| Autor: |
Gillies JA; a Desert Research Institute, University of Nevada System , Reno , Nevada , USA., Watson JG; a Desert Research Institute, University of Nevada System , Reno , Nevada , USA., Rogers CF; a Desert Research Institute, University of Nevada System , Reno , Nevada , USA., DuBois D; a Desert Research Institute, University of Nevada System , Reno , Nevada , USA., Chow JC; a Desert Research Institute, University of Nevada System , Reno , Nevada , USA., Langston R; b San Joaquin Valley Unified Air Pollution Control District , Fresno , California , USA., Sweet J; b San Joaquin Valley Unified Air Pollution Control District , Fresno , California , USA. |
| Abstrakt: |
A 14-month study was undertaken to assess the long-term efficiencies of four dust suppressants (i.e., biocatalyst stabilizer, polymer emulsion, petroleum emulsion with polymer, and nonhazardous crude-oil-containing materials) to reduce the emission of PM 10 from public unpaved roads. PM 10 emission rates were calculated for each test section and for an untreated section for comparison purposes. Emission rates were determined from PM 10 concentrations measured from 1.25 m to 9 m upwind and downwind of the road and above its surface. Calculated emission factors ranged between zero and 1,361 g-PM 10 /vehicle kilometer traveled (VKT) (average uncertainty = ±35 g-PM 10 / VKT) for the four types applied. One week after application, suppressant efficiencies ranged between 33% and 100% for the four types applied. After 8-12 months of exposure to weathering and 4,900-6,400 vehicle passes, the suppressant efficiencies ranged from zero to 95%. Roadway surface properties associated with low-emitting, well-suppressed surfaces are (1) surface silt loading and (2) strength and flexibility of suppressant material as a surface layer or cover. Suppressants that create surface conditions resistant to brittle failure are less prone to deterioration and more likely to increase long-term reduction efficiency for PM 10 emissions on unpaved roads. |
