Comparison of Ammonia Nitrogen Determination Methods and Application of NiuBoL Online Ammonium Nitrogen Sensor in Engineering Monitoring

Project Background and Industrial Application Requirements

Ammonia nitrogen is one of the important indicators for evaluating the degree of water pollution. It refers to nitrogen existing in water in the form of free ammonia (NH3) and ammonium ions (NH4+). In sewage treatment plant acceptance, aquaculture process control, and industrial wastewater discharge management, ammonia nitrogen concentration directly affects process regulation and compliant discharge.

Traditional laboratory ammonia nitrogen determination methods include Nessler's reagent spectrophotometry, salicylic acid-hypochlorite spectrophotometry, titration method, gas phase molecular absorption spectrometry, and ammonia gas-sensitive electrode method. These methods can meet the needs of offline analysis in terms of accuracy, but they have problems such as sampling lag, complex operation, high reagent consumption, and inability to achieve continuous monitoring. When building real-time water quality monitoring systems, system integrators need an online detection device with fast response, low maintenance, and standardized communication to achieve data collection, threshold alarming, and linkage control.

The NBL-WQ-NHN online ammonium nitrogen sensor directly measures ammonium ion content through the ion selective electrode method, combined with Pt1000 temperature compensation. It can quickly respond to concentration changes and provide stable and reliable process data support for engineering projects, reducing the frequency of manual sampling and lowering overall operation and maintenance costs.

Position of NBL-WQ-NHN Online Ammonium Nitrogen Sensor Products in the System

As a core device at the front-end perception layer, the NBL-WQ-NHN is mainly installed at key monitoring points such as biochemical tanks in sewage treatment, regulating tanks, aquaculture ponds, or discharge outlets. Together with multi-parameter water quality monitoring systems, PLC control units, and SCADA platforms, it forms a complete monitoring network. Real-time ammonium nitrogen data can be used for aeration volume regulation, carbon source dosing control, or emergency water exchange decisions, forming a closed-loop water quality management system.

The sensor adopts an integrated design with IP68 protection rating, adapting to long-term immersion conditions. The shell material ABS, PVC, and POM provides good corrosion resistance, suitable for deployment in complex water quality environments.

Communication and Protocol Compatibility

The sensor comes standard with an RS-485 interface and adopts the Modbus RTU protocol, supporting direct connection with industrial control systems:

• Compatible with mainstream PLC such as Siemens, Schneider, and Omron.

• Can be connected to various RTU, IoT gateways, and paperless recorders.

• Supports optional 4-20mA analog output to meet different automation system requirements.

• Multiple sensors (ammonium nitrogen, pH, dissolved oxygen, etc.) can be mounted on a single bus, simplifying wiring and integration work.

The standardized communication protocol ensures high system compatibility and strong scalability, with anti-interference capability meeting industrial site requirements, significantly shortening project debugging cycles.

NBL-WQ-NHN Online Ammonium Nitrogen Sensor Technical Parameters

NBL-WQ-NHN Online Ammonium Nitrogen Sensor Application Scenarios

1. Sewage Treatment Plant Process Control: Deployed at aeration tank and secondary sedimentation tank outlets to monitor ammonia nitrogen removal efficiency in real time, supporting parameter optimization of A/O, A2/O and other processes, and assisting compliant discharge management.

2. Aquaculture Pond Water Quality Management: Continuously track ammonia nitrogen concentration changes in fish, shrimp, and crab breeding ponds. Combined with pH and temperature data to assess non-ionic ammonia toxicity risk, guiding feeding volume adjustment and microbial agent use.

3. Industrial Wastewater Treatment and Circulating Water Systems: Suitable for wastewater treatment stations in chemical, pharmaceutical, electroplating and other industries, as well as factory recirculating aquaculture systems (RAS), realizing online monitoring of high-concentration ammonia nitrogen and linkage control of treatment units.

