ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Impact of peroxydisulphate on disintegration and sedimentation properties of municipal wastewater activated sludge

Stanisław Wacławek, Klaudiusz Grübel, Zuzanna Chłąd, Mariusz Dudziak, and Miroslav Černík

Centre for Nanomaterials, Advanced Technologies and Innovation, Technical University of Liberec, Studentská 1402/2, 461 17 Liberec, Czech Republic

E-mail: stanislaw.waclawek@tul.cz

Abstract: In the study, a thermally activated sodium peroxydisulphate (PDS; Na₂S₂O₈) was applied in order to disintegrate wastewater activated sludge (WAS). Chemical disintegration of WAS results in organic matter and polymer transfer from the solid phase to the liquid phase. Soluble chemical oxygen demand (SCOD) is often used to characterise the disintegration efficiency of WAS flocs and microorganisms cells. The present study was conducted in order to chemically disintegrate WAS using PDS in doses of 0.2 %, 0.4 %, 0.6 %, 0.8 % and 1.0 % activated at temperatures of 50°C, 70°C and 90°C for 30 min. The temperature rise induced the PDS to form free radicals, which resulted in an increase in SCOD, i.e. for the highest dose of PDS, the SCOD value attained 2140 mg dm⁻³ (almost a 15-fold increase over the WAS value). A further positive effect from using this method was a decrease in the sludge volume index (SVI) from 89.8 cm³ g⁻¹ to 30.6 cm³ g⁻¹. On the basis of the results obtained, it may be concluded that thermally activated PDS is suitable for disintegration and has a positive impact on WAS sedimentation properties.

Keywords: peroxydisulphate – chemical disintegration – soluble oxygen demand – sludge volume index

Full paper is available at www.springerlink.com.

DOI: 10.1515/chempap-2015-0169

Chemical Papers 69 (11) 1473–1480 (2015)