Evaluation on speciation and removal efficiencies of mercury from municipal solid waste incinerators.pdf

The Science of the Total Environment 246?. 2000 165?173 Evaluation on speciation and removal ef?ciencies of mercury from municipal solid waste incinerators in Taiwan U Moo Been Chang , Hsiu Tung Wu, Chien Kun Huang Graduate Institute of En¨ironmental Engineering, National Central Uni¨ersity, Chungli, Taiwan 320, PR China Received 6 July 1999; accepted 4 November 1999 Abstract Two large-scale municipal solid waste incinerators?. MWIs located in Taiwan were selected for conducting ?ue gas sampling to determine the chemical speciation of mercury by both USEPA Method 29 and Ontario Hydro Method ?.OHM . In addition, the emission characteristics and removal ef?ciencies of mercury were evaluated via isokinetic sampling of ?ue gas upstream and downstream of APCDs. Results indicated that the average removal ef?ciencies of Hg for MWI-A and MWI-B were 29.56 and 44.70%, respectively. In terms of mercury speciation by USEPA Method 29 and Ontario Hydro Method?. OHM , oxidized mercury ? Hg2q. , in the ?ue gas was predominant at the inlet of APCD for both incinerators. Less than 30% of mercury in the ?ue gas existed in the elemental form? Hg0. at APCD inlet. Mercury emitted from the stack also predominated as a form of Hg2q in MWI-A. Approximately 90% of total mercury emission from the stack existed in the form of Hg2q for MWI-A. Due to the higher removal ef?ciency of soluble mercury? Hg2q. in wet scrubber, less total Hg was actually emitted from MWI-B than MWI-A. Regarding the removal ef?ciency of Hg0 in the ?ue gas, the APCDs of MWI-A?. DSIqFF had a higher removal ef?ciency than that of MWI-B?. ESPqWS possibly due to the reduction of Hg2q which occurred in the wet scrubber. ? 2000 Elsevier Science B.V. All rights reserved. Keywords: MWIs; Ontari