PROJECT DESCRIPTION
BACKGROUND
Contaminants in wastewater from the brewing industry come mainly from equipment cleaning operations and treatment processes. The main pollutants are sulphates (1.2-2.0 Kg/h), bicarbonates (0.2-0.4 kg/hl) and nitrates (30-100 mg/l), which all cause severe environmental problems (especially in water bodies). The best techniques currently used for reducing pollutants in brewing industry wastewater are based on membrane processes (dead-end, cross-flow and dynamic filtration), as an alternative to conventional solid-liquid separations. These techniques reduce the presence of pollutants in effluents by 75-85%, enabling them to be discharged into river basins or used for irrigation. Other pollutant removal techniques include biological treatments (aerobic and anaerobic) and chemical oxidation. All these techniques reduce pollutant levels in wastewater from the different production stages, but they do not represent a zero-discharge solution and incur with high energy costs.
OBJECTIVES
LIFE-ANSWER aimed to demonstrate an integrated and innovative technology for treating wastewater from breweries, and other food and drink sectors. In particular, the proposed technology would combine electrocoagulation and bioelectrogenesis microbial treatments for the complete (100%) removal of wastewater pollutants. This technology would be implemented in Alovera (Spain) in a pilot waste water treatment plant (WWTP) able to treat 10 m3/h of wastewater. The final dry residue was expected to be valorised for both energy production (making the process energy efficient) and fertiliser. The project is in line with the Water Framework Directive and its objective of achieving good status for all EU water bodies.
The specific objectives of the project were to:
- Characterise the obtained treated water for each technology combination and identify its possible uses;
- Mitigate existing environmental and health impacts (diseases), as well as obtaining a reduction in the carbon footprint of WWTPs;
- Evaluate the wastewater situation in food and drink industries, assess and transfer the project results, and apply the best available technology in WWTPs;
- Assess the socio-economic impact of the demonstration plant implementation on the local economy, and also for European regions with similar water pollution problems; and
- Reach stakeholders with the benefits of using the LIFE ANSWER technology.
RESULTS
The LIFE ANSWER project demonstrated the technical and economic feasibility of electrocoagulation and bioelectrogenesis microbial (also called electrochemical) treatments in medium-to-small industry wastewater treatment plants, such as found in the brewery and other food and drink sectors. Using this technology, the project team aimed for a zero effluent discharge, to meet the most stringent discharge standards, while obtaining high-quality products from recovered materials.
To that end, the project team installed prototypes (electrocoagulation (EC), bioelectrochemical reactor, ultraviolet (UV), and ultrafiltration (UF) reactors) to treat 10 m3/hour of wastewater from beer production, in one of the three wastewater treatment plants in Alovera, in the province of Guadalajara (Spain). To prepare for the demonstration phase, the project team analysed industrial wastewater from a range of food and drink industries, concluding that wastewater flows are relatively homogeneous in terms of typology and concentration ratios. This means that the project technologies can be widely replicated. They also characterised the chemical and ecotoxicological properties of the wastewater, confirmed their suitability for treatment.
The project team designed, constructed and installed prototypes at Alovera’s facilities. The 12-month demonstration period, resulted in:
- The techno-economic validation of the technology proposed.
- Removal of organic matter and nutrients at a low operating cost: reductions of 58% P and 40% N with the EC process; reductions of 85% of organic matter and more than 50% of remaining P and N with this fixed-bed bioreactor (FBBR) process; and
- High-quality reclaimed water after the UF+UV process, which according to legislation, can be used for irrigation, street cleaning, car washing and for fire prevention.
- Reduction in the use of chemicals (coagulants/flocculants), while a major brewery industry waste product was reused, namely aluminium for the production of sacrificial anodes.
- A biogas enriched with methane and hydrogen, enabling reductions in energy consumption and, in turn, a 25% reduction of greenhouse gas emissions.
- The validation of the waste generated as fertiliser with high levels of P and N.
All the expected results were achieved, though values for COD and P reduction were higher than expected (though still within legal thresholds). However, the foreseen values were achieved when a final stage of reverse osmosis (RO) was added, as part of the tertiary treatment. The combination of project technologies and RO resulted in a discharged wastewater of potable quality, at a low operational cost.
Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).
