Phytoremediation of domestic wastewater using a hybrid constructed wetland in mountainous rural area

Abstract

The purpose of this study is to evaluate the efficiency of hybrid constructed wetlands (HCWs) in a rural mountainous area. The experiment was set up in small rural community named Tidili within the region of Marrakech, Morocco. The wastewater treatment plant was composed of three vertical flow constructed wetlands (VFCWs) working in parallel, followed by two parallel horizontal-subsurface flow constructed wetlands (HFCWs), with hydraulic loading rates of 0.5 and 0.75 m/m.d, respectively. The two units were planted with Phragmites australis at a density of 4 plants/m. Wastewater samples were collected at the inlet of the storage tank and at the outlet of the whole system (VFCWs, HFCWs) stages. The main removal percentages of total suspended solids (TSS), biochemical oxygen demand measured in a 5-day test (BOD), chemical oxygen demand (COD), total nitrogen, and total phosphorus were respectively 95%, 93%, 91%, 67%, and 62%. The system showed a very high capacity to remove total coliforms, fecal coliforms, and fecal streptococci (4.46, 4.31, and 4.10 Log units, respectively). Artificial neural networks (ANNs) were used to model the quality parameters (TSS, BOD, COD) and total coliforms and fecal streptococci. Based on the obtained results, the ANN model could be considered as an efficient tool to predict the studied phytoremediation performances using HCWs.

Phytoremediation of Industrial Waste Leachates by Planted Filters Composed of Phragmites australis (Cav) Trin ex Steud, Typha latifolia L. and Cyperus papyrus L.

“…The average removal efficiency is respectively 45.97% for nitrates and 40.2% for phosphates. These results are below of those obtained by Bensmina et al [22] who observed a reduction in nitrates and phosphates, respectively of 62% and 59% and those of Saloua et al [26] who obtained a reduction rate of 49% in phosphates. These reductions can be explained by the fact that nitrates and phosphates are used as nutrients by plants for their tissues growth [27], but also because they can be stored in roots, rhizomes, stems and leaves [28].…”

Evaluation of Wastewater Treatment by Microcosms of Vertical Subsurface Wetlands in Partially Saturated Conditions Planted with Ornamental Plants and Filled with Mineral and Plastic Substrates

“…These results are lower than those reported by García et al [14], who obtained removal results in systems with and without vegetation between 65% and 92%, whereas Vymazal [39] obtained removal averages of 91% and 97%. This could be due to the reduction of temperature in wetlands, which increases the lifespan of coliforms in wetlands and the HRT used in this study, which was three days, while reports from different authors estimate it as being between four and five days [39,27,54]. Furthermore, the presence of high concentrations of nutrients favors the development of FCs [55].…”

Coliform removal in a constructed wetland system used in post-swine effluent treatment

“…Vymazal (2009) reports that the CWS can remove between 1 and 4 log units of ThC. Certifying the efficiency of CWS, Elfanssi et al (2018) obtained remove over 4 units log in a hybrid constructed wetland system (vertical-horizontal) in domestic effluent treatment.…”