Application of Activated Carbon Obtained from Spent Coffee Ground Wastes to Effective Terbium Recovery from Liquid Solutions

Abstract

A process aimed at the recovery of terbium from liquid solutions using activated carbon (AC) derived from spent coffee grounds (SCG) was assessed. AC was obtained using the hydro-alcoholic treatment of SCG, followed by the physical activation of the as-obtained product. The AC exhibited both microporous and mesoporous structures, which were shown by the corresponding nitrogen adsorption–desorption isotherms and scanning electron microscopy (SEM) images. In addition, a certain graphitic character was found in the micro-Raman measurements. By use of this AC, terbium adsorption was investigated, and the influence of solution pH, temperature, and the adsorbent amount on terbium uptake was tested. In addition, adsorption isotherms and kinetic studies were also evaluated. The best fit was found for the type-1 Langmuir isotherm and pseudo-second-order kinetics model. Thermodynamic studies revealed that terbium adsorption is an endothermic and spontaneous process. Terbium desorption by the use of acidic solutions was also investigated. This work demonstrated that it is possible to recover this valuable metal from liquid solution using the present AC.

Mechanochemically Assisted Microwave-Induced Plasma Synthesis of a N-Doped Graphitic Porous Carbon-Based Aqueous Symmetric Supercapacitor with Ultrahigh Volumetric Capacitance and Energy Density

“…During the plasma treatment, it is seen in the videos that few gases are released, which might be CO, CO 2 , H 2 , and K vapor, and steam generated through the reactions depicted in eqs – ,, are beneficial for creating porous structures. 6 KOH + 2 normalC → 2 normalK + 3 H 2 + 2 K 2 CO 3 K 2 CO 3 → K 2 normalO + CO 2 K 2 CO 3 + 2 normalC → 2 normalK + 3 CO K 2 normalO + normalC → 2 normalK + CO CO 2 + normalC → 2 CO Now, to identify the possible phases formed in the developed HP-NGC and NGC, X-ray diffraction (XRD) with a suitable background subtraction was analyzed (Figure a), where the XRD pattern of HP-NGC revealed two distinguishable broad diffraction peaks at approximately 2θ values of 24° ( d spacing of 0.37 nm) and 43° ( d spacing of 0.21 nm) corresponding to the (002) and (100) planes, respectively. , Similarly, the XRD pattern of NGC also shows two diffraction peaks, where one peak appears at around 2θ of 23° ( d spacing 0.39 nm) due to the (002) plane, and the other one is of low intensity appearing at ∼42.2° for the (100) plane. However, the comparatively higher intensity (100) peak of HP-NGC compared to NGC indicates that HP-NGC is more ordered than NGC. , Additionally, a few small peaks are also observed, which might have appeared due to the presence of an insignificant amount of residual ash in the developed NGC and HP-NGC from coffee grounds. ,…”

“…However, the comparatively higher intensity (100) peak of HP-NGC compared to NGC indicates that HP-NGC is more ordered than NGC. 35,36 Additionally, a few small peaks are also observed, which might have appeared due to the presence of an insignificant amount of residual ash in the developed NGC and HP-NGC from coffee grounds. 30,37 After confirming the formation of the carbon structure, it is important to understand the nature of graphitization in the developed HP-NGC and NGC via Raman spectroscopy, as shown in Figure 2b.…”

Terbium Removal from Aqueous Solutions Using a In2O3 Nanoadsorbent and Arthrospira platensis Biomass

“…A pH of 8.5 was found to be optimal for terbium removal via Transcarpathian clinoptilolite [56]. Maximum terbium removal using 1-(2-pyridylazo)-2-naphthol (PAN)-doped hybrid silica was attained at pH 4.0 [59], via Ca(Ⅱ)-modified garlic peels at pH 3.5 [60], and via activated carbon at pH 5.0 [61]. Thus, the subsequent adsorption experiments were carried out at pH 4.0 for In2O3-NPs and pH 3.0 for spirulina biomass.…”

Nd(III) sorption using aminophosphonate-based sorbents – Sorption properties and application to the treatment of REE concentrate

“…different techniques can be used [15,16]: precipitation [14], solvent extraction ( [17][18][19][20], relayed supported membranes [21,22] and impregnated resins systems [23]). Chelating resins [24][25][26], ion-exchange resins [27,28], or carbon-based sorbents [29,30] are frequently offering competitive solutions for the treatment of dilute solutions. The selectivity for target metals can be enhanced using ion-imprinted materials such as resins [31] or functionalized silica-based composite [32].…”