Reusable Hyperbranched Polyethylenimine-Functionalized Ethyl Cellulose Film for the Removal of Phosphate with Easy Separation

Enmin Zong; Binlu Guo; Jiayao Yang; Chao Shi; Shengtao Jiang; Zhongqing Ma; Xiaohuan Liu

doi:10.1021/acsomega.0c04955

Reusable Hyperbranched Polyethylenimine-Functionalized Ethyl Cellulose Film for the Removal of Phosphate with Easy Separation

ACS Omega. 2020 Dec 24;6(1):505-515. doi: 10.1021/acsomega.0c04955. eCollection 2021 Jan 12.

Authors

Enmin Zong^{1

2}, Binlu Guo¹, Jiayao Yang³, Chao Shi³, Shengtao Jiang¹, Zhongqing Ma³, Xiaohuan Liu³

Affiliations

¹ College of Life Science, Taizhou University, 1139 Shifu Street, Taizhou 318000, PR China.
² School of Earth Sciences and Engineering, Nanjing University, Nanjing 210093, China.
³ School of Engineering, Zhejiang A & F University, 666 Wusu Street, Hangzhou 311300, PR China.

Abstract

The design of a reusable film adsorbent with easy solid-liquid separation for the removal of phosphate is necessary and significant but remains hugely challenging. Herein, the hyperbranched polyethylenimine-functionalized ethyl cellulose (HPEI-EC) film was successfully synthesized by a one-step solution-casting method. The structure and elemental composition of the HPEI-EC film were characterized by Fourier transform-infrared spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. The phosphate adsorption capacity of the HPEI-EC film was 15.53 mg g^-1, which is 12 times higher than that of EC. Significantly, the elongation at break of the HPEI-EC film was 13.43%, which is higher than that of the EC film (8.9%), and the HPEI-EC film had a considerable tensile strength of 13.21 MPa. Such good mechanical properties of the HPEI-EC film bring about the advantage of the saturated HPEI-EC film, allowing it to be easily taken out using a pair of tweezers, which significantly reduces the operation time and saves the cost in the application process. Furthermore, the HPEI-EC film possessed good reusability, and 71.6% of the original adsorption capacity of phosphate was retained even after five cycles. Moreover, the electrostatic interaction between protonated the amine group (-NH₃ ⁺) and the phosphate ion (PO₄ ^3-) is mainly responsible for the adsorption process. This study presents a low-cost and reusable film adsorbent for the effective removal of phosphate from water and provides an easy solid-liquid separation method for use in the adsorption field.