Insight into the comparison of thermally and Fe(II) activated persulfate on sludge dewaterability and disintegration

Abstract

The effects of thermally and Fe(II) activated potassium persulfate (PPS) on sludge dewatering performance were compared systematacially. Sludge dewaterability was monitored by measuring capillary suction time (CST) and sludge specific resistance to filtration (SRF), and the degradation effect was characterized by Chemical oxygen demand (COD), total organic carbon (TOC), ammonia nitrogen (NH4+-N) and extracellular polymeric substances (EPS). The Change of extracellular polymer substance (EPS) including soluble, loosely bound and tightly bound EPS (S-EPS, LB-EPS and TB-EPS) with time and PPS dosage was monitored to discuss the oxidation efficiency of thermally and Fe(II) activated PPS. Sludge supernate were analyzed by three dimensional fluorescence excitation-emission spectrum (3D-EEM) to confirm the proteins transformation. The result showed that sludge dewaterability in terms of CST and SRF were enhanced with increasing PPS dosage and condition time of both two activated methods. While Fe(II) activated PPS could reduce sludge CST and SRF to preferred values at low PPS dosage and short condition time. Maenwhile, sludge degradation effect was also more obvious. Mechanically, sludge TB-EPS in proteins and polysaccharides converted to SB-EPS was more quickly with Fe(II) activated PPS. Besides, thermally activated PPS tended to oxidize the protein in the supernatant first.

Activation of Peroxydisulfate by Bimetallic Nano Zero-Valent Iron for Waste-Activated Sludge Disintegration

“…This was an additional confirmation that the PDS was easily activated by the nZVI or bimetallic nanoparticles to form sulfate radicals. Analogous results were obtained by Guo et al [32], where Fe(II)-activated PDS caused the conversion of B-EPS to S-EPS.…”

Advances in Chemical Conditioning of Residual Activated Sludge in China

“…The most commonly used activation method is Fe 2+ activation, with a standard redox potential of 3.1 V for SO 4− , which exceeds that of the strongly oxidizing -OH and is more stable to oxidizing pollutants, making it more suitable for a wider range of applications. Guo et al [34] uses Fe 2+ activated potassium persulfate (PPS) for sludge treatment. The results showed that the Fe 2+ -activated PPS improved the dewatering performance of the sludge with a lower PPS dosage and a shorter treatment time.…”

“…The optimum dosing rates for PPS and Fe 2+ are 0.5 mmol/g and 1.0 mmol/g, respectively CS down to 25.1 s SRF down to 1.75 × 10 8 m/kg [34] Fe 2+ -perthiolate-tannic acid (TA)…”