Removal of Bismarck Brown and Disulfine Blue from Aqueous Solutions Using MWCNTs Functionalized by N-(3-nitrobenzylidene)-N'-trimethoxysilylpropyl-ethane-1,2-diamine

The applicability of N-(3-nitro-benzylidene)-N-trimethoxysilylpropyl-ethane-1,2-diamine onto multi walled carbon nanotubes(NBATSPED-MWCNTs) for removing Bismarck Brown and Disulfine Blue from aqueous solutions has been reported. This novel material was characterized by different techniques such as XRD, SEM and FT-IR. The influence of nanoparticle dosage, pH of the sample solution, individual dyes concentration, contact time between the sample and the adsorbent, temperature, and ionic strength of the sample solution were studied by performing a batch adsorption technique. The maximum removal of 15 mg L-1 of individual dyes from an aqueous sample solution at pH 8.0 for Bismarck Brown (BB) and at pH 6.0 for Disulfine Blue (DSB) was achieved within 65 min when an adsorbent amount of 50 mg was used. It was shown that adsorption of the Bismarck Brown (BB) and Disulfine Blue (DSB) follows the pseudo-second-order rate equation, while the Langmuir model explains equilibrium data. Isotherms had also been used to obtain the thermodynamic parameters such as free energy (ΔG0), enthalpy (ΔH0) and entropy (ΔS0) of adsorption. The negative value of (ΔGo, ΔHo and ΔSo) confirmed the sorption process was endothermic reflects the affinity of multi walled carbon nanotubes functionalized towards Bismarck Brown (BB) and Disulfine Blue (DSB). A maximum adsorption capacity in binary-component system (6.67 mg/g for Bismarck Brown (BB), and 9.36 mg/g for Disulfine Blue (DSB)).