The implementation of good practices in Wastewater Treatment plants (WWTPs) management mainly aims to minimize the energy consumption maintaining the effluent concentrations under the legal limits. In the last years, the increasing attention on the Circular Economy model encouraged the WWTPs management companies to search for new recovery purposes for their effluents and by-products, such as wastewater reuse, for industry or irrigation, energy production and raw material reservoir. In this context, the present study focuses on the possibility to recover biomass from a natural finishing treatment section of a WWTP. In particular, a case study has been established in Santerno WWTP located in Imola (Bologna, Italy). The Santerno plant collects the urban and industrial wastewater from Imola city and hinterland, 75,000 Population Equivalent, with an average influent flow rate of 25,000 m3/day. The plant is equipped with five Free Water Surface (FWS) basins, of which four are organized in two parallel lines (two basins each) and the fifth acts as a final receiver for the total flow before discharging in the Santerno river (Fiorentino et al. 2016). Seven months monitoring campaigns have been carried on the first basin (Basin 1). Basin 1 (volume is around 23,000 m3 with a water surface of 14,000 m2) has been chosen because it follows the secondary treatments. Half the effluent flow is retained within Basin 1 and Lemna minor (Duckweed) grows in this basin occupying its whole surface during summer. This aspect leads to an equilibrium between phytotreatment, due to Lemna Minor, and FWS lagoon. As removal efficiency displayed by Lemna minor depends on regular plant harvesting, planning a destination for biomass produced is a driving management element for a FSW. Literature reports several treatment options for final disposal of exhausted Lemna minor, such as drying and landfilling, as well as innovative opportunity for material or energy recovery, such as anaerobic digestion for methane production and drying and following cogeneration of electricity (Rahmi and Surindra, 2015). The waste-to-energy options outline a scenario of great appeal, from the circular economy perspective. Within the framework of a growing energy demand, the biorefinery industry is candidate to represent a growing opportunity: for this reason, the overall sustainability of the process must be ensured.
Recovery of floating biomass from free water surface basins: modeling for optimization and sustainability
fiorentino carmine;sara zanni
;maurizio mancini;alessandra bonoli
2018
Abstract
The implementation of good practices in Wastewater Treatment plants (WWTPs) management mainly aims to minimize the energy consumption maintaining the effluent concentrations under the legal limits. In the last years, the increasing attention on the Circular Economy model encouraged the WWTPs management companies to search for new recovery purposes for their effluents and by-products, such as wastewater reuse, for industry or irrigation, energy production and raw material reservoir. In this context, the present study focuses on the possibility to recover biomass from a natural finishing treatment section of a WWTP. In particular, a case study has been established in Santerno WWTP located in Imola (Bologna, Italy). The Santerno plant collects the urban and industrial wastewater from Imola city and hinterland, 75,000 Population Equivalent, with an average influent flow rate of 25,000 m3/day. The plant is equipped with five Free Water Surface (FWS) basins, of which four are organized in two parallel lines (two basins each) and the fifth acts as a final receiver for the total flow before discharging in the Santerno river (Fiorentino et al. 2016). Seven months monitoring campaigns have been carried on the first basin (Basin 1). Basin 1 (volume is around 23,000 m3 with a water surface of 14,000 m2) has been chosen because it follows the secondary treatments. Half the effluent flow is retained within Basin 1 and Lemna minor (Duckweed) grows in this basin occupying its whole surface during summer. This aspect leads to an equilibrium between phytotreatment, due to Lemna Minor, and FWS lagoon. As removal efficiency displayed by Lemna minor depends on regular plant harvesting, planning a destination for biomass produced is a driving management element for a FSW. Literature reports several treatment options for final disposal of exhausted Lemna minor, such as drying and landfilling, as well as innovative opportunity for material or energy recovery, such as anaerobic digestion for methane production and drying and following cogeneration of electricity (Rahmi and Surindra, 2015). The waste-to-energy options outline a scenario of great appeal, from the circular economy perspective. Within the framework of a growing energy demand, the biorefinery industry is candidate to represent a growing opportunity: for this reason, the overall sustainability of the process must be ensured.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
