Abstract
Experiments were designed to assess the potential protective effect of the presence of sulfide against the acute (48-h) toxicity of silver(I) to Daphnia magna. Tests were conducted in borosilicate glass beakers (250 ml) in moderately hard synthetic water. Toxicity solutions were replaced after 24 h by static renewal method. This paper describes the chemical system, and the acute toxicity results are presented in a companion paper. Sulfide was below detection limit (<5 nM) in controls with no sulfide added. Sulfide, added as zinc sulfide clusters at approximately 35- or approximately 350-nM concentration, dropped in concentration to approximately 25 and 250 nM, respectively, over the 24-h period of measurements. Silver also decreased in concentration during the experiment (up to 59%), and the rate of loss was greater in the absence of sulfide compared with the presence of sulfide. A filtration experiment indicated a 1:1 binding ratio of silver to sulfide and a conditional stability constant for the Ag(I)-zinc sulfide complex of log K′ = 8.9. The losses of sulfide and silver during the experiments highlighted the need for regular monitoring of the important chemical components of the system, even during short (48-h) toxicity tests.
Original language | English (US) |
---|---|
Pages (from-to) | 1286-1293 |
Number of pages | 8 |
Journal | Environmental Toxicology and Chemistry |
Volume | 21 |
Issue number | 6 |
State | Published - Jan 1 2002 |
Keywords
- Daphnids
- Silver
- Toxicity
- Zinc sulfide clusters
ASJC Scopus subject areas
- Environmental Science(all)
- Environmental Chemistry
- Health, Toxicology and Mutagenesis
- Toxicology