Effective removal of organics from Bayer liquor through combined sonolysis and ozonation: Kinetics and mechanism

Jianfeng Ran; Haisheng Duan; C Srinivasakannan; Jiashu Yao; Shaohua Yin; Libo Zhang

doi:10.1016/j.ultsonch.2022.106106

Effective removal of organics from Bayer liquor through combined sonolysis and ozonation: Kinetics and mechanism

Ultrason Sonochem. 2022 Aug:88:106106. doi: 10.1016/j.ultsonch.2022.106106. Epub 2022 Jul 29.

Authors

Jianfeng Ran¹, Haisheng Duan², C Srinivasakannan³, Jiashu Yao¹, Shaohua Yin⁴, Libo Zhang⁵

Affiliations

¹ Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650093, China; State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, Yunnan 650093, China.
² Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650093, China; State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, Yunnan 650093, China; Yunnan Wenshan Aluminum Co., Ltd., Wenshan, Yunnan 663000, China.
³ Chemical Engineering Department, Khalifa University of Science and Technology, Abu Dhabi, United Arab Emirates.
⁴ Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650093, China; State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, Yunnan 650093, China. Electronic address: yinsh@kust.edu.cn.
⁵ Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650093, China; State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, Yunnan 650093, China. Electronic address: zhanglibopaper@126.com.

Abstract

The presence of organic compounds in the waste liquor is of serious environmental concern that has plagued the development of alumina industry (Bayer Process). The present work attempts to develop a green and efficient process for removal of organics utilizing combined effect of sonolysis and ozonation (US/O₃). The effects of reaction duration, ozone concentration and ultrasonic power are assessed for sonolysis (US), ozonation (O₃) and combination of sonolysis and ozonation (US/O₃). The optimal conditions for US/O₃ treatment system is identified to be a reaction duration of 7 h, ozone concentration of 7.65 g/h, and ultrasonic power of 600 W. The total organic carbon (TOC) removal and decolorization are 60.13% and 87.1%, respectively. The process can be scaled-up to industrial scale, which could potentially serve to be a convenient, safe and sustainable alternative to the exisiting treatment technologies. Additionally, the treated waste water can be reused contributing to an improvement in the overall economics.

Keywords: AOPs; Bayer liquor; Organics; Ozonation; Sonolysis; US/O(3).

MeSH terms

Kinetics
Organic Chemicals
Ozone*
Wastewater
Water Pollutants, Chemical*
Water Purification*

Substances

Organic Chemicals
Waste Water
Water Pollutants, Chemical
Ozone