Sepiolite as carrier of the phosphate-accumulating bacteria Acinetobacter junii

Sepiolite in its original (OS) and purified form (PS) was tested as a carrier of the phosphate-accumulating bacteria Acinetobacter junii. The numbers of A. junii immobilized onto sepiolite were 5.57 and 8.12 × 109 CFU g− 1 for OS and PS, respectively. The immobilized bacteria were metabolically active and removed phosphate from synthetic wastewater. Better phosphate removal in reactors with immobilized bacteria when compared to reactors with planktonic bacteria was mainly due to the increased bacterial biomass and at a lower extent due to the increased bacterial phosphate-uptake rates. The bioaugmentation of an activated sludge with A. junii immobilized on OS significantly improved the phosphate removal from synthetic wastewater when compared to a conventional activated sludge.

Research Highlights
► Sepiolite immobilizes bacteria
► Bacteria immobilized on sepiolite are metabolically active
► Sepiolite is promising material for bioaugmentation of an activated sludge