US EPA

3460413 

Journal Article 

Microcystin release and Microcystis cell damage mechanism by alum treatment with long-term and large dose as in-lake treatment 

Han, J; Jeon, BS; Park, HD 

2016 

1 

Journal of Environmental Science and Health, Part A: Toxic/Hazardous Substances & Environmental Engineering
ISSN: 1093-4529
EISSN: 1532-4117 

Taylor and Francis Inc. 

51 

6 

455-462 

English 

26865010 

10.1080/10934529.2015.1128708 

WOS:000372423900001 

Most of our previous studies reported aluminum causes no cell damage or lysis, and no subsequent toxin release in conventional treatment of drinking water or in the laboratory, on the contrary, we investigated the effect of long-term and large-dose alum treatment, because the environmental conditions in lakes and treatment plants are widely different. The microcosm experiments were designed to simulate the effect of adding alum under the similar conditions of common lakes and reservoirs, and the bottle experiments were conducted to examine the budget or dynamics of microcystin after adding alum. In precipitate analyses, we also confirm the release and dynamics of microcystin and the damage mechanisms of Microcystis cells under alum treatment. In microcosms treated with alum alone, the extracellular microcystin-LR (MC-LR) concentration increased to approximately 82% in 7 days. Similar results were obtained in bottle experiments. By plotting the concentration of released microcystin over time, we inferred that the extracellular MC-LR concentration exponentially rose toward an asymptotic maximum. Moreover, in scanning electron microscope images, some cells exhibited torn membranes with miniscule traces of aluminum hydroxide coating. We conclude that alum treatment, particularly at maximum dosage administered over long periods, seriously damages Microcystis cells and induces microcystin release. Therefore, long-term application of large alum doses is not recommended as an in-lake treatment. 

Aluminum sulfate; damage mechanism; microcystin release tendency; Microcystis cell damage; Aluminum; Aluminum coatings; Bottles; Budget control; Cells; Chemical water treatment; Cytology; Failure (mechanical); Lakes; Potable water; Reservoirs (water); Scanning electron microscopy; Toxic materials; Aluminum sulfates; Conventional treatments; Damage mechanism; Environmental conditions; Lake sand reservoirs; Microcosm experiments; Microcystin release; Microcystis cells; Water treatment; aluminum hydroxide; aluminum salt; aluminum sulfate; chlorophyll a; drinking water; microcystin; microcystin LR; aluminum potassium sulfate; microcystin; Article; cell damage; cell structure; controlled study; high performance liquid chromatography; lake; microcosm; Microcystis; nonhuman; roentgen spectroscopy; scanning electron microscopy; water treatment; cell death; chemistry; drug effects; lake; metabolism; microbiology; Microcystis; procedures; water management; Alum Compounds; Cell Death; Drinking Water; Lakes; Microcystins; Microcystis; Water Purification