of combustion generated nanoparticles leads to major adverse health effects.
Public road transportation heavily depends on diesel fueled vehicles, which
greatly contribute to air pollution in urban centers. Retrofitting polluting older
buses with diesel particulate filter (DPF) is a cost-effective measure to quickly
reduce particulate emissions. This study experimentally analyses the impact of
DPF retrofitting on particulate emissions and engine performance aspects of
in-use diesel buses. DPFs from three different major manufacturers were
installed in 18 urban and intercity Euro III buses of a major Israeli bus company.
Particulate number (PN) concentration and size distribution were measured both
before and after DPF at different engine operating regimes. The average
increase in fuel consumption due to DPF retrofitting was measured to be less
than 2.5%, and backpressure increase is about one third of the acceptable limit.
No deterioration of buses engine, as well as vehicle drivability were detected.
The average reduction in total PN emissions was found to be higher than 97%,
with no substantial difference between the different DPF manufacturers.