Abstract
Life cycle assessment (LCA) is considered the most integrated and comprehensive tool available for evaluating the environmental sustainability of new technologies. Parallel assessment of impacts using LCA and techno-economic analysis (TEA) in developing new technology solutions for clean water is both a social and engineering necessity for sustainability. In this dissertation LCA and TEA models are developed for different configurations and scales of municipal wastewater reactive filtration (RF) in conjunction with or independently of iron-ozone catalytic oxidation with and without biochar integration (Fe-CatOx-BC-RF and BC-RF). Preliminary LCA and TEA models are developed for bubble belt filtration of dairy wastewater for nutrient removal and recovery with and without biochar integration. The RF technology demonstrates 90% – 99% total phosphorus removals, adsorption of phosphorus to biochar for recovery, and >90% destructive removal of observed micropollutants. The LCA results indicate that the addition of biochar to the RF process transforms this advanced wastewater technology into a negative emission technology (NET) and at the field pilot scale with 49.2 m3/day (9gpm) and the BC dose rate of 0.45 g/L the global warming potential (GWP) is – 1.21 kg CO2e. For the RF system installed at a 1130 m3/day (0.3 MGD) water resource recovery facility, modeled with the same rate of BC addition, the overall process changed from 0.02 kg CO2e/m3 to a carbon negative – 1.41 kg CO2e/m3. Preliminary modeling results for dairy wastewater treatment with biochar bubble filtration (BBF) show that integration of 1 kg of biochar per cubic meter of influent in the pilot field operation can sequester -3.2 kg CO2e/m3. A stochastic TEA for the cost of water treatment using Fe-CatOx-BC-RF technology shows that at scale, the mean cost for treating 1130 m3/day (0.3 MGD) WRRF secondary influent water using the C100 metric is US$0.18 ± US$0.01/m3 to achieve overall process carbon neutrality. Using the same BC dose in an estimation of a 3780 m3/day (1 MGD), the carbon neutral cost of treatment is reduced further to US$0.08 ± $0.01 with added BC accounting for US$0.03/m3. Large-scale deployment of biochar-integrated wastewater treatment technologies presents an excellent opportunity for decarbonization of the water sector while advancing high-efficiency pollutant removal and resource recovery. Overall, the results demonstrate the potential of carbon negativity to become a water treatment performance standard as important and attainable as pollutant and pathogen removal.