Effect of Mercuric Chloride on Carbon Dioxide and Methane Emissions from Water of Kaoping River and Chenching Lake

Abstract

To investigate the effect of mercuric chloride on carbon dioxide and methane emissions from water, different amounts of saturated mercuric chloride were added to the water of Kaoping River and Chenching Lake, and incubated at 25℃ for 6 days. Carbon dioxide and methane emissions decreased with increasing the amount of saturated mercuric chloride (69 mg mL(superscript -1) at 20℃) addition from 50 to 600 μL (3.45-41.4 mg) in 100 mL of water. Carbon dioxide and methane emissions decreased slightly when the amount of saturated mercuric chloride was higher than 200 μL (13.8 mg). Carbon dioxide and methane emissions had linear correlation with the amount of saturated mercuric chloride supplement between 0 and 100 μL. The brown color bottle had higher carbon dioxide and methane emissions from water than those of colorless bottle. The down-stream area of Kaoping River had the highest carbon dioxide and methane emissions, followed by the mid-stream area, and the upstream area and Chenching Lake had the lowest values. High carbon dioxide and methane emissions at the down-stream area might be due to high pollution. Therefore 100 μL of saturated mercuric chloride (6.9 mg) added in 100 mL of water to retard the microbial activity is a feasible method during the measurement of greenhouse gases emissions from water.