The objective of this study was to test the toxic action or better the non existence of toxicity of a new anti-slime compound compound by using the responses of D. polymorpha.
The 'Cool Puck' was developed to detach easily the biofilm from all substrates in closed cooling water systems, especially for getting rid of slime and biofilm in the filling of cooling towers.
The manufacturer claims that the product is not toxic for fish and macrofauna and only helps to loosen the biofilm from any substrate. A toxic compound like (sodium) hypochlorite is necessary to kill off the bacteria in the loosened biofilm.
Filtration rate, foot activity index and byssus thread production of D. polymorpha showed no significant differences between control and 50 mg, 100 mg and 200 mg 'cool Puck' concentrations (Table 1). The physiological activities of mussels showed a decrease of 24 to 31% at 400 mg concentration; indicating that 400 mg 'Cool Puck' is the level at wich activities are started to affect in D. polymorpha.
The supposed toxicity of the 'cool puck' showed to be detectable at concentrations of 6 to 8 times the starting point concentration wich is the normal concentration for application in cooling towers. The question on the supposed toxicity of blow down water in their receiving waters like lakes and rivers is negative, i.e. the ''Cool Puck' does not increase the toxicity of blow down water with concetration indexes of 4-6.
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