{"title":"Magnetic recyclable chitosan-graphene immobilized microcystinase A: Removal of microcystins from harmful microcystis blooms","authors":"","doi":"10.1016/j.psep.2024.09.029","DOIUrl":null,"url":null,"abstract":"<div><p>Harmful Microcystis blooms and microcystins have become a major hidden threat to the safety of the water environment. The application of enzymatic degradation of microcystins has been severely limited by the complex environment. In this study, chitosan-graphene (CG), prepared from green biomass, was employed as matrix material, loaded with 100–200 nm Fe<sub>3</sub>O<sub>4</sub> nanoparticles (MCG) and immobilized microcystinase A (MlrA@MCG). The preparation of MlrA@MCG was characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, vibrating sample magnetometer and fluorescence labelling. The results of the activity analysis demonstrated that MlrA@MCG exhibited superior degradation activity for MCs, as well as enhanced heat and alkaline resistance in comparison to free MlrA. Furthermore, MlrA@MCG can be recovered simply by means of a magnetic field, and its activity remains at 48.6 % after 10 repeated uses. More importantly, MlrA@MCG and the degradation products of MC-LR were not found to be cytotoxic to human cells. It is interesting that the immobilization of MlrA resulted in a reduction in the cytotoxicity of MCG. 0.2 U of MlrA@MCG can still degrade MC-LR from 232.64 μg L<sup>−1</sup> to 94.39 μg L<sup>−1</sup> in water from simulated severe Microcystis blooms within 24 h, showing excellent catalytic activity and stability. The study proposed a secure and efficacious approach for the elimination of microcystins from harmful Microcystis blooms, offering a promising avenue for the improvement of environmental safety.</p></div>","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":null,"pages":null},"PeriodicalIF":6.9000,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Process Safety and Environmental Protection","FirstCategoryId":"93","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0957582024011479","RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, CHEMICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Harmful Microcystis blooms and microcystins have become a major hidden threat to the safety of the water environment. The application of enzymatic degradation of microcystins has been severely limited by the complex environment. In this study, chitosan-graphene (CG), prepared from green biomass, was employed as matrix material, loaded with 100–200 nm Fe3O4 nanoparticles (MCG) and immobilized microcystinase A (MlrA@MCG). The preparation of MlrA@MCG was characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, vibrating sample magnetometer and fluorescence labelling. The results of the activity analysis demonstrated that MlrA@MCG exhibited superior degradation activity for MCs, as well as enhanced heat and alkaline resistance in comparison to free MlrA. Furthermore, MlrA@MCG can be recovered simply by means of a magnetic field, and its activity remains at 48.6 % after 10 repeated uses. More importantly, MlrA@MCG and the degradation products of MC-LR were not found to be cytotoxic to human cells. It is interesting that the immobilization of MlrA resulted in a reduction in the cytotoxicity of MCG. 0.2 U of MlrA@MCG can still degrade MC-LR from 232.64 μg L−1 to 94.39 μg L−1 in water from simulated severe Microcystis blooms within 24 h, showing excellent catalytic activity and stability. The study proposed a secure and efficacious approach for the elimination of microcystins from harmful Microcystis blooms, offering a promising avenue for the improvement of environmental safety.
期刊介绍:
The Process Safety and Environmental Protection (PSEP) journal is a leading international publication that focuses on the publication of high-quality, original research papers in the field of engineering, specifically those related to the safety of industrial processes and environmental protection. The journal encourages submissions that present new developments in safety and environmental aspects, particularly those that show how research findings can be applied in process engineering design and practice.
PSEP is particularly interested in research that brings fresh perspectives to established engineering principles, identifies unsolved problems, or suggests directions for future research. The journal also values contributions that push the boundaries of traditional engineering and welcomes multidisciplinary papers.
PSEP's articles are abstracted and indexed by a range of databases and services, which helps to ensure that the journal's research is accessible and recognized in the academic and professional communities. These databases include ANTE, Chemical Abstracts, Chemical Hazards in Industry, Current Contents, Elsevier Engineering Information database, Pascal Francis, Web of Science, Scopus, Engineering Information Database EnCompass LIT (Elsevier), and INSPEC. This wide coverage facilitates the dissemination of the journal's content to a global audience interested in process safety and environmental engineering.