Quantifying Emissions of PM_(10) Generated by the Implosion of Concrete Grain Silos

This study quantified the effect of imploding old concrete grain silos in Aqaba, Jordan, on the eastern side of the Gulf of Aqaba, an arid region, on air quality by measuring the PM_(10) concentrations before and after the implosion at four monitoring locations. The implosion of the silos forms part of a comprehensive plan to relocate and upgrade the Port of Aqaba, which is situated on the coast of the Red Sea, with the goal of freeing space for development and improving the infrastructure in the heart of the city. The demolition, which occurred at 11:00 a.m. (local time) on 13 January 2019, generated a massive cloud of dust that was transported to nearby areas. To characterize these emissions, descriptive statistics, graphical methods, inverse distance weighting interpolation, decision trees constructed with recursive partitioning, the Gaussian dispersion model, the modified box model, and regression analysis were applied. The PM10 concentrations were in compliance with the Jordanian 24-h standard of 120 μg m^(-3) prior to the implosion but substantially increased (although still varied by distance from the demolition site) at all four stations afterward, with the maximum values (259-587 μg m^(-3)) exceeding the pre-implosion ones by as much as 26 times. However, these high concentrations were short-lived, and the majority of the stations returned to background levels within 30-33 hours. According to our calculations on the implosion, the PM_(10) emission rate was 17 ± 2 mg m^(-2) s^(-1), which is equivalent to 215 ± 22 kg silo^(-1), and the air mixing height was 613 ± 72 m, or approximately eight times the height of the silos.