Advanced Water Management Centre

AWMC Seminar Program: Edward Barry & Dr Bernardino Virdis

Edward Barry

Abstract for confirmation presentation:

Purple phototrophic bacteria (PPB) are an emerging option for wastewater treatment that enables complete recovery of organics and nutrients through assimilation. Although this process appears promising as a new treatment platform, there are several considerations which must be taken into account if it is to be practically implemented. These include characterisation of mixed community activity in a domestic wastewater context. PPB have been studied extensively in the domain of hydrogen production, but the operating conditions cause different metabolic characteristics of the biomass. For example, ammonia has been identified as an inhibitory species for the production of hydrogen, but is always present in wastewater. As the goal of the process is to maximise ammonia and phosphate uptake, these processes are not well understood. Secondly, there has not been analysis into photo-irradiance of mixed culture biomass nor practical implementation into a photobioreactor. There have also been no studies addressing the hydrodynamics of PPB photobioreactors and their implication on reactor performance.

Computational fluid dynamics studies have been carried out on algae photobioreactors to assess the flow behaviour of the fluid, and solid biomass particles with different sparging rates and reactor configurations, but these have been greatly simplified to 2 dimensional simulations with basic reactor geometries. Thirdly, the interactions between hydrodynamics, photon delivery and biochemical equations have rarely been successfully implemented in CFD case studies. Finally, there is no understanding of the behavior of pathogens in IR photobioreactor systems, and modelling of pathogens in general in wastewater systems is limited.

Four research objectives have been proposed to advance these current limitations specifically in the context of development of PPB based photo-anaerobic membrane bioreactor (PAnMBR) systems for wastewater treatment. The identified research gaps are as follows;

1. Develop a mechanistic model for applications of PPB for domestic wastewater treatment and apply it for system assessment.

2. Develop a generic stochastic model for pathogen removal in wastewater treatment processes.

3. Quantify the interactions between cell growth and photon availability in order to extend the recently developed photoanaerobic model 1 (PAM1).

4. Optimise the design of the PAnMBR for maximal performance and minimal operating costs (energy expenditure) and capital expenditure.

 

Dr Bernardino Virdis

Analysis of electron transfer dynamics in mixed community electroactive biofilms. How can we boost electron-transfer rates?

In spite of great scientific efforts, practical applications of bioelectrochemical technologies are still limited by the low current densities attainable by electroactive biofilms. These biofilms are formed by multi-layered structures that are capable to achieve long-range electron transfer over distances exceeding 100 microns. While considerable research as focused on increasing the electron transfer rates at the biofilm/electrode interface by various forms of electrode treatment and/or decoration, very limited research has instead focused on methods to increase the long-range electron transfer rates.

In this seminar I will present our recent study on characterization of electron transfer dynamics in mixed community biofilms grown on transparent Indium Tin Oxide (ITO) electrodes by combining electrochemical measurements with Confocal Resonance Raman Microscopy. This approach allowed for the first time direct comparison of the redox process at the biofilm/electrode interface with the long-range cytochrome-mediated electron transfer inside the bulk biofilm. I will also show how incorporating self-assembling nanoparticles within the biofilms is able to greatly enhance the long-range electron transfer process.

Event Details
Date & Time: 
Friday, 23 October 2015
9am - 10am
Venue: AIBN Building 75, Level 1 Seminar Room
Speaker(s): 
  • Edward Barry
  • Dr Bernardino Virdis

Event Contact: awmcseminars@awmc.uq.edu.au