Authors: YuHsiang Cheng ChiChi Lin JyhJian Liu ChengJu Hsieh
Publish Date: 2013/11/27
Volume: 21, Issue: 5, Pages: 3744-3755
Abstract
This study investigates the temporal characteristics of black carbon and its potential emission sources as well as the fractions of BC in PM25 levels in Kaohsiung urban area which is an industrial city in southern Taiwan Concentrations of BC and PM25 are monitored continuously from March 2006 to February 2010 using an aethalometer and a tapered element oscillating microbalance monitor Additionally the presence of organic compounds or UV enhanced species in particles at the sampling site is determined using the DeltaC UVBCBC value According to longterm measurement results BC and PM25 concentrations are 333 and 340 μg m−3 respectively in the Kaohsiung urban area The ratio of BC/PM25 is approximately 11 Low concentration of BC and PM25 in the summer of this study period is mostly likely owing to meteorological conditions that favored dispersion of local air pollutants Nevertheless BC concentrations peaked markedly during morning hours 700–1100 likely owing to local traffic congestion Measurement results suggest that BC is released from local traffic activities and emitted from industrial activities at this sampling site Additionally DeltaC values are significantly higher than zero during January–March and November–December periods in this industrial urban area implying that UV enhanced species can be observed At this sampling site these UV enhanced species do not only originate from household activity and solid waste burning but also release from industrial activities The elevated DeltaC values during nighttime 1800–600 in the autumn and winter seasons are likely related to those UV enhanced species in the atmosphere which can be condensed on particle surface under low temperature conditions According to longterm measurement results significantly positive DeltaC values can be observed under temperatures 20 °C and relative humidity of 60–75 in this study Despite the household activity and solid waste burning the major sources of particles that are bound with UV enhanced species in this sampling site are industrial parks and a coalfired power plantThe authors would like to thank the National Science Council of the Republic of China Taiwan for financially supporting this research under Contract No NSC1012221E131026 Environmental Protection Administration of the Republic of China Taiwan is commended for providing the longterm measurement data
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