Suchergebnisse

International audience ; Climate change is predicted to induce more extreme events such as storms, heat waves, drought and floods. Dust storms are frequently occurring in northern China. Those storms degrade air quality by decreasing visibility and inducing cardiovascular and respiratory diseases. To control dust storms, the Chinese government has launched a large-scale afforestation program by planting trees in arid areas, but the effectiveness of this program is still uncertain because the trajectories and altitudes of dust transport are poorly known. In particular, afforestation would be effective only if dust transport occurs at low altitudes. To test this hypothesis, we analyzed the extreme dust storm from May 2 to 7, 2017, which resulted in record-breaking dust loads over northern China. For that, we used dust RGB-composite data from the Himawari-8 satellite and the cloud-aerosol lidar, moderate-resolution imaging spectroradiometer data, and surface monitoring data. The source regions of the dust storms were identified using the hybrid single-particle Lagrangian integrated trajectory model and infrared pathfinder satellite observation. Contrary to our hypothesis, results show that dust is transported at high altitude of 1.0-6.5 km over long distances from northwestern China. This finding explains why the afforestation has not been effective to prevent this storm. Results also disclose the highest particulate matter (PM) concentrations of 447.3 μg/m 3 for PM 2.5 and 1842.0 μg/m 3 for PM 10 during the dust storm. Those levels highly exceed Chinese ambient air quality standards of 75 μg/m 3 for PM 2.5 and 150 μg/m 3 for PM 10 .

International audience ; Climate change is predicted to induce more extreme events such as storms, heat waves, drought and floods. Dust storms are frequently occurring in northern China. Those storms degrade air quality by decreasing visibility and inducing cardiovascular and respiratory diseases. To control dust storms, the Chinese government has launched a large-scale afforestation program by planting trees in arid areas, but the effectiveness of this program is still uncertain because the trajectories and altitudes of dust transport are poorly known. In particular, afforestation would be effective only if dust transport occurs at low altitudes. To test this hypothesis, we analyzed the extreme dust storm from May 2 to 7, 2017, which resulted in record-breaking dust loads over northern China. For that, we used dust RGB-composite data from the Himawari-8 satellite and the cloud-aerosol lidar, moderate-resolution imaging spectroradiometer data, and surface monitoring data. The source regions of the dust storms were identified using the hybrid single-particle Lagrangian integrated trajectory model and infrared pathfinder satellite observation. Contrary to our hypothesis, results show that dust is transported at high altitude of 1.0-6.5 km over long distances from northwestern China. This finding explains why the afforestation has not been effective to prevent this storm. Results also disclose the highest particulate matter (PM) concentrations of 447.3 μg/m 3 for PM 2.5 and 1842.0 μg/m 3 for PM 10 during the dust storm. Those levels highly exceed Chinese ambient air quality standards of 75 μg/m 3 for PM 2.5 and 150 μg/m 3 for PM 10 .

International audience ; Climate change is predicted to induce more extreme events such as storms, heat waves, drought and floods. Dust storms are frequently occurring in northern China. Those storms degrade air quality by decreasing visibility and inducing cardiovascular and respiratory diseases. To control dust storms, the Chinese government has launched a large-scale afforestation program by planting trees in arid areas, but the effectiveness of this program is still uncertain because the trajectories and altitudes of dust transport are poorly known. In particular, afforestation would be effective only if dust transport occurs at low altitudes. To test this hypothesis, we analyzed the extreme dust storm from May 2 to 7, 2017, which resulted in record-breaking dust loads over northern China. For that, we used dust RGB-composite data from the Himawari-8 satellite and the cloud-aerosol lidar, moderate-resolution imaging spectroradiometer data, and surface monitoring data. The source regions of the dust storms were identified using the hybrid single-particle Lagrangian integrated trajectory model and infrared pathfinder satellite observation. Contrary to our hypothesis, results show that dust is transported at high altitude of 1.0-6.5 km over long distances from northwestern China. This finding explains why the afforestation has not been effective to prevent this storm. Results also disclose the highest particulate matter (PM) concentrations of 447.3 μg/m 3 for PM 2.5 and 1842.0 μg/m 3 for PM 10 during the dust storm. Those levels highly exceed Chinese ambient air quality standards of 75 μg/m 3 for PM 2.5 and 150 μg/m 3 for PM 10 .

