سنتز دو‌هيدروكسيد لايه اي منيزيم-آلومينيوم اصلاح شده با سيترات و كاربرد آن براي حذف سيانيد از پساب هاي صنعتي

In this research a citrate-modified Mg-Al layered double hydroxide (Mg-Al-LDH) was synthesized as adsorbent for removal of cyanide from aqueous solutions. The structural characteristics of the synthesized adsorbent were studied using FT-IR, XRD, FE-SEM, EDS, Zeta potential an‎d nitrogen adsorption-desorption tests. The results of the nitrogen adsorption-desorption test reveals the specific surface of 0.397 m2.g-1 for citrate-modified Mg-Al-LDH. In addition, the average pore size of it was obtained to be 18.37 nm. The effects of different parameters such as pH, contact time, cyanide initial concentration, an‎d temperature were studied. At pH 7, the synthesized adsorbent showed the highest removal efficiency 96 percent in one run Also, in the cyanide removal process, the equilibrium time of 50 min was observed. In addition, the kinetic data were fitted to pseudo-second-order model an‎d the adsorption isotherm data were well fitted with Langmuir isotherm model. The maximum cyanide adsorption capacity at optimum conditions obtained from Langmuir isotherm was 8.43 mg.g-1.Also the reusability tests were performed an‎d the results showed that up to 70 percent of the adsorption efficiency is kept after 4 cycles. The synthesized adsorbent is able to completely remove cyanide form solutions containing low concentrations of cyanide in 50 min. The proposed adsorbent due to bio-friendly composition an‎d low synthesis cost has the potential to be used as applied adsorbent for removal of trace amounts of cyanide.

كيومرث زرگوش

محمد ديناري , اسماعيل حيدري بفرويي