Alteration of bioaccumulation mechanisms of Cu by microalgae in the presence of natural fulvic acids
- Resource Type
- Authors
- Wen Shi; Xiaoman Fang; Weiyan Que; Xingfei Wu; Feili Li; Gaoxiang Zhang
- Source
- Chemosphere. 211
- Subject
- Environmental Engineering
Health, Toxicology and Mutagenesis
0208 environmental biotechnology
Inorganic chemistry
02 engineering and technology
010501 environmental sciences
01 natural sciences
Metal
Adsorption
Algae
Microalgae
Environmental Chemistry
Chlorella pyrenoidosa
Benzopyrans
Ternary complex
0105 earth and related environmental sciences
Aqueous solution
biology
Chemistry
Public Health, Environmental and Occupational Health
General Medicine
General Chemistry
biology.organism_classification
Pollution
020801 environmental engineering
Bioavailability
visual_art
Bioaccumulation
visual_art.visual_art_medium
Copper
- Language
- ISSN
- 1879-1298
The impact of natural fulvic acids (FAs) on the toxicity and bioaccumulation of Cu by Chlorella pyrenoidosa was studied. FAs extracted from Taihu Lake were separated into three fractions using dialysis bags: F1 ( 1000 Da). The results showed that the F3 fraction with a larger molecular weight contained less acidic groups and unsaturated aliphatic structures than F1 and F2, and it showed stronger alleviation of the toxicity of Cu to algae. In the presence of F1∼F3, the bioaccumulation curve of Cu in algae intersected with the straight line in the binary system of Cu-algae at approximately 5.3 × 10−3-6.0 × 10−3 mM of Cu equilibrium concentration, showing an inhibition of bioaccumulation of Cu in lower concentrations but an enhancement in higher Cu concentrations. The ratio of {Cu}ads/{Cu}int was used to clarify the transformation mechanism on adsorption; the transition interval occurred at a ratio of 3.5–4.4. This ratio indicated a shift from a mechanism of slow trending to equilibrium to a mechanism with rapid increase, which may be due to the bridging action of Cu to form a ternary complex of FA-Cu-algae and the occurrence of multilayer adsorption. The promotion order of F1> F3> F2 was consistent with percentages of the carboxyl group in total acidic functional groups in the FAs. This research is helpful for improving the accuracy of present models for the prediction of heavy metal risks in aqueous environments.