Source of toxicity in storm water: Zinc from commonly used paint

Abstract

A Department of Energy site in Paducah, Kentucky (USA), stores thousands of cylinders of depleted uranium hexafluoride. Breaches of the cylinders could result in the release of uranium and hydrogen fluoride. Beginning in 1996, a program was begun to paint the cylinders in order to prevent corrosion of the cylinders and the surfaces of the storage yards were converted to concrete. In 1998, storm water from the cylinder storage yards was found to be toxic to Ceriodaphnia, at concentrations exceeding limits in the site's discharge permit. A six-month study was conducted to identify the source of the toxicity in the storm water. Ceriodaphnia toxicity tests with the storm water resulted in 48-h median lethal concentrations (LC50) ranging from 12 to 94%; zinc concentrations in the storm water ranged from 0.08 to 0.54 mg/L. Acute toxicity tests with zinc and linear regression identified that zinc concentrations in the storm water were sufficient to account for the toxicity observed. By tracking the sources to the discharge point, newly painted cylinders were identified as the source of the zinc in the storm water. Rainwater collected directly from the painted cylinders contained up to 13 mg Zn/L. Laboratory and field tests showed that topcoating the cylinders would reduce the amount of zinc in the runoff from the cylinders.

Development of composite alginate bead media with encapsulated sorptive materials and microorganisms to bioaugment green stormwater infrastructure

“…to specifically tune capture different contaminants. Because our design goal for the beads was stormwater treatment, we decided to use iron-based sorptive materials because iron materials have previously been applied for dissolved P removal in stormwater 111,112 and because Al-or Zn-based sorbents hold the risks of spreading toxic Al or Zn metals 113,114 in the environment. Because coagulant dosage can change according to needs and the influent water quality, the characteristics of FeWTR may also vary temporally or if sourced from different water treatment plants; however, FeWTR would still be produced from ironbased water treatment processes.…”