A novel fluorescent-tagged polycarboxylic scale inhibitor: design, synthesis and application

Facing the hazards of equipment scaling, adding scale inhibitor is an effective and feasible method. Precise control of the dosage of water treatment agents is crucial for the treatment effect. By synthesizing a fluorescent tracer scale inhibitor, it is possible not only to utilize its scale inhibition performance but also to monitor and control the concentration of the scale inhibitor in circulating cooling water in real-time using its fluorescent properties. However, the lack of dynamic properties of fluorescent scale inhibitors is an important factor limiting their large-scale application. Therefore, a uniquely designed fluorescent-tagged scale inhibitor, named SG-AGE-AA/AMPS, was synthesized. It is composed of sodium 8-(3-(allyloxy)-2-hydroxypropoxy)pyrene-1,3,6-trisulfonate, acrylic acid, and 2-acrylamido-2-methylpropane sulfonic acid. The structural characteristics of SG-AGE and SG-AGE-AA/AMPS were confirmed using Fourier Transform Infrared Spectroscopy (FT-IR). Studies have shown that SG-AGE-AA/AMPS possesses both good scale inhibition and fluorescent properties. At a concentration of 20 mg/L, SG-AGE-AA/AMPS achieved a scale inhibition rate of 63% for CaCO3, with its fluorescence intensity exhibiting a good linear relationship with dosage (correlation coefficient R2 = 0.9986). The detection limit of SG-AGE-AA/AMPS was 0.79 mg/L. Dynamic simulation experiments of circulating cooling water indicated that SG-AGE-AA/AMPS demonstrated excellent dynamic scale inhibition and tracing performance. Additionally, fluorescent tracer technology provides a research idea for the automatic control of circulating water system and the prediction of scale.