Transformation of CuO Nanoparticles in the Aquatic Environment: Influence of pH, Electrolytes and Natural Organic Matter

Nanomaterials

Siyuan Zheng¹  Hang Hu¹  Weiling Yang¹  Cheng Peng²  Jianshe Liu²  Chensi Shen²  Jiyan Shi³ 

[1] Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China;Department of Environmental Science, College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China;Key Laboratory of Water Pollution Control and Environmental Safety of Zhejiang Province, Zhejiang University, Hangzhou 310058, China;

关键词: metal-based nanoparticles;    natural organic matter;    aggregation;    sedimentation;    dissolution;    speciation;   

DOI  :  10.3390/nano7100326

来源: DOAJ

【 摘 要 】

Many studies have shown the effect of solution chemistry on the environmental behavior of metal-based nanoparticles (NPs), except CuO NPs. Here, we investigated the agglomeration, sedimentation, dissolution, and speciation of CuO NPs by varying pH, ionic strength, ionic valence, and natural organic matter (NOM). The results showed that as the pH moved away from 6, the size of CuO agglomerates decreased, along with the enhanced NP suspension stabilization, due to the increase of electrostatic repulsive force. Increasing ionic strength and valence intensified the agglomeration and sedimentation of CuO NPs because of the compression of electrical double layers. The presence of humic acid and citric acid enhanced the dispersion and stabilization of CuO NP suspension, but l-cysteine showed a different impact. Decreasing pH, increasing ionic strength and all NOM improved the dissolution of CuO NPs, but the divalent electrolyte (CaCl2) inhibited the Cu2+ release from CuO NPs compared to the monovalent electrolyte (NaCl). In addition, X-ray absorption near edge structure (XANES) analysis demonstrated that the presence of l-cysteine transformed more than 30% of CuO NPs to Cu(I)-cysteine by coordinating with thiol group. This study can give us an in-depth understanding on the environmental behavior and fate of CuO NPs in the aquatic environment.

【 授权许可】

Unknown