Removal of cadmium (II) from aqueous solution using fermented grape marc as a new adsorbent

Abstract

Biosorption of cadmium from aqueous solutions using fermented grape marc is investigated in this paper as well as influence of the most important factors, such as: contact time, granulation of biosorbent and the initial concentration of metal ions, is investigated in this paper. The equilibrium sorption of cadmium ions is achieved after 15-20 min., depending on the initial concentration of metal ions. Such a short time needed to achieve the equilibrium indicates that mass sorption is dominate process. Langmuir, Freundlich and Dubinin-Radushkevich isotherm were used to describe the equilibrium sorption process, while Langmuir model was found to be the most conveniente. Maximum of sorption capacity is 20 mg g1. EDS spectrum analysis showed that the process of ion exchange is one of the main sorption mechanism. Minor changes observed in the FTIR spectrum of grape marc after the sorption of Cd(II) ions indicate forming a band between metal ions and partially ionized carboxyl and phenol groups from the biomass. The results of this study confirmed that the fermented grape marc, due to the porous structure and characteristic chemical composition, is good sorption material.

Green grape marc biosorbents preparation for mercury removal in aqueous media

“…Batch adsorption experiments were performed for both biosorbents GM-HCl and GM-CA by shaking the dispersion prepared by mixing 3 mg of the dry biosorbent with 3 ml of HgCl2 aqueous solution at known concentrations in the range of 23-300 mg L -1 [18,22]. The mixture was shaken for 20 h at room temperature and 250 rpm and filtrated through a 0.20 µm filter to remove the sorbent.…”

“…The adsorption data were fitted into four linearized Langmuir, Freundlich, Temkin, and D-R isotherms [22]. Langmuir isotherm model describes the formation of a monolayer adsorbate on the outer surface of the biosorbent, and it is represented in the following linear form [12,18,22,23,24]:…”

“…The linearized Freundlich equation [12,18,22,24] is used to describe the adsorption characteristics of the heterogeneous surface:…”

“…Furthermore, grape marc has been used as a potential biosorbent for the adsorption of organic compounds such as pesticides [16] and caffeine [17]. On the contrary, the application of grape marc for metal ions adsorption has been only little considered in the literature, such as the removal of Cd(II) ions [18], Cu(II), and Ni(II) ions [19] and Cr(VI), Cu(II), Ni(II) ions [20,21]. To our knowledge, the use of grape marc for mercury ion adsorption has not been considered in the literature.…”

Sorption Kinetics Of Cd(II) Ions On Fermented Grape Marc

“…Experimental results [11] showed that grape marc is a cellulosic material of multilayered structure whose layers are interconnected by a system of channels and pores, which form a relatively large specific surface area. The presence of pores is suitable for diffusion of metal ions and their adsorption on numerous internal active centers.…”