Department of Biology
Algal-derived organic matter as precursors of disinfection by-products and mutagens upon chlorination
Algal-derived organic materials (including algal cells, hydrophilic and hydrophobic proteins) from Chlamydomonas sp. (a common green alga in local reservoirs), were chlorinated in the laboratory (20 °C, pH 7, Cl2/DOC ratio of 20 mg Cl2 mg-1). Levels of disinfection by-products and mutagenicity (via Salmonella T100 mutation assay, -S9) over 2 h of chlorination time were determined. The hydrophilic proteins were more effective precursors of chloroform (35.9 μmol L-1 at 120 min), 35 times greater than that from the hydrophobic proteins; whereas the hydrophobic proteins were more potent precursors of direct-acting mutagens (maximum level of 50.1 rev μL-1 at 30 s) than the hydrophilic proteins (maximum level of 3.38 rev μL-1 at 60 min). The mutagenicity of the chlorinated solutions generally reached a peak level shortly after chlorination and then declined afterwards, a pattern different from that of chloroform generation. The results indicate that algal hydrophilic proteins, containing low aromaticity and difficult to be removed via coagulation/flocculation, are important chloroform precursors. It is also suggested that hydrophobic organic intermediates with low molecular weight formed during chlorination may serve as the direct-acting mutagens. © 2010 Elsevier Ltd.
Algal hydrophilic protein, Algal hydrophobic protein, Chlamydomonas sp., Chlorination intermediate by-products, Mutagenic potency
Source Publication Title
Lui, Y. S., J. W. Qiu, Y. L. Zhang, M. H. Wong, and Y. Liang. "Algal-derived organic matter as precursors of disinfection by-products and mutagens upon chlorination." Water Research 45.3 (2011): 1454-1462.