Adsorption of Cr(VI) ions onto goethite, activated carbon and their composite: kinetic and thermodynamic studies

Abstract

Hexavalent chromium was adsorbed from aqueous solution with three prepared and characterized adsorbents, namely goethite (G), activated carbon (AC) and their composite (GAC). The goethite particle was synthesized using the precipitation methods, and activated carbon was prepared from the stem bark of Daniellia oliveri tree and composite in a ratio of 1:5 goethite–activated carbon. The adsorption capacities of G, AC and GAC for Cr(VI) are 6.627, 5.455 and 6.354 mg/g with 0.02 g adsorbent within contact time of 60, 180 and 30 min for G, AC and GAC, respectively, for Cr(VI) adsorption at optimum pH of 3. The isotherm studied was best explained by Langmuir adsorption isotherm and fitted with the pseudo-second-order kinetic model. Desorption studies showed that 1.0 M HNO3 was a better desorbing agent than 0.1 M HNO3, 0.1 M HCl and 1.0 M HCl. Chromium was most desorbed (94.60% in Cr//G using 1 M HNO3). The result obtained revealed that goethite and activated carbon produced are favourable adsorbents and the composite of the two adsorbents gives a more favourable, economical and affordable adsorbent for the clean-up of heavy metal contamination.

The Adsorption of Copper, Lead Metal Ions, and Methylene Blue Dye from Aqueous Solution by Pure and Treated Fennel Seeds

“…The Freundlich model is linked to the formation of multilayer of MB on adsorbent heterogeneous surfaces ( [67,68]), while the uptake processes of Pb(II) and Cu(II) had high r 2 values for Langmuir than Freundlich. The Langmuir model is based on the premise Adsorption capacities of the adsorbents increased when contact time was increased [71]. Also, the removal rate of MB dye onto all adsorbents was rapid more than that of Pb(II) and Cu(II) cations.…”

Activated Carbon/Bentonite/Fe3O4 as Novel Nanobiocomposite for High Removal of Cr(VI) Ions

“…As shown, the AC/bentonite/magnetite nanocomposite has a sorption capacity comparable to those in previous studies. Also, by comparing this composite with AC, graphite, and graphite/AC 43, it can be concluded that the AC/bentonite/magnetite nanocomposite has a higher sorption capacity.…”

Harmful Impacts of Heavy Metals and Utility of Biosorption Technique for Their Removal from Wastewater: A Review

“…biomass 74.91for As(III) and 81.63 for As(V) (Prasad et al, 2013) Hydrilla verticilata 11.65 for As(III) (Nigam et al, 2013) Pretreated biomass of psychrotolerant Yersinia sp. strain SOM-12D3 159 for As(III) (Asadi Haris et al, 2018) Mn(II) Aspergillus niger 19.34 (Parvathi et al, 2007) Saccharomyces cerevisiae 18.95 (Parvathi et al, 2007) Glutaraldehyde Cross-linked Chitosan Beads 278 (Suguna et al, 2010) Raw Euphorbia mammillaris (corncob) biomass 6.54 (Adeogun et al, 2011) Acid-treated corncob biomass 7.87 (Adeogun et al, 2011) Raw and oxalic acid-modified Zea mays (maize husk) 8.52 and 9 (Adeogun et al, 2013) Nigerian kaolinite clay 111.11 (Dawodu et al, 2014) Rice (Oriza sativa) husk ash 3.21 (Adekola et al, 2016) Saccharum bengalense 21.72 (Imran et al, 2018) Co(II) PFBI (Fungal based biosorbent developed in the lab) 190 (Suhasini et al, 1999) Crab shell particles 322.6 (Vijayaraghavan et al, 2006) Citrus limon (lemon) peel as biosorbent 22 Tectona grandis (teak) leaves powder 29.48 (Vilvanathan et al, 2016) Lantana camara leaves' biosorbent 8.32 (Robert et al, 2018) Camellia sinensis (tea) and Coffea (coffee) powder 244 (Elsherif et al, 2019) Cr(VI) Pleurotus ostreatus 10.75 (Javaid et al, 2011) Brassica napus (canola) biomass 10.67 (Balarak et al, 2014) Tamarindus indica (tamarind) pod shell 40 (Desai et al, 2014) Ageratum conyzoides leaf powder 21.505 (Chandrakala et al, 2015) Mirabilis jalapa 23.255 (Begum et al, 2015) Phoenix dactylifera L. (date palm) fiber 62.5 (Rahman et al, 2017) Application of immobilized Musa paradisiaca L. (banana peels) into calcium alginate beads 109.890 (Sharma et al, 2018) Stems of Lantana camara plant 26.25 (Ravulapalli et al, 2018) Dan-iellia oliveri stem bark 5.455 (Adebayo et al, 2020) Goethite particle 6.627 (Adebayo et al, 2020) The heavy metal ion affinity of biosorbents is found to be enhanced by modifications on their surface, e.g., raw and oxalic acid-modified maize husk for adsorption of lead (II) (in table 2). It is found that using agricultural wastes as biosor...…”