Greywater quality changes in laboratory scale vegetative biofiltration prototypes

Greywater recycling and reuse is becoming a popular choice in many water-scarce regions. Greywater is the largest component of domestic indoor wastewater. However, in many arid regions, including the United Arab Emirates (UAE), this unconventional resource is under-utilized. Although, traditionally, a biofiltration system operates using stormwater, findings have shown that the operation of biofiltration systems in arid regions can be successful using greywater. This research endeavors to assess how the quality of the effluent from a biofiltration system changes with different vegetation, both native and introduced to the arid region (UAE). The prototype biofilters, planted with twelve ornamental plant species, were irrigated daily with an equal amount of synthetic greywater and the water quality parameters were monitored on a weekly basis. Analysis of variance (ANOVA) was performed in order to statistically evaluate the consistency of results between the three replicates of each of the twelve species and, subsequently, the variation of treatment effectiveness among the twelve species with respect to eight water quality parameters. Most of the plants show a high degree of consistency between replicates; however, significant differences were observed across the selected plant species. The species Ficus nitida and Canna indica performed well in reducing pH. Except in the earlier stages of the experiment, all the systems were found to reduce turbidity by almost 100%. Overall, it was observed that Ficus nitida, Canna indica and Pennisetum setaceum performed well to improve greywater quality in the biofiltration columns