TRE, TIE, TTE
Maxxam offers complete solutions for identifying agents responsible for toxicity in industrial effluents and sediments.
Maxxam draws on its diverse expertise to help solve complex toxicological problems. Aquatic toxicologists, chemists and wastewater treatment technologists work together to identify toxic agents and design processes for reducing effluent toxicity. Treatment processes can be tested using bench scale simulations or larger scale pilot plant facilities. On-site assistance can also be provided to help clients implement and operate new technologies.
Toxicity Reduction Evaluations (TRE)
Toxicity Reduction Evaluation (TRE) methods developed by the United States EPA are used to identify the causative toxicant(s), isolate their source, evaluate toxicity control options and confirm a reduction of effluent toxicity.
Toxicity Identification Evaluations (TIE)
The TIE procedures within TREs are designed to identify specific substances responsible for effluent toxicity. TIEs often consist of three phases:
- Identification of the toxicant group
- Identification of specific causative toxicants
- Confirmation of causative toxicants
Toxicity Treatment Evaluations of Toxic Effluents (TTE)
Bioassays can be used to monitor changes made to reduce effluent toxicity at the source. Representative TRE/TIE Projects
- Toxic pulp and paper mill effluent component identification using echinoderm fertilization bioassays. Through ultra-filtration and polyacrylamide gel elecrophoresis (PAGE) techniques, it was also determined that lignin-derived molecules (LDM) from the kraft mill were responsible for the observed toxicity.
- Investigation of pulp mill effluent toxicity in rainbow trout. The relation between acid volatile compounds and toxicity incidents was investigated and results found that CO2 was the probable causative agent of toxicity.
- Investigation of the role boron and other components play in the toxicity of polishing pond water from a slag refining mill. Special treatments included chromatography employing ion selective resins, activated charcoal and other treatments to define the role of boron in the observed toxicity in rainbow trout. Boron was identified as the principle agent of toxicity.
- Investigation of the toxicity of a mine effluent using the Ceriodaphnia dubia 7-day reproduction test. It was determined that TSS was responsible for approximately 50% of the observed effluent toxicity and a treatment method was developed to remove TSS and reduce effluent toxicity.
“Maxxam’s ecotox group has a superior understanding of the state-of-science and best practice with regard to laboratory toxicity test methods. It is largely because of this expertise that we have been successful in getting buy-in for important risk management decisions for sites with contaminated sediments such as the former Nanisivik mine site on Baffin Island. Maxxam’s depth of working knowledge about the strengths and limitations of individual laboratory toxicity tests, suitability for site-specific conditions, and emerging tools and trends, is unprecedented in Canada.”
Doug Bright, PhD, RPBio
Business Leader, Environmental Risk Assessment