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Water quality, phosphorus input reductions, analytical methods and lake internal/self-purification measures: a case study of Lake Froylandsvatn, Norway.
1994
Bratli J.L.
Phosphorus sorption in subsurface constructed wetlands: investigations focused on calcareous materials and their chemical reactions
2002
Molle, Pascal | Lienard, A. | Grasmick, A. | Iwema, A.
Phosphorus removal from wastewater has been of growing interest for some decades to avoid eutrophication in surface water. In subsurface constructed wetlands precipitation and adsorption are the main mechanisms responsible of P uptake. The use of calcareous media is attractive because of p-ca interactions. Two media (calcite and recycled crushed concrete (rcc)) were examined in batch and continuous systems. They show attractive sorption capacities using batch experiments, however experiments carried out in open reactors pointed out some limitation in retention capacities and effluent quality. rcc was sensitive to a strong dissolution leading to a quick phosphorus precipitation but induced high conductivity and ph values in the treated water. Calcite efficiency depended on the material dissolution rate, directly linked to the carbonate equilibrium of the solution. Microscopic observations of the calcite surface show crystal making of phosphorus precipitate. Crystal growth seems to be the main P uptake once materials surfaces are covered. No experimental condition allows to reach an effluent concentration below 2 mgp.l-1.
Afficher plus [+] Moins [-]Life Cycle environmental Assessment (LCA) of sanitation systems including sewerage: Case of Vertical Flow Constructed Wetlands versus activated sludge
2010
Roux, P. | Boutin, C. | Risch, E. | Heduit, A.
L'article présente l'application de l'Analyse du Cycle de Vie (ACV) à un système d'assainissement complet, incluant le réseau d'égout. Il présente d'abord les hypothèses retenues pour l'ACV concernant les deux systèmes de traitement des eaux usées ayant tous les deux la même charge nominale quotidienne de la DBO 5 et associés au même réseau d'égouts. Ces systèmes correspondent respectivement à (i) un "filtre planté de roseaux à lit vertical (VFCW)" pour lequelle un inventaire détaillé des flux émis et des ressources consommées a été élaboré et (ii) une STEP à « boues activées » boues » issue de la base de données d'ACV Ecoinvent LCI. Les résultats d'ACV soulignent l'importance de l'eutrophisation qui peut facilement s'expliquer par la suppression incomplète de l'azote total et du phosphore total dans un VFCW. De façon plus surprenante, l'impact du réseau semble considérable. Enfin, l'article analyse l'applicabilité et les limites de l'ACV pour les systèmes de traitement des eaux usées. / The article presents the application of Life Cycle Assessment (LCA) to a complete sanitation system including the sewer network. It first describes the LCA hypothesis which concerns two types of waste water-treatment plant with the same daily nominal load in BOD5 and associated to the same sewer network derived from the Life Cycle Inventory (LCI) database Ecoinvent. The two wastewater treatment systems compared are (i) a Vertical Flow Constructed Wetlands (VFCW) for which a detailed inventory was elaborated and (ii) an activated sludge stemming from the LCI database Ecoinvent. LCA scores of VFCW highlight the importance of eutrophication which can be easily explained by the incomplete removal of total N and total P in a VFCW. In a more surprising way, the impact of the network seems considerable. Finally, the article analyses the applicability and limitations of LCA for wastewater treatment with regard to water quality and the needed improvements of water status in LCA.
Afficher plus [+] Moins [-]Critical loads and exceedances for eutrophication and acidification in Flanders
2002
Neirynck, J. | Langouche, D. | Ridder, K. de | Wiedman, T. | Roskams, P. (Institute for Forestry and Game Management, Geraardsbergen, (Belgium))
Critical loads were estimated for over more than 1400 receptors supporting forest vegetation in northern Belgium using simple mass balance method. Necessary data were derived from old historical soil database, recent data from forest surveys, meteo data, level I and II plots and regional studies concerning elemental sequestration in woody biomass. Deposition estimates were performed with the OPS-model, which had been validated with deposition measurements of N and S in 6 level II plots over the period 1994-1998. In addition, an edge enhancement factor was calculated to account for enhanced deposition in plots situated in forest edges
Afficher plus [+] Moins [-]The potential impact of industrial wastes on water resources in Amman-Zarka basin
1991
Gedeon, R. (Ministry of Water and Irrigation, Amman (Jordan). Water Authority Laboratories)
Scarcity of water supply and increasing demand for water in a densely populated area like Amman-Zarka, as well as new threats and contaminants, have emerged, leaving the area with such diverse water quality problems as eutrophication in surface waters and nitrates in ground waters. The problem has been aggravated by increasing emissions of industrial effluents from more than 60 industries located in the catchment area of Amman-Zarqa. Thus the present work has been confined to assessing industrial wastes and their impact on water resources. Water, as part of the human environment, occurs in four main forms - as groundwater, in surface water bodies, in the sea and as vapour in the atmosphere. The present work deals with the first two only, with main objectives as follows: Assessment of man - made impacts on water quality in the area. Identification of sources of pollution and pollutant pathways and behaviour. Determination of trends of chemical constituents and organic pollutants in water resources
Afficher plus [+] Moins [-]Towards integrated national modelling with particular reference to the environmental effects of nutrients
1998
Alkemade, J.R.M. | Grinsven, J.J.M. van | Wiertz, J. | Kros, J. (National Institute of Public Health and the Environment, Bilthoven (Netherlands))
Nitrogen enrichment of European inland and marine waters with special attention to Danish policy measures
1998
Iversen, T.M. | Grant, R. | Nielsen, K. (National Environmental Research Institute (Denmark))
Emission reduction scenarios for nitrogen compounds and their impact on acidification, eutrophication and ozone formation in Flanders
1998
Mensink, C. | Beirens, F. (VITO, Boeretang 200, B-2400 Mol (Belgium))
Effects of eutrophication in drainage ditches
1998
Janse, J.H. | Puijenbroek, P.J.T.M. van (RIVM, Laboratory of Water and Drinking Water Research, P.O. Box 1, NL-3720 BA Bilthoven (Netherlands))
Nitrogen in Dutch freshwater lakes: trends and targets
1998
Molen, D.T. van der | Portielje, R. | Nobel, W.T. de | Boers, P.C.M. (Institute for Inland Water Management and Waste Water Treatment, Lelystad (Netherlands))