Green walls for greywater reuse: Understanding the role of media on pollutant removal

Abstract

Green walls offer multiple benefits to urban environments, but they are major water consumers and not optimal for use in dry climates. If green walls were engineered to treat greywater, they could become cost-effective and more widespread. However, it is not clear what impact watering green walls with greywater has on the life cycle of plants and media types, so each element needs to be assessed and optimised. This work presents the first step, by testing a range of potentially suitable media: (1) hydraulically slow coir, rockwool and fyto-foam, and (2) hydraulically fast perlite, vermiculite, growstone, expended clay and river sand. An unvegetated column experiment was conducted over two mo..