| Environmental hormones have become an important problem to environmental pollution, especially to drinking water safety. Studies on environmental hormones at present mainly focused on environmental investigation, toxicological study and establishment of estimational method. However, controlling and removal of environmental hormones in environment and drinking water are short of study accumulation. Steroid sex hormones and related synthetic compounds have been shown to be present in the aquatic environment, mainly as a result of inefficient removal in traditional water treatment plant which processes removal of high molecular weight (MW) organics, bacteria and suspended solids.Membrane technology is a new technology developed in the recent 40 years. Because of the effectiveness of membrane seperation, the application of membrane spread widely in water treatment. Nanofiltration (NF) is a newly membrane seperation technology and a pressure-driven membrane process between conventional reverse osmosis membranes and ultrafiltration membranes. The molecular weight cut-off (MWCO) of NF range from 200-2000. The molecular weight of most of Environmental hormones range from 200-500. Because of NF, the control of Environmental hormones pollution in water have taken a new prospect.In this study, important and contrasting environmental hormones including: DEP, DBP, DOP, DEHP, DCHP, bisphenol A, 4-nonylphenol, pentachlorophenol, 2,4-dichlorophcnol, estradiol, estriol, 17α-ethinylestradiol, estmne etc. listed as priority contaminants by US EPA were selected as the target compounds. The study applied NF process to remove environmental hormones from drinking water. The experimental retentions indicated that nanofiltration can be a valuable alternative for the removal of environmental hormones. Results indicated that NF removed more than 85% of environmental hormones and was a kind of effective method to remove environmental hormones. In addition, for obtaining the best effctiveness of removal of environmental hormones. The influence of operating pressure, feed environmental hormones concentration, pH, ionic strength on nanofiltration performance were studied. The seperation characteristics of nanofiltration membrane were also discussed. Experimental results showed that:(1) The operating pressure of experiment was a very prominent factor influencing flux of permeate. Increasing operating pressure, flux of permeate increase. Ionic strength also had influence on flux permeate. The higher the ionic strength of feed solution, the lower the flux of permeate. In the experiments, concentration of feed solution was the least prominent factor. Its change had little influence on flux of permeate. The effect of pH variation on flux was that flux increases with increasing pH, up to pH=7 and then started decreasing again with further increase in pH.(2) The pH value and ionic strength were two very prominent factors influencing rejection. At a lower pH therefore the rejection of environmental hormones was high, and it decreased with the increase of pH up to pH=7, then it increase with the increase of pH. The lowest rejection was obtained at near neutral condition between 6.5 and 7.5. The rejection increased with increasing ionic strength. And making operating pressure and concentration of feed solution higher, respectively would result in increasing rejection. Although rejection increased fluctuantly.(3 ) Obtained from the test result analysis: the removal of environmental hormones by NF had relation with molecular weight and characteristic parameter of molecular. The other factors such as shape of molecular were also important. In this study, for phenols, the rejections were affected by the kinds of substituents on benzene ring. For PAEs and estrin, increasing the molecular weigh, the rejections increase. Generally speaking, the bigger molecular weight, the longer the branced chain, having benzene ring, the easier ionization, the higher removal of environmental hormones.
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