For the purpose of solving the problem of corrosion and scaling of the industrial circulating cooling water system, the biodegradable materials such as carboxyethylthiosuccinic acid (CETSA), acrylic acid - 2 - acrylamide - 2 - methylpropanesulfonic acid copolymer (AA/AMPS), polyepoxysuccinic acid (PESA), 2 - phosphonobutane - 1,2,4 - Tricarboxylic acid (PBTCA), sodium lauroyl sarcosinate (LS) and methylbenzotriazole sodium salt (TTA - Na), as well as zinc sulfate heptahydrate were used as components to compound composite scale and corrosion inhibitors. Meanwhile, the corrosion and scale inhibition properties of inhibitors were tested according to GB/T 16632-2008 and GB/T 18175-2014. Results showed that the optimized formula of scale and corrosion inhibitors was 10 mg/L CETSA, 14 mg/L AA/AMPS, 20 mg /L PESA, 4 mg/L PBTCA, 10 mg/L LS, 10 mg/L TTA - Na and 1 mg/L ZnSO4·7H2O (calculated using the content of Zn2+). In the case of the optimal inhibitor, the scale inhibition rate was 96.35%, the corrosion rate was 0.007 2 mm/a, the corrosi on inhibit ion rate was 99.68%, and the corrosion and scale inhibition performances were good and environment - friendly. Moreover, the electrochemical test results showed that the composite scale and corrosion inhibitor was a cathode type corrosion inhibitor. The SEM observation revealed that the composite scale and corrosion inhibitor could form a protective film on the surface of carbon steel, which could be adsorbed on the calcium carbonate crystals to suppress their development.
