Reduction of emissions of confined animal production by the use of aluminum compounds

Confined animal production, in Germany for instance found in the Vechta/Cloppenburg area, can have various impacts on the environment. Both reactive nitrogen (N) and phosphorous (P) compounds from the animal manure are a threat to the regional soils and the groundwater. Agricultural politics is advocating a less intensive form of animal production, but occasionally it may take years before this policy becomes effective. In order to accelerate the relief of the environment, the use of technical means can be considered. To this end, the application of aluminum salts and drinking water treatment residues containing aluminum has been studied, particularly in the USA. These investigations have shown that the water-soluble P content in organic fertilizers and in soils can be reduced significantly. If applied in the field, a decrease of the P concentration in the runoff from soils can be achieved. By treating organic fertilizers. also the NH3 emission as a result of the decreased pH-values was reduced. Simultaneously, a better health of the animals in poultry production, and a better economic efficiency was achieved. Other positive effects are lower concentrations of heavy metals and hormones in the runoff. The results suggest, that also in Germany a reduction of non-point pollution may be achieved in the subject areas just mentioned. More research is needed, however, especially with respect to the optimally required quantity, as well as regarding the usefulness of other industrial by-products.