New derivatives of urea-grafted alginate for improving the sorption of mercury ions in aqueous solutions

Abstract Chemically-modified alginate (obtained by grafting urea on alginate, with different ratios; alginate-urea ( 1:1 ) and its new derivatives 1:2 an exceed of the percent amino group 7 %) was successfully tested for mercury sorption in aqueous solutions. The influence pH metal first investigated: optimum close to 5.5. Sorption isotherms were modeled using Langmuir Sips equations, capacity slightly increased % of–NH 2 sorbent maximum exceeded 200 mg Hg l −1 (1.07 mmol g ; (1:2)), this means two times reference material (i.e., non-modified alginate), also has a improved compared (1:1). Under selected experimental conditions equilibrium reached 6–8 h contact kinetic profiles pseudo-first order equation (PFORE), pseudo-second-order rate (PSORE) resistance intraparticle diffusion (RIDE). Surface functional groups, notably; –NH , –OH –COOH, involved alginate-urea, suggesting ion exchange, complexation and/or electrostatic interaction Hg(II) surface. use material, environmentally friendly simply obtained from renewable resource, reveals promising treatment low-metal concentration effluents: capacities are comparable alternative academic commercials sorbents.