Two media bed (gravel and Filtralite NR) were tested in a mesocosm to evaluate the removal of organic matter (as chemical oxygen demand (COD)), ammonia (NH4-N), nitrite, nitrate and solid matter (as total sus...Two media bed (gravel and Filtralite NR) were tested in a mesocosm to evaluate the removal of organic matter (as chemical oxygen demand (COD)), ammonia (NH4-N), nitrite, nitrate and solid matter (as total suspended solids (TSS)) for a synthetic wastewater (acetate-based) and a domestic wastewater. The use of Filtralite allowed average removal rates (6--16.8 g COD/(m^2·day), 0.8-1.1 g NH4-N/(m^2·day) and 3.1 g TSS/(m^2·day)) and removal efficiencies (65%-93%, 57%-85% and 78% for COD, NH4-N and TSS, respectively), higher than that observed in the experiments with gravel. The applied loads of COD, ammonia, nitrate and TSS seem to influence the respective removal rates but only for the treatment of domestic wastewater with nigher correlation coefficients for Filtralite. Regardless the type of media bed and the type of wastewater, nitrate was completely removed for nitrogen loading rates up to 1.3 g NO3-N/(m^2·day). There was no evidence of the influence of nitrate loads on the removal of organic matter.展开更多
This paper investigates the main characteristics of daylight on any window in a street canyon.The sky component and the light reflected from the surroundings are described to determine the vertical daylight factor(VDF...This paper investigates the main characteristics of daylight on any window in a street canyon.The sky component and the light reflected from the surroundings are described to determine the vertical daylight factor(VDF).Several street canyon types are characterized taking into account their different height/width and any level of the window is analysed.A simple calculation method uses trigonometric equations based on the sky and the geometry of the canyon.The results were previ-ously evaluated considering different daylight procedures obtained by other studies.This study reveals that the reflectance within an urban canyon plays an important role in the amount of daylight onto any window with more relevance in a deep canyon and low sky view.The graphical presentation that result from this investiga-tion can rapidly assist building and urban designers in an early stage design where assumptions and the lay out of the main design take place.展开更多
文摘Two media bed (gravel and Filtralite NR) were tested in a mesocosm to evaluate the removal of organic matter (as chemical oxygen demand (COD)), ammonia (NH4-N), nitrite, nitrate and solid matter (as total suspended solids (TSS)) for a synthetic wastewater (acetate-based) and a domestic wastewater. The use of Filtralite allowed average removal rates (6--16.8 g COD/(m^2·day), 0.8-1.1 g NH4-N/(m^2·day) and 3.1 g TSS/(m^2·day)) and removal efficiencies (65%-93%, 57%-85% and 78% for COD, NH4-N and TSS, respectively), higher than that observed in the experiments with gravel. The applied loads of COD, ammonia, nitrate and TSS seem to influence the respective removal rates but only for the treatment of domestic wastewater with nigher correlation coefficients for Filtralite. Regardless the type of media bed and the type of wastewater, nitrate was completely removed for nitrogen loading rates up to 1.3 g NO3-N/(m^2·day). There was no evidence of the influence of nitrate loads on the removal of organic matter.
基金supported with Portuguese national funds by FCT-Foundation for Science and Technology within the UID/ECI/04082/2013 project.
文摘This paper investigates the main characteristics of daylight on any window in a street canyon.The sky component and the light reflected from the surroundings are described to determine the vertical daylight factor(VDF).Several street canyon types are characterized taking into account their different height/width and any level of the window is analysed.A simple calculation method uses trigonometric equations based on the sky and the geometry of the canyon.The results were previ-ously evaluated considering different daylight procedures obtained by other studies.This study reveals that the reflectance within an urban canyon plays an important role in the amount of daylight onto any window with more relevance in a deep canyon and low sky view.The graphical presentation that result from this investiga-tion can rapidly assist building and urban designers in an early stage design where assumptions and the lay out of the main design take place.