Short-term impacts of Cu, CuO, ZnO and Ag nanoparticles (NPs) on anammox sludge: CuNPs make a difference

• DOI: 10.1016/j.biortech.2017.03.135
• Publication Date: 2017-03-24T23:18:38Z
• Authors: Zheng-Zhe Zhang; Jia-Jia Xu; Zhi-Jian Shi; Ya-Fei Cheng; Zheng-Quan Ji; Rui Deng; Ren-Cun Jin
• Keywords: Anammox

The increasing application of engineered nanoparticles (NPs) has posed an emerging challenge to wastewater treatment processes. The short-term impacts of CuNPs, CuONPs, ZnONPs and AgNPs on anaerobic ammonium oxidation (anammox) process were investigated firstly in this study. CuONPs, ZnONPs and AgNPs up to 50mgg-1 suspended solid (SS) did not affect anammox activity, reactive oxygen species (ROS) production or cell membrane integrity. However, 1.25mgg-1SS CuNPs significantly inhibited the anammox activity and the loads that caused 50% inhibition were 4.64±1.24 and 3.27±0.79mgg-1SS for anammox granules and flocs, respectively. 5mgg-1SS CuNPs caused serious accumulation of the toxic intermediate N2H4. Furthermore, CuNPs interacted with extracellular polymeric substances by specifically bonding to tyrosine or tryptophan-containing groups, C-O-C in polysaccharides and -OH in polymeric compounds. Therefore, this study calls for more attention to the risks of NPs to the anammox-based processes.