Moayedi Mahsa, Yousefi Nariman
Department of Chemical Engineering, Toronto Metropolitan University, 350 Victoria Street, Toronto, Ontario, M5B 2K3, Canada.
Department of Chemical Engineering, Toronto Metropolitan University, 350 Victoria Street, Toronto, Ontario, M5B 2K3, Canada.
Chemosphere. 2025 May;377:144321. doi: 10.1016/j.chemosphere.2025.144321. Epub 2025 Mar 24.
Xenobiotic pollutants such as polycyclic aromatic hydrocarbons (PAHs), originating from the incomplete combustion of organic substances, yield harmful effects on both the environment and public health. Existing research highlights that ligninolytic enzymes, including laccase, exhibit the capability to degrade different PAHs to varying degrees. Enzyme immobilization on a support enhances their suitability for industrial uses, typically leading to improved storage and operational stability. This study aims to enhance the elimination of PAHs such as naphthalene, anthracene, phenanthrene and pyrene and their mixture from water by merging the biocatalytic activity of laccase with the high adsorption capacity of a reduced graphene oxide (rGO) sponge. Our findings revealed that as the molecular weight and hydrophobic properties of PAHs increased, their affinity towards the rGO sponges became more pronounced. Conversely, it was noted that the elimination of naphthalene exhibited remarkable enhancement (achieving 75 % removal after 48 h individually, and 82 % removal in PAH mixtures), demonstrating faster removal kinetics in contrast to other PAHs. This improvement was attributed to the utilization of a bio-functionalized rGO sponge, indicating the notable role of immobilized laccase in the degradation of naphthalene. As observed, certain PAHs in the mixture were more susceptible to oxidation and enzymatic degradation, while those with a higher affinity for adsorption onto the rGO surface demonstrated reduced degradability. This selective mechanism effectively treated specific PAHs based on their structural characteristics, thus enhancing the overall efficiency in removing diverse PAH contaminants in mixtures. The results regarding PAH degradation by-products indicated that laccase primarily converted anthracene into 9,10-anthraquinone, most of which were adsorbed and subsequently eliminated by the rGO sponge acting as the enzyme's support.
多环芳烃（PAHs）等外源性污染物源自有机物的不完全燃烧，对环境和公众健康均产生有害影响。现有研究表明，包括漆酶在内的木质素降解酶具有不同程度降解不同PAHs的能力。将酶固定在载体上可提高其工业适用性，通常能改善储存和操作稳定性。本研究旨在通过将漆酶的生物催化活性与还原氧化石墨烯（rGO）海绵的高吸附能力相结合，增强从水中去除萘、蒽、菲和芘等PAHs及其混合物的效果。我们的研究结果表明，随着PAHs分子量和疏水性的增加，它们对rGO海绵的亲和力变得更加明显。相反，注意到萘的去除率显著提高（单独作用48小时后去除率达到75%，在PAH混合物中去除率为82%），与其他PAHs相比，其去除动力学更快。这种改善归因于生物功能化rGO海绵的利用，表明固定化漆酶在萘降解中发挥了显著作用。可以观察到，混合物中的某些PAHs更容易被氧化和酶解，而那些对rGO表面吸附亲和力较高的PAHs降解性降低。这种选择性机制基于其结构特征有效地处理了特定的PAHs，从而提高了去除混合物中多种PAH污染物的整体效率。关于PAH降解副产物的结果表明，漆酶主要将蒽转化为9,10 - 蒽醌，其中大部分被吸附，随后由作为酶载体的rGO海绵去除。
