ECN publicatie:
Titel:
Report on the activities of the international consultant, Prof. J. Slanina, in the project: 'Capacity development for acid rain and SO2 pollution in Guiyang' for the year 1999: project number: CPR/96/304/A/01/99
 
Auteur(s):
Slanina, J.
 
Gepubliceerd door: Publicatie datum:
ECN 1-12-1999
 
ECN publicatienummer: Publicatie type:
ECN-C--99-096 ECN rapport
 
Aantal pagina's: Volledige tekst:
24  Niet beschikbaar.

Samenvatting:
The acid deposition loads in the Chinese province Guizhou near Guiyangare very high, as indicated by ambient concentration measurements at two locations, North of Guiyang. Both are frequently exposed to pollutants emitted by Guiyang. One site (at Zhazuo) is in a valley, the other, Yunwushan, is on a mountain (1600 meter, about 600 meter over the average altitude of the surroundings). This combination is chosen not only in order to be able to measure cloud and fog water composition, but it can safely be assumed that the measurements at higher elevation represent a more regional situation compared to local influences at Zhazuo in the valley. The found values of 14.500 and 16.000 moles of potential acid per hectare per year agree reasonably well with the assessments made in the last report, based on throughfall data. It is very clear that nitric acid and nitrate (yet) constitute a minor contribution. But the contribution of ammonia (due to the use of fertilizer in rice fields and to untreated sewage) has quite a large contribution, in the order of 25%. These rather sizable nitrogen deposition fluxes caused by ammonia do not only contribute to the total amount of acid deposition but lead to eutrophication, too high nutrient fluxes, which will cause effects as eutrophication (algae blooms) of lakes and too high concentration of nitrate in groundwater (ground water containing more than 25 milligram of nitrate per liter should not be used as drinking water according to European regulations, due to the cancerogenic effect of nitrate). The contribution of occult deposition (deposition by way of fog and cloud droplets) is indeed important, as already expected. The highest contribution is observed at Yunwushan at higher elevations, about 30%. The contribution at Zhazuo is probably lower, about 15%. The uncertainty in these estimates, in view of the lack of meteorological data is very large. The data indicate that indeed in the order of half the acid deposition at locations such as Zhazuo and Yunwushan is caused by local sources (to be specific probably by the emissions of Guiyang) but the other half is caused by Long Range Transport of gases and aerosols. Emission abatement in the city of Guiyang, even if this process is 100% successful can only diminish acid deposition with about 50%. Obviously, as reported already earlier, the ambient sulfur dioxide concentrations encountered in Guiyang were so high as directly endangering human health. Measures taken in the past and future plans will indeed alleviate these problems considerably. The present plans for control of emissions, monitoring of deposition and occult deposition look fine and should ensure that the positive effects of emission abatement measures can be followed and optimized. As already stated, the plans for emission abatement are very good indeed, only care should be taken to implement the plans in such a way that transient environmental problems can be avoided. The main reason that severe effects have not yet been encountered seems to be in-situ neutralization of sulfuric acid by calcium carbonate dust, which is present in high concentrations in Guizhou province. A new emission inventory, describing a much larger area has been prepared. Measures taken in the past and future plans will indeed alleviate the air pollution problems considerably. As already stated, the plans for emission abatement are very good indeed, only care should be taken to implement the plans in such a way that transient environmental problems can be avoided, e.g. by reducing dust loads before sulfur reduction takes place. The present plans for control of emissions, monitoring of deposition and occult deposition look fine and should ensure that the positive effects of emission abatement measures can be followed and optimized. The participants in this project have been confronted with very unexpected situations (very high deposition loads, unsuitable conditions for envisaged measurements etc.), but have managed to adapt the direction of their in order to the necessary results


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