Page 26 - Air Pollution Control Engineering

01_chap_wang.qxd 05/05/2004 11:45 am Page 7
Air Quality and Pollution Control 7

Fig. 2. Bimodal mass distribution of flue gas dust from a chain grate boiler.

given in Table 1. The parts per million values are by volume and are calculated from the
mass per unit volume for the specific chemical substance noted.
The Federal Clean Air Act (CAA) has been amended periodically in an attempt to
adjust the law to current needs when economic and technological feasibility factors
are considered. Table 1 includes some of the modifications from the original standards.
Other standards on ambient air have been set to limit the amount of ambient air