Effective Removal of Copper (II) and Cadmium (II) by Adsorbent Prepared from Chitosan-modified Magnetic Biochar

Abstract

A novel chitosan-modified magnetic biochar composite (CC-Fe) was synthesized by embedding Fe 2 O 3 and assembling chitosan in two-step. The properties of CC-Fe were characterized systematically by elemental analysis, Brunauer-Emmett-Teller (BET) surface area, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and batch sorption processes. The prepared adsorbent composite was comprised of magnetic particulates of Fe 2 O 3 and multifunctional group, and thus exhibited high sorption capability to remove copper (II) or cadmium (II) from waste water. For both copper (II) and cadmium (II), CC-Fe demonstrated a higher sorption capability (98% and 97%) than the non-chitosan magnetic biochar (11% and 7%). The sorption experimental results showed that the composite is a potential sorbent to remove copper (II) and cadmium (II). Due to its excellent magnetic characteristic, the heavy metal-laden CC-Fe could be isolated again from treated solution and reused after the desorption treatment. The functional groups of CC-Fe made efforts to the removal of heavy metals.

Removal of cadmium(II) cations from an aqueous solution with aminothiourea chitosan strengthened magnetic biochar

“…Although the S BET and porosity of TMBC were lower than those of BC, the introduction of thiourea and CS groups into the structure of TMBC provided plenty of functional groups, which facilitated Cd(II) adsorption. This result was consistent with findings in the literature to some extent . Nonetheless, the preliminary study indicated that TMBC adsorbed higher amounts of Cd(II) from the solutions.…”

“…The pH of 6.71 of TMBC was lower than that of the BC and MBC; this could be explained by the fact that the alkaline MBC was put into 2% v/v acetic acid solution and was neutralized during the TMBC synthesis process. The BET surface area analysis showed a decrease from BC to MBC and TMBC, and this might have been caused by the fact that the sample surface or pore was probably covered by the metal oxides and/or CS groups during the modification process . The sample elemental composition analysis revealed that MBC had a higher iron content (2.83%) and lower carbon content (63.73%) than BC; this implicated the successful blending of carbon with iron in the MBC composite .…”

“…Its considerable amount of free amine and hydroxyl groups endow CS with excellent abilities of being a heavy‐metal‐ion adsorbent and a promising modification reagent for the adsorbent material matrix. For example, with the application of raw CS as a dispersing and soldering reagent, the affinities of BC adsorbents to Cd(II) and Pb(II) ions can be improved significantly; the decoration of the Eichhornia crassipes BC–γ‐Fe 2 O 3 composite with raw CS can improve Cr(VI) adsorption amount nearly fourfold, and the corn straw BC adsorbent soaked with raw CS solution could absorb 55.65 mg/g Cu(II) and 87.62 mg/g Cd(II) . Although these reported BC–CS composites showed acceptable heavy‐metal‐ion‐adsorption capacities, the deficiencies in solubility and the low stability of CS in acidic aqueous solution and the limitations in its structure still existed .…”

“…Although these reported BC–CS composites showed acceptable heavy‐metal‐ion‐adsorption capacities, the deficiencies in solubility and the low stability of CS in acidic aqueous solution and the limitations in its structure still existed . Researchers reported that aminothiourea‐modified CS had the characteristics of lower acidic water solubility and higher stability than raw CS and was more effective in metal‐ion adsorption, especially for Cd(II) chelating, because a large number of chelating‐group thioureas were introduced. Therefore, an aminothiourea‐modified CS derivative may be more practicable for BC modification.…”

Copper Adsorption by Magnetized Pine-Needle Biochar

“…The value maximum adsorption capacity evaluated applying the Langmuir adsorption model has been found to be qmax = 0.40 mmol•g −1 (25.4 mg•g −1 ) and qmax = 1.0 mmol•g −1 (63.5 mg•g −1 ) for the Cu(II) adsorption by pncm and pncom, respectively. This values are in the range of values determined for Cu(II) adsorption by magnetized and chemically modified biochars [15,[21][22][23][24]. Figure 4 shows FTIR spectra of solid samples corresponding to experiments performed at pH 3 and pH 6, and different Cu(II) concentrations.…”