| Three kinds of steroid estrogen such as estrone(E1)、17β-estradiol (E2)、17α-ethynylestradiol(EE2) were determined by solid phase extraction-high performance liquid chromatography(SPE-HPLC). Spike experiments together with deviation analysis were carried out to avaluate the method.A one-year term investigation of Hangzhou souce waters and landscape water aimed at physical-chemical parameter and steroid estrogen was carried out. According to "Environmental quality standards for surface water", CODMn indicate the source water belong to Ⅱ-Ⅲ, and nitrogen-phosphorous indicate inferior to Ⅲ, while steroid estrogens were detected occasionally which suggested little contamination aroused from E1, EE2 and E2. Landscape water was poorer than source water with steroid estrogens frequently detected.UV(/H2O2/TiO2) was adapted to control co-existing three steroid estrogens of estrone(E1),17β-estradiol(E2) and 17α-ethinyl estradiol(EE2) in aqutic solution. Degradation of three compounds fits first-order kinetic reaction, while different removal effects indicated competition between the three aimed compounds as mixed matrix. E1 takes advantages in competition, and sequence order of E2 and EE2 rely on light intensity with which enhanced, EE2 hold slight advantage. E1 can be efficiently removed by single UV process to 97.0% when light intensity of 24 W and reaction time of 50 min while removal ratios of E2 and EE2 were 32.0% and 28.2%, respectively. Under the circumstances, degradation rate constants of mixed three compound were 0.06489,0.00569 and 0.00600min-1. UV/H2O2 will significantly enhance the removal effect and with dosage of 10 mg/L for H2O2, degradation rate constants of E1,E2 and EE2 were 0.09775,001853 and 0.02039 min-1. Catalyst TiO2 could accelerate degradation rate of E1, E2 and EE2 with constants raised to 0.10480,0.02282 and 0.02245 min-1., In process associated with UV, three mixed steroid estrogens removal efficiency followed the sequence of E1>E2≈EE2.Influence factors didn’t change the degradation advatange of E1. Additon of H2O2 and TiO2 help to raise the removal efficiency and degradation rate. Influences as initial concentration, pH value, existence of cations and anions were evaluated which showed no alternation on El’s superior degradation. Higher initial concentration led to lower removal efficiency and degradation rate, low pH value a could increase removal ratio of steroid estrogens, cations has little influence on degradation of steroid estrogen, and presence of anions have negative effect on degradation, inhibitory sequence was HCO3->SO42->CO32->NO3-The study also concerned the competitive degradation about three steroid estrogen and their by-products. The results shows that E1 was much more photosensitivity than E2、EE2 and most reactable with hydroxyl radicals with highest removal ratio. The character of E2 and EE2 were similar on both photosensitivity and combie with hydroxyl radicals. For degradation of E2 by UV/H2O2, E1 had more powerful influence than EE2, and for degradation of EE2, E1 had more powerful influence than E2, while for degradation of E1, inhabit effect of EE2 and E2 had little difference. Under co-existing mixed condition, degradation rate were inhabited by the other two combinations and the sequence was E2≈EE2>E1.Degradation of E1 and E2 could result a kind of by-product, this by-product could generate in 0-15 minutes during E1 degradation and 30 mintues of E2 degradation. The by-product has the similar structure of E1 and can also be degradation by UV/H2O2 process. |
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