Improving sono-activated persulfate oxidation using mechanical mixing in a 35-kHz ultrasonic reactor: Persulfate activation mechanism and its application

Yonghyeon Lee; Seojoon Lee; Mingcan Cui; Jeonggwan Kim; Junjun Ma; Zhengchang Han; Jeehyeong Khim

doi:10.1016/j.ultsonch.2020.105412

Improving sono-activated persulfate oxidation using mechanical mixing in a 35-kHz ultrasonic reactor: Persulfate activation mechanism and its application

Ultrason Sonochem. 2021 Apr:72:105412. doi: 10.1016/j.ultsonch.2020.105412. Epub 2020 Dec 8.

Authors

Yonghyeon Lee¹, Seojoon Lee¹, Mingcan Cui², Jeonggwan Kim³, Junjun Ma⁴, Zhengchang Han⁴, Jeehyeong Khim⁵

Affiliations

¹ School of Civil, Environmental, and Architectural Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea.
² School of Civil, Environmental, and Architectural Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea. Electronic address: cmc05@korea.ac.kr.
³ Korea Environmental Industry and Technology, 215 Jinheung-no, Eunpyeong-gu, Seoul 03367, Republic of Korea.
⁴ Nanjing Green-water Environment Engineering Limited by Share Ltd, C Building No. 606 Ningliu Road, Chemical Industrial Park, Nanjing, China.
⁵ School of Civil, Environmental, and Architectural Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea. Electronic address: hyeong@korea.ac.kr.

Abstract

This study investigated the degradation of ibuprofen (IBP), an activated persulfate (PS), when subjected to ultrasonic (US) irradiation and mechanical mixing (M). The effects of several critical factors were evaluated, including the effect of rpm on M, PS concentration, and initial pH, and that of temperature on IBP degradation kinetics and the PS activation mechanism. The resulting IBP oxidation rate constant was significantly higher at 400 rpm. As the PS load increased, the IBP oxidation rate constant increased. The value of the IBP reaction rate increased with decreasing pH; below pH 4.9, there was no significant difference in the IBP oxidation rate constant. The IBP oxidation activation energy when using the US/M-PS system was 18.84 kJ mol^-1. In the US/M-PS system, PS activation was the primary effect of temperature at the interface during the explosion of cavitation bubbles. These encouraging results suggest that the US-PS/M process is a promising strategy for the treatment of IBP-based water pollutants.

Keywords: Acoustic cavitation; Hydroxyl radical; Ibuprofen; Mechanical mixing; Sonochemiluminescence; Sulfur radical.