Mercury

2. hazards
1) Surface active agent is a source material for producing
detergents. As organic matter, synthetic detergents can be
bio-degraded, consuming the dissolved oxygen in the water.
Permernant bubbles appear when the concentration of
surface active agent reaches .
Anionic surfactant produces bubbles in water more
easily than other surfactants.e.g. in 1963,a 0.6 m-thick
sheet of bubbles appeared on the surface of Ohio river
of America, due to the pollution of detergents;
The speed and level of reoxygenation in bubble-covering
river will be largerly reduced. e.g. the pollution of
detergents in Thames river of Britain caused water
deoxidation and people could even smell hydrogen
disulfide along the river.