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Updated: Jun 25, 2026

An Anaerobic Biosensor Assay for the Detection of Mercury and Cadmium
Published on: December 17, 2018
Ultraviolet absorbance as a proxy for total dissolved mercury in streams
Jason A Dittman1, James B Shanley, Charles T Driscoll
1Syracuse University, Department of Civil and Environmental Engineering, 151 Link Hall, Syracuse, NY 13244, USA. jadittma@syr.edu
Dissolved total mercury (THg(d)) in streams strongly correlates with dissolved organic carbon (DOC) and its hydrophobic acid fraction (HPOA). UV(254) absorbance is an excellent proxy for estimating THg(d) in drainage waters.
Area of Science:
- Environmental Chemistry
- Aquatic Ecology
- Biogeochemistry
Background:
- Mercury contamination in aquatic ecosystems is a significant environmental concern.
- Dissolved organic matter (DOM) plays a crucial role in mercury transport and speciation in streams.
- Understanding the relationship between DOM properties and mercury is vital for effective water quality monitoring.
Purpose of the Study:
- To investigate the relationship between dissolved total mercury (THg(d)) and dissolved organic carbon (DOC) characteristics in forested watersheds.
- To evaluate the utility of UV absorbance as a proxy for THg(d) concentration.
- To assess the feasibility of using optical properties for cost-effective mercury monitoring.
Main Methods:
- Collection of stream water samples across diverse hydrologic and seasonal conditions.
- Analysis of samples for THg(d), DOC concentration, DOC composition (including hydrophobic acid fraction - HPOA), and UV(254) absorbance.
- Statistical analysis to determine correlations between THg(d) and DOC parameters.
Main Results:
- A strong positive correlation was observed between THg(d) and DOC (r(2)=0.87).
- Stronger correlations were found between THg(d) and the HPOA fraction of DOC (r(2)=0.91) and UV(254) absorbance (r(2)=0.92).
- UV(254) absorbance emerged as a highly effective proxy for THg(d) concentration.
Conclusions:
- Optical properties of dissolved organic matter, particularly UV(254) absorbance, are excellent indicators of THg(d) in streams.
- This approach offers an inexpensive and efficient method for estimating THg(d) flux.
- The potential for in-situ sensors facilitates intensive monitoring of mercury dynamics in aquatic systems.
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