Adsorption of thallium(I) on rutile nano-titanium dioxide and environmental implications

Weilong Zhang; Yang Wu; Jin Wang; Juan Liu; Haifeng Lu; Shuijing Zhai; Qiaohui Zhong; Siyu Liu; Wanying Zhong; Chunling Huang; Xiaoxiang Yu; Wenhui Zhang; Yongheng Chen

doi:10.7717/peerj.6820

Adsorption of thallium(I) on rutile nano-titanium dioxide and environmental implications

PeerJ. 2019 May 16:7:e6820. doi: 10.7717/peerj.6820. eCollection 2019.

Authors

Weilong Zhang¹, Yang Wu¹, Jin Wang¹, Juan Liu¹, Haifeng Lu², Shuijing Zhai³, Qiaohui Zhong^{1

4}, Siyu Liu¹, Wanying Zhong¹, Chunling Huang¹, Xiaoxiang Yu¹, Wenhui Zhang¹, Yongheng Chen¹

Affiliations

¹ Innovation Center and Key Laboratory of Water Quality and Conservation in the Pearl River Delta, Ministry of Education, School of Environmental Science and Engineering, Guangzhou University, Guangzhou, China.
² Wuhan Digital Engineering Institute, Wuhan, China.
³ Key Laboratory of Humid Subtropical Eco-geographical Processes, Ministry of Education, College of Geography Science, Fujian Normal University, Fuzhou, China.
⁴ Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, China.

Abstract

Rutile nano-titanium dioxide (RNTD) characterized by loose particles with diameter in 20-50 nm has a very large surface area for adsorption of Tl, a typical trace metal that has severe toxicity. The increasing application of RNTD and widespread discharge of Tl-bearing effluents from various industrial activities would increase the risk of their co-exposure in aquatic environments. The adsorption behavior of Tl(I) (a prevalent form of Tl in nature) on RNTD was studied as a function of solution pH, temperature, and ion strength. Adsorption isotherms, kinetics, and thermodynamics for Tl(I) were also investigated. The adsorption of Tl(I) on RNTD started at very low pH values and increased abruptly, then maintained at high level with increasing pH >9. Uptake of Tl(I) was very fast on RNTD in the first 15 min then slowed down. The adsorption of Tl(I) on RNTD was an exothermic process; and the adsorption isotherm of Tl(I) followed the Langmuir model, with the maximum adsorption amount of 51.2 mg/g at room temperature. The kinetics of Tl adsorption can be described by a pseudo-second-order equation. FT-IR spectroscopy revealed that -OH and -TiOO-H play an important role in the adsorption. All these results indicate that RNTD has a fast adsorption rate and excellent adsorption amount for Tl(I), which can thus alter the transport, bioavailability and fate of Tl(I) in aqueous environment.

Keywords: Adsorption behavior; Rutile nano-titanium dioxide; Thallium.

Grants and funding

This work was supported by the Natural Science Foundation of China (Nos. 41573008, 41873015, 41573119, 41773011 and U1612442), the Guangdong Provincial Natural Science Foundation (2017A030313247), the Environmental Protection Ministry of Public Welfare Research Projects (201509051), the Guangzhou University’s 2017 training program for young top-notch personnel (BJ201709) and the 16th “Challenge Cup” Undergraduate Program and Provincial Undergraduate Training Project for Innovation (201811078128). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.