| Popis: |
Large quantities of mercury (Hg) have been placed in municipal landfills from a wide array of sources, including fluorescent lights, batteries, electrical switches, thermometers, and general waste. Despite its known volatility, persistence, and toxicity in the environment, the fate of this Hg has not been widely studied. Using automated flux chambers and atmospheric sampling, we quantified the primary pathways of Hg vapor releases to the atmosphere at two municipal landfill operations in south Florida for eight days in April 1997. These pathways included landfill gas (LFG) releases from passive and active vent systems, passive emissions from landfill surface covers of different ages (including CH4 “hot spots”), and emissions from daily activities at a working face (WF). Hg vapor was released to the atmosphere at readily detectable rates from all sources measured. Emission rates ranged from ~1 to 20 ng m-2 hr-1 over aged surface covers (generally comparable to background soils), from ~6 to 2400 ng... |
