Influence of solids on the removal of emerging pollutants in electrooxidation of municipal sludge with boron-doped diamond electrodes

• Electrooxidation of sludge is limited by solid particles.
• Selected emerging pollutants are partially degraded using BDD electrodes (51–69%).
• Sorption of emerging pollutants (> 98%) reduces electrooxidation efficiency.
• Electrooxidation of soluble organic matter occurs faster than for particulate organics.

Electrooxidation of waste activated sludge (WAS) was performed using boron-doped diamond (BDD) electrodes to evaluate the removal of emerging pollutants: 4-[2-(4-hydroxyphenyl) propan-2-yl]phenol (bisphenol A); nonylphenols (including isomers); and (5-chloro-2-(2,4-dichlorophenoxy)phenol) (triclosan). The applied current density was 28.5 mA cm− 2, and the treatment times evaluated were 60, 120, and 180 min. Partial degradation of selected emerging pollutants was obtained with efficiencies of 51% for bispenol A, 69% for nonylphenols, and 62% for triclosan. Organic matter was partially oxidized, mainly in the soluble phase. Most of the organic matter (78%) and emerging pollutants (> 98%) were found to associate with solid particles in WAS, which limited the efficiency of the process.