Reclaimed municipal wastewater for forage production

Abstract

This study aims to evaluate the possibility of using reclaimed municipal wastewater for agricultural purpose. We assessed the validity of municipal wastewater treatment, analyzing its chemical characteristics before and after the biological stabilization by pond treatment (WSP). The reclaimed municipal treated wastewater (TWW) was used to irrigate Cenchrus ciliaris. Experiments were carried out in greenhouse, from July 2013 to July 2014, comparing the effects of TWW with the water normally used for irrigation (tap water, TW) on the growth and flowering parameters of C. ciliaris. During this study, total coliforms, fecal coliforms, Escherichia coli, and Salmonella spp. were detected in TW, TWW, soils and plants under irrigation. Our results evidenced that TWW increased plant growth, producing taller plants with respect to TW. Total coliforms and fecal coliforms in TWW, TW, soils and plants were under the threshold recommended by the World Health Organization (WHO). Salmonella was never found in TW, TWW, or soil and plants irrigated with TWW. The absence of pathogens suggests that the pond treatment is an effective method to reclaim wastewater, lowering biochemical oxygen demand (BOD), chemical oxygen demand (COD) and pathogens. In this respect, TWW can be used as a valid alternative to freshwater for irrigation of fodder species.