Efficient degradation of disodium adenosine triphosphate by Ca–Al-LDH-supported Fe-activated persulfate and in situ adsorption of the phosphate products

• Published in: Journal of cleaner production Vol. 426; p. 139106
• Main Authors: Qiu, Shangkai, Li, Mengmeng, Zhang, Lisheng, Yuan, MingYao, Feng, MengHan, Guo, ChangBin, Zhang, Keqiang, Wang, Feng
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 10.11.2023
• Subjects: Adsorption; Catalytic degradation; Disodium adenosine triphosphate; Fe-LDHs; Persulfate; Fe-LDHs; Disodium adenosine triphosphate; Adsorption; Catalytic degradation; Persulfate
• ISSN: 0959-6526; 1879-1786
• DOI: 10.1016/j.jclepro.2023.139106

To efficiently treat organophosphorus pollutants and synchronously recover phosphorus resources, Fe-loaded layered double metal hydroxides (Fex/Ca–Al-LDHs) were successfully prepared via coprecipitation and impregnation. The effects of the Fex/Ca–Al-LDHs on the degradation of disodium adenosine triphosphate (5-ATP-Na2) in water and in situ separation of the oxidation product, PO43−, were analyzed. The amount of Fe impregnated into the Fex/Ca–Al-LDHs considerably influenced the capacity of the composite for the oxidative separation of 5-ATP-Na2. A 5-ATP-Na2 removal rate of 94.43% was achieved at pH 3 when the Fe content of the Fe0.4-LDHs, catalyst dosage, and potassium persulfate (PS) concentration were 0.4 mol L−1, 0.6 g L−1, and 0.8 mmol L−1, respectively. The removal rate of the Fex-LDHs/PS system was maintained at 71.81% after three oxidation adsorption−desorption cycles. The system was effective for the removal of other organophosphorus species and practical treatment of various sewage types. The activity of the catalyst is derived from the active Fe species (FeCl3, Fe(OH)2, and Fe2O3), which promoted the cyclic conversion of Fe(II) and Fe(III). An increase in the Fe(II) content promoted the activation of PS, enabling rapid pollutant degradation. The main pathway for 5-ATP-Na2 degradation involved oxidation by SO• 4− and •OH; the generated PO43− was primarily removed by adsorption on the Ca–Al-LDHs. The novel Fe-LDHs/PS catalytic adsorption system prepared in this study is an innovative platform for the efficient catalytic degradation of organophosphorus and simultaneous adsorption of the oxidation product, PO43−. [Display omitted] •Fe0.4-LDHs can efficiently degrade 5-ATP-Na2 and in situ adsorption of phosphate.•The removal rate of 75 mg/L 5-ATP-Na2 by Fe0.4-LDHs is 94.43%.•The quenching reaction shows the degradation of 5-ATP-Na2 is dominated by SO.• 4−.•Electron transfer can promote the cyclic transformation of Fe(II) and Fe(III).