Mercury

2) The large amount of phosphates such as trimeric
sodium phosphate ( 三 聚 磷 酸 钠 Na 5 P 3 O 10 )
contained in detergents can cause eutrophy( 富 营
养 化 ) to the water bodies. It’s estimated in Britain
and U.S. and other other countries that 30%~75%
phosphorus in the urban sewage comes from
detergents. Also due to the large amount of
discharged waste water, it would constitute
hazards to aquatic plants and fish.
3) Surface active agents can accelerate the
emulsification and dispersion of petrol, PCBs and
other indissolvable organic matters in water, thus
raising the difficulty of waste water treatment.