Advanced Reduction Processes for Degradation of Refractory Organics in Landfill Leachate

Ali Albalgane, Junkui Cui, Weihua Song, Yang Deng

Research output: Contribution to journalArticlepeer-review

Abstract

Hydroxyl radicals generated from advanced oxidation processes (AOPs) are broadly applied to mitigation of refractory organics in landfill leachate. However, following treatment by AOPs, the wastewater still contains highly oxidized organics that are recalcitrant to further chemical oxidation, thereby providing a challenge to established wastewater-treatment technologies. This study aimed to validate whether advanced reduction processes (ARPs), an emerging chemical degradation process driven by highly reductive hydrated electrons (eaq-), can effectively decompose persistent and complex organics in a Fenton pretreated landfill leachate. Results showed that ARPs poorly cleave C-C bonds in the Fenton pretreated leachate organic matter (LOM) due to low reactivity of the mixed organics toward eaq-. However, eaq- and ultraviolet (UV) irradiation during the ARP treatment could attack certain chromophores to reduce UV254 absorbance by 53%. The transformation particularly occurred to the low-molecular-weight (<10 kDa) and hydrophobic LOM fractions. Meanwhile, the carboxylic content declined after the ARP treatment, whereas the phenolic concentration remained constant, suggesting that eaq- principally reacted with electron withdrawing groups rather than electron donating moieties on the Fenton pretreated LOM. This study highlights that ARPs can serve as a promising post-treatment after AOPs for treatment of refractory organic wastes in landfill leachate.

Original languageEnglish
Article number04022046
JournalJournal of Environmental Engineering (United States)
Volume148
Issue number9
DOIs
StatePublished - 1 Sep 2022

Keywords

  • Advanced oxidation processes (AOPs)
  • Advanced reduction processes (ARPs)
  • Chemical reduction
  • Hydrated electrons
  • Leachate organic matter
  • Refractory organic wastewater

Fingerprint

Dive into the research topics of 'Advanced Reduction Processes for Degradation of Refractory Organics in Landfill Leachate'. Together they form a unique fingerprint.

Cite this