نوع مقاله : پژوهشی
نویسندگان
پژوهشکده ی علوم محیطی، دانشگاه شهید بهشتی
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
In this study, upon synthesizing GO by Hummer method, EDTA was anchored to the GO surface by covalent band. The obtained nanocomposite was successfully characterized by SEM and FT-IR. Then, GO and EDTA-GO nanocomposites as nanofillers were used in the polyethersulfone nanofiltration membranes matrix. To achieve this purpose, nanofillers were introduced into PES matrix using phase inversion technique. FE-SEM, water contact angle, and overall porosity technique were used to investigate the effect of GO and EDTA-GO nanocomposites on membrane morphology and hydrophilicity. The effects of GO and EDTA-GO nanocomposite on membrane performance were studied in terms of pure water flux, antifouling properties, desalination, and removal efficiency of heavy metal ions Cu2+, Pb2+, and dye (in single-component system) and salt-dye (in binary system) were investigated. With increasing EDTA-GO concentration to 0.25 wt.% (NFM3), the contact angle decreased from 76.17° to 54.85° and the overall porosity increased from 61.1% to 75.9%. The water flux in the NFM3 membrane was 13 kg m-2 h-1 more than that of the NFM0 membrane. FRR, Rt, and Rir values in NFM3 membrane are 63%, 41%, and 33%, respectively, indicating flux recovery and improvement of antifouling properties as a result of nanofiltration membrane modification. The result of desalination tests showed that the highest (55%) and lowest (20%) percentages of desalination were related to Na2SO4 and NaCl salts, respectively, in all membranes. By modifying the membrane to 0.25 wt.% EDTA-GO, the removal efficiency rates for Cu2+ and Pb2+ metal ions in the single-component system increased from 21% to 88% and from 19% to 85% compared to the unmodified NFM0 membrane, respectively. CR dye removal efficiency for all modified nanofiltration membranes was more than 98%. Increasing the Na2SO4 concentration in the dye-salt binary system had no significant effect on the removal percentage of CR. Due to the efficiency of EDTA-GO nanofiller modified membrane in desalination and removal of dye and heavy metals, it can be used as a suitable membrane in wastewater treatment.
کلیدواژهها [English]
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