Preparation of Activated Carbon-Reinforced Composite Beads Based on MnO[sub.2]/MCM-41@Fe[sub.3]O[sub.4] and Calcium Alginate for Efficient Removal of Tetracycline in Aqueous Solutions

• Published in: Polymers 2024-04, Vol.16 (8)
• Main Authors: Zheng, Zhigong, Shi, Ronghui, Zhang, Xiaoping, Ni, Yonghao, Zhang, Hui
• Format: Article
• Language: English
• Subjects: Analysis; Calcium compounds; Carbon, Activated; Composite materials; Identification and classification; Iron oxides; Properties; Silica; Tetracycline; Tetracyclines
• ISSN: 2073-4360; 2073-4360
• DOI: 10.3390/polym16081115

Tetracycline (TC) is a common antibiotic; when untreated TC enters the environment, it will cause a negative impact on the human body through the food chain. In the present study, MnO[sub.2] /MCM-41@Fe[sub.3] O[sub.4] (FeMnMCM) prepared using a hydrothermal and redox method and Camellia oleifera shell-activated carbon (COFAC) prepared through alkali activation were encapsulated using alginate (ALG) and calcium chloride as a cross-linking matrix to give the composite beads COFAC–FeMnMCM–ALG. The resultant COFAC–FeMnMCM–ALG composite beads were then carefully characterized, showing a high immobilization of MnO[sub.2] /MCM-41@Fe[sub.3] O[sub.4] , with porous COFAC as an effective bioadsorbent for enriching the pollutants in the treated samples. These bead catalysts were subsequently applied to the oxidative degradation of TC in a Fenton oxidation system. Several parameters affecting the degradation were investigated, including the H[sub.2] O[sub.2] concentration, catalyst dosage, initial TC concentration, and temperature. A very high catalytic activity towards the degradation of TC was demonstrated. The electron paramagnetic resonance (EPR) and quenching results showed that ·OH and ·O[sub.2] [sup.−] were generated in the system, with ·OH as the main radical species. In addition, the COFAC–FeMnMCM–ALG catalyst exhibited excellent recyclability/reusability. We conclude that the as-prepared COFAC–FeMnMCM–ALG composite beads, which integrate MnO[sub.2] and Fe[sub.3] O[sub.4] with bioadsorbents, provide a new idea for the design of catalysts for advanced oxidation processes (AOPs) and have great potential in the Fenton oxidation system to degrade toxic pollutants.