Online Residual Chlorine Sensor for Seafood Processing Wastewater Treatment

DCL2.2 Residual Sensor

A medium-sized seafood processing plant generates approximately 500 m³ of wastewater per day from the processing of shellfish and fish products. After preliminary treatment, including screening and oil removal, sodium hypochlorite (NaOCl) is dosed for disinfection before biological treatment.

To ensure regulatory compliance and protect downstream biological processes, the plant needed to maintain residual chlorine levels within a controlled range. Due to the high salinity of the wastewater (6–9%) and continuous operation requirements, reliable online monitoring was essential.

Solution
DABECO recommended the DCL2.2MA20-M12 Residual Chlorine Sensor for real-time monitoring of disinfected wastewater.

Key advantages include:

Measurement range: 0.05–20.00 ppm

High-resolution monitoring: 0.01 ppm

Suitable for high-salinity water and seawater applications

Stable operation in industrial wastewater environments

Standard 4–20 mA output for easy PLC integration

IP68 protection for harsh and humid conditions

Results
After more than 6 months of continuous operation, the sensor delivered stable and reliable performance:

Residual chlorine maintained within the target range of 0.4–1.9 ppm

Excellent agreement with laboratory DPD testing

Stable sensor output with minimal drift

Reliable operation despite seasonal temperature and salinity variations

Reduced maintenance requirements and improved process control

Customer Benefits
By implementing the DCL2.2MA20-M12, the seafood processing plant achieved:

✔ Continuous residual chlorine monitoring

✔ Improved disinfection control

✔ Protection of biological treatment efficiency

✔ Regulatory compliance for wastewater discharge

✔ Reduced operational and maintenance costs

Product Used: DCL2.2MA20-M12 Residual Chlorine Sensor