Eco-friendly bifunctional scale inhibitor for mixed scale control: synthesis, efficiency and mechanism

• T.X. Yang¹, S.Q. Bai¹, S.X. Chen², W.H. Sun¹, G.J. Zhao¹ and M.J. Zhou¹

¹ Green Intelligence Environmental School, Yangtze Normal University, No. 16 Juxian Road, Fuling, Chongqing, 408100, China
² Faculty of Agriculture, Life, and Environmental Sciences, Zhejiang University, No. 866 Yuhangtang Road, Xihu, Hangzhou, 310058, China

Abstract: The formation of mineral scale poses a serious challenge in industrial water systems, leading to reduced operational efficiency and substantial economic losses. Currently, scale inhibitors are the most effective method for scale control, and the pursuit of environmentally friendly and efficient scale inhibitors is crucial. Herein, a high-performance, nitrogen/phosphorus-free, biodegradable scale inhibitor with dual functions of corrosion inhibition and scale prevention, namely modified poly-epoxysuccinic acid (PESA-GA), was synthesized by grafting gallic acid (GA) onto the poly-epoxysuccinic acid (PESA) backbone. The functional groups, chemical structure and molecular mass of PESA-GA were characterized using FT-IR spectroscopy, ¹³C NMR spectroscopy and viscosity measurements. The environmental compatibility, corrosion inhibition and scale inhibition efficacy were assessed through biodegradation analysis, weight loss measurements, and scale inhibition tests. The results indicated that approximately six GA units were incorporated per PESA molecule. The biodegradation half-life of PESA-GA was 7.15 days, extending beyond that of PESA by 0.81 days, facilitating long-term scale inhibition. Compared with PESA, the corrosion inhibition performance was significantly enhanced to 96.05%, representing approximately a 2-fold increase relative to the pre-modification level. The scale inhibition efficiencies for mixed scales composed of CaCO₃, CaSiO₃, and nSiO₂·mH₂O increased by 20.00%, 26.69%, and 22.93%, respectively, highlighting the significantly enhanced performance. PESA-GA primarily inhibits scale formation by adsorbing onto nanosized particles in solution, thereby impairing their capacity to serve as nucleation templates for scale deposition. The results of this study provide practical evidence for developing environmentally friendly scale inhibitors, preventing scaling, conserving water and energy, and reducing carbon emissions.

Keywords: green scale inhibitor, mixed scale, corrosive inhibitor, scale inhibitor, inhibition mechanism

Int. J. Corros. Scale Inhib., 2026, 15, no. 4, 230-252
doi: 10.17675/2305-6894-2026-15-4-9

Download PDF (Total downloads: 66)

Back to this issue content: 2026, Vol. 15, Issue 4 (pp. 1-... (in progress))