ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Solubility enhancement of phenanthrene using novel chelating surfactant

Jing-Ru Diao, Bao-Wei Zhao, Feng-Feng Ma, Xuan Wang, and Wen-Jie Ding

School of Environmental and Municipal Engineering, Lanzhou Jiaotong University, Lanzhou, 730070, China

E-mail: baowei.zhao@yahoo.com

Abstract: A novel chelating surfactant denoted as sodium N-lauroyl ethylenediamine triacetate (N-LED3A) with both surface activity and chelation functions was studied for phenanthrene (PHE) solubilisation ability. The critical micelle concentration (CMC) of N-LED3A was measured, and the effects of the initial N-LED3A concentration, temperature, pH value and coexisting ions (Na⁺, Ca²⁺ and Cu²⁺) on PHE solubilisation by N-LED3A were investigated. The results demonstrated that PHE solubility was efficiently enhanced by N-LED3A, especially with N-LED3A concentrations above the CMC, which was 707 mg L^-1 when measured at 25°C. The temperature influenced the apparent PHE solubility slightly and the apparent solubility of PHE was significantly affected by the pH. Na⁺ and Ca²⁺ were shown to increase the PHE solubility, while Ca²⁺ exhibited a better promoting ability than Na⁺. A suitable quantity of Cu²⁺ could significantly enhance the solubilisation capacities of N-LED3A at pH 5. The mechanism of the interaction between Cu²⁺ and N-LED3A was further confirmed by Fourier transform infrared spectroscopy (FTIR). These results reveal that Cu²⁺ can be chelated with N-LED3A to form a chelate complex. The results implied that N-LED3A had the potential to remediate soils contaminated by both organics and heavy metals.

Keywords: chelating surfactant – phenanthrene – solubility enhancement – copper(II) – chelation

Full paper is available at www.springerlink.com.

DOI: 10.1515/chempap-2015-0199

Chemical Papers 70 (3) 375–383 (2016)