10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
A PPWD-SDEP-IC System for Hourly Measurements of Ambient PM2.5 Inorganic Ions and Precursor Gases
CHI-YU TIEN, Chao-Ting Hsu, Ssu-Yin Lai, Yung-Chen Chiang, Chuen-Jinn Tsai, National Chiao Tung University
Abstract Number: 139 Working Group: Instrumentation
Abstract A 2-stage Semi-Dry Electrostatic Precipitator (SDEP) was developed and integrated with the parallel plate wet denuder (PPWD) and IC as a PPWD-SDEP-IC system for hourly monitoring of PM2.5 inorganic ions and precursor gases measurement. Carbon fiber bundles are used as the discharge electrodes in the first stage to lower the background concentrations of NH4+ and NO3- which are artifacts due to corona discharge of the traditional EP. The second stage of the SDEP is to collect charged particles in the electric field. The SDEP has the particle collection efficiency as high as 93-100 % for 14-700 nm NaCl particles generated in the laboratory at the operating flow rate of 5 L/min, and PM2.5 collection efficiency of 98.1 % for incense smoke (MMAD of 241 nm). The inorganic ion recovery efficiencies of lab-generated non-volatile particles (Na2SO4, (NH4)2SO4) and volatile particles (NH4NO3) are very good, which are 95% for Na+ and 90% for SO42-, 110 % for NH4+ and 90 % for SO42-, as well as 107% for NH4+ and 99% for NO3-. By combining the PM2.5 inlet, SDEP, PPWD, IC and automatic extraction and injection system, the PPWD-SDEP-IC system was demonstrated to have a very good performance for ambient PM2.5 inorganic ions and precursor gases monitoring in the field comparison tests in which manual porous metal denuder sampler (PDS) and honeycomb denuder sampler (HDS) were used as references.