<p>This study investigates the removal of diclofenac from water by adsorption onto a dealuminated Y-type zeolite (DAY), followed by destructive regeneration of the spent adsorbent using homogeneous advanced oxidation processes. Two oxidation systems were evaluated: the Fenton reaction (<InlineEquation ID="IEq1"> <EquationSource Format="TEX">$\text {HO}^{\bullet }$</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mtext>HO</mtext> <mo>∙</mo> </msup> </math></EquationSource> </InlineEquation>) and thermally activated peroxodisulfate (SO<InlineEquation ID="IEq2"> <EquationSource Format="TEX">$_{4}^{\bullet -}$</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mrow /> <mrow> <mn>4</mn> </mrow> <mrow> <mo>∙</mo> <mo>-</mo> </mrow> </mmultiscripts> </math></EquationSource> </InlineEquation>). For the Fenton process, two catalysts were tested: ferrous ion (Fe<InlineEquation ID="IEq3"> <EquationSource Format="TEX">$^{2+}$</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mrow /> <mrow /> <mrow> <mn>2</mn> <mo>+</mo> </mrow> </mmultiscripts> </math></EquationSource> </InlineEquation>) and the Fe(II)–EDDS complex, using ethylenediamine-N,N′-disuccinic acid as a chelating agent. The influence of the oxidation process and of the localization of radical generation on regeneration efficiency was assessed. Regeneration performance was quantified by the adsorption capacity recovery ratio (<InlineEquation ID="IEq4"> <EquationSource Format="TEX">$q_0/q_{0,1}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <msub> <mi>q</mi> <mn>0</mn> </msub> <mo stretchy="false">/</mo> <msub> <mi>q</mi> <mrow> <mn>0</mn> <mo>,</mo> <mn>1</mn> </mrow> </msub> </mrow> </math></EquationSource> </InlineEquation>) obtained from Langmuir isotherm modelling. The results show that adsorbent regeneration is feasible over several adsorption-regeneration cycles, but that the recovered adsorption capacity decreases with cycle number. For Fenton regeneration with Fe<InlineEquation ID="IEq5"> <EquationSource Format="TEX">$^{2+}$</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mrow /> <mrow /> <mrow> <mn>2</mn> <mo>+</mo> </mrow> </mmultiscripts> </math></EquationSource> </InlineEquation>, the adsorption capacity recovery was 71.9% after the second cycle and decreased to 19.8% after the third. In contrast, thermally activated peroxodisulfate yielded higher regeneration efficiencies, with 91.1% and 50.5% recovery after the second and third cycles, respectively, which is attributed to the greater persistence of SO<InlineEquation ID="IEq6"> <EquationSource Format="TEX">$_{4}^{\bullet -}$</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mrow /> <mrow> <mn>4</mn> </mrow> <mrow> <mo>∙</mo> <mo>-</mo> </mrow> </mmultiscripts> </math></EquationSource> </InlineEquation> and its ability to oxidize adsorbed diclofenac within the zeolite pores. When the Fe(II)–EDDS complex was used at pH 3, the regeneration rates increased to 75.2% (second cycle) and 39.1% (third cycle), and at pH 7, the Fe(II)–EDDS complex further improved adsorption capacity recovery. Overall, immobilizing the Fe(II)–EDDS catalyst on the zeolite surface enhances regeneration efficiency for DAY.</p>

Regeneration of dealuminated zeolite Y for diclofenac adsorption using Fenton and peroxodisulfate advanced oxidation processes

期刊论文
发表日期：

2026年4月17日

查看全文

Lionel Domergue

摘要

This study investigates the removal of diclofenac from water by adsorption onto a dealuminated Y-type zeolite (DAY), followed by destructive regeneration of the spent adsorbent using homogeneous advanced oxidation processes. Two oxidation systems were evaluated: the Fenton reaction ( $\text {HO}^{\bullet }$ ${HO}^{∙}$ ) and thermally activated peroxodisulfate (SO $_{4}^{\bullet -}$ $_{4}^{∙ -}$ ). For the Fenton process, two catalysts were tested: ferrous ion (Fe $^{2+}$ $^{2 +}$ ) and the Fe(II)–EDDS complex, using ethylenediamine-N,N′-disuccinic acid as a chelating agent. The influence of the oxidation process and of the localization of radical generation on regeneration efficiency was assessed. Regeneration performance was quantified by the adsorption capacity recovery ratio ( $q_0/q_{0,1}$ $q_{0} / q_{0, 1}$ ) obtained from Langmuir isotherm modelling. The results show that adsorbent regeneration is feasible over several adsorption-regeneration cycles, but that the recovered adsorption capacity decreases with cycle number. For Fenton regeneration with Fe $^{2+}$ $^{2 +}$ , the adsorption capacity recovery was 71.9% after the second cycle and decreased to 19.8% after the third. In contrast, thermally activated peroxodisulfate yielded higher regeneration efficiencies, with 91.1% and 50.5% recovery after the second and third cycles, respectively, which is attributed to the greater persistence of SO $_{4}^{\bullet -}$ $_{4}^{∙ -}$ and its ability to oxidize adsorbed diclofenac within the zeolite pores. When the Fe(II)–EDDS complex was used at pH 3, the regeneration rates increased to 75.2% (second cycle) and 39.1% (third cycle), and at pH 7, the Fe(II)–EDDS complex further improved adsorption capacity recovery. Overall, immobilizing the Fe(II)–EDDS catalyst on the zeolite surface enhances regeneration efficiency for DAY.