International audience ; Climate change is predicted to induce more extreme events such as storms, heat waves, drought and floods. Dust storms are frequently occurring in northern China. Those storms degrade air quality by decreasing visibility and inducing cardiovascular and respiratory diseases. To control dust storms, the Chinese government has launched a large-scale afforestation program by planting trees in arid areas, but the effectiveness of this program is still uncertain because the trajectories and altitudes of dust transport are poorly known. In particular, afforestation would be effective only if dust transport occurs at low altitudes. To test this hypothesis, we analyzed the extreme dust storm from May 2 to 7, 2017, which resulted in record-breaking dust loads over northern China. For that, we used dust RGB-composite data from the Himawari-8 satellite and the cloud-aerosol lidar, moderate-resolution imaging spectroradiometer data, and surface monitoring data. The source regions of the dust storms were identified using the hybrid single-particle Lagrangian integrated trajectory model and infrared pathfinder satellite observation. Contrary to our hypothesis, results show that dust is transported at high altitude of 1.0-6.5 km over long distances from northwestern China. This finding explains why the afforestation has not been effective to prevent this storm. Results also disclose the highest particulate matter (PM) concentrations of 447.3 μg/m 3 for PM 2.5 and 1842.0 μg/m 3 for PM 10 during the dust storm. Those levels highly exceed Chinese ambient air quality standards of 75 μg/m 3 for PM 2.5 and 150 μg/m 3 for PM 10 .

International audience ; Since the 2000s, among organic contaminants, alkylphenols and alkylphenol polyethoxylates have been listed as hazardous substances by several national, European and international agencies because they are considered endocrine disruptors. Among the molecules classified as priority substances in terms for monitoring and action, nonylphenols and octylphenols and their polyethoxylated derivatives receive particular attention, especially in developing countries. Effluents from treatments plants are considered to be the largest source of alkylphenols in the environment. Although legislation concerning their use has become increasingly strict, these substances are still found in the environment, especially in water resources. The existing water and wastewater treatment plants have not been designated for these emerging contaminants. Conventional treatments such as biodegradation, sand filtration, carbon adsorption and/or chemical oxidation in place are not effective in their elimination removal. No appropriate methods have been developed to deal them at the urban or industrial scale. Thus, alkylphenols have become a relevant research topic for scientists interested in water engineering issues related to their treatment. However, the challenge is not simple, as it is difficult to remove trace contaminants from complex mixtures of substances in a way that is chemically effective, technologically simple, economically viable, and environmentally friendly.The main objective of this chapter is to summarize recent trends in proposed advanced treatment methods for the removal of alkylphenols and alkylphenol polyethoxylates from wastewater. After general and brief considerations on these emergingcontaminants, this chapter focuses on adsorption-oriented processes, biotechnological methods, and advanced oxidation processes. Among the advanced methods described and discussed are removal of alkylphenols and alkylphenol polyethoxylates by adsorption onto cyclodextrin polymers, clays or molecularly imprinted polymer, biodegradation using microalgae or constructed wetlands or by sequential anaerobic-aerobic digestion processes, treatments based on ozone-carbon coupling, electrochemical degradation, photocatalysis, zero-valent iron-activated persulfate coupling and catalytic ozonation. Among these technologies, advanced oxidation processes, in association with biodegradation and/or adsorption, seem to be the technique of the future, although their costs still prevent their widespread use.

