In the present study, indigo blue dye removal efficiency of activated carbon (AC) and natural clay (NC) was evaluated and compared, firstly in an adsorption unit, and then in an adsorption coupling ultrafiltration (A/UF) system. Effect of operating variables like pH, contact time, adsorbent dosage, initial dyes concentration during the adsorption was investigated and consequently optimised. The optimal conditions were employed for the adsorbents during the removal of the dye in the A/UF system. The optimal amount of NC and AC was 0.4 g/L and 0.3 g/L, respectively, and NC and AC displayed adsorption capacity of 57 mg/g and 53 mg/g, respectively, at this condition. Application of UF reveals a decrease of membrane fouling for both adsorbents in A/UF system. In addition, colour retention, when the adsorbents were used in A/UF, increased significantly from 90.5% to 99% as compared to using adsorption only. The efficiency of the membrane regeneration was estimated by the determination of the water permeability after rinsing. It is noteworthy to mention that a total regeneration of the membrane after the application of continous hybrid A/UF was achieved, however, the use of UF alone exhibited a fouling decrease by 40%.

The main objective of our work is to test the performance of powder activated carbon (PAC) and granular activated carbon (GAC) in the retention of humic substances in the presence of lead. The adsorption tests conducted in synthetic solutions of distilled water. The results showed that, the removal efficiency of humic substances varies with the agitation time was obtained maximum efficiency after 180 minutes for PAC and 300 for the GAC. However, on granular activated carbon (GAC) recorded an improvement in the removal of humic substances in the order of 1.60%. The reaction rate is the same for the activated carbon powder (PAC). By against, for the GAC the removal rate of humic substances in the presence of lead is slower. A comparison between our results with the absorption of humic substances without the presence of lead showed that the elimination of humic substances (10 mg/l) in the presence of lead (5mg/l) on powder activated carbon (1 g/L) is disturbed. The removal efficiencies decrease with the increase on the pH of medium in an interval ranging from 2 to 12.The variation of the mass of lead has recorded an inhibiting role in the adsorption of humic substances for both activated carbons.

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