Italy: A municipal treatment plant may be able to realise energy neutrality, pilot results show

A treatment facility managed by Servizi Ambientali S.p.A. in Borghetto Santo Spirito, a touristy municipality edged by the Mediterranean Sea, located in the Province of Savona, Liguria, Italy, has realised positive results in the first six months of a ten-month-long pilot project that feature the ZeeLung* Membrane Aerated Biofilm Reactor (MABR) and LEAPprimary* Advanced Primary Treatment Technologies from GE Water & Process Technologies.

Around six months into the pilot programme – the first in Europe – to prove its ability to achieve energy neutrality, the ZeeLung MABR technology has shown:

  • Four or five times more aeration energy savings in comparison to fine bubble aeration
  • The possibility of bringing down 50 per cent of the biological volume as compared to orthodox activated sludge processes, while also maintaining the same effluent limits
  • Removal of up to 80 per cent of nitrogen without internal nitrate recirculation

“We continue to be vigilant on new technologies launched in the market that aim to improve operational costs and the overall plant sustainability. It is for this exact reason that we welcomed the opportunity to host the first European pilot plant for GE’s ZeeLung MABR at our wastewater treatment plant, located in Borghetto [Santo Spirito],” general manager of Servizi Ambientali, Giovanni Paolo Paganelli, said. “During the ongoing pilot project, GE Water & Process Technologies’ unique solution is helping us understand our potential to reduce energy consumption while increasing water treatment capacity and achieving greater nutrient removal without expanding our footprint. This helps to control costs and create operational efficiencies that will help the plant run better and more economically.”

Servizi Ambientali needed to bring up its wastewater treatment capacity within the bounds of its existing footprint, and thus began its unique pilot programme in December 2016 in order to find out how much energy they could save by using ZeeLung MABR and how close they could come to realising energy neutrality if GE’s Monsal* advanced digestion technology was included in a plant design for the future. The pilot test will be concluded at the end of summer this year.

GE’s ZeeLung technology has demonstrated an oxygen transfer efficiency of up to 40 per cent, with only two metres of water level available, compared to six to eight per cent for an orthodox fine bubble aeration system. On top of that, because of the simultaneous nitrification-denitrification that takes place in the ZeeLung reactor, the pilot keeps to within its parameters for nitrogen removal.

“Servizi Ambientali S.p.A. is really embracing the future of wastewater treatment as they move towards energy neutrality,” Chris Jeffery, global sales leader, engineered systems – GE Water & Process Technologies, said. “It’s exciting to see how our ZeeLung MABR is helping them reach their goals in terms of reducing their energy consumption as well as intensifying nutrient removal, something that this pilot programme is proving out quite well.”

About 60 kilometres west of Genoa and near Loano, Borghetto Santo Spirito is renowned for its pristine beaches. The water treatment plant presently serves around 90,000 residents in the towns of Balestrino, Boissano, Borghetto Santo Spirito, Ceriale, Loano, Pietra Ligure, and Toirano. It has a maximum wastewater capacity of approximately 30 million litres (30,000 cbm) a day


*Trademark of General Electric Company; and may be registered in one or more countries.