Application of Humic Acid Isolated From Kalimatan Peat Soil Modifying Magnetite for Recovery of Gold

Abstract

Humic acid modifying magnetite particles (Mag-HA) were developed for recovery of gold from chloride solution (HAuCl4). The Mag-HA particles were prepared by co-precipitation procedure with Fe(III) and Fe(II) chloride salts, sodium hydroxide, and humic acid. FTIR characterization for Mag-HA after modification indicated the presence of the specific absorption for functional groups of humic acid and Fe-O bonds, though with lower intensity. The Mag-HA particles exhibited a typical superparamagnetic characteristic with a saturation magnetization of 66.99 emu/g. The Mag-HA particles were applied for AuCl4- adsorption and results showed that the optimum adsorption of [AuCl4]- onto Mag-HA was found at pH 3. The adsorption kinetics can be described by a pseudo-second order equation and the adsorption isotherm of the Mag-HA particles agreed well with Langmuir adsorption equation. The maximum adsorbed amount of [AuCl4]- was 0.62 mmol/g and the XRD analysis confirms that the adsorption of Au(III) by Mag-HA was accompanied by the formation of elemental gold.

The Effectiveness of Magnetite Modified Gallic Acid Synthesized by Sonochemical Method As AuCl4- Adsorbent-Reductor

“…The active group that plays a role in the adsorption process is the phenolic group. The part of phenolic groups in adsorbing AuCl4has also been reported by Rahmayanti et al, 2019 andRahmayanti et al, 2020). They used humic acid and ascorbic acid as AuCl4adsorbents.…”

“…The adsorption method using gallic acid is an option. The presence of phenolic groups in gallic acid not only acts as an adsorbent but also as a reducing agent so that Au (III) can be reduced to Au (0) (Rahmayanti et al, 2016a;Rahmayanti et al, 2016b;Santosa et al ., 2020;Fitriani, 2020;Rahmayanti et al, 2019;Rahmayanti et al, 2020). Gallic acid was modified using magnetite to facilitate the adsorption process and the separation between the adsorbent and the post-adsorption adsorbate.…”

Study of Adsorption-Desorption on Batik Industrial Dyes (Naphthol Blue Black) on Magnetite Modified Humic Acid (HA-Fe3O4)

“…The magnetite modified humic acid preparation was carried out following the method of Rahmayanti et al [ 6 ] with a slight change. 5.56 g (0.01 mol) of FeS 04.7 H20 was dissolved in 200 mL of distilled water and added to 11.12 g (0.02 mole) of FeCl 3.6 H20, which was dissolved in 200 mL of distilled water.…”

Aplikasi Asam Humat Hasil Isolasi Tanah Gambut Kalimantan sebagai Adsorben Zat Warna Naphtol Blue Black dan Indigosol Blue: Studi Perbandingan Model Kinetika dan Isoterm Adsorpsi

“…Asam humat memiliki kandungan gugus -COOH dan -OH yang melimpah yang dapat berperan sebagai situs aktif dalam mengadsorpsi adsorbat termasuk zat warna [10]. Interaksi antara asam humat dengan adsorbat dapat terjadi melalui interaksi elektrostatik, pembentukan kelat, pertukaran ion dan ikatan hidrogen [11][12][13].…”