Upgrading wastewater treatment plants by Low cost Innovative technologies for energy SElf-Sufficiency and full recycling

PROJECT DESCRIPTION

BACKGROUND

Europe generates up to 40 billion m3 of municipal wastewater per year, but only around 1 billion m3 of this is currently reused. This is mainly because of the high costs of conventional tertiary treatments needed to achieve strict quality requirements, especially for irrigation in agriculture.

Wastewater treatment results in 0.5 kWh/m3 in energy consumption (equivalent to the energy generation of two nuclear power plants), over 27 million tonnes of CO2eq/year and 3.5 million tonnes of sewage sludge that must be managed by the plant operators.

This wastewater has great energy and resource potential mostly from the organic matter from sewage sludge. Currently this is only partially recovered in the form of biogas. While Europe produced 2.5 million m3 of biogas from sewage sludge in 2016, about 15% of the potential biogas was burned in disposal torches.

Sewage sludge is a good source of nutrients and organic matter for agriculture purposes, but its usage in agriculture still raises many concerns due to the potential presence of heavy metals, emerging pollutants or pathogens.

OBJECTIVES

The main objective of the LIFE ULISES project is to demonstrate a set of technologies to improve the resource efficiency of wastewater treatment plants. This will include:

an anaerobic pretreatment and aeration process to reduce energy demand;

an upgrading process to increase biogas production;

an enzymatic hydrolysis and membrane-based struvite precipitation for the use of sludge as fertiliser; and

a solar-based tertiary treatment for water reuse.

All these processes will be tested and validated in a pilot plant located in El Bobar, Almera, Spain.

RESULTS

Expected results:

up to 15 Nm3/y of biomethane produced, able to supply biofuel for 120 cars;

pre-treatment of 15 m3/day of wastewater, removing 75% of the chemical oxygen demand and producing 1.5 m3/day of biogas;

reduction of around 30% of energy consumption and 1 900 tonnes of CO2eq/year;

over 200 litres/day of hydrolysed biofertilizer with phytostimulant properties produced;

0.6 kg/day of struvite and 150-200 litres/day of concentrated fertiliser produced; and

350 m3/day of reclaimed water that meets quality requirements for irrigation produced.

LIFE ULISES will address many of the key pillars of the EUs environmental policies on energy, water and circular economy.