Yongxin Zhang

A bottom-up inventory of atmospheric emissions of five precedent-controlled toxic heavy metals (HMs), including mercury (Hg), arsenic (As), lead (Pb), cadmium (Cd), and chromium (Cr), from primary anthropogenic sources in China is established for the period 2000–2010. Total emissions of HMs demonstrate a gradually ascending trend along with the increase of coal consumption and industrial production, which are estimated at approximately 842.22 t for Hg, 4196.31 t for As, 29272.14 t for Pb, 795.29 t for Cd, and 13715.33 t for Cr for 2010. Coal combustion is found to be the primary source of HMs emissions. Owing to the dramatic differences of coal use by industrial and power sectors among provinces, spatial allocation performs remarkably uneven characteristics, and spatial distribution features are demonstrated by allocating the emissions into 0.5° × 0.5° grid cells with GDP and population as surrogate indexes. Further, HMs emissions from specified anthropogenic sources under three different control scenarios for the target year 2015 are projected, and collaborative and specialized control strategies are proposed to meet the demand of emission reduction goals of different regions. In the future, a whole processes control management system will be the most effective way for control of HMs.

Particulate matter (PM) emitted from stationary sources can be classified into filter particulate matter (FPM) and condensable particulate matter (CPM). Because CPM significantly contributes to total emission, a method and an instrument for testing and measuring CPM were developed on the basis of the principle of dilution and condensation. Then, a parallel sampling analysis of CPM and FPM was carried out at the inlet of a desulfurization system and stack of coal-fired units. Results showed that CPM accounted for 76.73% of the total particulate concentration and the removal efficiencies of FPM and CPM were 94.93 and 65.37%, respectively, after wet flue gas desulfurization (WFGD) and wet electrostatic precipitator (WESP). The microscopic morphology, ion concentration, and organic components of CPM were analyzed. CPM was dispersed after formation, and most of them were smaller than 2.5 μm. The main element components were Al, Ca, Na, Fe, Si, C, O, S, F, and Cl. Na+ was the most abundant metal cation in the CPM sample. The main parts of the inorganic anions were F– and Cl–. C10–C19 and C20–C29 were the main components of the alkanes, while the alkanes above C30 were only 3.93 and 6.29% at the WFGD inlet and WESP outlet, respectively.