Adding exogenous protein relieves the toxicity of nanoparticles to anammox granular sludge by adsorption and the formation of eco-coronas

• Published in: Environmental science. Nano Vol. 9; no. 5; pp. 1794 - 184
• Main Authors: Ma, Wen-Jie, Wang, Xin, Zhang, Jiang-Tao, Guo, Jie-Yun, Lin, Yan-Xu, Yao, Yu-Xi, Li, Gui-Feng, Cheng, Ya-Fei, Fan, Nian-Si, Jin, Ren-Cun
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 19.05.2022
• Subjects: Adsorption; Ammonium; Ammonium compounds; Aquatic environment; Coronas; Electron microscopy; Electronic materials; Enzymatic activity; Enzyme activity; Fuel cells; Fuel technology; Heme; Long-term effects; Magnesium oxide; Nanoparticles; Nitrogen removal; Oxidation; Removal; Serum; Serum albumin; Sludge; Stress; Toxicity; Transmission electron microscopy; Wastewater; Wastewater treatment
• DOI: 10.1039/d1en01138c
• ISSN: 2051-8153

MgO nanoparticles (NPs) are widely used in bactericides, fuel cells and electronic materials and are frequently detected in aquatic environments. Anaerobic ammonium oxidation (anammox) is a highly efficient and economical autotrophic nitrogen removal process. To date, the effects of MgO NPs on anammox granular sludge have remained unknown. This work systematically evaluated the short- and long-term effects of MgO NPs on anammox process performance and explored an effective strategy to relieve stress. The half maximal inhibitory concentration (IC 50 ) of MgO NPs to anammox granular sludge was 69.5 mg L −1 . During the long-term experiment, the anammox process experienced a reduction in nitrogen removal ability under the stress of 50.0 mg L −1 MgO NPs. Moreover, the enzymatic activity and synthesis of heme c significantly decreased. Adding 40.0 mg L −1 bull serum albumin (BSA) effectively relieved the stress caused by 50.0 mg L −1 MgO NPs, and the anammox activity recovered to 97.0% of the original level. Multiple spectral analyses verified the adsorption of MgO NPs by BSA. Furthermore, the formation of an eco-corona was observed by transmission electron microscopy, which also contributed to decreasing the biotoxicity of the MgO NPs. The results of this study provide guidance for treating NP-containing wastewater during the anammox process. MgO nanoparticles (NPs) are widely used in bactericides, fuel cells and electronic materials and are frequently detected in aquatic environments.