International audience ; Since the 2000s, among organic contaminants, alkylphenols and alkylphenol polyethoxylates have been listed as hazardous substances by several national, European and international agencies because they are considered endocrine disruptors. Among the molecules classified as priority substances in terms for monitoring and action, nonylphenols and octylphenols and their polyethoxylated derivatives receive particular attention, especially in developing countries. Effluents from treatments plants are considered to be the largest source of alkylphenols in the environment. Although legislation concerning their use has become increasingly strict, these substances are still found in the environment, especially in water resources. The existing water and wastewater treatment plants have not been designated for these emerging contaminants. Conventional treatments such as biodegradation, sand filtration, carbon adsorption and/or chemical oxidation in place are not effective in their elimination removal. No appropriate methods have been developed to deal them at the urban or industrial scale. Thus, alkylphenols have become a relevant research topic for scientists interested in water engineering issues related to their treatment. However, the challenge is not simple, as it is difficult to remove trace contaminants from complex mixtures of substances in a way that is chemically effective, technologically simple, economically viable, and environmentally friendly.The main objective of this chapter is to summarize recent trends in proposed advanced treatment methods for the removal of alkylphenols and alkylphenol polyethoxylates from wastewater. After general and brief considerations on these emergingcontaminants, this chapter focuses on adsorption-oriented processes, biotechnological methods, and advanced oxidation processes. Among the advanced methods described and discussed are removal of alkylphenols and alkylphenol polyethoxylates by adsorption onto cyclodextrin polymers, clays or molecularly imprinted ...

International audience ; Since the 2000s, among organic contaminants, alkylphenols and alkylphenol polyethoxylates have been listed as hazardous substances by several national, European and international agencies because they are considered endocrine disruptors. Among the molecules classified as priority substances in terms for monitoring and action, nonylphenols and octylphenols and their polyethoxylated derivatives receive particular attention, especially in developing countries. Effluents from treatments plants are considered to be the largest source of alkylphenols in the environment. Although legislation concerning their use has become increasingly strict, these substances are still found in the environment, especially in water resources. The existing water and wastewater treatment plants have not been designated for these emerging contaminants. Conventional treatments such as biodegradation, sand filtration, carbon adsorption and/or chemical oxidation in place are not effective in their elimination removal. No appropriate methods have been developed to deal them at the urban or industrial scale. Thus, alkylphenols have become a relevant research topic for scientists interested in water engineering issues related to their treatment. However, the challenge is not simple, as it is difficult to remove trace contaminants from complex mixtures of substances in a way that is chemically effective, technologically simple, economically viable, and environmentally friendly.The main objective of this chapter is to summarize recent trends in proposed advanced treatment methods for the removal of alkylphenols and alkylphenol polyethoxylates from wastewater. After general and brief considerations on these emergingcontaminants, this chapter focuses on adsorption-oriented processes, biotechnological methods, and advanced oxidation processes. Among the advanced methods described and discussed are removal of alkylphenols and alkylphenol polyethoxylates by adsorption onto cyclodextrin polymers, clays or molecularly imprinted ...

International audience ; Since the 2000s, among organic contaminants, alkylphenols and alkylphenol polyethoxylates have been listed as hazardous substances by several national, European and international agencies because they are considered endocrine disruptors. Among the molecules classified as priority substances in terms for monitoring and action, nonylphenols and octylphenols and their polyethoxylated derivatives receive particular attention, especially in developing countries. Effluents from treatments plants are considered to be the largest source of alkylphenols in the environment. Although legislation concerning their use has become increasingly strict, these substances are still found in the environment, especially in water resources. The existing water and wastewater treatment plants have not been designated for these emerging contaminants. Conventional treatments such as biodegradation, sand filtration, carbon adsorption and/or chemical oxidation in place are not effective in their elimination removal. No appropriate methods have been developed to deal them at the urban or industrial scale. Thus, alkylphenols have become a relevant research topic for scientists interested in water engineering issues related to their treatment. However, the challenge is not simple, as it is difficult to remove trace contaminants from complex mixtures of substances in a way that is chemically effective, technologically simple, economically viable, and environmentally friendly.The main objective of this chapter is to summarize recent trends in proposed advanced treatment methods for the removal of alkylphenols and alkylphenol polyethoxylates from wastewater. After general and brief considerations on these emergingcontaminants, this chapter focuses on adsorption-oriented processes, biotechnological methods, and advanced oxidation processes. Among the advanced methods described and discussed are removal of alkylphenols and alkylphenol polyethoxylates by adsorption onto cyclodextrin polymers, clays or molecularly imprinted polymer, biodegradation using microalgae or constructed wetlands or by sequential anaerobic-aerobic digestion processes, treatments based on ozone-carbon coupling, electrochemical degradation, photocatalysis, zero-valent iron-activated persulfate coupling and catalytic ozonation. Among these technologies, advanced oxidation processes, in association with biodegradation and/or adsorption, seem to be the technique of the future, although their costs still prevent their widespread use.

