Impact of ultrasonic treatment on dewaterability of sludge during Fenton oxidation

Jianguo Jiang*, Changxiu Gong, Sicong Tian, Shihui Yang, Yujing Zhang

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

10 Citations (Scopus)

Abstract

Fenton oxidation was compared with Fenton oxidation coupled with ultrasonication (Fenton + US) for sludge dewatering. Different Fenton reagent (H2O2, Fe2+) concentrations, pH, and reaction times were studied in different systems on the basis of the specific resistance to filtration (SRF) and capillary suction time (CST). It was found that Fenton + US can significantly reduce Fe2+ and H2O2 dosages and reaction times. After ultrasonication of the system at pH 3, with an ultrasonic frequency of 25 kHz and a sound energy density of 100 W/L, the Fe2+, H2O2 dosage, and reaction time were reduced by 66.7, 75.0, and 75.0 %, respectively, when compared with Fenton oxidation at the same dewaterability of sludge. The microstructure of sludge and hydroxyl radical (center dot OH) density in Fenton oxidation and Fenton + US was further examined. Fenton + US produced more center dot OH in a sludge system than did individual Fenton oxidation. The concentration of center dot OH in Fenton + US fell from 79.2 to 6 mg/L over 3.5 h, while the concentration of center dot OH in Fenton oxidation fell from 59.6 to 1 mg/L over 2 h, thus destroying the microstructure of sludge more effectively. Sludge treated using Fenton + US for 30 min showed a much thinner and looser microstructure.

Original languageEnglish
Pages (from-to)8081-8088
Number of pages8
JournalEnvironmental Monitoring and Assessment
Volume186
Issue number12
DOIs
Publication statusPublished - Dec 2014
Externally publishedYes

Keywords

  • Sludge
  • Ultrasonic coupling
  • Fenton oxidation
  • Dewaterability
  • Microstructure
  • WASTE-ACTIVATED-SLUDGE
  • SEWAGE-SLUDGE
  • EXCESS SLUDGE
  • DISINTEGRATION
  • REDUCTION
  • DIGESTION
  • REAGENT
  • PH
  • PEROXIDE
  • REACTOR

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