Circular economy: The case of a shared wastewater treatment plant and its adaptation to changes of the industrial zone over time

Abstract Due to the increase on fresh water demand, wastewater treatment facilities need to be proactive to increase the circularity of water cycles. They have to go further than the traditional end-of-pipe service. In the present study a common wastewater treatment facility, for the tanning cluster of Barcelona, was investigated and environmentally assessed (through Life Cycle Assessment, LCA, methodology). In addition, its continuous changes for improvement and adaptation to the cluster are presented and discussed. Results show that about 97% reduction of 9 evaluated impact categories were achieved by technological improvement of wastewater treatment processes over the last 6 years with a minimum financial investment. In addition, the plant is prepared for the forthcoming changes in industrial tanning processes, like metal-free tanning, new salinity regulations, etc. This is a successful example of how small and medium size enterprises (SMEs) can organize themselves and share services and facilities through circular economy principles to innovate and find their own market niches.