Abstract: In order to study the cross flow filtration performance of disk ceramic membrane from different sludge, a dynamic filtration device with an average ceramic disc aperture of 2 μm was adopted to conduct experiments on thermal hydrolyzed sludge, digested sludge, and AO sludge. The impact of sludge with different properties on filtration permeation flux, the filtered concentrated liquid and clear liquid were investigated. The results indicated that under the operating conditions of normal temperature feeding, a membrane rotation speed of 900 r/min, and a transmembrane pressure difference of 0.1 MPa, the permeation flux of the disc ceramic membrane decayed rapidly within 20 minutes, and then with the increase of time, the overall trend fluctuated and declined. After 90 minutes, the filtration fluxes of thermal hydrolyzed sludge, digested sludge, and AO sludge stabilized at 22.93, 13.97, and 14.20 L/（m2·h）, respectively. The disc ceramic membrane has a significant interception effect on particulate matter and dissolved organic matter of sludge from the three sources. After the digested sludge was filtered through the membrane, the solid content of the concentrated liquid could reach to 11.85%. The disc ceramic membrane cross-flow filtration system could achieve high-efficiency concentration and filtration of sludge simultaneously, providing a new approach for the solid-liquid separation treatment of sludge.

Key words: sewage sludge, thermal hydrolysis, anaerobic digestion, disk ceramic membrane, solid-liquid separation