The toxicity of MEA and amine waste water samples using standardised freshwater bioassays

Abstract

Water samples provided by Tel-Tek AS were assessed for their toxicity to freshwater organisms from three trophic groups. The water samples included pure monoethanolamine (MEA) and two amine waste water mixtures described as Amine Reactor Waste (ARW) and treated amine waste water (TW). The toxicity of these three test solutions to the unicellular algae Pseudokirchneriella subcapitata, the freshwater crustacean Daphnia magna, and the embryos of the zebra fish Danio rerio were performed in accordance with standard protocols. Of the three taxonomic groups tested, the algae were found to be the most sensitive to both MEA and ARW followed by daphnids, with the zebra fish embryo the least sensitive. For the algae, EC50 concentrations of 151 mg/L MEA, 0.019% ARW and 2.4% TW where similar to that recorded in previous tests performed at NIVA in 2009. The pattern in toxicity for TW was different with the lowest EC50 concentration calculated in the zebra fish followed by the algae and daphnids. However, the EC50 concentrations for TW were very close ranging from 1.91% TW in the zebra fish to 3.4% TW in daphnids.