CuCr-Layered Double Hydroxide Intercalated with 2-mercaptoethane sulfonate: Highly Selective and Efficient Removal of Heavy Metals from Environmental Water samples

ABSTRACT: In this work, CuCr-layered double hydroxide nanosheet intercalated with 2-mercaptoethane sulfonate (MES-LDH) have been successfully fabricated via a facile method. The MES-LDH coated on carbon cloth was used for effective removal of heavy metals (Co(II), Ni(II), Zn(II), Pb(II), Cd(II), and Hg(II) ) that exhibits superior selectivity and higher adsorption capacity for Hg(II) ions even in the presence of high concentration levels of competitive ions. The Hg(II) ions and thiol groups interactions are the basis for the high selectivity. Sorption isotherm for removal of heavy metal ions agrees with the Langmuir model suggesting a monolayer adsorption. The MES-LDH exhibits a record high saturation heavy metal ions capacity of over 2500 mg g-1 and distribution coefficients of 4.10 × 106 mL g-1 that is placed at the top of materials known for removal of heavy metal ions. The sorption kinetics for heavy metal follows a pseudo-second-order model suggesting a chemisorption with the adsorption mechanism via M-S and M-SO4 bindings. Moreover, we observed efficient heavy metal removal in tap water, well water, river water, and seawater, excellent efficiency in recycling studies and good stability of the sorbent.

کلیدواژه ها:

Environmental water samples ، Layered double hydroxide ، Selective removal ، Heavy metals ، 2-mercaptoethane sulfonate