When opening new taxiways at airports it is impossible to get rid of all the usual residual concrete dust from new pavements. Sweepers that are generally used at airports (similar to road sweepers) will only pick up a percentage. I dont know of any meachine that will guarantee that every single particle is removed. The dust after a while will dissipate. It actually always looks worse because of the blast from the engines out the back. More of a danger is loose stones from degraded taxiways that can be ingested and cause damage to blades.