Decentralized wastewater treatment of commercial and residential buildings using the ecotechnology of constructed wetlands

Abstract

The aim of this study is to show the performance of vertical flow constructed wetlands (VFCW) applied to wastewater treatment from commercial and residential buildings under different organic and hydraulic loading rates. During two years two systems were evaluated: (i) system 1 - commercial building: compound by one Baffle Anaerobic Reactor (BAC) followed by VFCW (superficial area 189 m²); (ii) system 2 - residential building: compound by one BAC followed by VFCW (superficial area 3,141 m²). The operational and analytic monitoring of the wetlands systems determined hydraulic loading rate applied from 130 to 12 mm.d^-1 and organic loading rate applied from 87 to 1.9 gCOD, for systems 1 and 2 respectively. The different loadings applied were due to actual demand and the systems 1 and 2 showed average concentration removals efficiencies of 75% and 93% to COD, of 88% and 97% to BOD and of 83% and 94% to SS, respectively. These results lead us to recommend the use of VFCW as a decentralized wastewater treatment technology.

Keywords:
Wastewater; Treatment; Constructed wetlands; Performance