Domestic wastewaters reuse reclaimed by an improved horizontal subsurface-flow constructed wetland: A case study in the southeast of Spain.

The aim of this case study was to assess the performance of a horizontal subsurface flow constructed wetland (HF-CW) located in southeastern Spain, filled with blast furnace slags (BFS), planted with Phragmites australis and designed to treat artificially aerated domestic wastewater to produce effluents suitable for agriculture reuse. The water quality parameters, included in the Spanish regulations for reclaimed wastewater reuse as agricultural quality 2.1, were monitored for one year. Data for all studied parameters, except electrical conductivity (EC) and sodium adsorption ratio (SAR), met the Spanish standards for reclaimed wastewater reuse due to the high evapotranspiration (ET) during the summer. The introduced improvements were effective for turbidity, total suspended solids (TSS), total nitrogen (TN), Escherichia coli (E. coli) and, specially, for total phosphorus (TP) with an average abatement of 96.9±1.7%. The improved HF-CW achieved similar or better percentage abatements than those reported using some hybrid systems.