Abstract
The acidogenic phase of a two-stage anaerobic digestion process using distillery molasses slops effluent with high sulfate concentrations (4.2-5.1 g/l) was investigated. Removal of sulfate was studied at pH 5.8, 6.2, 6.6 and in two different reactors: continuous stirred tank reactor and an upflow fixed film fixed bed reactor. Batch experiments were carried out to obtain the maximum specific growth rates of sulfate reducing bacteria (SRB) at the above mentioned pH values. The biological sulfate removal increased with pH and so did the acetic acid production from the fermentative bacteria and SRB. For the same pH and hydraulic retention time the sulfate reduction was more efficient in the fixed film reactor than in the CSTR. The soluble sulfides from the sulfate reduction presented at the acidogenic reactor effluent were precipitated before the methanogenic phase to avoid biogas contamination and methanogenic bacteria inhibition; under such conditions, sulfide concentrations in the biogas thus produced were very low and high methane volumetric rates of production were achieved.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.