Within the scope of studying the hydraulic behaviour of vertical-flow wetland in order to model these systems, differential pressure transducers were used on experimental vertical sand columns to understand the effects of a batch feed on the gaseous and hydraulic phases. Three transducers were set up at three different depths in the column. The system operates in a batch mode. Two types of flow regime were tested. The first one consists of one batch of 10 litres every 8 hours. In this regime, the transducer signal shows four consecutive phases: the influence of the water head on the top of the filter and the infiltration of the batch inside the filter that both increase the pressure, the drainage of the pores that decrease the pressure to a depression and finally the aeration of the pores that restore the pressure to atmospheric pressure. For the second flow regime (a batch of 4 litres every 3 hours) the same consecutive steps are present except the infiltration of the batch. In addition, the drainage and the aeration of the pores are simultaneous over the entire depth of the column and are incidental to the end of the surface dewatering. This is not the case for the first regime where occurrence of those steps depends on the depth. In addition to the understanding of the different steps occurring when a batch volume percolates, those measurements provide useful information on the saturation of the media, the rate of drainage and aeration of the pore, the gas flow, the infiltration rate.

[Departement_IRSTEA]MA [TR1_IRSTEA]TED / EPURE | To improve total nitrogen removal, a full-scale experimental study was conducted on a hybrid constructed wetlands plant designed for 100 p.e.. The plant composed of a 1st stage of vertical filters (fed with raw wastewater) followed by a 2nd stage of horizontal filters was monitored over one year measuring hydraulic conditions, physico-chemical conditions, gas emission, oxygen of the gas phase and regular treatment performances by 24 h composite samples. Different vertical filter configurations (media depth, intermediate and passive aeration system) were tested as well as two horizontal filter designs. The N removal is discussed on efficiency of each stage in relation to the season and the load applied. This study leads to draw the limit of the plant configuration and gives some design avenues of hybrid systems to reach high and regular level of nitrogen removal with acceptable surface area per person.

International audience | Les changements de productivité des forêts ont été étudiés intensément à partir des années 1990, à la suite des événements relatifs au dépérissement des forêts européennes. Dans cette contribution, on analyse les problèmes méthodologiques soulevés par ce type d'étude, les sources de données disponibles pour l'analyse, et les éléments de diagnostic acquis sur plusieurs espèces forestières du territoire français. Les implications pour le cadre théorique qui prévalait dans les années 1980 concernant la productivité des peuplements forestiers sont enfin discutées. problèmes méthodologiques, sources de données, cadre théorique, éléments du diagnostic

[Departement_IRSTEA]MA [TR1_IRSTEA]TED / EPURE | Within the scope of studying the hydraulic behaviour of vertical-flow wetland in order to model these systems, differential pressure transducers were used on experimental vertical sand columns to understand the effects of a batch feed on the gaseous and hydraulic phases. Three transducers were set up at three different depths in the column. The system operates in a batch mode. Two types of flow regime were tested. The first one consists of one batch of 10 litres every 8 hours. In this regime, the transducer signal shows four consecutive phases: the influence of the water head on the top of the filter and the infiltration of the batch inside the filter that both increase the pressure, the drainage of the pores that decrease the pressure to a depression and finally the aeration of the pores that restore the pressure to atmospheric pressure. For the second flow regime (a batch of 4 litres every 3 hours) the same consecutive steps are present except the infiltration of the batch. In addition, the drainage and the aeration of the pores are simultaneous over the entire depth of the column and are incidental to the end of the surface dewatering. This is not the case for the first regime where occurrence of those steps depends on the depth. In addition to the understanding of the different steps occurring when a batch volume percolates, those measurements provide useful information on the saturation of the media, the rate of drainage and aeration of the pore, the gas flow, the infiltration rate.

[Departement_IRSTEA]MA [TR1_IRSTEA]TED / EPURE | With the aim of improving the WSP effluent quality, different types of Vertical Flow Constructed Wetlands and Intermittent Sand Filters were tested in a pilot plant in Aurignac (France). The effectiveness of each design for upgrading the effluent from the pond was studied over a period of two years. Physicochemical parameters were monitored by taking composite samples over 24 hours and weekly punctual samples. The hydraulic behaviour of the filters was studied by tracing methods (using NaCl) and monitoring the infiltration rate. This paper describes the influence of: (a) the characteristics of the medium (presence of Phragmites, depth, type of sand), (b) feeding modes and (c) the presence of an algae clogging layer on the performance of the beds. Overall, both Vertical Flow Constructed Wetlands and Intermittent Sand Filters are appropriate systems for retaining algae, completing organic matter degradation and nitrifying the WSP influent. The design and operation bases, the hydraulic behavior and the advantages and disadvantages (in terms of efficiency and maintenance) of the different configurations were determined.