International audience ; Since the 2000s, among organic contaminants, alkylphenols and alkylphenol polyethoxylates have been listed as hazardous substances by several national, European and international agencies because they are considered endocrine disruptors. Among the molecules classified as priority substances in terms for monitoring and action, nonylphenols and octylphenols and their polyethoxylated derivatives receive particular attention, especially in developing countries. Effluents from treatments plants are considered to be the largest source of alkylphenols in the environment. Although legislation concerning their use has become increasingly strict, these substances are still found in the environment, especially in water resources. The existing water and wastewater treatment plants have not been designated for these emerging contaminants. Conventional treatments such as biodegradation, sand filtration, carbon adsorption and/or chemical oxidation in place are not effective in their elimination removal. No appropriate methods have been developed to deal them at the urban or industrial scale. Thus, alkylphenols have become a relevant research topic for scientists interested in water engineering issues related to their treatment. However, the challenge is not simple, as it is difficult to remove trace contaminants from complex mixtures of substances in a way that is chemically effective, technologically simple, economically viable, and environmentally friendly.The main objective of this chapter is to summarize recent trends in proposed advanced treatment methods for the removal of alkylphenols and alkylphenol polyethoxylates from wastewater. After general and brief considerations on these emergingcontaminants, this chapter focuses on adsorption-oriented processes, biotechnological methods, and advanced oxidation processes. Among the advanced methods described and discussed are removal of alkylphenols and alkylphenol polyethoxylates by adsorption onto cyclodextrin polymers, clays or molecularly imprinted polymer, biodegradation using microalgae or constructed wetlands or by sequential anaerobic-aerobic digestion processes, treatments based on ozone-carbon coupling, electrochemical degradation, photocatalysis, zero-valent iron-activated persulfate coupling and catalytic ozonation. Among these technologies, advanced oxidation processes, in association with biodegradation and/or adsorption, seem to be the technique of the future, although their costs still prevent their widespread use.

International audience ; Since the 2000s, among organic contaminants, alkylphenols and alkylphenol polyethoxylates have been listed as hazardous substances by several national, European and international agencies because they are considered endocrine disruptors. Among the molecules classified as priority substances in terms for monitoring and action, nonylphenols and octylphenols and their polyethoxylated derivatives receive particular attention, especially in developing countries. Effluents from treatments plants are considered to be the largest source of alkylphenols in the environment. Although legislation concerning their use has become increasingly strict, these substances are still found in the environment, especially in water resources. The existing water and wastewater treatment plants have not been designated for these emerging contaminants. Conventional treatments such as biodegradation, sand filtration, carbon adsorption and/or chemical oxidation in place are not effective in their elimination removal. No appropriate methods have been developed to deal them at the urban or industrial scale. Thus, alkylphenols have become a relevant research topic for scientists interested in water engineering issues related to their treatment. However, the challenge is not simple, as it is difficult to remove trace contaminants from complex mixtures of substances in a way that is chemically effective, technologically simple, economically viable, and environmentally friendly.The main objective of this chapter is to summarize recent trends in proposed advanced treatment methods for the removal of alkylphenols and alkylphenol polyethoxylates from wastewater. After general and brief considerations on these emergingcontaminants, this chapter focuses on adsorption-oriented processes, biotechnological methods, and advanced oxidation processes. Among the advanced methods described and discussed are removal of alkylphenols and alkylphenol polyethoxylates by adsorption onto cyclodextrin polymers, clays or molecularly imprinted ...