Abstract. East Asia contributes to nearly 50% of the global anthropogenic mercury emissions into the atmosphere. Recently, there have been concerns about the long-range transport of mercury from East Asia, which may lead to enhanced dry and wet depositions in other regions. In this study, we performed four monthly simulations (January, April, July and October in 2005) using CMAQ-Hg v4.6 for a number of emission inventory scenarios in an East Asian model domain. Coupled with mass balance analyses, the chemical transport of mercury in East Asia and the resulted mercury emission outflow were investigated. The total annual mercury deposition in the region was estimated to be 821 Mg, with 396 Mg contributed by wet deposition and 425 Mg by dry deposition. Anthropogenic emissions were responsible for most of the estimated deposition (75%). The deposition caused by emissions from natural sources was less important (25%). Regional mercury transport budgets showed strong seasonal variability, with a net removal of RGM (7-15 Mg month −1 ) and PHg (13-21 Mg month −1 ) in the domain, and a net export of GEM (60-130 Mg month −1 ) from the domain. The outflow caused by East Asian emissions (anthropogenic plus natural) was estimated to be in the range of 1369-1671 Mg yr −1 , of which 50-60% was caused by emissions from natural sources. The emission outflow repCorrespondence to: C.-J. Lin (jerry.lin@lamar.edu) resented about 75% of the total mercury emissions in the region, and would contribute to 20-30% of mercury deposition in remote receptors.

Abstract. East Asia contributes nearly 50% of the global anthropogenic mercury emissions into the atmosphere. Recently, there are concerns for the long-range transport of mercury from East Asia to North America, which may lead to enhanced dry and wet depositions in North America. In this study, we performed four monthly simulations (January, April, July and October in 2005) using CMAQ-Hg v4.6 in an East Asian model domain. Coupled with a mass balance analysis and a number of emission inventory scenarios, the chemical transport of atmospheric mercury, the seasonal mercury transport budgets and mercury emission outflow from the East Asian region were investigated. The total annual mercury deposition in the region for the modeling year is estimated to be 821 Mg, with 396 Mg contributed by wet deposition and 425 Mg contributed by dry deposition. Regional mercury transport budgets show strong seasonal variability, with a net removal of RGM (7~5 Mg mo−1) and PHg (13~21 Mg mo−1), and a net export of GEM (60~130 Mg mo−1) from the study domain. The annual outflow caused by the East Asian emission is estimated to be in the range of 1369~1671 Mg yr−1, primarily in the form of GEM. This represents about 75% of the total mercury emissions (anthropogenic and natural) in the region. The emission outflow from this source region would contribute to 20~30% of mercury deposition in areas remote from anthropogenic emission sources.

The emission of toxic metals during the incineration of solid wastes containing metals presents potential environmental and health hazards. Some of the metals in the effluent gases are of submicron size which conventional air pollution control devices may not always effectively collect. One of the alternative control technologies for heavy metal emissions is to use sorbents to capture metals through various mechanisms during incineration. Of the available incineration systems, the fluidized bed incinerator appears to be suitable for this purpose.The objective of this work was to experimentally study the characteristics of metal capture by various bed sorbents during fluidized bed incineration of wastes containing lead chloride. Experiments were carried out in a 76.2 mm ID fluidized bed of sand, limestone and aluminum oxide. Combustible test materials contaminated with lead chlorides were incinerated in the bed with different sorbents under different incineration conditions. The observed results indicated that the metal capture process is highly promising.Capture efficiency was observed to range from 4.9% to 94.5% depending on sorbent type and incinerator operating conditions. NOTATION a average particle diameter, mm P" vapor pressure, mm Hg Pb, lead concentration in agglomerated sorbent cluster, ppm Pb, lead concentration in incinerated bed sorbent, ppm Pb, lead concentration in original sorbent, ppm Ph, lead concentration in test wood, ppm T Incinerator temperature,°C U superficial velocity, cm/sec w" mass of collected agglomerated sorbent cluster, g w" mass of collected incinerated bed sorbent, g Iv, mass of original sorbent, g w,.. mass of test wood, g 1jJ. percent metal capture by agglomerated sorbent cluster IjJb percent metal capture by bed sorbent IjJj percent metal capture by cyclone ash IjJr total percent metal capture by sorbent c/J specific capture capacity, Ilg/g p density, g/cm 3

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