Selection Guide

Accuracy Selection: For conventional aquaculture and secondary sewage treatment, the 0～10 mg/L or 0～100 mg/L range is recommended. The 0.01 mg/L resolution can meet most process monitoring needs. For high-concentration industrial wastewater scenarios, select the 0～1000 mg/L range. Accuracy indicators are suitable for engineering control rather than precision metering. Regular calibration can maintain long-term stability.

Communication Method Selection: Prioritize the RS-485 Modbus RTU version for easy large-scale networking and PLC integration. For existing analog systems, the 4-20mA output configuration can be selected.

Installation Environment Selection: Use 3/4 NPT pipe thread for submersible installation. The installation angle must be tilted more than 15 degrees to avoid horizontal or inverted placement. When selecting points, avoid strong disturbance areas and bottom sediment layers. It is recommended to equip protective structures to extend service life.

Power Supply Selection: 12～24V DC wide voltage range, adapting to different on-site power conditions. The low power consumption design is convenient for off-grid monitoring stations powered by solar energy.

System Integration Precautions

• Before first use, remove the protective cover and soak in clean water for activation for 2 hours, then perform two-point calibration.

• RS-485 bus wiring should use shielded twisted pair cables with correct grounding and reasonable address settings to avoid conflicts.

• Regularly check sediment on the electrode surface and clean with deionized water. Avoid long-term immersion in distilled water or contact with silicone grease.

• Apply waterproof treatment to installation wiring points and ensure cables have anti-corrosion capability.

• Data collection frequency is recommended to be 1-5 minutes, flexibly adjusted according to process control requirements.

• Replace the electrode promptly when it fails. When not in use for a long time, store dry and put on the protective cap.

FAQ

Technical Questions

Q1: Does the sensor measure total ammonia nitrogen or non-ionic ammonia?

It measures ammonium ion (NH4+) content in water, i.e., the main form of total ammonia nitrogen (TAN). Combined with on-site pH and temperature, the non-ionic ammonia ratio can be calculated.

Q2: What are the differences between the ion selective electrode method and the traditional Nessler's reagent method?

The online electrode method requires no chemical reagents, enables continuous measurement, and has a short response time, making it more suitable for process control; while the Nessler's method is a laboratory offline analysis method.

Q3: How are temperature and pH effects on measurement results handled?

It has built-in Pt1000 automatic temperature compensation. The working pH range is 4～10. It is recommended to monitor pH simultaneously in actual applications to further improve data accuracy.

Selection Questions

Q1: How to choose different ranges?

For aquaculture and low-concentration sewage monitoring, prioritize 0-10 or 0-100 mg/L range. For high-concentration industrial wastewater, select 0-1000 mg/L range.

Q2: How does the IP68 protection rating perform in actual applications?

Under conventional water quality conditions, combined with appropriate maintenance, long-term stable operation can be achieved.

Q3: Does it support mixed networking with sensors from other manufacturers?

As long as the master station supports Modbus RTU protocol, it can be connected, with good compatibility.

Procurement/Project Questions

Q1: Can cable length and connector be customized?

Yes. Lengths beyond 5 meters can be customized. Standard M16-5 core waterproof connector male head.

Q2: What technical support is available for bulk project procurement?

Communication protocol documents, installation guidance, and debugging support can be provided.

Summary

Ammonia nitrogen determination methods are diverse. Laboratory spectrophotometry, titration, etc., are suitable for precise analysis, while online ammonium nitrogen sensors are more suitable for engineering scenarios requiring continuous monitoring. NiuBoL NBL-WQ-NHN combines the ion selective electrode method with industrial-grade design, providing system integrators with a stable, easy-to-integrate, and open-protocol solution that helps build reliable water quality monitoring and control systems.

In engineering procurement decisions, it is recommended to conduct on-site verification based on specific water quality characteristics, control objectives, and existing automation architecture to ensure the sensor delivers sustained value throughout the project lifecycle.

NBL-WQ-NHN Online Ammonia Nitrogen Sensor Data Sheet

NBL-WQ-NHN-4S Online Ammonia Nitrogen Sensor.pdf

NBL-WQ-NHN-4 online ammonium nitrogen sensor.pdf

NBL-WQ-NHN Ammonia Nitrogen Water Quality Sensor.pdf