Title
Influence of free ammonia on the performance of a polyhydroxyalkanoate (PHA) microbial enrichment sequential batch reactor (SBR) at pilot scale
Author
Segami, Miki (TU Delft Civil Engineering and Geosciences)
Contributor
Kleerebezem, Robbert (mentor)
de Kreuk, Merle (graduation committee)
van Lier, Jules (graduation committee)
Tamis, Jelmer (graduation committee)
Welles, Laurens (graduation committee)
Degree granting institution
Delft University of Technology
Date
2019-07-09
Abstract
A pilot-scale PHA microbial enrichment reactor fed on OFMSW leachate was monitored in order to assess the influence of free ammonia nitrogen (FAN) on its performance. The enrichment reactor consisted of a SBR with a 12-hours cycle which included a feast phase, a settling phase and a famine phase with external nitrogen addition. Based on the microscope pictures and FISH analysis, at least two different PHA producing bacteria were identified: small (< 2.5 μm) and big PHA producing bacteria (< 5 μm). Big PHA bacteria appeared from FAN concentrations higher than 50 mg/L, but concentrations higher than 150 mg/L were highly toxic for the whole PHA microbial enrichment. Finally, it was found that a FAN concentration around 60-70 mg/L might produce a microbial enrichment with good settling properties (SVI30 < 80 mL/g and BLAS < 5%) and maximum PHA yields (around 0.50 g PHA/g sCOD), possibly due to the presence of big PHA producers which are assumed to be more efficient and heavier after feast. However, this FAN concentration may lead to a lower settleable biomass production yield (around 0.30 g VSS/g sCOD). Since these results are not conclusive, it is suggested to test the observations of this pilot study in lab-scale experiments to evaluate the potential of FAN as an additional selective pressure in a PHA microbial enrichment.
Subject
Polyhydroxyalkanoates
microbial enrichment reactor
free ammonia
pilot scale
sequential batch reactor
To reference this document use:
http://resolver.tudelft.nl/uuid:2b7ab289-8a38-4cad-bc3a-bd113a9213b5
Embargo date
2024-07-09
Part of collection
Student theses
Document type
master thesis
Rights
© 2019 Miki Segami