EARTH

[3901-12-03] Short-term influence of CuO, ZnO nanoparticles and CNTs on anammox granules by batch assays

Yuxia Song¹, ○Chongjian Tang^1,2, Cheng Yu¹, Chengshan Duan¹, Chukuang Jiang¹, Lin Zhang¹ (1. Central South University, 2. Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution)

Chairman: Kyoungkeun Yoo （Korea Maritime and Ocean University）, Naoki Hiroyoshi (Hokkaido University)

Keywords:Anammox, Nanoparticle, Batch test, Inhibition kinetics

The spread application of nanoparticles (NPs) in consumer and industrial products indicates the importance of studying NPs release to the water body and their potential risks to the biological process for wastewater treatment. The present study investigated the short-term effects of ZnO nanoparticles (NPs), CuO NPs and multi-walled CNTs (carbon nanotubes) on anaerobic ammonium oxidation (anammox) process by batch tests. Results indicated that both CuO NPs and CNTs up to 500 mg gVSS^-1, did not inhibit anammox activity. However, a significant inhibition occurred under ZnO NPs addition of 5-100 mg gVSS^-1.The half inhibitory concentration (IC₅₀) of ZnO NPs was found to be 11.6 mg gVSS^-1 during 12 h exposure. Haldane model evaluation showed that the kinetic characteristics of the two substrates (ammonium/nitrite) conversion on anammox with exposure to ZnO NPs (11.6 mg gVSS^-1) were quite different. Non-competitive inhibition was observed on nitrite conversion kinetics, while competitive inhibition dominated on ammonium conversion kinetics. The inhibition was alleviated after ammonium concentrations increased. The inhibition of anammox activity induced by higher concentrations of ZnO NPs was due to the release of zinc ions from ZnO NPs dissolutions.