Novel insights into the dehalogenation mechanism and ecotoxicity assessment of 6:2 Cl-PFESA from density functional theory calculations

The electroplating industry is the main source of 6:2 chlorinated polyfluorinated ether sulfonate(6:2 Cl-PFESA)pollution,which presents risks to human health and the environment.It is therefore crucial to develop effective 6:2 Cl-PFESA degradation techniques.Persulfate oxidation is a potential treatment method for 6:2 Cl-PFESA due to its outstanding oxidative degradability following the generation of the sulfate radical(SO_(4)^(•−))and hydroxyl radical(•OH).It has proven difficult to acquire a full understanding of the reaction mechanism and formation of intermediate(IM)products through conventional experimental studies because they are costly and time-consuming.Therefore,a theoretical analysis method based on density functional theory(DFT)calculations was applied.The DFT results showed that electron transfer for the degradation of 6:2 Cl-PFESA could be initiated by the protonated sulfate radical(HSO_(4)•,ΔG≠SET=9.16 kcal/mol),rather than SO4•−(ΔG≠SET=41.60 kcal/mol).After desulfonation,the reaction underwent stepwise decarboxylation cycles under the action of•OH,leading to the elimination of the CF_(2) units until there was complete mineralization into HCl,HF,and CO_(2).Furthermore,the IMs and the end products of 6:2 Cl-PFESA were evaluated using ECOSAR and TEST software.The low bioaccumulation of the short-chain IMs meant that they could be considered safe in terms of ecotoxicity and health effects.This research determined the theoretical and mechanistic basis of the effects of persulfate in the treatment of water containing 6:2 Cl-PFESA,and its structural analogues.

Blue economy:A new era of petroleum microbiology in a changing climate

The productivity and health of our ocean hold some good solutions to the world’s challenges in socio-economy.However,climate change and waste discharge are changing the marine capacity to buffer human impacts,further challenging the marine industry,primarily in offshore oil and gas,shipping,and fishery operations.These encourage the blue economy,a sustainable development approach to utilize marine resources.Petroleum microbiology dealing with microbes that can respond,degrade,and alter crude oils,offers an unprecedented opportunity to achieve the knowledge-and science-based blue economy.However,the new-era petroleum microbiology for supporting the blue economy has yet to be systematically discussed.This review introduces the climate change impacts on key marine industrial sectors,highlights the critical role of advanced petroleum microbiology in supporting sustainable development,and offers insight into the challenges and future research opportunities in availing of petroleum microbiology for benefiting our marine environment and responsible economic growth.