Life Cycle Assessment of Various Filtering Media for Greywater Treatment Using Greenwall Filtration System

Abstract

The risk of global water crisis is becoming more evident due to the increase in overall global urban population and reduction of freshwater availability. Treated greywater using greenwall technology was identified as a potential method to produce water for non-potable applications. The filtering media in greenwall technology acts as a growing media for the plants and as a filtration medium. In this study, the pollutant removal efficiency and environmental impacts associated with two filtering medias (coir pith and perlite) were investigated. The coir pith was found to have higher removal efficiencies for both COD and TSS removal compared to perlite. Besides, the life cycle of each filtering media used for greywater treatment in greenwall technology were compared. Coir pith was found to have a higher environmental impact on global warming potential (1.19568 kg CO2 eq.) and freshwater consumption (0.00066295 m3), while perlite was found to have a higher environmental impact in terms of fossil depletion (0.045562 kg oil eq.) and terrestrial ecotoxicity (0.008508135kg 1,4-DB eq). In conclusion, this study provides a framework for in-depth data analysis of the entire life cycle of filter media and a decision-making tool for the selection of suitable filtering media for greenwall filtration system.