Nitrate Nitrogen Detection in Sewage & ST-800 Series Full-Spectrum Nitrate Sensor

        The nitrogen sources in domestic sewage are generally organic nitrogen and ammonia nitrogen, while the content of nitrate nitrogen (NO3-N) is very low. However, the nitrification process in sewage treatment technology will increase the nitrate nitrogen content in the effluent. Since the presence of nitrate nitrogen affects phosphorus removal efficiency and total nitrogen discharge, determining the nitrate nitrogen content in sewage is of great significance for sewage treatment plants.

        By adopting advanced full-spectrum technology and high-precision ultraviolet absorption method, the ST-800 Series Full-Spectrum Nitrate Sensor has been developed. This sensor uses a stable light source covering the ultraviolet-visible spectral range of 200–550 nm, and can be equipped with sensors of different optical path lengths for nitrate nitrogen measurement. During measurement: water samples flow through the measurement channel; the sensor’s light source emits light that passes through a lens into the channel; the target substance (nitrate nitrogen) in the water absorbs part of the light; the unabsorbed light is reflected back to the sensor’s detector via a mirror on the other side of the channel. This completes the optical measurement of nitrate nitrogen, and the built-in transmitter calculates the nitrate nitrogen concentration.

        The ST-800 Series Full-Spectrum Sensor can continuously measure nitrate nitrogen concentration in water online. It is suitable for nitrate nitrogen measurement in fields such as sewage, surface water, and industrial water—especially in sewage treatment, it can perform real-time online measurement of nitrate nitrogen in aeration tanks when controlling the denitrification process.

        The ST-800 Series Full-Spectrum Sensor is equipped with a built-in brush-type self-cleaning device, which can periodically clean the detection surface. This extends the sensor’s service life and makes it widely applicable to various harsh water quality conditions.

Typical Applications

        On-site applications including sewage, surface water, industrial water, groundwater, pipe networks, and sponge cities—used for influent pollutant monitoring, in-process treatment monitoring, and effluent monitoring.

Instrument Features

• The world’s first reflective full-spectrum technology, covering the ultraviolet-visible spectral range (200–550 nm).

• Optical measurement: no reagent consumption, simple and convenient installation and maintenance.

• Equipped with AI intelligent algorithm capability: broad-spectrum scanning and AI calculation enable continuous improvement of measurement accuracy during use.

• Customizable multi-parameter measurement: NO3-N (nitrate nitrogen), nitrite, CODeq (equivalent chemical oxygen demand), TOCeq (equivalent total organic carbon), BODeq (equivalent biochemical oxygen demand), DOCeq (equivalent dissolved organic carbon), SAC254 (specific absorbance at 254 nm), TSSeq (equivalent total suspended solids), etc.

• Standard integrated self-cleaning device: regular self-cleaning ensures long-term stable operation.

• Built-in transmitter: no preamplifier or display unit required, directly outputting isolated RS485 and 4-20mA signals for more stable and accurate long-distance transmission.

• Calibration, data logging, and diagnostics can be performed on a PC or smartphone via a Bluetooth/USB adapter.

• Undergoes pressurized aging test and pre-calibration before delivery to ensure the sensor is stable and reliable.