Pharmaceuticals removal and nutrient recovery from wastewaters by Chlamydomonas acidophila

Wastewater treatment plants are a major source of human pharmaceutical residues (PR) in the aquatic environment, which are considered to be of emerging concern. The microalga Chlamydomonas acidophila has shown to be a promising technology to recover the nutrients from wastewater and therefore, the aim of this study was to evaluate the ability of this species to also remove PRs commonly present in wastewaters (atenolol, caffeine, carbamazepine, clarithromycin, erythromycin, lidocaine, propranolol and simvastatin). Batch assays were carried out (50 mL, 90 rpm, 43 μmol photons m^-2 s ^-1, 22 °C) comprising the wastewater with the pharmaceutical mixture at three concentrations: CHigh, CModerate and CEnv. The results demonstrated that this microalga does not seem to be affected by pharmaceuticals in wastewater at concentrations well above those detected in urban effluents; additionally it is able to degrade the antibiotics erythromycin and clarithromycin better than other microalgae species and enhances their removal from wastewater by 93 - 65% and 64 - 50% respectively. Furthermore, it exhibited a high assimilation of ammonium and phosphates reaching values of around 9 mgNH₄ L^-1d^-1 and 3 mgPO₄ L^-1d^-1 compared to other species. Therefore, Chlamydomonas acidophila appears to be a promising agent for urban wastewater treatment.