Research Progress on the Degradation of Organic Pollutants in Wastewater via Ultrasound/Periodate Systems: A Review

Abstract

In recent years, the efficient removal of organic pollutants from wastewater has emerged as a critical area of global research interest. Against this backdrop, an array of innovative technologies for wastewater treatment has been developed. Among numerous advanced oxidation processes (AOPs), periodate (PI), an emerging oxidizing agent in AOPs, has garnered significant attention from researchers. Particularly, the integration of ultrasound (US)-activated PI systems has been recognized as an exceptionally promising approach for the synergistic degradation of organic pollutants in wastewater. In this paper, we conducted a thorough analysis of the mechanisms underlying the degradation of organic pollutants using the US/PI system. Furthermore, we comprehensively delineated the effects of ultrasonic power, periodate concentration, temperature, pH, coexisting inorganic ions, and dissolved organic matter on the removal efficiency of organic pollutants and summarized application cases of the US/PI system for the degradation of different pollutants. Finally, we also offered prospective discussions on the future trajectories of US/PI technology development.

Keywords: AOPs; activation mechanisms; cavitation effects; periodate; ultrasound.

Figure 1

Schematic representation of the oxidation mechanism within the US/PI framework. (Herein, green symbolizes iodine atoms, orange symbolizes oxygen atoms, and blue denotes oxygen ions.).

Figure 2

The influence of ultrasonic power on the degradation efficiency across various dye types. (a) The impact of varying levels of ultrasonic power on the degradation efficiency of Bright Blue R dye [40]. Reproduced with permission from Elsevier. (b) The progression of degradation for Acid Blue 92 dye under disparate ultrasonic power [35]. Reproduced with permission from Elsevier. (c) The governing principles underlying the influence of ultrasonic power on the decomposition process of Acid Orange 7 dye [37]. Reproduced with permission from Elsevier. (d) The influence of ultrasonic power on the degradation efficiency of Methylene Blue Dye [43]. Reproduced with permission from Elsevier.

Figure 3

PI concentration on the degradation efficiency across a spectrum of targeted pollutants. (a) The trajectory of PFOA degradation efficiency as a function of escalating PI concentration [34]. Reproduced with permission from Elsevier. (b) The efficacy of pollutant removal in authentic industrial wastewater subjected to varying PI concentrations [45]. Reproduced with permission from Elsevier. (c) The associated modifications in the degradation rate of the dye Brilliant Blue R consequent to differing PI concentrations [40]. Reproduced with permission from Elsevier.

Figure 4

Temperature variations on the degradation efficiency of selected pollutants across various types of industrial wastewater. (a) Variations in the overall degradation performance of industrial wastewater subjected to differing temperatures [45]. Reproduced with permission from Elsevier. (b) The efficacy of Ramazol Black B removal under varying temperature [48]. Reproduced with permission from Elsevier. (c) The influence of temperature fluctuations on the degradation efficiency of Bisphenol A within wastewater treatment systems [24]. Reproduced with permission from Elsevier.

Figure 5

pH variability on the degradation efficiency across pollutants. (a) Varied degradation rates of perfluorooctanoic acid (PFOA) across pH spectra [34]. Reproduced with permission from Elsevier. (b) The degradation trajectory of Ramazol Black B under diverse pH scenarios [48]. Reproduced with permission from Elsevier. (c) The pronounced impact of pH on the removal efficiency for the dye Brilliant Blue R [40]. Reproduced with permission from Elsevier.

Figure 6

The Impact of Varied Ions on Pollutant Degradation Efficiency: (a) the comparative effects of Na₂SO₄, Na₂CO₃, and NaCl on Acid Orange 7 degradation [37]. Reproduced with permission from Elsevier. (b) Analysis of sodium sulfate, sodium carbonate, and sodium chloride on Ramazol Black B dye removal [48]. Reproduced with permission from Elsevier. (c) The contribution of KBr to the decomposition of PFOA and its influence on fluoride removal efficiency [34]. Reproduced with permission from Elsevier. (d) The role of bromide ions, as represented by KBr, in enhancing the degradation of Malachite Green [57]. Reproduced with permission from Elsevier.