Reuse of urban-treated wastewater from a pilot-scale horizontal subsurface flow system in Sicily (Italy) for irrigation of Bermudagrass (Cynodon dactylon (L.) Pers.) turf under Mediterranean climatic conditions

Abstract

Constructed wetlands (CW) are one of the most important biological technology for the treatment and reuse of wastewaters. The aim of this study was to evaluate the reuse of treated wastewater (TWW) from CW for irrigation of Bermudagrass turf (Cynodon dactylon (L.) Pers.) and assess the effects of TWW on the biometric and qualitative parameters of the turfgrass and on chemical–physical soil properties. The research was carried out in Sicily (Italy) in a pilot-scale horizontal subsurface flow system which was fed with urban TWW following secondary treatment from an activate sludge wastewater treatment plant. The pilot-system included three separate parallel units. The outflow TWW flowed downhill into three storage tanks which were connected to sprinkler systems. Bermudagrass plots were irrigated with freshwater (FW) and with TWW from planted units and unplanted unit. The TWW quality did not affect the visual turf quality and colour. The above-ground biomass yield of Bermudagrass was on average 1.31 kg m−2 in the TWW-irrigated plots. There was not a significant variation of soil pH, but an increase in organic matter content and salinity were recorded in TWW-irrigated plots. The results confirm that TWW provides an additional water source and fertilisers where the supply of FW is limited.