Résumé:
Textile industry discharges and urban wastewater drain large quantities of heavy metals that represent a potential risk to ecosystems and human health. Among the proposed treatments, adsorption techniques seem particularly promising.
The objective of this study is to propose a treatment of sanitation of these waters based on the use of a composite synthesized of two materials a hydroxyapatite and a chitosan (CS/HAP) extracted from the waste of shrimps Aristeus antennatus (heads and carapaces) and of tests and spines of sea urchins Paracentrotus lividus with a chemical treatment followed by a thermal activation according to a well determined protocol in order to study and define the adsorption capacity of an inorganic pollutant Nickel (Ni) with two concentrations 20 mg/l and 25 mg/l. The methodology adopted consisted in analyzing the composite by infrared and then testing it for its power of adsorption of Nickel as a function of time, mass, pH and temperature.
The optimal conditions for maximum removal of Nickel : an adsorbent mass of 0.3g and a contact time of 30min respectively, a temperature of 25°C and a pH of 6.2. The Langmuir model which expresses and confirms the saturation level of the adsorbent, The results of the experiments carried out allowed to obtain a maximum adsorption capacity of b=16.27mg/g.
According to our results, the selected marine biomass is very promising for the treatment of waters contaminated with inorganic pollutants. The value of local natural resources can be fully exploited in the context of sustainable development by reducing the pressure on the environment and conferring considerable added value to underutilized natural materials.
