Preparation, characterization, and physical properties of lightweight ceramics by using sewage sludge ash

In the present study, sewage sludge ash (SSA) was added to clay to prepare lightweight ceramics for sustainable construction materials. The characterization and the effect of different concentrations of SSA on the physical and mechanical properties of the samples were studied. The results showed that the organic matter in SSA facilitated the combustion process. SSA addition reduced the bulk density from (1.94 to 1.32 g/cm3). Otherwise, the water absorption, the apparent porosity and the loss on ignition increased with the increase in SSA concentration. The addition of SSA lowered the compression strength but still within the standard range of the construction materials at concentration up to (30 wt.%). Furthermore, heavy metals are solidified inside the sintered samples, since Cu, Cd, Fe, Zn, Cr, Mn, Ni, and Pb, concentrations in the leachate met the range of Egyptian standard specification.