PERFORMANCE OF VEGETATIVE BIORETENTION SYSTEM FOR GREYWATER REUSE IN ARID CLIMATES

摘要

Water Sensitive Urban Design (WSUD) technologies are acknowledged to play a significant role in improving the quality of stormwater in the urban landscape. However, findings have shown that greywater, the residential wastewater except that originates from toilet and kitchen, could be used to operate the vegetative bioretention system in the arid climates. A positive signal was received when investigated in the laboratory settings, however, a better picture and a more representative result can be obtained if the system is studied in a field scale. The study intended to explore further, the effectiveness of using the vegetative bioretention to treat urban greywater. This WSUD system can play a dual role in improving greywater quality and landscape aesthetics. Selection of appropriate plants for them is also an important research question. Twelve different species of native and exotic plants in triplet planted in 36 prototype bioretention columns in the laboratory. The columns were irrigated by synthetic greywater and the removal efficiency of heavy metals and other common water quality parameters were monitored on a regular basis. The retention of heavy metals in the water, plants (leaves, stem and roots) and soil were also investigated. It was found that the Pennisetum seateceum provides more consistency and efficiency in removing heavy metals from greywater.