Efficient removal of Imidacloprid and nutrients by microalgae‐bacteria consortium in municipal wastewater: effects, mechanism, and importance of light

Abstract

BACKGROUND With the rapid development of society, a large amount of wastewater and pesticides enter the water bodies globally, posing a threat to both the environment and the health of people and other living things. In this paper, an algal strain Scenedesmus sp. was isolated from a municipal wastewater treatment plant (WWTP); its interaction effect with wastewater bacteria on the removal of IMI and conventional pollutants in municipal wastewater was evaluated. RESULTS In this study, an algae‐bacteria system was constructed with municipal wastewater, with the aim of exploring the removal effects and mechanisms of the consortium system on Imidacloprid (IMI, 20 mg L−1 and 60 mg L−1) and conventional nutrients from municipal wastewater. The results showed that no IMI was removed under 20 μmol m−2 s−1. However, under 60 μmol m−2 s−1, more than 90% of IMI was removed in the algae‐wastewater group (AWG) with Scenedesmus sp.; this value is much higher than the 50.4% (20 mg L−1) and 36.1% (60 mg L−1) achieved by the wastewater group (WG) without Scenedesmus sp. Meanwhile, the removal efficiency of nitrogen was 82.3% (20 mg L−1) and 71.9% (60 mg L−1) in AWG, both of which are higher than the 73.4% and 59.1% in WG, respectively. Moreover, Scenedesmus sp. TXH has a strong resistance to IMI and 4 degradation products (including IMI‐urea, 4(5)‐hydroxy‐IMI, Nitrosimine, and a substance with m/z of 176) were found in AWG. CONCLUSION Using consortium to treat municipal wastewater containing IMI is an effective and safe way. © 2022 Society of Chemical Industry (SCI).

Microalgae-Enabled Wastewater Treatment: A Sustainable Strategy for Bioremediation of Pesticides

“…The environmental factors such as light intensity and temperature have been identified as key parameters to be optimized during the treatment as they can interfere with the interaction of microalgae and bacteria in the symbiotic system. Temperature influences the stability and adsorption ability of the microalgae-bacteria consortium while light plays an important role in the enzyme activity of microorganisms [130].…”