Advanced Water Management Centre

Emma Thompson Brewster presents AWMC Seminar Program

Emma Thompson Brewster presents: A mechanistic model of electrodialysis for complex solutions

Abstract: Electrochemical processes have recently been identified as having potential to succeed in a variety of unconventional applications with one such application being the concentration of nutrients from wastewater. Although electrochemical models exist, the majority of these models concern simple solutions, with little explanation of the mechanisms essential for modelling electrochemical systems with more complex solutions like urine, domestic or agri-business wastewater. The aim of this study is to develop a physico-chemical modelling approach for the separation and concentration of nutrient ions from synthetic wastewater. Key mechanisms included in the model are ion transport through diffusion and migration (Nernst-Planck equation), the influence of pH on the competitive charge transport of ions, ion transport through ion exchange membranes based on fundamental characteristics of the membranes, and total cell potential including the contribution of resistance from the solutions, membranes and electrodes. The results support that membrane resistance and membrane parameters have the greatest influence on the modelled concentration profiles compared to the ionic transport in the bulk solution. The results show the proposed mechanisms of charge proportioning between different ions, the pH calculations and current leakage accurately describe the experimental data. Future work will extend the model to account for precipitation in real wastewater solutions.

Dr Jianhua Guo presents: ­Metagenomic analysis of anammox communities in three different microbial aggregates (flocs, biofilm and granules)

Abstract: The discovery of anammox bacteria not only has stimulated the appreciation of their applied and ecological significance, but also provided economically attractive and environmentally friendly alternative to current wastewater treatment processes. Although approaches based on metagenomic comparisons of different sludge aggregates are still scarce, they have great potential to understand the abundance, diversity and functional traits in various anammox reactors. This study presents the metagenomic comparison of taxonomic and functional profiles of the microbial community in different anammox sludge aggregates. The anammox bacterial communities in both biofilm and granule showed relatively high abundance and diversity, compared to flocs exposed to low dissolved oxygen (DO) conditions. Four of the five known genera of anammox bacteria were detected in the three cultures except Candidatus Jettenia, which was absent in granules. Candidatus Kuenenia composited the major population of anammox bacteria in these three cultures. The genomic assembly of the Candidatus Kuenenia in the granule was very similar to the published reference genome of Candidatus K. stuttgartiensis. Genes involved in metabolism of anammox process were highly enriched in biofilm and granules. In particular, the abundance of hydrazine synthase gene (hzs) in biofilm was around 486 times more pronounced than in granules. The knowledge gained in this study highlights an important role of biofilm at a liquid-solid interface in sustaining slow-growing microorganisms and illustrates the potential to facilitate metagenomic analysis for optimization of reactor operation.

Host: Advanced Water Management Centre
Event Details
Date & Time: 
Friday, 28 August 2015
9am - 10am
Venue: AIBN Building 75, Level 1 Seminar Room
  • Emma Thompson Brewster
  • Dr Jianhua Guo

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