Construction and evaluation of prototype subsurface flow wetland planted with Heliconia angusta for the treatment of synthetic greywater

The present work describes the method of construction and evaluation of prototype wetland system (root zone method) and the removal of various contaminants from the synthetic greywater by root zone treatment process using Heliconia angusta. The various waste water parameters such as chemical oxygen demand (COD) (27.63%), Biological oxygen demand (BOD5) (48.62%), residual chlorine (47.5%), Total suspended solids (TSS) (81.95), Total dissolved solids (TDS) (36%), turbidity (97.21%), pH (43.13%), alkalinity (38.89%), indole producing fecal coliforms count (12.5%) showed a significant reduction as compared with the BSI and CPCB standards. There was also a considerable decrease observed in heavy metal concentration. Furthermore, bacterial of rhizosphere of H. angusta was isolated and the synthetic greywater was treated using isolated bacterial consortium under laboratory conditions. There was reduction in all the parameters; 39.72% in COD, 70% in BOD, 25% in residual chlorine, 61.65% in TSS, 18.66% in TDS, 46.15% in Total solids (TS), 92.12 in turbidity, 41.56% in pH, 41.52% in alkalinity. Reduction in metals concentration under in vitro conditions was also observed to be 97.82% in sodium, 69.48% in potassium, 58.72% in calcium, 94.88% in lead, 94.19% in chromium, 93.65% in magnesium and 93.69% in iron. Further research can be initiated for the treatment of blackwater and also for sludge treatment (sludge disintegration) and nutrient removal (phosphorus recycling from waste water treatment). Also, construction of in situ wetlands, various types, use of raw materials for energy efficiency and reduction in operational cost will be noteworthy for environmental applications. (C) 2014 Elsevier Ltd. All rights reserved.