Reclaimed municipal wastewater as source of water and nutrients for plant nurseries

A three year experimental activity was carried out to evaluate the possibility of reusing Reclaimed Wastewater (RWW) in Pistoia’s nursery area (Central Italy). The research was aimed at: 1. identifying the best tertiary treatment facilities in order to make the effluent in compliance with the current Italian legislation for RWW reuse, 2. evaluating the effects of RWW irrigation on some ornamental, 3. quantifying fertilizing value and environmental impacts of RWW irrigation. In this paper the results of the last year experimental activity are presented. Experimental results indicated that filtration and disinfection with peracetic acid plus UV were very effective in indicator bacteria removal; as a matter of fact, neither Escherichia coli nor Total Coliforms were detected in any samples of pilot plant effluent. Results of an agronomical experiment indicated the suitability of the tertiary effluent for the irrigation: at the end of the growing season a higher (or equal) total dry mass was detected in RWW irrigated plants than well-water (WW) irrigated ones. Finally, the tertiary effluent can be considered as an important source of fertilizer for container-grown plants. As a matter of fact RWW irrigation showed to be able to replace at least one of the traditional fertilization treatments.