Extensive use of synthetic dyes has fostered the growth of dyestuff industry, bringing not only economic benefits but also huge amount of wastewater. Such wastewater is color-intense, potentially carcinogenic and mutagenic in nature, making pre-disposal treatment necessary. Conventional activated sludge biotreatment system is believed to be one of the most promising techniques in dealing with synthetic dyes effluents, however the sludge poor settling properties makes the installation of large sedimentation tanks necessary thus making the process high in capital cost and space consuming.

Aerobic sludge granulation process is a novel process developed in recent decades, in which activated sludge are granulated into cell aggregates with diameter ranged from 0.2 mm to 5 mm. With its advant...[ Read more ]

Extensive use of synthetic dyes has fostered the growth of dyestuff industry, bringing not only economic benefits but also huge amount of wastewater. Such wastewater is color-intense, potentially carcinogenic and mutagenic in nature, making pre-disposal treatment necessary. Conventional activated sludge biotreatment system is believed to be one of the most promising techniques in dealing with synthetic dyes effluents, however the sludge poor settling properties makes the installation of large sedimentation tanks necessary thus making the process high in capital cost and space consuming.

Aerobic sludge granulation process is a novel process developed in recent decades, in which activated sludge are granulated into cell aggregates with diameter ranged from 0.2 mm to 5 mm. With its advantages in higher biomass density and faster settling velocity, higher volumetric pollutant removal can be achieved with simpler sludge settler designs; together with the unique oxygen shielding effect by the outer layer bacteria in aerobic bacterial granules, we believe that it is also possible to develop a simultaneous anaerobic/aerobic process system using aerobic granules.

In this project, we have designed a method in cultivating the aerobic granules for successful azo dye wastewater treatment; demonstrating their capabilities in performing simultaneous anaerobic/aerobic process for decolorization and aromatic amines removal; we have also optimized the process performances by varying 4 operational parameters including sludge particle size, bulk dissolved oxygen concentration, biomass concentration and nutrient concentration.