3. Concentration and Deposition of Acidifying Compounds

Abstract

Publisher Summary This chapter presents a study on the concentration and deposition of three acidifying compounds—namely, sulphur dioxide (SO2), nitrogen oxides (NOx), and ammonia (NH3), together with their reaction products in the atmosphere. These reaction products are acids (HNO2, HNO3, H2SO4) and airborne particles or aerosols. The findings of the study demonstrate that two thirds of the acid deposition in the Netherlands is formed by dry deposition. Since 1980, the total acid deposition has shown a downward trend. The decrease from about 6800 mol H+ ha-1yr-1 in 1980 to about 4800 mol H+ ha–1yr–1 in 1989 can be attributed to the decrease in SO2 emissions in Western Europe. The Netherlands contributed almost 55% of the total deposition in the Netherlands in 1989. The largest Dutch contribution to the total deposition in the Netherlands in 1989 was made by agriculture. The dry deposition of NH3 contributed about 25% to the total potential acid deposition in 1989. The share of NHx in the total acid deposition was on average about 45% in the Netherlands in 1989 and about 80% of this originated from the Netherlands and 20% from outside the country.