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Aerobic granulation for wastewater bioremediation: A review


  • Mohammad Zain Khan,

    1. Department of Civil, Environmental and Geomatic Engineering, Chadwick Building, University College London, Gower Street, WC1E 6BT, London, UK
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  • Pijush Kanti Mondal,

    1. Institute of Bioengineering and Biotechnology, Center of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
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  • Suhail Sabir

    Corresponding author
    1. Faculty of Science, Environmental Research Laboratory, Department of Chemistry, Aligarh Muslim University, Aligarh 202 002, UP, India
    • Faculty of Science, Environmental Research Laboratory, Department of Chemistry, Aligarh Muslim University, Aligarh 202 002, UP, India.
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  • The following are the major points of this review:

     1. Both mixed and pure cultures can be used for cultivating aerobic granules. Generally, mixed culture is employed for degrading a mixture of toxic compounds, and pure culture is useful for degrading a specific toxicant.

     2. Aerobic granules are used to treat wastewater containing higher organic loading rates as well as fluctuations in organic loading rates.

     3. There is a strong contradiction regarding the effect of DO, HRT and the starvation period on biogranulation.

     4. Further research is needed to explore the feasibility of using stored granule as inoculums for rapid startup.


Rapid industrialisation and urbanisation releases numerous toxic compounds into natural water bodies, polluting these pristine fresh water resources. This is a subject of great concern, and the attention of environmentalists around the world has been increased towards this problem in recent years. Several techniques have been proposed for efficient wastewater treatment, most of them presenting some limitations, such as poor capacity, the generation of waste products, incomplete mineralisation and a high operating cost. Currently, aerobic granulation treatments are considered to be the most effective and economic alternative. Aerobic granulation is a process of microbial self-immobilisation that results into a cell-structured shape, characterised by dense biomass. Aerobic granules have a number of advantages over conventional bioflocs, such as a round and compact structure, good settling ability, high biomass retention and the ability to withstand high organic loading rates. Aerobic granulation technology has been demonstrated to be useful for a wide variety of wastewaters, including industrial, nutrient-rich and toxic. This paper presents a state-of-the-art review of effective aerobic granulation technology for wastewater treatment selected from the point-of-view of basic concepts of aerobic granulation, characterisation and factors that affect aerobic granulation, demonstrating the effectiveness of the cell-immobilisation (aerobic granulation) technique. © 2012 Canadian Society for Chemical Engineering