Keywords: fractionation, green roof water recycling systems, GROW, grey water recycling, horizontal flow reed beds, HFRB, organic strength, vertical flow reed beds, VFRB, constructed wetlands, grey water reuse, water quality, hydrophobicity, water resource management, urban grey water
Constructed wetlands for urban grey water recycling
Three differently configured constructed wetlands: a Horizontal Flow Reed Bed (HFRB), Vertical Flow Reed Bed (VFRB) and a novel constructed wetland (the Green Roof Water Recycling System (GROW) patent number GB 2375761) were compared for treatment of weak organic strength domestic grey water for reuse over a period of nine months. Influent and effluent were characterized in terms of standard water quality parameters and also by size and hydrophobicity to determine the organic fractions of grey water targeted during treatment. All three wetlands achieved significant reduction in key pollutants ranging from 87?93% BOD5, 70?88% SS and 2.1?2.8 log reduction indicator microorganisms. Removal of pollutants occurred across a wide range of particle size. Hydrophilic organic fractions were preferentially removed compared to the hydrophobic components of the grey water.