Construction of microalgae-bacteria consortium to remove typical Neonicotinoids Imidacloprid and Thiacloprid from municipal wastewater: Difference of algae performance, removal effect and product toxicity.

The studies on the removal of Neonicotinoids pesticides (NNIS) and their degradation products have attracted more and more attention. However, the simultaneous removal of pesticides and conventional pollutants remain inadequately understood. In this study, a green alga strain Scenedesmus sp. TXH was isolated from a wastewater treatment plant and the microalgae-bacteria system was constructed with municipal wastewater. The removal effect of consortium system on Imidacloprid (IMI)/Thiacloprid (THI) and conventional nutrients was employed. Results showed that Scenedesmus sp. TXH achieved 71.24 % and 9.71 % removal of IMI and THI in wastewater under 100 μmol m−2 s−1 of light intensity, much higher than the 55.54 % and 2.71 % without inoculating Scenedesmus sp. TXH. The removal efficiency of the two pollutants was obviously different, which may be attributed to the different functional groups of pollutants. Meanwhile, a much faster removal of conventional pollutants (TDN, TDP and sCOD) occurred in algae-wastewater group. Based on the identified products from mass spectrometer, the main reaction pathways were found and products have lower toxicity evaluated by Ecological Structure-Activity Relationship (ECOSAR) program. This study provided valuable information for the development of NNIS removal with microalgae, which could further enhance the feasibility of microalgae applications in removing NNIS and conventional pollutants. [Display omitted] • Algae-bacteria consortium removed 71.24 % of IMI and 9.71 % of THI. • More than 80 % and 90 % of TDN and TDP were removed by algae-bacteria consortium. • The main way of removing pesticide by algae-bacterial consortium was biodegradation. • More degradation products of THI were detected in algae-bacteria consortium. • Scenedesmus sp. TXH can be used as a promising species for IMI/THI treatment. [ABSTRACT FROM AUTHOR]