Emerging contaminants and nutrients recovery by Picocystis sp. under continuous culture in contaminated secondary municipal wastewater effluent

Abstract

This study assesses the growth and the recovery ability of the Chlorophyta Picocystis sp., cultivated in wastewater supplemented by a model mixture of emerging contaminants (EMCs). The mixture of EMCs consisted of three pharmaceuticals, diclofenac (DCF), sulfadiazine (SDA), and oxytetracycline (OTC), and the plastics precursor bisphenol A (BPA). Continuous cultures were carried out for 27 days in a set of four columns of photobioreactors connected in series to investigate the daily EMCs and nutrient recovery. Picocystis was able to grow in contaminated wastewater with daily biomass productivity of 0.5 ± 0.05 g L−1 d−1. Picocystis exhibited high daily EMCs removal efficiencies reaching 100 %, 83–92 %, 93–95 %, and 66–70 % of 1 mg L−1 initial concentration of OTC, DCF, BPA, and SDA, respectively. Besides, Picocystis showed daily nutrient recovery rates of 40 % for nitrogen and total organic carbon and 27 % for phosphorus.These results pointed to the promising application of Picocystis in a continuous bioremediation system for the removal of emerging contaminants and nutrients from wastewaters.