Co-coagulation of micro-nano bubbles (MNBs) for enhanced drinking water treatment: A study on the efficiency and mechanism of a novel cleaning process

Jinsuo Lu; Xiaojiang Huang; Zhiqiang Zhang; Heliang Pang; Kunyu Chen; Haozhe Xia; Yiyu Sui; Rongwen Chen; Ziang Zhao

doi:10.1016/j.watres.2022.119245

Co-coagulation of micro-nano bubbles (MNBs) for enhanced drinking water treatment: A study on the efficiency and mechanism of a novel cleaning process

Water Res. 2022 Nov 1:226:119245. doi: 10.1016/j.watres.2022.119245. Epub 2022 Oct 13.

Authors

Jinsuo Lu¹, Xiaojiang Huang², Zhiqiang Zhang³, Heliang Pang³, Kunyu Chen², Haozhe Xia², Yiyu Sui², Rongwen Chen², Ziang Zhao²

Affiliations

¹ School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; State Key Laboratory of Green Building in West China, Xi'an University of Architecture and Technology, Xi'an 710055, China. Electronic address: lujinsuo@xauat.edu.cn.
² School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
³ School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; State Key Laboratory of Green Building in West China, Xi'an University of Architecture and Technology, Xi'an 710055, China.

PMID: 36283233
DOI: 10.1016/j.watres.2022.119245

Abstract

MNBs (Micro-nano bubbles) are widely used in cleaning processes for environmental treatments, but few studies have examined the interaction of MNBs with coagulation. In this study, a novel process, i.e., MNBs-coagulation, was developed for enhanced drinking water treatment. The humic acid (HA) removal efficiency was used to evaluate the effectiveness of MNBs-coagulation for drinking water treatment. The hydrolysis component ratio of polymeric aluminum chloride (PACl) with and without MNBs, the complexation strength of HA and PACl, and flocculent functional group characterization were used to analyze the mechanism of the MNBs-coagulation process to enhance drinking water treatment. The results of a Jar test showed that the MNBs-coagulation process could improve the removal efficiency of HA (up to a 27.9% increase in DOC removal). In continuous-flow experiments to remove HA, MNBs-coagulation can increase the removal efficiency of UV₂₅₄ by about 26.5% and with no significant change in turbidity. These results are attributed to the inherent hydroxyl radical generating properties of MNBs, the forced hydrolysis of PACl by MNBs to increase the Al_c percentage, and the ability of MNBs to increase the complexation strength of HA with PACl. At the same time, the MNBs-coagulation process has a strong anti-interference ability, almost no interference from anions and cations such as Cl^-, SO₄^2- and Ca²⁺, and has a good performance in natural surface water. In summary, MNBs-coagulation has strong potential for practical applications to enhance the efficiency of drinking water treatment.

Keywords: Drinking water treatment; Enhanced coagulation; Forced hydrolysis; MNBs; PACl.

MeSH terms

Aluminum Chloride
Aluminum Hydroxide
Drinking Water*
Flocculation
Humic Substances / analysis
Water Purification* / methods

Substances

Drinking Water
Aluminum Hydroxide
Humic Substances
Aluminum Chloride