Control of mercury pollution

Abstract

When a ²⁰³Hg(NO₃)₂ solution was kept at 25°C in glass or polypropylene containers, 50 and 80% of original radioactivity was adsorbed to the containers’ walls after I and 4 days, respectively. However, no loss in radioactivity was observed if the solution was supplemented with HgCl₂ as carrier (100 μg Hg²⁺/ml) and stored in either container for 13 days. When ²⁰³Hg²⁺ was dissolved in glucose basal salt broth with added carrier, levels of ²⁰³Hg²⁺ in solution (kept in glass) decreased to 80 and 70% of original after 1 and 5 days and decreased even more if stored in polypropylene (60 and 40% of original activity after 1 and 4 days, respectively). In the absence of carrier, decreases of ²⁰³Hg²⁺ activities in media stored in either container were more pronounced due to chemisorption (but) not diffusion. The following factors affecting the removal of mercurials from aqueous solution stored in glass were examined: type and concentration of adsorbent (fiber glass and rubber powder); pH; pretreatment of the rubber; and the form of mercury used. Rubber was equally effective in the adsorption of organic and inorganic mercury. The pH of the aqueous ²⁰³Hg²⁺ solution was not a critical factor in the rate of adsorption of mercury by the rubber. In addition, the effect of soaking the rubber in water for 18 hr did not show any statistical difference when compared with nontreated rubber. It can be concluded that rubber is a very effective adsorbent of mercury and, thus, can be used as a simple method for control of mercury pollution.