Approaching the binding between Cu(II) and aerobic granules by a modified titration and µ-XRF

Abstract

Interactions between metals and activated sludge can substantially affect the fate and transport of heavy metals in wastewater treatment plants. Therefore, it is important to develop a simple, fast and efficient method to elucidate the interaction. In this study, a modified titration method with a dynamic mode was developed to investigate the binding of Cu(II), a typical heavy metal, onto aerobic granules. The titration results indicated that pH and ionic strength both had a positive effect on the biosorption capacity of the granular sludge. The µ-XRF results demonstrated that the distribution of metals on the granular surface was heterogeneous, and Cu showed strong correlations and had the same “hot spots” positions with other metal ions (e.g., Ca, Mg, Fe etc.). Ion exchange and complexing were the main mechanisms for the biosorption of Cu(II) by aerobic granules. These results would be beneficial for better understanding of Cu(II) migration and its fate in wastewater treatment plants.

Keywords

aerobic granules / Cu(II) / modified titration / µ-XRF analysis

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Acknowledgements

The authors wish to thank the National Natural Science Foundation of China (Grant Nos. 51322802 and 21377123), the Program for Changjiang Scholars and Innovative Research Team in University, and the Fundamental Research Funds for the Central Universities (WK2060190040 and WK3530000002) for the partial support of this study. Authors also wish to thank the Shanghai Synchrotron Radiation Facility, Shanghai, China for µ-XRF analysis.

Supplementary material is available in the online version of this article at http://dx.doi.org/10.1007/s11783-015-0803-0 and is accessible for authorized users.

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2014 Higher Education Press and Springer-Verlag Berlin Heidelberg