Emerging contaminants are defined as chemicals that are not currently(or have only recently been)regulated and about which there are concerns regarding their impact on human or ecological health.Such contaminants are ...Emerging contaminants are defined as chemicals that are not currently(or have only recently been)regulated and about which there are concerns regarding their impact on human or ecological health.Such contaminants are widely detected in air,water,soil,sediment,and biotic environments.It is against this backdrop of urgency that we have curated this special issue titled“Emerging Contaminants Control:Science and Technology,”with the goal of uniting the latest scientific insights and pioneering strategies to address this global concern.This special issue embarks on a comprehensive examination of the emerging contaminants dilemma,covering aspects such as risk assessment,remediation technologies,environmental surveying,and the broader implications for policy.Through a collection of articles,we probe deep into the core of this issue,showcasing studies that range from appraising environmental risks to forging new methods for treatment and scrutinizing the occurrence of contaminants across different environmental settings.展开更多
Fluorochemicals(FCs)are oxidatively recalcitrant,environmentally persistent,and resistant to most conventional treatment technologies.FCs have unique physiochemical properties derived from fluorine which is the most e...Fluorochemicals(FCs)are oxidatively recalcitrant,environmentally persistent,and resistant to most conventional treatment technologies.FCs have unique physiochemical properties derived from fluorine which is the most electronegative element.Perfluorooctanesulfonate(PFOS),and perfluorooctanoate(PFOA)have been detected globally in the hydrosphere,atmosphere and biosphere.Reducing treatment technologies such as reverses osmosis,nano-filtration and activated carbon can remove FCs from water.However,incineration of the concentrated waste is required for complete FC destruction.Recently,a number of alternative technologies for FC decomposition have been reported.The FC degradation technologies span a wide range of chemical processes including direct photolysis,photocatalytic oxidation,photochemical oxidation,photochemical reduction,thermally-induced reduction,and sonochemical pyrolysis.This paper reviews these FC degradation technologies in terms of kinetics,mechanism,energetic cost,and applicability.The optimal PFOS/PFOA treatment method is strongly dependent upon the FC concentration,background organic and metal concentration,and available degradation time.展开更多
Aqueous solutions of phenol were oxidized by hydrogen peroxide assisted by microwave(MW)irradiation.A simple kinetic model for the overall degradation of phenol in the presence of excess H_(2)O_(2) is proposed in whic...Aqueous solutions of phenol were oxidized by hydrogen peroxide assisted by microwave(MW)irradiation.A simple kinetic model for the overall degradation of phenol in the presence of excess H_(2)O_(2) is proposed in which the degradation rate of phenol is expressed as a linear function of the concentrations of phenol and H_(2)O_(2).A detailed parametric study showed that the degradation rate of phenol increased with increasing[H_(2)O_(2)]until saturation was observed.Phenol degradation followed apparent zero-order kinetics under MW radiation or H_(2)O_(2) oxidation.However,after 90 min of irradiation,the observed kinetics shifted to pseudo first order.The overall reaction rates were significantly enhanced in the combined MW/H_(2)O_(2) system,mainly because microwave could accelerate H_(2)O_(2) to generate hydroxyl radical(·OH)and other reactive oxygen intermediates.The observed synergetic effects of the MW/H_(2)O_(2) process resulted in an increased in the net reaction rate by a factor of 5.75.When hydrogen peroxide is present in a large stoichiometric excess,the time required to achieve complete mineralization is reduced significantly.展开更多
文摘Emerging contaminants are defined as chemicals that are not currently(or have only recently been)regulated and about which there are concerns regarding their impact on human or ecological health.Such contaminants are widely detected in air,water,soil,sediment,and biotic environments.It is against this backdrop of urgency that we have curated this special issue titled“Emerging Contaminants Control:Science and Technology,”with the goal of uniting the latest scientific insights and pioneering strategies to address this global concern.This special issue embarks on a comprehensive examination of the emerging contaminants dilemma,covering aspects such as risk assessment,remediation technologies,environmental surveying,and the broader implications for policy.Through a collection of articles,we probe deep into the core of this issue,showcasing studies that range from appraising environmental risks to forging new methods for treatment and scrutinizing the occurrence of contaminants across different environmental settings.
文摘Fluorochemicals(FCs)are oxidatively recalcitrant,environmentally persistent,and resistant to most conventional treatment technologies.FCs have unique physiochemical properties derived from fluorine which is the most electronegative element.Perfluorooctanesulfonate(PFOS),and perfluorooctanoate(PFOA)have been detected globally in the hydrosphere,atmosphere and biosphere.Reducing treatment technologies such as reverses osmosis,nano-filtration and activated carbon can remove FCs from water.However,incineration of the concentrated waste is required for complete FC destruction.Recently,a number of alternative technologies for FC decomposition have been reported.The FC degradation technologies span a wide range of chemical processes including direct photolysis,photocatalytic oxidation,photochemical oxidation,photochemical reduction,thermally-induced reduction,and sonochemical pyrolysis.This paper reviews these FC degradation technologies in terms of kinetics,mechanism,energetic cost,and applicability.The optimal PFOS/PFOA treatment method is strongly dependent upon the FC concentration,background organic and metal concentration,and available degradation time.
基金This research was supported by Hong Kong General Research Fund(HKU7195/06E)the authors would like to thank HKU Faculty of Engineering to support Dr.X.X.Zhang with the PostDoctor+1 种基金This work was supported by the China Postdoctoral Science Foundation Funded Project(Grant No.20100471716)Zhejiang Provincial Natural Science Foundation of China(Grant No.Y5100075)
文摘Aqueous solutions of phenol were oxidized by hydrogen peroxide assisted by microwave(MW)irradiation.A simple kinetic model for the overall degradation of phenol in the presence of excess H_(2)O_(2) is proposed in which the degradation rate of phenol is expressed as a linear function of the concentrations of phenol and H_(2)O_(2).A detailed parametric study showed that the degradation rate of phenol increased with increasing[H_(2)O_(2)]until saturation was observed.Phenol degradation followed apparent zero-order kinetics under MW radiation or H_(2)O_(2) oxidation.However,after 90 min of irradiation,the observed kinetics shifted to pseudo first order.The overall reaction rates were significantly enhanced in the combined MW/H_(2)O_(2) system,mainly because microwave could accelerate H_(2)O_(2) to generate hydroxyl radical(·OH)and other reactive oxygen intermediates.The observed synergetic effects of the MW/H_(2)O_(2) process resulted in an increased in the net reaction rate by a factor of 5.75.When hydrogen peroxide is present in a large stoichiometric excess,the time required to achieve complete mineralization is reduced significantly.
