The environmental problem targeted by LIFE AMIA is water scarcity and the low rate of wastewater reuse, along with the intensive energy consumption of conventional wastewater treatment plants (WWTPs) and the pollution caused by micropollutants and pathogens that are not currently removed by conventional WWTPs.
LIFE AMIA aims to reuse wastewater in agricultural irrigation and aquifer recharge to protect the aquatic environment against pollution caused by pathogens and micropollutants not removed by conventional wastewater treatment plants (WWTPs), at significantly reduced energy requirements. To this end, a novel process consisting of an anaerobic-aerobic compact treatment, a microalgae raceway and a combination of adsorption and advanced oxidation process (AOP) will be validated. The new concept of WWTP will recover nutrients (algae) and reduce the net energy consumption. Consequently, this will reduce the emissions of greenhouse gases (GHG) by means of: anaerobic treatment that produces biogas and consumes less energy; microalgae treatment with low energy requirements; and adsorption & electro-oxidation technology supplied by renewable energy.
Expected results: definition of a new concept of WWTP mainly focused on the fulfilment of the water reuse requirements in the Water Framework Directive, at low energy requirements, and giving added value to the by-products; an energy self-sufficient plant which can produce more energy than it consumes (13.90 kWh/day vs 4.51 kWh/day); reduction of total sludge production by 40%, minimising sludge management costs; GHG emissions reduction of 0.686 tons/year: 57.5% CO2 and 63.16% N2O; continuous operation in a municipal WWTP with organic loading rate (OLR) of 3 kg COD/m3d with a reduction of 87% of chemical oxygen demand (COD) in the A2C process, and the subsequent increase of OLR up to 12 kg COD/m3 by means of co-digestion; global COD efficiency removal of at least 98% in the complete system; production of 0.36 m3 CH4/kg COD removed from a biogas stream with methane (CH4) content of 68%,which implies energy production of 12.46 kWh/day; reduction of 90% of priority substances; anaerobic digestion of aerobic excess biomass in the same tank which involves saving a further 52% of cationic polyelectrolyte due to lower sludge production and its better dewaterability, and a total reduction (100%) of ferric sulphate; reduction of nutrient removal energy consumption from 0.35 kWh/m3 of extended aeration system to 0.18 kWh/m3 of the HRAP (49%). A 10% increase in phosphorus removal efficiency due to the implementation of the high rate algal ponds (HRAP) process. Algal biomass will be richer in nutrient content for use as a biofertiliser; AOP technology which reduces energy consumption by 44.63% compared to conventional UV lamps. Additionally, solar panels will power it; and new system replication in European market to improve the performance of existing WWTPs and to implement in new WWTPs, with high impact for European Water Agencies.