Bubble performance of a novel dissolved air flotation(DAF) unit

Abstract： ES-DAF, a novel DAF with Iow cost, high reliability and easy controllability, was studied. Without a costly air saturator, ESDAF consists of an ejector and a static mixer between the pressure side and suction side of the recycle rotary pump. The bubble size distribution in this novel unit was studied in detail by using a newly developed CCD imagination through a microscope. Compared with MDAF under the same saturation pressure, ES-DAF can produce smaller bubble size and higher bubble volume concentration, especially in lower pressure. In addition, the bubble size decreases with the increase of reflux ratio or decrease of superficial air-water ratio. These results suggested that smaller bubbles will be formed when the initial number of nucleation sites increases by enhancing the turbulence intensity in the saturation system. 作 者： CHEN Fu-tai    PENG Feng-xian    WU Xiao-qing    LUAN Zhao-kun   作者單位： CHEN Fu-tai,WU Xiao-qing,LUAN Zhao-kun(State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences,Beijing 100085, China)

PENG Feng-xian(Changsha Vocational School of Environmental Technology, Changsha 410004,China) 

期 刊： 環境科學學報(英文版)  ISTICSCI   Journal： JOURNAL OF ENVIRONMENTAL SCIENCES  年，卷(期)： 2004, 16(1)  分類號： X703  Keywords： dissolved air flotation(DAF)    bubble size distribution    air saturation system    CCD imagination