Ram, J. L., J. U. Walker, P. P. Fong. 1994.   Enhanced Toxicity of Zebra Mussel Control Chemicals in Pure Water. - Department of Physiology, Wayne State University.

Proceedings of The Fourth International Zebra Mussel Conference, Madison, Wisconsin, March 1994

Enhanced Toxicity of Zebra Mussel Control Chemicals in Pure Water

Abstract
Previous studies have shown that deionized water enhances the toxicity of potassium chloride (KC1) to zebra mussels approximately 10-fold, compared to its toxicity in normal aquarium water. In order to determine whether the enhanced toxicity caused by deionized water is a general effect or is specific to KC1, the effects of deionized water on the toxicity of other toxic chemicals was investigated. In addition, we tested whether purified water produced for use in a high pressure turbine drive system (high purity condensate (HPC) water) was as effective as laboratory deionized water in enhancing the effect of a toxic chemical.

Toxicity of sodium hypochlorite was enhanced approximately two orders of magnitude in deionized water: in aquarium water, 10 mg/L < LC50 < 100 mg/L; in deionized water, 0.1 mg/L<LC50<1 mg/L. A shift of two orders of magnitude in toxicity was also observed for ouabain: in aquarium water, 10-4 M < LC50 < 10-3 M; in deionized water, 10-6 M < LC50 < 10-5 M. Virtually no shift in toxicity due to deionized water was observed for niclosamide and for Ended. For niclosamide, LC50 in deionized water was slightly less than 10-5 mg/L and in aquarium water slightly above 10-5 mg/L. For Ended LC50 was between 5 and 10 mg/L in both media.

The largest shift in toxicity in deionized water occurred for Noxfish (rotenone), for which LC50 shifted from approximately 1 mg/L in aquarium water to less than 10-4 mg/L in deionized water. Thus, the enhancement of toxicity due to deionized water is not an additive effect, but varies with the toxic substance, probably according to the mechanism of toxicity.

HPC enhanced toxicity of KC1 as effectively as did laboratory deionized water. KCI was approximately 10 times more toxic to zebra mussels in both HPC and laboratory deionized water than it was in aquarium water. Death occurred within 24 hours, and during an additional 24 hours after return of the mussels to aquarium water, mussels in sensitive groups continued to die. Thus, HPC may prove to be convenient for use in power plants' zebra mussel control applications in service water systems, since it is a by-product of steam-generated, supercritical power plants and is effective at enhancing the toxicity of chemicals that may be useful for controlling zebra mussel infestations.

Entire Paper
Keywords: Chemical_control, Industry, Zebra_mussel
Product Type: Publication, Proceedings
User Type: Industrial_and_Municipal