Effects of Potassium and Dissolved Organic Matter on Comparative Toxicities of Thallium and Heavy Metals to Freshwater Algae
Abstract
Thallium (Tl) is a trace metal widely used as a technology-critical element (TCE) in high technology industry nowadays. Due to rapid growth and frequent use of high technology, concentration of thallium in aquatic environments is likely to increase over time. Toxicity of thallium to aquatic organisms has been widely investigated. Importantly, water chemistry can alter metal toxicity to aquatic organisms. Although previous studies demonstrated that toxicity of thallium to aquatic creatures was higher than several heavy metals such as Cu, Cd, Hg, and Pb, it remains unclear how water characteristics affect relative toxicity of thallium to heavy metals. Potassium (K+) and thallium (Tl+) ions are biogeochemical analogues, and the presence of K+ could influence the toxicity of Tl+ to aquatic creatures. Dissolved organic matter is an important natural matrix in waters affecting metal species and toxicity. In this study, we will conduct bioassays in the laboratory to assess effects of K+, humic and fulvic acids on the relative toxicity of Tl+ and some heavy metals commonly detected in polluted waters to the freshwater blue-green alga Microcystis aeruginosa and green alga Pseudokirchneriella subcapitata. The 96-h flow cytometry-based algal toxicity experiments will be conducted. The toxicity endpoints including chlorophyll auto-fluorescence, enzyme activity, reactive oxygen species, and membrane integrity will be evaluated using appropriate dyes. Total and dissolved metal concentrations will be analyzed using inductively coupled plasma-mass spectrometry. The obtained information of this study is essential on the establishment of TCE regulatory guideline in aquatic environments.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.H41J1826T
- Keywords:
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- 0414 Biogeochemical cycles;
- processes;
- and modeling;
- BIOGEOSCIENCES;
- 0432 Contaminant and organic biogeochemistry;
- BIOGEOSCIENCES;
- 1834 Human impacts;
- HYDROLOGY;
- 1880 Water management;
- HYDROLOGY