M. Ridaoui

Typologie morphologique et pétrographie des travertins plio-quaternaires du géosystème karstique de l'Oued Aggai (Causse de Sefrou, Moyen-At las, Maroc). Moussa K. et Boualla N. La sédimentation plio-quaternaire d'Oran (Ouest Algérie) : Aspects stratigraphiques et sédimentologiques. Géomorphologie, lithostratigraphie et sédimentologie des dépôts quaternaires du bassin hydrographique de l'Oued Salloum (région Sidi Abdalwahid, extrémité sud-est de la boutonnière d'Ahouli-Mibladane, Stratigraphie , sédimentologie et âge de la formation du cordon littoral « post-ouljien » de Témara (sud-ouest de Rabat,Maroc). Etude préliminaire d'une formation palustre holocène du bassin d'Ouarzazate à Skoura (sud-est du Maroc) Apport de l'observation du paysage côtier actuel et de l'organisation des séquences littorales sur la paléogéographie du pléistocène récent au nord-ouest de Rabat (Maroc). Reconstitution de l'environnement lacustre actuel et de l'évolution ...

The adsorption of a reactive dye, Reactive Yellow 84, from aqueous solution onto animal bone meal was investigated. The experiments were carried out to investigate the factors that influence the dye uptake by the adsorbent, such as the contact time under agitation, adsorbent amount, initial dye concentration, temperature and pH of dye solution. The experimental results show that the amount of dye adsorbed increases with an increase in the amount of animal bone meal. The maximum adsorption occurred at the pH value of 6.6. The equilibrium uptake was increased with an increase in the initial dye concentration in solution. The experimental isotherm data were analyzed using Langmuir isotherm model. The maximum monolayer adsorption capacity was 57.15 mg/g. The adsorption has a low temperature dependency and was endothermic in nature with an enthalpy of adsorption of 2.52 kJ/mol.

The adsorption of a reactive dye, Reactive Yellow 84, from aqueous solution onto animal bone meal was investigated. The experiments were carried out to investigate the factors that influence the dye uptake by the adsorbent, such as the contact time under agitation, adsorbent amount, initial dye concentration, temperature and pH of dye solution. The experimental results show that the amount of dye adsorbed increases with an increase in the amount of animal bone meal. The maximum adsorption occurred at the pH value of 6.6. The equilibrium uptake was increased with an increase in the initial dye concentration in solution. The experimental isotherm data were analyzed using Langmuir isotherm model. The maximum monolayer adsorption capacity was 57.15 mg/g. The adsorption has a low temperature dependency and was endothermic in nature with an enthalpy of adsorption of 2.52 kJ/mol.

ABSTRACT Using sedimentological and pollen analysis, a reconstruction is presented here for the origin and history of a temporary pool from the quartzitic-sandstone Benslimane Plateau (W. Morocco). The pool is one of many that originated from the dismantling of a past hydrographical network, dated to the end of the Lower Pleistocene. Infilling of the pool began only recently between 5000 and 4000 cal. BP, and probably was in response to Neolithicinduced degradation of the regional vegetation cover. The almost continuous pollen occurrence of Isoetes velata-type, Myriophyllum alterniflorum and Ranunculus-type throughout the palynological sequence indicates that the organisation of local plant communities in concentric belts (a central aquatic community, an intermediate amphibious one, and a peripheral terrestrial one) has remained unchanged since the Mid-Holocene. The stability of the vegetation structure and composition over more than 4000 years confirms the adaptation of the hydrophytic communities to human-induced disturbances (mainly grazing). The long-term pool longevity is attributed to an equilibrium between wind erosion and sedimentation. The sediment accumulation balance that was null or negative during most of the Pleistocene became positive under the influence of Neolithic activities,which may also be linked to unfavourable climatic conditions. These results have important implications for the long-term conservation of biodiversity, as these rare habitats are rapidly declining. Since temporary pools also protect the quartzitic-sandstone plateau fromerosion, their disappearance could trigger the reorganisation of the hydrological network and the resumption of soil erosion.