Magnetization and ZIF-67 modification of Aspergillus flavus biomass for tetracycline removal from aqueous solutions: A stable and efficient composite
Akram Kiani Kori, Bahman Ramavandi, Seyed Mohammad Mehdi Mahmoodi, Farahnaz Javanmardi
Abstract
In the present work, the biomass of Aspergillus flavus (AF) was modified using magnetic nanoparticles MnFe 2 O 4 and metal-organic framework of ZIF-67, and its ability to remove tetracycline antibiotic (TCH) was investigated. With the help of physicochemical tests, AF biomass modification with ZIF-67 and MnFe 2 O 4 magnetic nanoparticles was confirmed. Based on the BET value, AF-MnFe 2 O 4 -ZIF-67 (139.83 m 2 /g) has a higher surface value than AF (0.786 m 2 /g) and AF/MnFe 2 O 4 (17.504 m 2 /g). Also, the magnetic saturation value revealed that the modified biomass can be isolated from the treated solution using a simple magnetic field. Maximum TCH elimination (99.04%) using AF-MnFe 2 O 4 -ZIF-67 was obtained at pH 7, adsorber mass of 1 g/L, adsorption time of 40 min, and TCH content of 10 mg/L. The thermodynamic study indicated that the TCH abatement using the desired composite is spontaneous and exothermic. The experimental results showed that the adsorption process is compatible with the pseudo-second-order kinetic and Freundlich model. The maximum adsorption capacity for AF, AF-MnFe 2 O 4 , and AF-MnFe 2 O 4 -ZIF-67 was quantified to be 9.75 mg/g, 25.59 mg/g, and 43.87 mg/g, respectively. The reusability of the desired adsorbers was examined in up to 8 steps. The outcomes showed that the adsorbers can be used several times in TCH elimination. The provided composite can remove TCH from hospital wastewater, so it can be suggested for use in water and wastewater treatment works.