Table 2 Results of batch (ad)sorption-desorption experiments that highlight the wide-ranging rate of OM desorption from minerals

¹⁸⁴

Commercial iron oxide powder

Natural organic matter (NOM), collected from wetland pond

Acid (HCl), base (NaOH), or inorganic salts (NaCl, Na₂SO₄, Na₃PO₄) added before adsorption

Hysteresis coefficient (h) between 0.72 and 0.86 for pH 4.1 and between 0.78 and 0.92 for pH 6.0, indicating that desorption was very limited

¹⁸⁵

Iron oxide powder

NOM from wetland pond, separated into hydrophobic and hydrophilic fractions

Acid (HCl), base (NaOH), or inorganic salts (NaCl, Na₂SO₄, Na₃PO₄) added before adsorption

Hysteresis coefficient (h) between 0.81 and 0.91 for hydrophobic NOM, h between 0.821 and 0.984 for hydrophilic NOM, indicating desorption was very limited

¹⁸⁶

Uncoated, FeO(OH)-coated, and Al₂O₃-coated sands

Terrestrial humic acid extracted from commercially available peat

Uncoated vs (hydr)oxide coated sands

At pH 4.1, hysteresis coefficient (h) between 0.70 and 0.96 for metal (hydr)oxide coated sands, indicating limited desorption. For uncoated sands, h was between 0.41 and 0.78, suggesting higher desorption potential

¹⁸⁷

Soils (Vitric Phaeozem, Haplic Chernozem, Chromic Luvisol, Calcaric Phaeozem, and Chromic Cambisol) and phyllosilicate clay fractions (Ca-montmorillonite, kaolinite, and illite)

Dissolved organic carbon (DOC) extracted from pine forest floor

Near-neutral pH; phosphate treatment used to block reactive hydroxyl groups

In samples without phosphate treatment, between 13% and 50% of DOC was desorbed, with greater desorption in the phyllosilicate clay compared to the soil clay fractions

¹⁸⁸

AmorphousAl(OH)₃, goethite, and low organic C subsoil

NOM, extracted from Oa horizon of an Entic Haplorthod

Desorption using solutions with a range of pH and inorganic anions (Cl^-, SO₄^2-, and H₂PO₄^-)

Under normal conditions, desorption of NOM was <3%, desorption reached 60% in the presence of high concentrations of H₂PO₄^-

¹⁷⁷

Kaolinite, illite, and geothite

14C-labelled monomers (glucose, acetylglucosamine, phenylalanine, salicylic acid, and citric acid)

Also measured microbial carbon use efficiency (CUE)

40–99% of monomers across all treatments were retained after desorption with NaN₃, the range was reduced to 3–55% after subsequent desorption using PO₄^3-

¹⁸⁹

Vertisol soil from crop field (bulk soil and its clay size fraction)

Carbamazepine (CBZ)

No CBZ, CBZ co-introduced, or CBZ introduced after DOM pre-adsorption

The hysteresis coefficient (HI) for CBZ-clay was 0.91 versus 0.64 in CBZ-bulk soil, HI decreased following pre-adsorption of DOM

³⁹

Organic matter-poor, alkaline soils (Fluvent, Rhodoxeralf, and Loess)

DOM extracted from mature composted biosolids

Four sequential desorption steps

Up to 83% of sorbed DOM was retained after desorption

¹⁹⁰

Pure clays (kaolinite, illite, smectite) with and without Fe oxide (haematite, goethite, ferrihydrite) coatings

DOC extracted from medic shoot

Effect of goethite coating on different clay types, effects of different Fe oxide coatings on illite

Across all treatments, 5.7–14.4% of sorbed DOC was desorbed

¹⁹¹

Soil clay fractions (kaolinite-illite, smectite, and allophane)

DOC extracted from wheat straw

Adsorption measured under varying electrolyte conditions: 0.1 M and 0.01 M Ca(NO₃)₂ and NaNO₃

6.4% to 55.3% of adsorbed DOC was desorbed

¹⁹²

Soil clay fractions (kaolinite–illite, smectite, allophane)

DOC extracted from wheat straw

Untreated clay, C removed, and sesquioxide removed

30% to 71% of adsorbed DOC was desorbed across clay type; highest desorption in kaolinite-illite

¹⁹³

Pure minerals (kaolinite, illite, montmorillonite, ferrihydrite, and goethite)

14C-labelled carboxylic acids and amino acids

For carboxylic acids: Fe oxides retained 83–100%, while phyllosilicates retained 31–85%. For amino acids: glutamic acid retention was 53–98% on Fe oxides versus 0–48% on phyllosilicates; lysine retention was 41–99% on phyllosilicates and 13–50% on Fe oxides