Effects of water chemistry on the dissolution of ZnO nanoparticles and their toxicity to Escherichia coli

• Published in: Environmental pollution (1987) Vol. 173; pp. 97 - 102
• Main Authors: Li, Mei, Lin, Daohui, Zhu, Lizhong
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.02.2013; Elsevier
• Subjects: Animal, plant and microbial ecology; Applied ecology; aquatic organisms; Biological and medical sciences; calcium; Calcium - chemistry; cations; chemistry; Dissolution; dissolved organic matter; Drinking Water; Drinking Water - chemistry; drug effects; Ecotoxicology, biological effects of pollution; Environmental Quality Incentives Program; Escherichia coli; Escherichia coli - drug effects; Fresh Water; Fresh Water - chemistry; Fundamental and applied biological sciences. Psychology; General aspects; hydrochemistry; magnesium; Magnesium - chemistry; Metal Nanoparticles; Metal Nanoparticles - chemistry; Metal Nanoparticles - toxicity; nanoparticles; Toxicity; Water chemistry; Water Pollutants, Chemical; Water Pollutants, Chemical - chemistry; Water Pollutants, Chemical - toxicity; zinc; Zinc Oxide; Zinc Oxide - chemistry; Zinc Oxide - toxicity; ZnO nanoparticles; Water chemistry; ZnO nanoparticles; Toxicity; Dissolution; Pollution; Nanoparticle; Escherichia coli; Bacteria; Environment; Enterobacteriaceae
• ISSN: 0269-7491; 1873-6424; 1873-6424
• DOI: 10.1016/j.envpol.2012.10.026

The dissolution of ZnO nanoparticles (nano-ZnO) plays an important role in the toxicity of nano-ZnO to the aquatic organisms. The effects of water chemistry such as pH, ionic components, and dissolved organic matter (DOM) on the dissolution of nano-ZnO and its toxicity to Escherichia coli (E. coli) were investigated in synthetic and natural water samples. The results showed that the toxicity of nano-ZnO to E. coli depended on not only free Zn2+ but also the coexisting cations which could reduce the toxicity of Zn2+. Increasing solution pH, HPO42−, and DOM reduced the concentration of free Zn2+ released from nano-ZnO, and thus lowered the toxicity of nano-ZnO. In addition, both Ca2+ and Mg2+ dramatically reduced the toxicity of Zn2+ to E. coli. These results highlight the importance of water chemistry on the toxicity evaluation of nano-ZnO in natural waters. ► The effects of water chemistry on the toxicity of nano-ZnO were investigated. ► Increasing solution pH, HPO42−, and DOM reduced nano-ZnO toxicity to E. coli. ► Ca2+ and Mg2+ could dramatically reduce the toxicity of nano-ZnO to E. coli. ► Free Zn2+ ions and water hardness together controlled nano-ZnO toxicity in waters. The toxicity of nano-ZnO to E. coli depended on not only free Zn2+ but also Ca2+ and Mg2+ which could reduce the toxicity of Zn2+.