Green Roof Plant Responses to Greywater Irrigation

Abstract

Water is an essential natural resource and is even known to be the cause of many wars of history. While people depend on it to survive, they also use it for everyday activities and several other purposes. As for plants, water is an essential factor, one they need for growth. Although irrigation is really important for certain agricultural plants, many criticise its water consumption especially on scientific platforms and media. This naturally pushes the world to find alternative ways to decrease the water consumption where possible. Greywater (GW) use is one of these alternative ways. This study aims to focus on two different but ecologically useful recent phenomena; GW use and green roofs. GW use makes it possible to decrease water consumption by replacing irrigation water, while green roofs (GRs) are known to increase biodiversity in urban areas and to decrease heat island effect and as a result reduce the costs of air conditioning. Since the main purposes of this study are to evaluate the use of GW on GRs to examine if there might be an ecologically and economically more beneficial way to keep the roof green, we used a prepared greywater simulation (PGWS) to measure green roof plants' responses to it. Two different greywater models, non-diluted prepared greywater simulation (N-D.PGSW) and 50% diluted prepared greywater simulation (%50-D.PGWS), were used for irrigation; while tap water (TW) irrigation and no irrigation (N-I) were the other two conditions to make the study more reliable.

Sustainable green roofs: a comprehensive review of influential factors

“…Yet, there were no reported adverse effects on plants due to greywater for irrigation (Agra et al 2018 ). In a study for indicating the plants’ response to greywater irrigation, Yalcinalp et al ( 2019 ) compared two different greywater models and tap water for GR irrigation. They showed that the use of greywater provides more positive effects on plant growth compared to that of tap water.…”

“…They showed that the use of greywater provides more positive effects on plant growth compared to that of tap water. Also, utilizing greywater can reduce the irrigation costs of the GR (Yalcinalp et al 2019 ). Hence, by using greywater in GRs, it is possible to sustain plant growth, reduce the use of potable water, and reduce demands on municipal wastewater treatment plants (Xu et al 2020 ).…”