Impact of Molecular Mass of Natural Organic Matter on Biological Removal of Iron

Removal of iron in groundwater using biological filtration column are researched. Natural organics with different molecular mass can be removed using molecule filtration membrane. Test results showed that the molecular mass of organic influenced effluent quality. The greater is organic molecular mass, the lower the removal rate of iron, DOC and UV254. Removal rate of DOC and UV254 in groundwater with organic of molecular mass less than 1000 were 82.4% and 65.8%，respectively，but Removal rate of DOC and UV254 in groundwater with organic of molecular mass more than 30000 were 28.5% and 54.3% respectively.