Dissolution of Microparticles of Cadmium, Lead and Thallium in Water

Anthropogenic activity seriously damages the environment. Cadmium, lead and thallium are toxic elements that are especially hazardous for nature. In polluted air, they are pre-sent in the form of microparticles 2-3 μm in size and belong to the PM2.5 fraction. Such par-ticles can be transported over long distances, penetrate into water and dissolve, and then enter the food chain. This poses a severe threat to human and animal health due to the bioaccumulation of metals. Therefore, it is important to study the properties of toxic met-als of this size. In this work, we developed a radiation-chemical method for obtaining mi-croparticles of cadmium, lead and thallium corresponding to the PM2.5 fraction, and stud-ied their properties in aqueous solutions. In the absence of oxygen, the metals do not dis-solve. Over time, they agglomerate and settle. When exposed to air, the particles quickly dissolve in water, usually within a few minutes. This process involves the disappearance of small particles and a decrease in the size of larger ones. The rate of dissolution increas-es in the Pb-Cd-Tl series. Cadmium dissolves approximately 4-5 times faster than lead, and thallium more than 10 times faster. Acidification of water accelerates this process. Studying the properties of microparticles of heavy metals is important for assessing their migration in the environment, health risks, and developing methods for preventing pollu-tion.