Toxicity assessment of Tehran water treatment sludges using bioassay tests

Abstract

The 48-, 72- and 96-h acute toxicity and 14-d chronic toxicity of the sludge of treatment plant No. 1, 3 and 5 were examined based on the survival percentage and fertility changes of Daphnia magna and Eisenia fetida. The highest percentage of D. magna death in the acute toxicity test appeared in treatment plant No. 1 sludge sample. The 48-h and 72-h LC₅₀ of treatment plant No. 1 sludge on D. magna were calculated to be 86.81 and 44.307% volume of the sludge, respectively. The release of untreated sludge into the environment could adversely affect the life of organisms.

Keywords:

• Water treatment sludge
• eco toxicity
• acute and chronic
• Daphnia magna
• Eisenia fetida
• LD50

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Additional information

Funding

This work was supported by School of Public Health, Shahid Beheshti University of Medical Sciences [grant number, 307.3777]