| dc.description.abstract | The management of fertilizers is important to produce food, but it also has an influence on the environment since it may have negative impacts on the quality of the air, soil, and water. Heavy metals are naturally present in soils and in the raw materials used to make fertilizers. Heavy metal emissions during production or in final fertilizer product can have adverse effects on biodiversity, impacting various organisms and ecological systems. The thesis investigates the environmental impacts of heavy metal emissions in the production of NPK fertilizers. Supported by Yara-Norway, the study addresses regulations surrounding heavy metal emissions at both the production and product level. It lists various techniques for mitigating heavy metal contamination. The different production methods for NPK fertilizers are explained, and the Nitrophosphate route is examined in detail. The thesis calculates the required raw materials based on established principles and collects conventional emissions data from Yara's monitoring system. The methodology provided by Yara is utilized to calculate heavy metal emissions during production. Conducting a Life Cycle Assessment up to the factory gate, the thesis explores the goal, scope, and inventory analysis. It compares different scenarios, taking into account different phosphate rocks and the presence or absence of heavy metal emissions. While heavy metal emissions during production may not be significant in terms of quantity, it is acknowledged that they may accumulate over time and still hold importance. The study finds that heavy metal emissions have notable impacts on Terrestrial, Marine, and Freshwater ecotoxicities, as well as Human carcinogenic and non-carcinogenic toxicities. The thesis emphasizes the importance of raw material sources and their compositions, as well as the potential long-term consequences of heavy metal emissions, despite their relatively small immediate impact. | |
