Diagnosis and evaluation of an early-stage green bio-sorption reactor by life cycle assessment

A life cycle assessment (LCA) was applied for an emerging green bio-sorption reactor (GBR) to support its early stage research and development for upgrading aging wastewater treatment plant (WWTP). An oxidation ditch was selected and assumed to be upgraded to GBR and the LCA was modeled for these two systems in five scenarios. Landfilling and agricultural application of end-of-life alum sludge were considered for the GBR. The results showed that the performance of GBR without accounting for the landfilling of alum sludge was more sustainable compared with the oxidation ditch by reducing the chemicals requirement. However, counting the landfilling of alum sludge on the life cycle of GBR compromised the sustainability, particularly in eutrophication potential and global warming potential. The good issue is that the agricultural application of the alum sludge as an alternative could minimize the environmental damaging impacts and promise the superiority of the GBR. Thus, in the processes reusing the alum sludge for sewage treatment, the final disposal of the end-of-life alum sludge should be taken into consideration. (C) 2018 Elsevier Ltd. All rights reserved.