Kinetics and mechanism of Pseudoanabaena cell inactivation, 2-MIB release and degradation under exposure of ozone, chlorine and permanganate

Lei Li; Cuiwen Zhu; Chuanqi Xie; Chen Shao; Shuili Yu; Laicai Zhao; Naiyun Gao

doi:10.1016/j.watres.2018.10.023

Kinetics and mechanism of Pseudoanabaena cell inactivation, 2-MIB release and degradation under exposure of ozone, chlorine and permanganate

Water Res. 2018 Dec 15:147:422-428. doi: 10.1016/j.watres.2018.10.023. Epub 2018 Oct 10.

Authors

Lei Li¹, Cuiwen Zhu², Chuanqi Xie³, Chen Shao², Shuili Yu⁴, Laicai Zhao⁵, Naiyun Gao²

Affiliations

¹ State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China.
² State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai, 200092, China.
³ Department of Bioproducts and Biosystems Engineering, University of Minnesota, Saint Paul, MN, 55108, United States.
⁴ State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China. Electronic address: ysl@tongji.edu.cn.
⁵ Shenzhen Shenshui Baoan Water Group Co., Ltd., Shenzhen, 518000, China.

PMID: 30342337
DOI: 10.1016/j.watres.2018.10.023

Abstract

The organic pollutants produced by cyanobacteria cells, such as off-flavor compounds (e.g. 2-methylisoborneol, 2-MIB) and hazardous toxins (e.g. microcystins), are commonly detected in water sources. Although studies have shown that oxidation using potassium permanganate (KMnO₄), chlorine and ozone helps to remove cyanobacteria cells, the potential effects of these oxidants on cell viability and the release of off-flavor substances have scarcely been explored. This study investigated the impacts of three widely used oxidants on Pseudanabaena sp. (a common species of 2-MIB producing cyanobacteria) inactivation, and on the release and degradation of intracellular 2-MIB. Experiments using KMnO₄ showed that both the cell viability and 2-MIB release fit to a two-stage second-order kinetic model with a threshold of KMnO₄ exposure (ct). No significant variations in the cell viability and 2-MIB release occurred until the exposure reached ct because KMnO₄ was primarily consumed by the dissolved and cell-bound organic matters before it damaged the cell. However, chlorine permeates the cell membrane more easily, causing rapid algae inactivation and the subsequent cell lysis and 2-MIB release. Unlike permanganate and chlorine, which are unable to degrade the released 2-MIB because of their insufficient oxidation potentials, ozone is capable to inactivate the cell and degrade 2-MIB as well. When the initial O₃ concentration is above a certain level (1.0 mg ·L^-1 in this study), the released 2-MIB can be substantially oxidized. Therefore, the choice of a suitable oxidant and a proper dose is highly important in the control of off-flavor compounds during the treatment of algae-containing raw water.

Keywords: 2-Methylisoborneol; Intracellular organic matter; Kinetic model; Pre-oxidation; Release.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Chlorine
Kinetics
Manganese Compounds
Oxidation-Reduction
Oxides
Ozone*
Potassium Permanganate
Water Purification*

Substances

Manganese Compounds
Oxides
Potassium Permanganate
permanganic acid
Chlorine
Ozone