Life Cycle Assessment of Various Filtering Media For Greywater Treatment Using Greenwall Filtration System
The research focuses on investigating the treatment performance of using coir pith and perlite as the filtering media in greenwall greywater filtration system. Thereafter, cradle- to-grave life cycle assessment was conducted using GaBi Software to compare the environmental impacts that caused by each phase of using various filtering media.
Global water crisis has become alarming due to the increase in population and reduction in freshwater availability. Treated greywater is identified to be one of the potential alternatives to curb freshwater consumption. Natural treatment technology such as greenwall system has been gaining impetus due to the multifunctional properties and low carbon footprint. The filtering media in greenwall technology acts as a growing media for the plants and as a filtration medium. Attributed to the presence of carbon and biological activities in coir pith, it was found that coir pith can remove higher concentration of COD and TSS compared to perlite. On top of that, the environmental impacts associated with each filtering media used for greywater treatment in greenwall technology were evaluated. The cradle-to-grave life cycle assessment (LCA) of each media was conducted using GaBi Software following ReCiPe model. The LCA is in accordance to ISO 14044: 2016 framework by setting goal and scope, system boundary and corresponding functional units for the 2 filter medias based on their ability to remove 80% of COD. The inventory analysis records and analyzes the transfers within the system boundary in terms of materials, energy and emissions and an impact assessment will be conducted for each respective impact categories. Coir pith was found to have a higher environmental impact in terms of global warming potential and freshwater consumption, while perlite was found to have a higher environmental impact in terms of fossil depletion and terrestrial ecotoxicity. Through comparing the environmental impact contributed by filtering media through LCA, in dept understanding on the environmental impact associated from material extraction to disposal was evaluated. of filter media. By comparing the removal efficiency and environmental impacts of various filter media, coir pith was identified to be the most suitable filtering media for the greenwall system.