RMIT University
Browse

Biohythane Production from Domestic Wastewater Sludge and Cow Dung Mixture Using Two-Step Anaerobic Fermentation Process

journal contribution
posted on 2024-11-03, 10:21 authored by Faraz Sufyan, Mehmood Ali, Sadia Khan, Nazia Hossain
The current study explored bioenergy, particularly biohythane (a combination of biohydrogen (bioH2) and biomethane (bioCH4)), production from cow dung and untreated domestic wastewater sludge to valorize the waste into a value-added product. The experimental study consisted of a two-step process: dark fermentation (DF) and anaerobic digestion (AD) with a range of processing conditions varying the temperature and pH (acidic, neutral, and basic). The study maintained thermophilic conditions (55 °C) for bioH2 production and mesophilic conditions (35 °C) for bioCH4 production. The highest yields of bioH2 and bioCH4 were obtained at a pH of 5.5 (108.04 mL H2/g VS) and a pH of 7.5 (768.54 mL CH4/g VS), respectively. Microorganisms, such as Lactobacillus brevis and Clostridium butyricum, in the wastewater sludge accelerated the conversion reaction resulting in the highest bioH2 yield for an acidic environment, while Clostridium and Bacilli enhanced bioCH4 yield in basic conditions. The maximum cumulative yield of biohythane was obtained under basic pH conditions (pH 7.5) through DF and AD, resulting in 811.12 mL/g VS and a higher volumetric energy density of 3.316 MJ/L as compared to other reaction conditions. The experimental data were modelled using a modified Gompertz’s model at a 95% confidence interval and showed the best-fitting data from experimental and simulation results for biohythane production. The regression coefficient R2 value was highly significant at 0.995 and 0.992 for bioH2 and bioCH4 with the change in pH during biohythane production. Thus, this study presented an effective pathway to utilize untreated domestic wastewater sludge as an inoculum, showcasing the potential of biohythane production and the generation of valuable metabolic end-products across a broad range of pH conditions.

History

Related Materials

  1. 1.
    DOI - Is published in 10.3390/su151914417
  2. 2.
    ISSN - Is published in 20711050

Journal

Sustainability

Volume

15

Number

14417

Issue

19

Start page

1

End page

12

Total pages

12

Publisher

MDPI AG

Place published

Switzerland

Language

English

Copyright

Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

Former Identifier

2006126627

Esploro creation date

2023-12-03