ADSORPTION BEHAVIOR OF 17A-ETHINYLESTRADIOL ONTO ACTIVATED SLUDGE DERIVED FROM MEMBRANE BIOREACTOR

摘要

The adsorption behavior of 17a-Ethinylestra-diol (EE2) onto activated sludge from a membrane bioreactor (MBR) was investigated. The effect of mixed liquor suspended solids (MLSS), sludge particle size and initial EE2 concentration on adsorption efficiency and the contributions of different sludge components to EE2 adsorption were discussed. Results showed that when initial EE2 concentrations were 1-500 ^g-L-1, the time to reach adsorption equilibrium was 4h and the adsorption profiles matched both Langmuir and Freundlich isotherms. The EE2 adsorption rate displayed an inverse relationship with its initial concentration. With the increase of MLSS, the EE2 concentration in the sludge decreased remarkably. The total EE2 adsorption efficiency exhibited a linear correlation with MLSS concentrations. In addition, the EE2 adsorption effect decreased with the increase of sludge particle size. The contributions of each sludge component to EE2 adsorption were revealed to be positively correlated with their abundance. It was confirmed by reaction kinetics analysis that both adsorption and biodegradation contributed to the removal of EE2 in activated sludge system, and adsorption provided the prerequisite conditions for further biodegradation.