Enhanced methane production using pretreated sludge in MEC-AD system: Performance, microbial activity, and implications at different applied voltages

Anna Joicy, Hwijin Seo, Myoung Eun Lee, Dong Hoon Kim, Si Kyung Cho, Yongtae Ahn

Research output: Contribution to journalArticlepeer-review

19 Scopus citations

Abstract

Although various pretreatment methods are employed to promote sludge hydrolysis and thereby promoting methane production in the subsequent microbial electrolysis cell assisted anaerobic digestion (MEC-AD) system, the questions arise are, “which pretreatment method on waste activated sludge (WAS) maximises the sludge hydrolysis and what is the optimal applied voltage on anaerobic digestion (AD) to stimulates the direct interspecies electron transfer (DIET) performance and thereby accelerating the methane production fed with pretreated WAS?” was still unanswered. Herein, firstly, a series of pretreatment methods to hydrolyse and mineralise the organic matter of WAS was performed to evaluate solubilization efficiency and thereafter, the influence of different applied voltages (0.3 V, 0.6 V, and 0.9 V) on coupled MEC-AD reactors fed with pretreated WAS was investigated to apprehend the DIET promotion for methane production. The results indicated that in MEC-AD reactors, the methane yield increased by 27.2%, 44.8%, and 37.3% when the applied voltages were 0.3 V, 0.6 V, and 0.9 V, respectively. Therefore, the alkaline-thermal pretreatment (ATP) enhanced the sludge hydrolysis in WAS, followed by an applied voltage of 0.6 V in the MEC-AD reactor fed with pretreated WAS, enhanced methane production under DIET stimulation induced by the increased abundance of electroactive microorganisms (EAM) and the advanced electron transfer. Besides, the energy balance estimation validates that with an applied voltage of 0.6 V in MEC-AD could achieve higher net energy input.

Original languageEnglish
Pages (from-to)40731-40741
Number of pages11
JournalInternational Journal of Hydrogen Energy
Volume47
Issue number96
DOIs
StatePublished - 12 Dec 2022

Keywords

  • Applied voltage
  • DIET
  • Methane yield
  • Pretreatment
  • Waste activated sludge

Fingerprint

Dive into the research topics of 'Enhanced methane production using pretreated sludge in MEC-AD system: Performance, microbial activity, and implications at different applied voltages'. Together they form a unique fingerprint.

Cite this