Enhancing mechanical properties of polyvinyl alcohol/sodium alginate gel beads by graphene oxide for the aerobic sludge immobilization in wastewater treatment

Van, Tuyen-Nguyen; Quang, Trung-Do; Hung, Thuan-Tran; Xuan, Quang-Chu; Van, Tuan-Hoang; Kim, Hyungu; Ahn, Daehee

doi:.0..

DOI: https://doi.org/10.4491/eer.2022.403

Enhancing mechanical properties of polyvinyl alcohol/sodium alginate gel beads by graphene oxide for the aerobic sludge immobilization in wastewater treatment

Tuyen-Nguyen Van¹, Trung-Do Quang², Thuan-Tran Hung¹, Quang-Chu Xuan¹, Tuan-Hoang Van³, Hyungu Kim⁴, and Daehee Ahn^4,5^†

¹Center for Advanced Materials and Environmental Technology, National center for technological progress, Hanoi, Vietnam
²Laboratory of Environmental Chemistry, VNU University of Science, Vietnam National University, Hanoi, Vietnam
³Phenikaa University Nano Institute (PHENA), Phenikaa University, Hanoi 12116, Vietnam
⁴Bluebank Co., Ltd, Yongin-si, Gyeonggi-do, 17058, Republic of Korea
⁵Department of Environmental Engineering and Energy, Myongji University, Yongin, Gyeonggi-do, 17058, Republic of Korea

Corresponding Author: Daehee Ahn ,Tel: +82-31-321-5901, Email: dhahn@mju.ac.kr

Received: July 28, 2022; Accepted: January 8, 2023.

ABSTRACT

This study reinforced polyvinyl alcohol/sodium alginate (PVA/SA) gel beads immobilizing aerobic sludge with graphene oxide (GO) as a nanofiller. The different types of beads were made by various concentrations of GO (0.02, 0.2; 2; 20, and 200 mg/L). The effect of GO on beads structure was observed by comparing the mechanical properties of chemical oxygen demand (COD) and NH4+-N removal efficiencies. The results showed that the PVA/SA/GO gel carriers have excellent reinforcement properties compared to non-GO gel carriers, while sphericity factor and methyl blue absorption are the same. The strongest carrier contains 200 mg/L GO, referred to as GO6. In addition, the highest COD and NH4+-N removal efficiencies of GO6 gel carriers were 97 and 96.67%, respectively, which is higher than a non-GO PVA/SA (GO1) gel carrier. The addition of GO (200 mg/L) was thus an effective way to improve the mechanical strength of PVA/SA gel beads due to the strong interaction between GO and the PVA/SA matrix. It can also promote COD and NH4+-N removal efficiency of immobilized bacteria inside the beads

Keywords: Activated sludge | Graphene oxide | Immobilization | Polyvinyl alcohol-sodium alginate | Wastewater treatment