Detoxification of Disperse Yellow 3 Contaminated Wastewater Using Constructed Wetlands

The textile manufacturing industry allows for the release of toxic dyes into the environment. Environment and Climate Change Canada has focused on the dye Disperse Yellow 3, which is imported in large quantities as a potential concern for both human health, as well as the environment. Constructed wetlands are a low maintenance and cost-effective method of treating contaminated wastewater. To test their effectiveness at degrading the dye, a 72-hour algal bioassay utilizing the green algae species Raphidocelis subcapitata was used to determine the EC₅₀ growth for Disperse Yellow 3. The bioassay was then used to determine if constructed wetlands planted with or without the native species blue flag iris (Iris versicolor) could reduce the toxicity of Disperse Yellow 3 at various concentrations based around the EC₅₀ growth. The 72-hour algal bioassay determined that the EC₅₀ growth for Disperse Yellow 3 was 0.13 mg/L. The results found that constructed wetlands were capable of reducing the toxicity at all concentrations tested such that there was no statistically significant difference in the toxicity. While plants' presence in the wetlands did not provide a significant effect, constructed wetlands may be a feasible option to be used as a pre-treatment process for textile mills prior to release.