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[Identification of key toxicants in a bleaching effluent--a case study]
1School of the Environment, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing University, Nanjing 210093.
Ying Yong Sheng Tai Xue Bao = the Journal of Applied Ecology
|January 5, 2002
Summary
The toxicity identification evaluation (TIE) identified free and total residual chlorine (Cl2, HClO, and ClO-) as the primary toxicants in bleaching effluent. Reducing these chlorine compounds significantly decreased effluent toxicity.
Area of Science:
- Environmental Chemistry
- Ecotoxicology
Context:
- Bleaching processes in industries generate toxic effluents.
- Understanding effluent toxicity is crucial for environmental protection.
Purpose:
- To identify the primary toxicants in a specific bleaching effluent.
- To confirm the role of residual chlorine species in effluent toxicity.
Summary:
- Toxicity Identification Evaluation (TIE) procedures were employed, including Phase I (characterization), Phase II (fractionation), and Phase III (deletion).
- Initial tests indicated volatile toxicants reducible by sodium thiosulfate.
- Phase III confirmed that decreasing free and total residual chlorine concentrations (Cl2, HClO, ClO-) directly reduced effluent toxicity.
Impact:
- Identifies specific chemical species responsible for effluent toxicity.
- Provides a basis for targeted treatment strategies to mitigate environmental harm.
- Contributes to safer industrial discharge practices.