Comparative and integrative environmental assessment of advanced wastewater treatment processes based on an average...

Pharmaceuticals are normally barely removed by conventional wastewater treatments. Advanced technologies as a post-treatment, could prevent these pollutants reaching the environment and could be included in a centralized treatment plant or, alternatively, at the primary point source, e.g. hospitals. In this study, the environmental impacts of different options, as a function of several advanced treatments as well as the centralized/decentralized implementation options, have been evaluated using Life Cycle Assessment (LCA) methodology. In previous publications, the characterization of the toxicity of pharmaceuticals within LCA suffers from high uncertainties. In our study, LCA was therefore only used to quantify the generated impacts (electricity, chemicals, etc.) of different treatment scenarios. These impacts are then weighted by the average removal rate of pharmaceuticals using a new Eco-efficiency Indicator EFI. This new way of comparing the scenarios shows significant advantages of upgrading a centralized plant with ozonation as the post-treatment. The decentralized treatment option reveals no significant improvement on the avoided environmental impact, due to the comparatively small pollutant load coming from the hospital and the uncertainties in the average removal of the decentralized scenarios. When comparing the post-treatment technologies, UV radiation has a lower performance than both ozonation and activated carbon adsorption.