SMARTech n.

Integrated municipal WWTP

Key enabling process(es)

SMART-product(s)

SMARTech2b

Manresa (Spain)

Mainstream SCEPPHAS

P-rich sludge, PHA

The municipal WWTP of Manresa (Barcelona, Spain) receives an average flow rate of 27,000 m3/ day. It consists of a pre-treatment (gross and grit removal), primary treatment with a clarifier and a secondary biological stage. There are two main treatment lines in the secondary stage; each one has three anoxic reactors (1,460 m3) and one aerobic reactor (6,782 m3). It uses a Modified Ludzack-Ettinger Process (MLE) for COD and N removal with conventional nitrification/denitrification. Air is bubbled from the bottom of the aerobic tanks with membrane diffusers. An internal recycle pipe connects the aerobic zone to the anoxic one to bring the nitrate to be denitrified in the anoxic zone. At the end of the secondary stage, two settlers separate the biomass from the treated effluent. Settled biomass returns to the entrance of the anoxic reactor by an Archimedes screw. Phosphorus is removed by chemical precipitation with FeCl3. The effluent, after leaving the secondary settler, can be chlorinated and it is disposed to the environment at the Cardener River, which is considered a sensitive area.

SMARTech2b is the key to enable secondary mainstream energy-efficient resource recovery. It applies the mainstream SCEPPHAR (Short - Cut Enhanced Phosphorus and PHA Recovery) and consists of two SBR; one for heterotrophic bacterial growth operated under anaerobic/anoxic/aerobic sequence (HET-SBR), and another SBR for autotrophic nitrifiers growth (AUT-SBR), an interchange vessel and a chemical system for P-recovery as struvite. The integrated system accomplishes enhanced N-removal and P-recovery in municipal WWTP.PHA will be recovered from the anaerobic purge of the SBR. The liquid volume of each SBR vessel is 2500 L, for the interchange vessel is the same as for the SBR and for the struvite precipitation vessel is 400 L.

The pilot-scale system will have a reaction volume of 6-8 m3 and will be installed at the Manresa municipal WWTP (Spain) to treat about 10 m3/d of sewage in 3 cycles of 8 hours per day. The main objectives of the pilot- plant implemented as a mainstream treatment for municipal wastewater are to: (1) treat 10m3/d of wastewater after primary treatment; (2) achieve an effluent with P < 1 mg/L and TN <10 mg/L without addition of external carbon source nor FeCl3 for P precipitation; (3) remove N via nitrite with a removal up to 90%; (4) recover around 50% of P in the influent as struvite; (5) produce a waste sludge with PHA content up to 30% without addition of external carbon source.

 

smarttech2b
smarttech2b 2
smarttech2b 3

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SMART-Plant is a member of the ICT4WATER cluster

SMART-Plant member of the European Sustainable Phosphorus Platform