Functional pH-neutralizing beads designed for strong acid/base spill responses

Abstract

Neutralizers are often used to neutralize the spill in strong acid/base spillage accidents. However, current neutralizers exhibit extremely high neutralization rates, making it difficult to control the spill pH; further, a high heat of neutralization and hazardous gases are generated. The residual neutralizer also contributes to environmental pollution. To address these problems, we developed a novel functional pH-neutralizing bead. This bead was prepared by mixing mesoporous alumina, magnetic nanoparticles, and a sodium alginate hydrogel, and subsequently impregnating neutralizing agents in the bead pores. The developed beads could slowly release the neutralizing agent, thereby improving control of the neutralization rate and minimizing the generation of hazardous gases and the heat of neutralization. Furthermore, the magnetic nanoparticles in the beads retained their magnetism even after the addition of neutralizing acids or bases with a 5 M concentration; moreover, the neutralizing beads could be effortlessly recovered using a magnet. Thus, compared with the currently used neutralizers, the use of functional pH-neutralizing beads may mitigate the potential hazards and environmental pollution caused during acid/base spillage accidents.