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This paper presents a review of adsorption isotherms of some dyes from aqueous solutions by biomaterial. In this paper, we reported Typha waste as a model of biomaterial classified as a low-cost adsorbent. The paper also briefly discusses about the literature information from the definition of dyes and adsorbents, bibliometric analysis, adsorption phenomena, adsorption isotherm models, and factors affecting the adsorption, to the use of Typha species waste as a low-cost adsorbent. The operational parameters factors are explained in terms of pH, adsorbent dosage, contact time, and initial dye concentration that will affect the process of removing textile dye. The solution of pH turns out to be the most important condition in the adsorption process for anionic dye, a low pH value are preferable in contrast to cationic dye where the suitable pH value is high. For the adsorbent dose, the adsorption capacity increase along with the increment of adsorbent dosage due to the increase of theavailable amount of adsorption site. The contact time between the adsorbent and dye affects the efficiency of dye removal where a strong attraction force will shorten the time. As for the effect of dye initial concentration, increasing the initial concentration enhances the increment of adsorbent surface area to adsorb dyes. Several isotherm models are described. The Langmuir model is frequently used to evaluate the adsorption capacity of the Typha species waste as adsorbents. This review paper suggested that the accuracy level obtained from adsorption processes is greatly dependent on the successful modeling of adsorption isotherms. Typha biomaterial wastes can be considered as the new useful low-cost natural adsorbents for dye clean-up  operations in aquatic systems.

In this work, batch adsorption experiments were carried out for the removal of Methylene Blue (MB) from aqueous solutions using Typha australis leaf as a low cost adsorbent. The effects of some variables governing the efficiency of the process such as adsorbent mass, pH, ionic strength, contact time and temperature were investigated. The adsorption kinetic data were analyzed using the Pseudo First Order (PFO) and Pseudo Second Order (PSO) models. The experimental equilibrium data were analyzed using Langmuir and Freundlich isotherm models. The results show that the PSO model is the best for describing the adsorption of MB by Typha australis for all initial MB concentrations. The equilibrium data fitted well with the Langmuir model with the monolayer adsorption capacity for MB-Typha australis leaf system was of 103.12 mg g-1. The values of activation parameters such as free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) were also determined as - 4.44 kJ mol−1, 55.13 kJ mol−1 and 203.21 J mol−1 K−1, respectively. The thermodynamics parameters of MB-Typha australis system indicate spontaneous and endothermic process. These results indicate that the Typha australis leaf can be feasibly employed for the eradication of MB from aqueous solution.

Tél.: 00 222 741 91 03 RESUME L'étude de la qualité physicochimique des effluents de la ville de Nouakchott s'est déroulée au cours du mois de mars et avril 2009. Les paramètres étudiés sont la température, le pH, la conductivité, des chlorures, matières en suspension, calcium, magnésium, sodium, potassium, bicarbonates, nitrates, ammonium, orthophosphates, sulfates, fer et chrome. Les résultats des analyses présentés dans ce travail ont révélé que ces eaux usées ont des températures pouvant atteindre 26,3 °C. Le pH varie entre 6,91 et 7,76. L'existence d'une forte salinité avec des valeurs maximale en conductivité électrique en chlorures et sodium respectives de 5,5 mS/cm, 1633 mg/l et 390 mg/l. La totalité des prélèvements ont un rapport d'adsorption de sodium inférieur à 10 donc un risque minimal d'accumulation du sodium. Les nitrates et ammonium présentent des teneurs maximales respectives de 3,50 mg/l et 292,02 mg/l confirmant l'abondance de la forme ammoniacale dans les eaux usées. La présence des ions orthphosphates, sulfates, potassium, calcium et magnésium à des teneurs variables pouvant être bénéfiques pour les cultures et la présence du fer et du chrome dont les teneurs maximales pouvant atteindre respectivement 542 µg/l et 368 µg/l. L'application de l'analyse en composante principale sur ces résultats fait apparaître, globalement, deux sortes d'effluents irrigués dans le périmètre maraîcher de Sebkha: des effluents industriels présentant une forte salinité et des effluents domestiques présentant des teneurs élevées en ammonium.