A new analytical method based on Co-Mo nanoparticles supported by carbon nanotubes for removal of mercury vapor from the air by the amalgamation of solid-phase air removal

Abstract

Heavy metals are a major cause of environmental pollution, and mercury is a well-known toxicant that is extremely harmful to the environment and human health. In this study, new carbon nanotubes coated with cobalt and molybdenum nanoparticles (Co-Mo/MWCNT) were used for Hg0 removal from the air by the amalgamation of solid-phase air removal method (ASPAR). In the bench-scale setup, the mercury vapor in air composition was produced by the mercury vapor generation system (HgGS) and restored in a polyethylene airbag . In optimized conditions, the mercury vapor in the airbag passed through Co-Mo/MWCNT and was absorbed on it. Then, the mercury was completely desorbed from Co-Mo/MWCNT by increasing temperature up to 220 °C and online determined by cold vapor atomic absorption spectrometry (CV-AAS). The recovery and capacity of Co-Mo/MWCNT were obtained at 98% and 191.3 mg g-1, respectively. The Repeatability of the method was 32 times. The mercury vapors absorbed on Co-Mo/MWCNT adsorbent could be maintained at 7 days at the refrigerator temperature. The Co-Mo/MWCNT as a sorbent has many advantages such as; high capacity, renewable, good repeatability and chemical adsorption (amalgamation) of mercury removal from the air. The method was successfully validated by MCA and spiking of real samples.