Major Ionic Characteristics of Wet Deposition and Airmass Movement in Industrial Areas of Eastern Thailand
The sixty-five rainwater samples were collected at Kasetsart University at Siracha Campus station of Chonburi Province, eastern Thailand during January to October 2015. The study presented the total amount of rainwater samples was 1057.6 mm. pH values ranged from 4.1 to 5.6. Overall months except May, were evaluated an average pH values less than 5.6 and March revealed a lowest pH value. EC values ranged from 0.98 to 3.97 mS/m. The major ionic volume weighted mean (VWM) concentrations were considered the following order; Na+ > SO42- > NH4+ > Ca2+ > Cl- > NO3- > K+ > Mg2+. The major ions of cation and anion were Na+ and SO42-, 42.12 and 38.25 eq/L, respectively. An ionic concentrations of dry season were higher than wet season. The neutralization factor (NF) showed NH4+ and Ca2+ were mainly neutralized substances. Factor analysis was used for grouping the ionic species. A pairs of ionic species interpreted an excellent correlation. Two components were exposed by using Principle Component Analysis (PCA). The first component was originated from anthropogenic activities, expressed NO3-, SO42-, NH4+ and Ca2+ and the second component dispersed from marine, expressed Cl-, K+, Na+ and Mg2+. The trajectories were indicated the airmass movement came from southeast in dry seasons (flowed from the gulf of Thailand and Cambodia) and southwest as the local wind in wet season.
Index Termsó Acid rain, Airmass, Back trajectory, Industrial area, Wet deposition.