Biological oxygen consumption respiration meter

Biological oxygen consumption respiration meter

The ASP Con (activated sludge plant controller) instrument is a monitoring system used in wastewater treatment plants that can automatically clean, calibrate, and measure multiple parameters. These data include the respiration rate curve of activated sludge activity indicators; Can provide continuous monitoring data, such as dissolved oxygen pH、MLSS、SVI、 Potassium and ammonia nitrogen, etc.

Dissolved oxygen is a key parameter that affects the effluent quality and operational energy consumption of wastewater treatment plants. The biggest innovation of ASP Con technology is the establishment of a dissolved oxygen control system based on respiration rate. ASP Con can be used as an independent monitoring system for data analysis or directly connected to the control system (such as PLC) of the wastewater treatment plant for dynamic optimization and control, thereby achieving better effluent quality and saving aeration costs.

■Oxygen consumption rateBiological oxygen consumption respiration meter

ASP Con measures 16 different parameters, including 12 direct parameters and 4 indirect parameters:

■ ControlOptimization system for aeration in sewage treatment plant

If you want ASP Con to be at a running level, you need to go throughsewage treatment plantThe PLC/SCADA system accepts real-time monitoring data input from ASP Con for controlProcess parameters of sewage treatment plant.

ASP Con installed in the aeration system of sewage treatment plantscenterLocation, convenient for obtaining samples of activated sludge mixture, and analyzing the following data on the basis of continuous operation:

■ Aeration optimization

• Aeration tank control area division: According to the process flow and control requirements of the sewage treatment plant, the aeration tank is divided into relatively independent control areas for the convenience of instrument layout and control scheme formulation.

• Aeration optimization ASP Con instrument installation: Determine the instrument type, quantity, and installation location based on the parameter requirements to achieve the control objectives of each functional area.

• Aeration optimization mechanism: Determine the pollutant load and actual treatment capacity of the influent based on the changes in OUR of the aeration tank, and then adjust the dissolved oxygen control level of the aeration tank. This can be determined through data analysis using ASP Con software.

• Construction of aeration optimization system: By using PLC/SCADA to calculate and analyze the data collected on site and ASP Con software data, the parameters that meet the process control requirements are obtained, and the operation of each control equipment is guided. For the renovation project, establish a system parallel to the current control platform. During the construction process, the existing system can operate normally, and the two control systems can be flexibly switched to fully ensure the safe operation of the sewage treatment plant.

• During the process of inputting real-time monitoring data from ASP Con into the sewage treatment plant, the control system PLC/SCADA software can be modified, or our provided software can be used to optimize the parameters of the aeration tank operation by combining the monitoring data with the process flow settings, in order to achieve better effluent quality and save aeration costs in the sewage treatment plant..

■Installation location

According to the process control parameters and monitoring requirements of the sewage treatment plant, it is recommended to install the ASP Con instrument at three locations in the sewage treatment plant:

•In the entrance area of sewage treatment plant structures, it can reflect the inflow situation and serve as a feedforward control sensor, such as detecting whether there is high concentration of ammonia nitrogen. If there is, additional aeration is required and the set point is automatically adjusted as needed.

•As an independent system, ASP Con is installed at the center of the aeration tank to ensure a reasonable dissolved oxygen concentration in the tank and to control the aeration process in the sewage treatment plant.

•Installing ASP Con at the outlet of sewage plant structures can reflect the effluent effect and automatically adjust the setting values of various parameters based on the results.

■energy saving

The application case study and actual operation of ASP Con show that energy consumption can be reduced by 15-40%. By using ASP Con software to obtain the respiratory rate curve analysis, it was found that the oxygen transfer efficiency is highest at lower oxygen concentrations, and the required for organic matter biodegradation was analyzedCarbonization critical oxygen concentrationandThe critical oxygen concentration for nitrification is used to obtain a reasonable dissolved oxygen setting range and stable dissolved oxygen control for the aeration tank, resulting in better effluent quality and cost savings for the sewage treatment plantcanConsumption.ASP-ConCase study of respiratory rate curve graph and network connection graphas shown in the figure below.

■technical parameters

ASP Con parameter priority list and tolerance

•Level 1 is a key parameter for equipment control that can be accurately measured.

•Level 2 is an important parameter of the equipment that can be accurately measured.

•Level 3 is an important parameter of the equipment that can be measured accurately.

■Electrodes and sensorsprocess

ASP Con has two dissolved oxygen electrodes and two independent potassium electrodesandammonianitrogenISE electrode, a solid-state measurement sensor, and a pH sensor for testing.

■ Built in dissolved oxygen electrode

Used to measure the respiration rate of captured sludge mixture samples. Based on the location of the instrument, measurements can be taken to determine:

•Inlet load (at the inlet)

•Processing level (located at further processing position)

The sample is taken out from the aeration tank and vibrated in the internal seal. The sealing device is equipped with an independent and efficient aeration device, which provides sufficient dissolved oxygen concentration during the breathing process

•Oxygen consumption rate (OUR)

•Carbonization critical dissolved oxygen

•Nitrification critical dissolved oxygen

•Nitrification degree (%)

Once the dissolved oxygen concentration is sufficiently increased and aeration is turned off, the oxygen consumption rate OUR in the measuring device will decline. This is displayed as an OUR measurement value. After the end of breathing, the internal sample of the instrument will become zero dissolved oxygen, and then the built-in dissolved oxygen electrode can be used for zero calibration.

In the later stage of the instrument operation cycle, the built-in dissolved oxygen electrode will be lifted into the air and complete the highest value calibration. During this process, the dissolved oxygen electrode is wiped clean, so we now have an automatically calibrated and cleaned dissolved oxygen electrode.

External dissolved oxygen electrode

The external dissolved oxygen electrode is always located in the mixed solution. RunAfter a certain period of time, wash the leaves and perform automatic cleaning; It is immersed in a mixed solution with the built-in dissolved oxygen electrode (as previously described * clean calibration). Adjust the calibration curve of the external dissolved oxygen electrode to match the reading of the internal dissolved oxygen electrode.

The dissolved oxygen electrode can be replaced. The lifespan of dissolved oxygen electrodes depends on the number of cycles set. The general lifespan range is 6 to 12 months.

Solid state sensors

The sensor is located at the discharge outlet and placed in the mixed liquid sample to monitor respiratory movement. It has two sensor groups, which means it can accurately measure high concentration mixtures (1000mg/l-20000mg/l) and low concentrations (0-100mg/l).

When the collected sample has not undergone precipitation treatment, the sensor will measure the MLSS concentration or the amount of microorganisms in the system.

After the sample is left to stand for 30 minutes, the system will first measure the TSS in the supernatant, and then measure the solid concentration of the precipitate (RAS).

Ammonia nitrogen, pH, and potassium ion electrodes

These ion selective electrodes are installed on the external piston of the measuring device. The electrode is spherical in shape and easy to replace. Simply release the fixing clip and slide out the electrode.

When the piston is lifted to the calibration position, all electrodes and sensors are automatically cleaned. The calibration solution comes from the standard reservoir, and as long as the calibration solution is filled, the cleaning and calibration process is automatic.

PT100 temperature sensor

Provide operationstemperature datainformation

■Engineering Case

ASP Con applied to the treatment of wastewater from a paper mill in the UK to study the effluent situation of paper mill wastewater. ASP Con provides real-time online monitoring of wastewater discharge from paper mills. The data analyzed by ASP Con software is shown in the following figure:

■Appendix

ASP Con electric or manual winch accessories and lifting installation diagram: