**5. Study of the zinc adsorption**

*Trace Metals in the Environment - New Approaches and Recent Advances*

**4.2 Study of the Cu2+ isotherms adsorption on the raw chitin**

for Cu2+ adsorption assays are shown in **Figure 6b**.

depends on the origin of the raw chitin.

double electric surface layer.

[59] on the algae.

observed in the toxicological and physiological effect of copper. A similar behavior of copper retention was observed according to Balistrieri [58] on metal oxide surfaces, according to Fisher [29] on phytoplankton, and according to Xue et al.

**Figure 6a** shows the evolution of the adsorption capacity (Qe) expressed in milligrams of metal per gram of material as a function of the residual content (Ce) of Cu2+ at equilibrium. The results of calculating the average removal percentages

Examination of the different isotherms shows that Cu has a high affinity for Clan. For a residual concentration of 1 mg/l, the adsorbed amount reaches 95 mg/g for Clan and 40 mg/g for Ccre. This example proves that the adsorption of Cu2+

From **Figure 4b**, it is clear that Cu2+ shows a particularly great preference for Clan. The percentage of Cu2+ adsorption on Clan varies between 99.07% to 5 mg/l and 93.2% to 100 mg/l, whereas on the Ccre, it varies between 81% to 5 mg/l and 68% at 100 mg/l; this shows that the adsorption of Cu2+ on these supports increases when the concentration decreases, and this is in agreement with the study carried out by Okieimen [60], which found that the percentage of CuCl2 adsorption on the original Arachis Hypogea cellulose varies between 70% to 200 mg/l and 30% to 500 m/l. Likewise, Elliott [61] having studied the adsorption of Cu2+ on Al2O3 has argued that an increase in the ionic strength of the adsorbent-adsorbent system reduces the adsorption of Cu2+ through the effect of the activity coefficients and the

*(a) Experimental Cu (II) adsorption isotherms on the raw chitin, (b) Effect of the origin of the raw chitin on* 

Ccre 42.25 0.14 1.00 Ccra 17.19 −3.45 0.99 Clan 204.67 −4.58 1.00

*Values of Freundlich parameters deduced from Cu2+ adsorption isotherms on the raw chitin.*

**Kf mg/g 1/n R**

**246**

**Table 5.**

**Figure 6.**

*the Cu (II) elimination efficiency.*
