Assessment of Trace Estrogenic Contaminants Removal by Coagulant Addition, Powdered Activated Carbon Adsorption and Powdered Activated Carbon/Microfiltration Processes

摘要

Increasing attention is being paid to health and environmental risk as a result of theudpresence of trace steroid estrogens in the effluent discharged from municipal sewage treatmentudplants. This paper focuses on assessment of removal of these trace compounds using 3H-labelledudestrone as the model compound. Jar tests over a range of ferric chloride dosage and pH conditionsudshowed that coagulation was ineffective in removal of estrone from secondary effluent. Theudexperiments showed that the combination of PAC and microfiltration could be effective for removaludof trace estrone from water. The rate and extent of estrone removal by PAC are functions of PACuddosage and retention time of PAC in the system. Mathematical analysis of the results using audhomogeneous surface diffusion model (HSMD) indicates that the adsorption of estrone on PAC canudbe limited by film diffusion and internal surface diffusion. The surface and film mass transferudcoefficients were determined to be 9.72 x 10-10 cm2/min and 1.963 cm/min, respectively, under theudconditions used.