Ionic complexation, metal coordination, and physiological stress effects of polyborate

Abstract

Organic agents exhibit efficacy in water quality stabilization, yet entail inherent risks of nitrogen and phosphorus diffusion losses. This work introduces a versatile inorganic polyborate slow-release preparations (PSRPs) agents. The effectiveness of the PSRPs in terms of scale inhibition, corrosion resistance, and antibacterial activity was empirically validated within a simulated cooling station operating at a circulation rate of 6 L/h and 636 L/h. The [BO3] units dissociate from the PSRPs complex with Ca0.8Mg0.2, forming slightly soluble, flocculent complexes. The complexes exhibit flexibility and low adhesiveness, enhancing to settle and separate from aquatic environments. Notably, self-propagating boronizing on carbon steel surfaces is characterized by the coordination of Fe with B and O atoms from polyborates. Such coordination notably hinders the transition of iron into its oxidative and ionic forms. Moreover, the study highlights the significant physiological stress effects exerted by high concentrations of borate salts on algae and bacteria. Under the influence of PSRPs, the deposition of scale decreased from 376.9 g/m2 to 35.3 g/m2, the corrosion rate decreased from 1.60 mm/y to 0.22 mm/y, and the antibacterial efficiency increased to 81.8 %. This work is a significant attempt to develop new multifunctional inorganic water treatment agents.