Development and characterization of fungal biofilm for the accumulation of polyphosphate from wastewater

Phosphorus is primarily mined from non-renewable mineral ores in an unsustainable way. Therefore the development of technologies to recuperate phosphorous from different sources is of importance. Meanwhile, current biological wastewater treatment technology generates large quantities of sludge and has limited removal efficiencies for phosphorous. New technologies should aim not only to decrease the production of sludge but also to increase the removal efficiency of phosphorous (P) while increasing the valorization of the biomass generated. In this work, the potential of using fungal biofilm for the treatment of wastewater and the generation of valuable biomass was explored. Three fungi strains Mucor circinelloides, Mucor hiemalis and Aspergillus niger were found to form biofilm attached to a flexible polypropylene textile. After 72 hours of cultivation, biofilm fungi Mucor circinelloides and Mucor hiemalis showed P removals of about 98±3 % and 68±8 % respectively Moreover Aspergillus niger reached only P removals of 15±5 %. From the studied strains Aspergillus niger was found to have the best attachment capability and flocculation efficiency. The flocculation capacity of Aspergillus niger in kaolin suspensions (up to 2 g/L) was in the order of 80% and 90% after 24 and 48 hours cultivation respectively. These results showed that these strains have great potential for polyphosphate accumulation from wastewater.