Comparison of Permanganate Preoxidation and Preozonation on Algae Containing Water: Cell Integrity, Characteristics, and Chlorinated Disinfection Byproduct Formation

Abstract

Aqueous suspensions of Microcystis aeruginosa were preoxidized with either ozone or permanganate and then subjected to chlorination under conditions simulating drinking water purification. The impacts of the two oxidants on the algal cells and on the subsequent production of dissolved organic matter and disinfection byproducts were investigated. Preozonation dramatically increased disinfection byproduct formation during chlorination, especially the formation of haloaldehydes, haloacetonitriles, and halonitromethanes. Preoxidation with permanganate had much less effect on disinfection byproduct formation. Preozonation destroyed algal cell walls and cell membranes to release intracellular organic matter (IOM), and less than 2.0% integrated cells were left after preozonation with the dosage as low as 0.4 mg/L. Preoxidation with permanganate mainly released organic matter adsorbed on the cells' surface without causing any damage to the cells' integrity, so the increase in byproduct formation was much less. More organic nitrogen and lower molecular weight precursors were produced in a dissolved phase after preozonation than permanganate preoxidation, which contributes to the significant increase of disinfection byproducts after preozonation. The results suggest that permanganate is a better choice than ozone for controlling algae derived pollutants and disinfection byproducts.

Prechlorination of algae-laden water: The effects of transportation time on cell integrity, algal organic matter release, and chlorinated disinfection byproduct formation

“…1). A previous study also reported that cell damage induced by elevated oxidant dose could promote protein and amino acid release (Xie et al, 2013). In addition, the proteins were mainly released during the preoxidation period, and prolongation of simulated transportation time did not have an obvious influence on the protein concentrations.…”

“…The initial DOC value in the prepared algal suspension was determined to be 0.27 mg/L, which might be due to the desorption of the loosely bound AOM on the cells (Xie et al, 2013). The increased DOC and DON values with prolongation of simulated transportation time were due not only to the further release of AOM from cyanobacterial cells damaged by prechlorination, but also to the rising ratios of damaged cells (Fig.…”

KMnO 4 –Fe(II) pretreatment to enhance Microcystis aeruginosa removal by aluminum coagulation: Does it work after long distance transportation?

“…Prior to Fe(II) addition, KMnO 4 can react with the organic matter, such as the dissolved organics and the surface-absorbed AOM on algae cells (Eq. (1)) (Xie et al, 2013). The surface-absorbed AOM serves as a protective barrier to stabilize the algae cells, and this effect enhances the difficulty of removing algae cells by conventional processes (Clasen et al, 2000).…”

Removal of Disinfection By-products Formation Potential by Combination of Preoxidation and Coagulation Sedimentation Processes

“…KMnO 4 pre-oxidation [8] can enhance algal cell removal and control chlorinated DBPs. The impacts of O 3 on coagulation for NOM and DBP precursor removal are conflicting and site specific [9,10].…”