A gas scrubber employing liquid droplets injected into a flowing gas stream at a higher velocity than the gas velocity, having means to create a gradient of increasing pressure downstream from the droplet injection site, which gradient decelerates the gas and thereby increases the velocity of the droplets relative to the gas, thus increasing the total path length of the droplets through the gas, so as to allow substantial increase of scrubber collection efficiency without use of increased scrubber size or increased liquid droplet flow rate.