This project is focused on the use of aerobic granular systems at pilot scale to treat both urban and industrial wastewaters. Results obtained with granular aerobic reactors at laboratory scale are promising but there are few works done at pilot or industrial scale. Therefore, more information about the stability of granules and their performance at large scale is needed in order to establish aerobic granulation as a feasible treatment. The present project comprises two sub-projects where the operation of aerobic granular reactors at pilot scale (100 L) will be studied during long term experiments. The operation will be carried out under different conditions to obtain data for the reactor design at large scale and optimize nutrient removal processes at full scale.
In the sub-project presented by the group of the Universidad de Santiago de Compostela (USC), an aerobic granular unit integrated in a system for the treatment of piggery waste will be used to remove COD and nutrients from the liquid fraction of slurry and minimize sludge production. Firstly, the performance of the unit will be optimized in terms of organic matter and nitrogen removal and the quality (filterability) and quantity of sludge generated will be characterized. The efficiency of the anaerobic digestion for the treatment of both granules and solid fraction of slurry will be determined and phosphate removal by precipitation will be evaluated. Finally, all units will be integrated to know the global efficiency and to do the cost estimation of the integrated system.

The sub-project proposed by the group of the Universitat Autònoma de Barcelona (UAB) is focused on the study of the stability of a granular sludge reactor treating urban wastewaters and the development of a mathematical model which could be used to optimize the process and to design the reactor at full scale. During the operation of the granular system, effects of applied loads, temperature and presence of toxic compounds on the efficiency of nitrogen and phosphorous removal and granules integrity will be evaluated. A mathematical model which would take into account the influence of operational conditions on soluble compounds removal and physical properties of granules will be developed. The model will be calibrated and validated with results obtained from reactors treating urban wastewater and liquid fraction of slurry.

As an alternative to the conventional activated sludge treatment plants a combination of a bioreactor with granular sludge coupled to membrane systems is proposed, in order to obtain high carbon and nitrogen removal efficiencies from urban and industrial wastewaters, and to produce treated effluents which can be further reused.

In the present project the most favourable hydrodynamic conditions to develop the granules in aerobic conditions will be studied, with the subsequent research of the effect of the wastewater composition on the granules formation. The development and application of granular systems will be performed both with wastewater characterized by its high Carbon/Nitrogen (C/N) ratio, using the nitrification-denitrification processes, and also with wastewater having a low C/N ratio, using the advanced processes of partial nitrification and anaerobic ammonia oxidation (Anammox).

Different operational conditions will be tested in order to maximize the organic matter and nitrogen removal efficiencies for each wastewater studied. The granular sludge produced during the operation of the reactors will be quantified and characterized to evaluate their further management in the sludge line. The best operational conditions for the operation of the membrane system (kind of membrane, fouling, cleaning protocols….) together with the physical-chemical and microbiological quality of the obtained effluents will be studied. The possibility to reuse these effluents in the industry, agriculture or for irrigation, complying with international and national regulations, will also be evaluated.

This project is part of a partnership with a company (Espina y Delfín) for the design and construction of aerobic granular reactors.
The specific objectives of this project are the development of a pilot-scale system for the aerobic treatment of an effluent from a fish canning industry with granular biomass and to evaluate the minimization of sludge production in the system. Moreover, the characterization of the effluent generated in the system and the study of their suitability for reuse in the industrial processes in which it was originated.

This project is based on the study of aerobic granular sludge. In order to understand the mechanism of granulation it is necessary not only to know how to develop the granules but also the type of microorganisms involved. The basic objectives of this project is to study the mechanisms of formation of aerobic granules to study of the operation of different types of reactors: airlift, stirred tank reactor, etc. and the effect of the reactor configuration on granulation process.