Influence of microalgae on organic micropollutants removal from water by powdered activated carbon

Abstract

This study investigates how two morphologically distinct microalgae, Chlorella vulgaris and Arthrospira platensis, at different growth phases, affect the adsorption of ibuprofen, caffeine, and diclofenac onto two powdered activated carbons (AC1 and AC2). Experiments were utilizing dechlorinated tap water (DCTW) matrix where microalgae were added. Experiments were performed with/without pre-chlorination and with/without filtration through 0.45 ?m filter to assess the influence of total and dissolved algal organic matter. Organic micropollutants (OMPs) were analyzed using gas chromatography coupled with mass spectrometry. Results indicate that the effect of microalgae morphology on OMPs? removal efficiency is different for different carbons. Species and growth phase-dependent variations were observed in some cases. A. platensis in the stationary phase in the water reduced diclofenac removal by AC2 (from 99 % to range of 44 %-62 %), while C. vulgaris in the exponential phase reduced it to the range of 16 %-74 % in comparison to effectiveness of AC2 in DCTW without microalgae (99%). Removal of uncharged caffeine remained stable, suggesting minimal influence from algal matrices or AC variability. For negatively charged ibuprofen and diclofenac the observed effects were more variable and not always consistent, likely due to limitations in experimental methodologies.