(1) Chelation. Part of the active groups in the scale inhibitor have a certain chelating force on the scaling cations, and chelation occurs. Therefore, the addition of PESA can block some scaling cations, inhibit their reaction with anions, and thus prevent scaling.

(2) Low dose effect. Adding a much lower concentration of cations compared to the scaling components in water can inhibit a large amount of scaling

The crystallization effect of ions and the demonstrated scale inhibition effect. This is because in supersaturated solutions, there are a large number of small crystal scales smaller than the critical radius. Due to the special adsorption ability of the added scale inhibitors on the crystal nuclei and active points in the small crystals, they can be adsorbed on them through physical or chemical reactions, greatly increasing the interface energy. The higher the interface energy, the larger the critical radius of the crystal, and the more difficult it is for the small crystals to precipitate from water, thus achieving a macroscopic low-dose effect.

(3) Lattice distortion effect. During crystal growth, the lattice first grows at the twisted position of the crystal, which is a stable position at the crystal interface. When the solution is supersaturated, the probability of slightly soluble salt molecules reaching the twisted position is high, so the crystal can grow normally; When there is a scale inhibitor in the solution, it will adsorb at the twisted position of the crystal, occupying the normal lattice position for crystal growth, inhibiting the regular growth of the crystal, thereby greatly disrupting the regularity of the crystal and causing lattice deformation. Due to the irregular shape of distorted crystals, it is difficult to form hard scale blocks through ordered and tightly arranged arrangements. Even if scale blocks are formed, they can only be loose soft scale, thus achieving the purpose of scale inhibition.