Experimental Study on the Produce of Air Negative Ions from Liquid Water Evaporation

Abstract

It was revealed that liquid water surfaces, including water drop’s surface might generate Negative Water Ions/molecules to air with probability of (1/11)⁸ among the water surface molecules by the author’s previous paper. Three experiments by spraying water from shower nozzle had been performed on a bathtub covered by soft plastic film with thickness of 10 mm during Aug.-Sep. 2019. The densities of negative ion (DNI) and the atmospheric parameters had been recorded. The experimental results showed that DNI increased immediately after spraying waters in orders with big variations. High DNI up to -190000 ion/cm³ were recorded under spraying water temperatures about 45°C. The sliding averaged (for 10 instant values) DNI were direct proportion to differences of saturated vapor pressure of spraying water and air vapor pressure, and increasing of relative humidity (under constant air temperature). The liquid water drops become positively charged after evaporation with negative ions. After stopping water spray DNI might keep at high level in a short time interval, then decrease gradually with vibrations by processes of mixing and water phase exchange in a cloud-fog system with -/+ air ions. These experiments proved that neutral liquid water drops may generate air negative water ions/molecules by evaporation and positive charged water drops.