Unlocking the Potential of Chemical Industry Wastewater: Prospective Life Cycle Assessment and Future Opportunities from Anaerobic Digestion

Sustainable water management of industrial effluents is a fundamental point to reduce environmental stress across productive sectors. Tapping into industrial wastewater’s potential through novel approaches could provide solutions for increasing energy efficiency and strengthening circularity initiatives, meanwhile decreasing environmental pressure from industrial activities. In this regard, the integration of anaerobic digestion in industrial wastewater treatment systems poses opportunities for energy recovery, alongside possible valorisation of biomethane as a marketable product or into sustainable chemical transformation pathways. Early-stage testing with prospective Life Cycle Assessment (p-LCA) is a valuable strategy towards overcoming technical challenges, addressing upscaling from preliminary phases and tackling uncertainties related to sustainability performance. The latter not only supports adopting and transitioning towards alternative waste & wastewater treatment technologies but also underscores its future potential within industrial settings. This research presents a p-LCA case study for an anaerobic digestion approach for chemical industry wastewater, supporting its future deployment. The tailored approach is based on expanded granular sludge bed reactor coupled with different product valorisation pathways. Process engineering equations and tools such as Piccinno and colleagues are used for upscaling laboratory performance data. Environmental modelling is conducted with ecoinvent 3.10 cut-off coupled with Premise in Brightway 2.5, using the EF v3.1 impact assessment method. As a point of comparison, the baseline wastewater treatment is analysed as well, modelled from chemical composition parameters and site-specific conditions using the Doka LCA - LCI calculation tool. Preliminary results highlight the potential of the anaerobic digestion approach for chemical wastewater effluents, showcasing opportunities for comparable scoring to the baseline model. Advanced improvements at experimental testing and modelling levels could further emphasize the benefits from upscaling these technologies and valorising its key products. In addition, this study underpins the intersection of technology development and sustainability assessment, and its role for supporting decision making in the industrual settings and scaling-up processes.