The University of Southampton
University of Southampton Institutional Repository

Quantification of methane losses from the acclimatisation of anaerobic digestion to marine salt concentrations

Quantification of methane losses from the acclimatisation of anaerobic digestion to marine salt concentrations
Quantification of methane losses from the acclimatisation of anaerobic digestion to marine salt concentrations
The research assessed losses in methane production as a result of raising digester salt concentrations to marine values, and of increasing the feedstock sulphate concentration. Acclimatisation of inoculum from a municipal wastewater biosolids digester was begun by raising the concentration of chloride salts (Na, Mg, Ca and K) to 6–9 g L?1, as initial experiments showed higher concentrations caused severe inhibition. After stable operation for four retention times salt content in the reactors and the feed was increased by 1 g L?1 every 14 days, up to 31.1 g L?1. The digesters were fed daily in semi-continuous mode and monitored for performance and stability criteria including specific methane production (SMP). SMP was 6–7% less than in controls using the same feedstock without saline addition. After steady-state conditions were achieved at high chloride salinity, magnesium chloride was partially replaced by magnesium sulphate to give a range of sulphate concentrations. Higher sulphate concentrations caused initial instability, indicated by volatile fatty acid accumulation. This subsequently reduced and stable operation was achieved at marine sulphate concentrations, but with a ?5% loss in SMP due to interspecies substrate competition. High sulphate also affected pH, leading to gaseous H2S production proportional to the applied sulphate load
0960-1481
497-506
Roberts, Keiron P.
da377993-082e-4693-8814-8983ab028258
Heaven, Sonia
f25f74b6-97bd-4a18-b33b-a63084718571
Banks, Charles J.
5c6c8c4b-5b25-4e37-9058-50fa8d2e926f
Roberts, Keiron P.
da377993-082e-4693-8814-8983ab028258
Heaven, Sonia
f25f74b6-97bd-4a18-b33b-a63084718571
Banks, Charles J.
5c6c8c4b-5b25-4e37-9058-50fa8d2e926f

Roberts, Keiron P., Heaven, Sonia and Banks, Charles J. (2016) Quantification of methane losses from the acclimatisation of anaerobic digestion to marine salt concentrations. Renewable Energy, 86, 497-506. (doi:10.1016/j.renene.2015.08.045).

Record type: Article

Abstract

The research assessed losses in methane production as a result of raising digester salt concentrations to marine values, and of increasing the feedstock sulphate concentration. Acclimatisation of inoculum from a municipal wastewater biosolids digester was begun by raising the concentration of chloride salts (Na, Mg, Ca and K) to 6–9 g L?1, as initial experiments showed higher concentrations caused severe inhibition. After stable operation for four retention times salt content in the reactors and the feed was increased by 1 g L?1 every 14 days, up to 31.1 g L?1. The digesters were fed daily in semi-continuous mode and monitored for performance and stability criteria including specific methane production (SMP). SMP was 6–7% less than in controls using the same feedstock without saline addition. After steady-state conditions were achieved at high chloride salinity, magnesium chloride was partially replaced by magnesium sulphate to give a range of sulphate concentrations. Higher sulphate concentrations caused initial instability, indicated by volatile fatty acid accumulation. This subsequently reduced and stable operation was achieved at marine sulphate concentrations, but with a ?5% loss in SMP due to interspecies substrate competition. High sulphate also affected pH, leading to gaseous H2S production proportional to the applied sulphate load

Text
__soton.ac.uk_ude_PersonalFiles_Users_sh7_mydocuments_SHnow_Res_Papers_Roberts_Salt_RENE_Published_Roberts et al 2015 Salt - scholar text.pdf - Accepted Manuscript
Download (1MB)

More information

Accepted/In Press date: 21 August 2015
e-pub ahead of print date: 3 September 2015
Published date: February 2016
Organisations: Water & Environmental Engineering Group

Identifiers

Local EPrints ID: 381367
URI: https://eprints.soton.ac.uk/id/eprint/381367
ISSN: 0960-1481
PURE UUID: f3685c55-613a-4cce-92dd-b5f55de57019

Catalogue record

Date deposited: 02 Oct 2015 10:28
Last modified: 03 Dec 2019 06:49

Export record

Altmetrics

Contributors

Author: Keiron P. Roberts
Author: Sonia Heaven

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of https://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×