The effects of chlorine, ozone and chlorine dioxide on Scenedesmus sp. cultures were studied. Algal cell viability and chlorophyll concentration decreased, and the concentration of dissolved organic substances increased with increasing applied oxidant concentration. Pretreatment with chlorine dioxide (1, 3 or 5 mg l-1) or ozone (2.6, 4.6 or 8.1 mg l-1) on algal cultures enhanced algal flocculation with alum, while prechlorination with 10 or 20 mg l-1 increased the required dosage of alum by 15%. Scanning electron micrographs of oxidized cells revealed drastically adverse effects upon the cell surface architecture: in addition to the oxidation of noncellular organic materials, the oxidants damaged both cell surface structures and intracellular components. A model explaining the effects of the different oxidants on microalgal flocculation is suggested.
- Scenedesmus sp.
- algal cell surface architecture
- chlorine dioxide
- microalgal flocculation
- scanning electron microscopy
ASJC Scopus subject areas
- Environmental Engineering
- Civil and Structural Engineering
- Ecological Modeling
- Water Science and Technology
- Waste Management and Disposal