Assessing the environmental impact of five Pd-based catalytic technologies in removing of nitrates

摘要

Emerging technologies involving chemical catalytic processes to remove nitrate from water have proven efficient and cost-effective. However, the environmental impact of noble metals and metals at the nanoscale used in these processes has become a topic of serious concern. The aim of this research was to develop a system for evaluating the environmental impact of technologies associated with Pd-based catalytic denitrification. This research performed life cycle assessment (LCA) based on a detailed analysis of the technologies to examine the environmental burden associated with all stages of the removal process. We then applied analytical hierarchy process (AHP) to determine the weights of various burdens. We implemented the proposed system to determine the relative environmental friendliness of 5 processes used for the removal of nitrate. These five methods use Cu-Pd/TNTs, H_2 + Pd-Cu/TiO_2, Pd-Cu/TiO_2, Pd/ZnO, and Pd-Cu/FeO as catalysts for the removal of nitrate. The results indicate that the use of palladium and the consumption of electricity have a major environmental impact; while the use of Pd-Cu/TiCb as catalyst was the most environmentally friendly of the five processes evaluated.