Human transport by land, sea and air has increased exponentially through time in intensity, paralleling rises in population, prosperity and rates of technological change. Transport has considerable ecological effects, many of them detrimental to environmental sustainability. This volume brings together international experts from a variety of disciplines to review the ecological effects and their causes in terms of road, rail, ship and aircraft transport. The contributors have different attitudes and agendas. Some are ecologists, some planners, others social scientists. Focus ranges from identification of threats and amelioration of damaging effects through to future design of transport systems to minimize environmental degradation. Some chapters consider restricted areas of the globe; others the globe itself. Views encompass deep pessimism and cautious optimism. Uniquely, the volume considers transport effects in all environments. This is the first book that attempts to discuss the relationship between human transport and all ecosystems. It appeals not only to the specialist environmentalist by picking out novel topics, but also to anyone involved in transport issues as it tackles the issues from an historical perspective, encompassing the past, present and future of the effects of human transport.

We estimated the total inorganic fluxes of nitrogen (N), sulfur (S), chloride (Cl-, sodium (Na⁺, calcium (Ca²⁺, magnesium (Mg²⁺, potassium (K⁺ and hydronium (H⁺. The resistance deposition algorithm that is programmed as part of the CALMET/CALPUFF modeling system was used to generate spatially-distributed deposition velocities, which were then combined with measurements of urban and rural concentrations of gas and particle species to obtain dry deposition rates. Wet deposition rates for each species were determined from rainfall concentrations and amounts available from the National Acid Deposition Program (NADP) monitoring network databases. The estimated total inorganic nitrogen deposition to the Tampa Bay watershed (excluding Tampa Bay) was 17 kg-N ha-¹ yr-¹ or 9,700 metric tons yr-¹, and the ratio of dry to wet deposition rates was ~2.3 for inorganic nitrogen. The largest contributors to the total N flux were ammonia (NH₃ and nitrogen oxides (NO x at 4.6 kg-N ha-¹ yr-¹ and 5.1 kg-N ha-¹ yr-¹, respectively. Averaged wet deposition rates were 2.3 and 2.7 kg-N ha-¹ yr-¹ for NH₄ ⁺ and NO₃ -, respectively.

The objectives of this work were to characterize and compare the chemical composition of the water-soluble fraction of the PM₁₀ particles (Dp < 10μm) in two sites: one inside the Metropolitan Area of São Paulo (MASP) and another, 250km apart, inside the State Park of Serra do Mar (CUNHA) part of the Atlantic Forest Reserve, both located in São Paulo State, Brazil. The atmospheric particles were collected during dry and wet season. The morphologic parameters of the particles were characterized for the different size fractions of the collected material. In the aqueous extract of the particulate fine fraction the major ions (Na⁺, K⁺, Mg²⁺, Ca²⁺, Cl-, NO₃ -, NH₄ ⁺, SO₄ ²-) and trace elements (Al, Mn, Fe, Pb, Cd, Zn, Ti, Ni, Cu, Co, Ba) were determined. The morphological characteristics of the particles collected within the MASP are typical of polluted environment while in CUNHA there is no evidence of this type of contribution. Regarding the solute concentrations it was observed that the most abundant major ions and trace elements were K⁺, Ca²⁺, Na⁺, Cl- and Pb, for CUNHA and NO₃ -, SO₄ ²-, NH₄ ⁺ and Mn, Ni, Pb, Co, Cd and Ba for MASP. These differences are associated with the different sources of the particles. In the urban area they are predominantly of pollution origin, mainly from vehicle emissions, and road dust suspension, while in the State Park they are mainly of biogenic, terrigenous and oceanic origins. For these reasons the CUNHA region can be considered to be a regional reference site for studies concerning eventual disturbances in the Cunha background site, derived from transported pollution.