Pilot results show potential for municipal wastewater treatment plant in Italy to achieve energy neutrality

Borghetto Santo Spirito, a tourist town on the Mediterranean Sea and managed by Servizi Ambientali SPA, has achieved positive results during the first six months of a 10-month pilot featuring GE Water & Process Technologies’ innovative technologies including ZeeLung Membrane Aerated Biofilm Reactor (MABR) and LEAPprimary advanced primary treatment technology.

Nearly six months after the start of a pilot program to demonstrate its potential to achieve energy neutrality, GE’s ZeeLung MABR technology has shown:

An aeration energy savings of four to five times compared to fine bubble aeration.

The potential to reduce the biological volume by 50 percent compared to the conventional activated sludge process, while achieving the same effluent limits.

Up to 80 percent nitrogen removal without the need for internal nitrate recirculation.

“We continue to be vigilant on new technologies launched in the market that aim to improve operational cost 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 (SV),” said Giovanni Paolo Paganelli, general manager of Servizi Ambientali. “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.”

Needing to increase treatment capacity within its existing footprint, Servizi Ambientali SPA began a first-of-its-kind pilot program in December 2016 to determine how much energy it could save by employing ZeeLung MABR and what the potential could be for energy neutrality should it include GE’s Monsal* advanced digestion technology into a future plant design. Servizi Ambientali SPA will continue the pilot test of Water & Process Technologies’ equipment through the end of summer 2017.

To date, the ZeeLung technology has demonstrated an oxygen transfer efficiency of up to 40 percent, with only 2 meters of water level. This compares to 6-8 percent for a conventional fine bubble aeration system. Additionally, due to the simultaneous nitrification-denitrification that occurs in the ZeeLung reactor, the pilot is meeting parameters for nitrogen removal.

“Servizi Ambientali SPA is really embracing the future of wastewater treatment as they move towards energy neutrality,” said Chris Jeffery, global sales leader, engineered systems—GE Water & Process Technologies. “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 program is proving out quite well.”

Known for its pristine beaches, Borghetto Santo Spirito is near Loano, in the Province of Savona, in the Italian region of Liguria, and is approximately 60 kilometers west of Genoa. The wastewater treatment plant currently serves approximately 90,000 residents in the towns of Borghetto S. Spirito, Loano, Pietra Ligure, Toirano, Boissano, Balestrino and Ceriale. It handles a maximum wastewater flow of about 30 million liters per day or 30,000 cubic meters per day.