A state-of-the-art review of quinoline degradation and technical bottlenecks.

Quinoline is a critical raw material for the dye, metallurgy, pharmaceutical, rubber, and agrochemical industries, and its use poses a serious threat to human health and the ecological environment. Quinoline has carcinogenic, teratogenic and mutagenic effects on the human body through food accumulation. However, due to the steric hindrance of its bicyclic fused structure and its long photooxidation half-life, quinoline is too difficult to decompose naturally. To date, numerous technologies have been used to degrade quinoline, whereas only a few have been reviewed. Therefore, this paper is focused on offering a comprehensive overview of the state of quinoline degradation in an effort to improve its degradation efficiency and fully utilize the carbon and nitrogen within quinoline without causing any damage to the environment. Accordingly, the strains, research progress and mechanisms of various methods for degrading quinoline are explored and elucidated in detail, especially quinoline biodegradation and the combination of these technologies for efficient removal. The state-of-the-art processes and new findings of our team on the biofortification of quinoline degradation are also presented. Finally, research bottlenecks and gaps for future research were identified along with the prospects and resource utilization of quinoline. These discussions facilitate the realization of the zero discharge of quinoline.