Dual purpose microalgae-based biorefinery for treating pharmaceuticals and personal care products (PPCPs) residues and biodiesel production

Microalgal biotechnologies have emerged with high potential for removal of various organic pollutants, such as pharmaceutical and personal care products (PPCPs), from waste streams. In the present study, the removal mechanisms for three typical PPCPs and the lipid performance of Chlamydomonas sp. Tai-03 were thoroughly investigated. Bisphenol A (BPA) and Tetracycline (TCY) achieved complete removal while only similar to 20% Sulfamethoxazole (SMX) could be removed, even at low concentrations of 1 mg L-1. The mechanisms of elimination showed variation as only SMX could be removed through biodegradation, while similar to 682% TCY and similar to 14% BPA were removed by a combination of photolysis and hydrolysis. Analysis revealed three intermediates of SMX biodegradation, two of which exhibited high toxicity. Moreover, the lipid content of Chlamydomonas sp. Tai-03 increased from 5 to 49.5% with the addition of SMX, TCY and BPA, with lipid quality varying according to the type of PPCPs. In particular, the dominant component (C18:1) abundance was increased by 15.2% at 10 mg L-1 TCY. Overall, these findings provide a baseline for optimization of microalgal biodiesel production coupled with efficient PPCPs treatment biotechnology. (C) 2019 Elsevier B.V. All rights reserved.