Chemistry Reference
In-Depth Information
Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
2 Emissions from Different Source Categories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
2.1 Animal Houses and Manure Storages ................................................ 143
2.2 Application of Manure and Mineral Fertiliser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
2.3 Emissions from Grazing Animals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
2.4 Emission of NH
3
from Other Agricultural Sources ................................. 148
2.5 Emissions from Nonagricultural Sources, e.g. Urban Areas and Traffic ........... 148
3 Spatial Distributions in Emission
s
......................................................... 149
4 Site-Specific Long-Term Trends in Emissions ............................................ 153
5 Long-Term Trends in Emissions on European Scale ...................................... 154
6 Regulation of Emissions, Future Scenarios and Impact of Climate Change . . . . ......... 155
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
1
Introduction
Ammonia (NH
3
) emissions lead to significant environmental impacts in Europe not
only with respect to formation of ambient air PM with potential health impact but
also with respect to nitrogen depositions to natural surfaces with potential impact on
biodiversity. NH
3
deposits very fast to most surfaces and may thus through a high
atmospheric nitrogen (N) input significantly contribute to stress of ecosystems close
to ammonia sources [
1
], a stress that on the long term may lead to loss of biodiver-
sity [
2
-
4
]. Release related to agricultural activities is the dominating source of
European NH
3
emissions [
5
,
6
]. In the vicinity of large animal farms, the atmo-
spheric load to ecosystems can be totally dominated by a single farm [
7
]
contributing to N depositions of even 50-80 kg N/ha/year [
8
,
9
], depending on
distance to source, source strength and local climatic conditions. Such high local N
loadings are a factor of five to ten beyond the critical loads for the sensitive
terrestrial ecosystems (e.g. [
10
], Table 1). In Europe, about 90-95% of NH
3
emissions arise from agricultural sources, with main contributions from animal
housings (34-43%), manure handling (22-26%) and mineral fertiliser (17-26%)
[
11
]. It should be noted that organic bound N in the manure is not a direct source of
NH
3
. The emission strength is therefore mainly related to the manure or fertiliser
content of TAN (Total ammonia N (NH
3
and NH
4
+
)), the pH in the manure or
fertiliser and the ambient air temperature and wind speed. Emission estimates are
often derived on the basis of national emission factors for NH
3
relating certain
agricultural production methods to specific emission rates [
12
], e.g. aggregating
results from multiplying census data of farm animals for all animal categories with
estimated emission factors per animal [
13
].
2 Emissions from Different Source Categories
Emission of NH
3
to the atmosphere is a physical process taking place from wet
surfaces [
14
]. This process is highly temperature dependent and varies therefore
during day and over seasons [
15
,
16
]. The regional variation is a function of
