Abstract: The porous ceramsite with tailings addition of 77% was prepared with low silica iron tailings as raw materials. And the effect of the prepared ceramsite on the sewage water treatment was investigated through biological aerated filter at laboratory. The results showed that since the ceramsite has features of surfaces roughening, internal porous and the apparent density, the apparent porosity and the average pore diameter of 1.33 g/cm³, 54% and 19.80 μm respectively, the concentration of heavy metals in leaching solution in heavy metals leaching tests reached the national environmental quality standards for surface water. The biological aerated filter with the ceramsite as filter has a good effect on treating the sewage in simulation, with the removal rate of COD_Cr, NH+₄-N and TN of 84.26%, 84.01% and 25.87% respectively; There are numerous microbial species on the ceramsite filter, and total biological phospholipid per unit of ceramiste mass can be up to 371.63 nmol/g at water inlet, and 90.79% and 9.21% at ceramiste's surface and interior respectively. 

Key words: Low silica iron tailings, Porous ceramsite, Biological aerated filter, Sewage water treatment, Microbial morphology