Selective recovery of precious metals by persimmon waste chemically modified with dimethylamine. Bioresour Technol

Department of Applied Chemistry, Saga University, 1-Honjo, Saga 840-8502, Japan.
Bioresource Technology (Impact Factor: 4.49). 05/2009; 100(18):4083-9. DOI: 10.1016/j.biortech.2009.03.014
Source: PubMed


Persimmon waste was chemically modified with dimethylamine (DMA) to obtain a tertiary-amine-type gel, named DMA persimmon waste gel (DMA-PW). It was found to be effective for the adsorption of Au(III), Pd(II), and Pt(IV) in hydrochloric acid medium. In contrast, base metals such as Cu(II), Zn(II), Fe(III), and Ni(II) were not practically adsorbed. The formation of ion pairs of the metal chloro complex anions with the protonated adsorption gels was proposed as the main adsorption process. The gel exhibited selectivity only for precious metals with a remarkably high capacity for Au(III), i.e., 5.63 mol/kg dry gel and comparable capacities, i.e., 0.42 and 0.28 mol/kg for Pd(II) and Pt(IV), respectively. According to the kinetic and electrochemical studies, the adsorption rate of Au(III) was greatly enhanced by the chemical modification. Also, its excellent adsorption characteristics for the precious metals were confirmed by adsorption and elution tests using a column packed with the DMA-PW gel.

Download full-text


Available from: Katsutoshi Inoue, May 29, 2014
  • Source
    • "The maximum adsorption capacities of these precious metals on these modified gels as well as the DMA-PW gel evaluated according to the Langmuir's equation are listed inTable 3 together with those on other adsorbents for comparison.Table 3. The maximum adsorption capacities of gold(III), platinum(IV) and palladium(II) on various adsorbents. Persimmon extract tannin (PT) powder 5.89 - - 0.1 [33] Crosslinked persimmon tannin (CPT) 7.7 - - 0.1 [33] Crosslinked persimmon waste (CPW) 4.95 - - 0.1 [35,36] Dimethylamine modified persimmon waste (DMA-PW) 5.63 0.28 0.42 0.1 [35,36] Quaternary ammonium modified persimmon tannin (QAPT) 4.16 0.52 0.84 0.1 [37] Tetraethylenepentamine-modified persimmon tannin (TEPA-PT) 5.93 1.48 1.76 0.1 [38] Glycidyltrimethyl ammonium chloride modified persimmon tannin (GTA-PT) 3.30 1.00 1.67 0.1 [39] Aminoguanidine modified persimmon tannin (AG-PT) 8.90 1.00 2.00 0.1 [40] Bisthiourea modified persimmon tannin (BTU-PT) 5.22 0.70 1.72 0.1 [41] Quaternary ammonium modified microalgal residue 1.33 2.95 0.1 [43] Crosslinked microalgal residue 3.25 0.15 0.25 0.1 [44] Crosslinked chitosan 1.6 2.1 0.01 [1] Collagen fiber immobilized bayberry tannin 0.495 0.80 pH = 5.6 [45] Lysine modified cross-linked chitosan 0.35 0.66 1.03 pH = 1 for Pt; pH = 2 for Pd, and Au [46] Glycine modified cross-linked chitosan 0.86 0.62 1.13 pH = 2 [47] PEI-modified corynebacterium glutamicum 1.66 0.1 [48] Ethylenediamine modified chitosan nanoparticle 0.87 1.30 pH = 2 [49] Thiourea-modified chitosan microsphere 0.66 1.06 pH = 2 [50] Duolite GT-73 0.58 0.26 pH = 2 [51] Polyallylamine modified Escherichia coli biomass 2.50 pH = 3 [52] Dimethylamine modified waste paper 4.60 0.90 2.10 1 [42] Among these modified persimmon tannin gels, the high adsorption capacities of TEPA-PT, GTA-PT, AG-PT and BTU-PT not only for gold(III) but also for platinum(IV) and palladium(II) are noteworthy though the concentration range of hydrochloric acid effective for the high adsorption is limited. Also for these modified persimmon tannin gels, the exceptionally high adsorption capacities for gold(III) are attributable to the combination of adsorption and reduction into metallic gold particles by the aid of polyphenolic groups of persimmon tannin, which was confirmed by the observations using optical microscope and XRD. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Novel and environmentally benign adsorbents were prepared via a simple sulfuric acid treatment process using the wastes of astringent persimmon, a type of biomass waste, along with persimmon tannin extract which is currently employed for the tanning of leather and as natural dyes and paints. The effectiveness of these new biosorbents was exemplified with regards to hydrometallurgical and environmental engineering applications for the adsorptive removal of uranium and thorium from rare earths, cesium from other alkaline metals such as sodium, hexa-valent chromium from zinc as well as adsorptive recovery of gold from chloride media. Furthermore, reductive coagulation of gold from chloride media for the direct recovery of metallic gold and adsorptive recovery of palladium and platinum using chemically modified persimmon tannin extract were studied.
    Full-text · Article · Oct 2015 · Metals - Open Access Metallurgy Journal
  • Source
    • "Several research groups reported the adsorption of several metal ions in aqueous solution to various types of biomass (e.g. microorganisms, polyphenols and polysaccharides) [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18]. Effective use of biomass is also an important issue for a sustainable society. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Various types of protein-rich biomass were examined as selective and environment-friendly absorbents for precious metal ions. In the presence of base metal ions, Au3+, Pd2+ and Pt4+ ions were selectively adsorbed to samples of protein-rich biomass. Among the biomass samples tested, egg-shell membrane exhibited the highest adsorption ability and had high selectivity for Au, Pd and Pt ions. The maximum adsorption amount of Au, Pd and Pt ions to egg-shell membrane was approximately 250, 110 and 50 mg/g, respectively, in the presence of 0.1 M HCl. Microscopic observations and metal-ion desorption studies suggested that the precious metal ions were adsorbed and a portion of them was reduced to form metal nanoparticles on the egg-shell membrane, leading to high adsorption ratios. Investigations using glycoproteins indicated the importance of sugar chains in the adsorption of Au ions to the egg-shell membrane. Successful recovery of Au, Pd and Pt ions from industrial waste solutions was also demonstrated using egg-shell membrane. Biomass sheets (1 mm thick) made from egg-shell membrane also exhibited adsorption abilities for precious metal ions.
    Full-text · Article · May 2014 · PROCESS BIOCHEMISTRY
  • Source
    • "The increasing demand for the Platinum Group Metals (PGMs) for production of catalysts and in related industries, combined with the limited resources available, has led to increasing interest in the recovery of these strategic elements [49]. Up to now, only a few studies have been carried out on the separation of PGMs using tannin derivatives [50] [51] [9] [46] [48]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Valonea tannin (TA) and formaldehyde condensation reaction was carried out under alkaline condition to prepare the valonea tannin–formaldehyde resol resin (TAR). Obtained resin was used as adsorbent for recovery of palladium (II) and rhodium (III) ions from chloride-containing solutions. This kind of recovery was very simple and useful for generating little secondary wastes. Interaction of adsorption also was investigated: Chloropalladium (II) species were reduced to Pd(0), while hydroxyl groups of TAR were oxidized during the adsorption. Proposed adsorption of the aquachlororhodium (III) species mostly takes place via ligand exchange mechanism. TAR, Rh-adsorbed TAR, and Pd-adsorbed TAR were characterized by scanning electron microscopy, energy-dispersive spectrometry, X-ray diffraction spectroscopy, and Fourier transform infrared–attenuated total reflection spectroscopy.
    Full-text · Article · Apr 2013 · The Chemical Engineering Journal
Show more