A method for oxidative degradation of 1,4-dioxane （1,4-D） in waste water using a combination of ozone oxidation with UV irradiation （ozone/UV） treatment was investigated. The results showed that 1,4-D was degraded...A method for oxidative degradation of 1,4-dioxane （1,4-D） in waste water using a combination of ozone oxidation with UV irradiation （ozone/UV） treatment was investigated. The results showed that 1,4-D was degraded by ozone/UV treatment up to 90 min. The optimum concentration for the injected ozone gas was about 40 g·m^3 under a constant level of UV irradiation. Furthermore, solid phase extraction and GC-MS analysis showed no specific or reproducible peaks due to by-products of 1,4-D. It was therefore concluded that 1,4-D was completely degraded by ozone/UV treatment. In contrast, the amount of 1,4-D remaining decreased slowly in the presence of HCOf or CI. It was suggested that the degradation of 1,4-D, which results from .OH oxidation, was retarded by the presence of HCO3 or CI, which act as radical scavengers.展开更多
Climate change policies imply significant reductions of energy use in buildings. For this, prevailing energy performance standards fall short, notwithstanding the emergence of stricter national building regulations. R...Climate change policies imply significant reductions of energy use in buildings. For this, prevailing energy performance standards fall short, notwithstanding the emergence of stricter national building regulations. Regulations cover new built and renovation projects. New built houses that miss the best energy performance are soon candidate for energy upgrading. We investigate the architectural and economic aspects of upgrading recently built detached massive brick houses in Flanders （Belgium）. For representing actual building practices, consecutive upgrading steps from ｜ower to higher energy performance levels are considered. Questions addressed are： What is technically feasible in upgrading such houses？ Which construction works are easy, which difficult？ What are the architectural and financial consequences of a thorough upgrading？ The analysis shows that deep energy transformations are financially unacceptable, related to the irrevocab｜e character of investments in energy efficiency attributes of massive brick houses. This confirms that energy performance endowment measures should be designed and implemented at the time of first construction of a building.展开更多
文摘A method for oxidative degradation of 1,4-dioxane （1,4-D） in waste water using a combination of ozone oxidation with UV irradiation （ozone/UV） treatment was investigated. The results showed that 1,4-D was degraded by ozone/UV treatment up to 90 min. The optimum concentration for the injected ozone gas was about 40 g·m^3 under a constant level of UV irradiation. Furthermore, solid phase extraction and GC-MS analysis showed no specific or reproducible peaks due to by-products of 1,4-D. It was therefore concluded that 1,4-D was completely degraded by ozone/UV treatment. In contrast, the amount of 1,4-D remaining decreased slowly in the presence of HCOf or CI. It was suggested that the degradation of 1,4-D, which results from .OH oxidation, was retarded by the presence of HCO3 or CI, which act as radical scavengers.
文摘Climate change policies imply significant reductions of energy use in buildings. For this, prevailing energy performance standards fall short, notwithstanding the emergence of stricter national building regulations. Regulations cover new built and renovation projects. New built houses that miss the best energy performance are soon candidate for energy upgrading. We investigate the architectural and economic aspects of upgrading recently built detached massive brick houses in Flanders （Belgium）. For representing actual building practices, consecutive upgrading steps from ｜ower to higher energy performance levels are considered. Questions addressed are： What is technically feasible in upgrading such houses？ Which construction works are easy, which difficult？ What are the architectural and financial consequences of a thorough upgrading？ The analysis shows that deep energy transformations are financially unacceptable, related to the irrevocab｜e character of investments in energy efficiency attributes of massive brick houses. This confirms that energy performance endowment measures should be designed and implemented at the time of first construction of a building.
