water samples, automatic moistening and emptying the mixing barrel.Realize the sample retention function of mixed water sample and instantaneous water sample.
Realize the functions of PH water quality automatic analyzer and thermometer for in-situ measurement or instantaneous water sample measurement.
Realize the function of COD, TOC, NH-N, TP, TN automatic water quality analyzer to measure mixed water samples.
Necessary anti freezing or anti-corrosion facilities shall be provided.
A manual comparison sampling port with mixed water samples is set.
The pipeline of the automatic water quality sampling unit is open pipe, and the water flow direction is marked.
High quality PVC, PPR and other hard pipes that do not affect the analysis results shall be used.
The sampling port is set in the center of the flow path at the head of the water intake of the standardized metering weir (slot) of the flow monitoring system, and the direction of the water intake is consistent with the direction of the water flow: when measuring the confluence drainage, collect water at the place where the water is fully mixed after the confluence.
The selection of sampling pump is reasonable, and the installation position is convenient for pump maintenance.
