Performance of Wetland Roof Treating Domestic Wastewater in The Tropic Urban Area

Bui Xuan Thanh, Vo Thi Dieu Hien, Nguyen Phuoc Dan, Phan Thi Hai Van,Nguyen Thanh Tin

 

ABSTRACT

This study evaluated the treatment efficiency of four plants, namely Axonopus compressus (2); Melampodium paludosum (3); Tradescantia spathacea compacta (4); Catharanthus roseus (L) G. Don (5), in the wetland roof system (WR). Five WRs (including the control system) were operated at the two hydraulic loading rates (HLR1 of 220 m3/ha.day and HLR2 of 417 m3/ha.day), corresponding to organic loading rates (OLR1 of 31 kg COD/ha.day and OLR2 of 71 kg COD/ha.day). The studied plants had the ability to grow in the roof conditions with domestic wastewater as a nutrient source. The removal efficiencies (mean ± SD) of the control (1), (2), (3), (4), (5) were approximately 55 ± 4; 68 ± 5; 71 ± 4; 65 ± 5 and 65 ± 10% (or 20 ± 2; 25 ± 5; 30 ± 7; 25 ± 3 and 23 ± 3 kg COD/ha.day) and 16 ± 6; 41 ± 9; 40 ± 20; 44 ± 22; 7 ± 6% (1.8 ± 0.8; 4.8 ± 0.8; 4.4 ± 2.2; 4.8 ± 2.2; 0.6 ± 0.5 g TP/ha.day) and 41 ± 5; 56 ± 3; 59 ± 4; 55 ± 7; 54 ± 9% (or 1.7 ± 0.3; 2.4 ± 0.2; 2.5 ± 0.3; 2.4 ± 0.4; 2.2 ± 0.5 kg TN/ha.day) at 192 - 247 m3/ha.day of HLR, respectively for COD, TP and TN. Generally, Axonopus compressus (2) and Melampodium paludosum (3) were the most suitable plants treating domestic wastewater for the conditions of WR.

 

Keywords: Wetland roof; Axonopus compressus; Melampodium paludosum; Hydraulic loading rate

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doi:10.11912/jws.2.1.79-86