Electrostatic and functional group-mediated biosorption of microalgae and lead using biosafe Aspergillus oryzae 3.042...

Co-occurring algal blooms and lead (Pb) pollution pose severe threts to freshwater ecosystems. In this study, Aspergillus oryzae (A. oryzae) 3.042 fungal pellets (FPs) were produced to harvest Chlorella pyrenoidosa, creating fungal-algal pellets (FAPs), which were used as heavy-metal capture materials. Under optimized conditions (2 mm diameter, 180 rpm, 3 g·50 mL^-1, pH 3-7), FPs achieved 95 %-99 % algae removal efficiency, with these factors significantly influencing removal efficiency. Under complex water conditions, including microalgae concentration, Pb concentration and N:P ratio, FPs achieved satisfactory microalgae removal efficiency, demonstrating its advantages in water body restoration. Multiscale characterization revealed that FAPs formation relies primarily on electrostatic attraction complemented by functional-group interactions. Furthermore, FAPs structure facilitates Pb immobilization via chemisorption (94 mg·g^-1), mediated by surface amide, carboxyl, and phosphate groups, forming {FAPs-tyrosine-Pb} complexes. A. oryzae 3.042, utilizing FPs technology, is biosafe, high-efficient, and sustainable solution for microalgae harvesting and Pb remediation in water.