Dissolved organic matter and estrogenic potential of landfill leachate

The estrogenic potentials of leachate samples collected at Laogang Sanitary Landfill in Shanghai, China were measured together with the associated dissolved organic matter (DOM) in leachate samples. Over 99% of the DOM in fresh leachate was removed upon 3–7 years of landfill, leaving only DOM with strong fluorescent activity. Anoxic or aerobic treatment of landfill leachate can further degrade DOM of MW < 300 Da and transform those with fluorescent activity of MW > 105 Da to those of 2000–105 Da. Neither landfilling nor storage in anoxic pond effectively removed estrogenic potential of leachate. Fractionation test revealed that residual organic matters of MW 3000–14 000 Da and of <600 Da with high UV254 contributed most of the estrogenic activities in leachate. Aerobic SBR treatment considerably reduced the estrogenic potential of these organic matters in leachate.