Investigation of highly selective regenerative cellulose microcolumn for selenium detection and efficient recovery

- Functionalized cellulose, L-cysC, was synthesized via one-step reaction.
- L-cysC can effectively recovery the toxic selenium compounds from waste waters.
- L-cysC-Se(IV) could be easily eluted and can be reused many times.
- Set up a coupling technique for economic and accurate determination of Se(IV).

Selenium (Se) is one of contaminants required to be regulated during water treatment. In this paper, we aim to prepare a novel functionalized cellulose, l-cysteine (L-Cys) modified surface of cellulose (L-CysC), with simple technology, and L-CysC can remove toxic selenium compounds entirely at pH values of 4.5. Meanwhile, L-CysC microcolumn-UV-spectrophotometry was developed for effective and economic determination of trace Se (IV). The BBD (Box-Behnken Design) of RSM (Response Surface Methodology) was applied to study the influences of reaction temperature, molar ratio and catalyst dosage. The surface functionalization effect was detected with FTIR, SEM, zeta potential, EDS, XPS and TGA techniques. Under optimum adsorption conditions (pH = 4.5, T = 318 K), The maximum removal capacity of L-CysC microcolumn toward Se (IV) was found to be 105.1 mg/g. The surface adsorption processes were evaluated by Langmuir isotherms and the kinetically proceeded according to Second-order kinetics model. Furthermore, L-CysC could be easily regenerated through the desorption of the Se (IV) anions using the mixture of 3.0 M HCl and 2% KClO3.

The principle diagram of recycling selenium.