Phosphate Removal from Water by Using Biomass Obtained from Arthrospira platensis

Eutrophication is a significant issue in aquatic systems that receive wastewater from anthropogenic sources. The reduction of phosphate concentration in wastewater and water bodies is essential to reduce the risk of eutrophication. In this study, biomass obtained from Arthrospira platensis was used to reduce the phosphorus concentration in water. The biomass samples were characterized by spectroscopic and morphological techniques, such as vibrational spectroscopy (FTIR and Raman) and microscopy assay (SEM). Adsorption studies were conducted to evaluate the removal efficacy of the biomass. Phosphate removal capacity was strongly influenced by pH, with the highest effectiveness observed under acidic conditions (88% removal at pH 4.4) and rapid initial adsorption reaching equilibrium. Kinetic modelling showed a maximum removal efficacy (qe = 2.4 mg g−1 and k2 = 0.305 min−1). Isothermal adsorption analysis showed that the Langmuir model described properly experimental results showing physical chemical parameters (qmax = 2.8 mg g−1 and KL = 1.41 L mg−1).