Transformation of TiO2 (nano)particles during sewage sludge incineration

Titanium dioxide (TiO2) (nano)particles are produced in large quantities and their potential impacts on ecosystems warrants investigations into fate after disposal. TiO2 particles released wastewater retained by treatment plants accumulate digested sludge, which is increasingly incinerated industrialized countries. Therefore, we investigated the changes of Ti-speciation during incineration as-received sludge spiked with anatase (d=20–50 nm) or rutile (d=200–400 using X-ray absorption spectroscopy (XAS) transmission electron microscopy (TEM). In were dominant Ti bearing minerals both remained unaffected anaerobic treatment. During incineration, reacts hematite to members hematite-ilmenite solid solution series (Hem-Ilm). Up 80% as transformed Hem-Ilm, a distorted 6-fold coordinated (Ti(IV)sulfate) incineration. 30% 60% Hem-Ilm Ti(IV)sulfate represented phases fly bottom ash, respectively. Fe spatially correlated ash derived from whereas only thin layer reacted Fe, line XAS data. This study highlights transient nature nano-Ti species sewage