Chemically activated high grade nanoporous carbons from low density renewable biomass (Agave sisalana) for the removal of pharmaceuticals

Abstract

Enlarging the range of viable nanoporous carbon precursors, namely by the acid treatment of low density biomass residues, can overcome issues related with the availability and quality of raw materials that have potential impact on cost and quality grade of the final product. Experiments Nanoporous carbons were prepared following a two-step process: H 2 SO 4 digestion/polycondensation of biomass waste (Agave sisalana, sisal) to obtain acidchars that were further activated with KOH or K 2 CO 3. Selected synthesized nanoporous carbons were tested for the removal of pharmaceutical compounds-ibuprofen and iopamidol-in aqueous solutions. Findings The structure and density of the acid-chars are highly dependent on the concentration of H 2 SO 4 used in the digestion and polycondensation steps. An adequate choice of the acid-char synthesis conditions, activating agent and contact method allowed to feature nanoporous carbons with specific surface areas ranging from 600 to 2300 m 2 g-1 and apparent densities reaching 600 kg m-3. The adsorption capacity of a sample obtained by KOH-activation for the removal of micropollutants from water was twice higher than the value attained by golden activated carbon (Cabot-Norit) commercialized for this specific purpose.

More Sustainable Chemical Activation Strategies for the Production of Porous Carbons

“…400 °C), [36,39] which explains the lower pore development achieved with K 2 CO 3 compared to KOH (Table 1). [40–44] Besides, as mentioned above, K 2 CO 3 is one of the products during KOH activation, so that for T >600–700 °C, reactions (1) to (4) also take place during KOH activation, yielding additional pore development. However, K 2 CO 3 has two important additional advantages over KOH.…”

Solar Light-Induced Methylene Blue Removal over TiO2/AC Composites and Photocatalytic Regeneration

“…The XRD patterns of TiO 2 calcined at 200 • C, activated carbon, and TiACX composites are displayed in Figure 2. The XRD pattern of the AC derived from spent coffee grains displays two broad bands at around 2θ = 25.5 • and 44.0 • [ICDD 25-284], which are characteristic of (002) and (100) reflections from an amorphous-like carbon structure (highlighted with "#" symbol in Figure 2) [29]. These two bands are the only reflections detected in the diffractogram of the TiAC60 composite due to the considerable amount of carbon component present in this sample.…”

“…AC is produced by the carbonization and activation of raw materials with a high carbon content and, preferentially, with a high density [20,21]. Several studies reported the production of ACs from waste materials, such as, fruit seeds [22][23][24], leather scraps [25], tires, cork [26,27], sisal [28,29] and coffee residues [30]. In the particular case of AC prepared by the activation of spent coffee grains, literature studies report large volume of pores and a high adsorption capacity for phenol [30] and H 2 S [31].…”

SILVER SULFATE (Ag2SO4): MOLECULAR ANALYSIS AND ION TRANSPORT

“…Densitas (146)(147)(148)(149) 2,61 g/cm 3(150) Titik didih (151)(152)(153)(154) Titik leleh (155)(156)(157)(158) 1.085 °C; 1.985 °F; 1.358 K (dekomposisi) 652 °C; 1.206 °F; 925 K Kelarutan dalam air (159-161) Dalam pelarut lain 0,79 gr/100 mL (20 °C) 1,30 gr/100 mL (80 °C) Larut dalam asam nitrat Tidak larut dalam etanol Struktur kristal (123,162,163) Ortorombik…”