Research

Environmental Bioprocess engineering involves using biological materials and biocatalysts for processes that benefit the environment. It is an exciting and growing field in which chemical engineering principles are applied to the use of biologically-based processes. The field is interdisciplinary, involving biotechnology, chemical engineering, microbiology and biochemistry and has a wide range of application areas including the production of food, pharmaceuticals, chemicals and the treatment of industrial wastes. Students can focus on fundamental engineering, chemistry and/or biology and interact with other faculty and industry on problems of economic and social importance.

The three main areas of my research are (1) Biological wastewater treatment; (2) Biological treatment of air emissions; and (3) Wastes to value-added products.

Biological Wastewater Treatment – This has been very active over the past 20 years.   In the past four years it has involved 2 M.A.Sc., 8 Ph.D. students, a PDF and many others along with collaborations with other students and faculty.  My recent efforts have been on understanding how microbial processes adapt to change (temperature, oxygen, substrate or toxic shocks) as microbial flocs and biofilms (Morgan and Allen, 2005a,b; Nadarajah et al., 2010, 2007; Zhang and Allen 2008) and improving treatment system robustness.  In addition, I have been examining how process conditions can be used to affect microbial flocs for improved disinfection (Scott et al., 2005) and enhance settling (Yang et al., 2010) and biofilm formation (Goode et al. 2007, Goode and Allen, 2010). Highlights include a clear linkage between system disturbances and deflocculation and the corresponding shifts in floc surface characteristics, floc strength and the efflux of monovalent ions and key microbial species.

Biological Air Treatment: The biological treatment of waste of gas streams is another exciting area of interest. The technology is being applied in Europe extensively and, because of its economic and environmental benefits will see increasing development and application in North America. The research includes projects on bed design, kinetics, microbiology and modelling. This research has involved 1 M.A.Sc.,  3 Ph.D. students, 2 PDFs and many others.  Highlights of the research include: the development of a new mechanism and model for the rapid degradation of hydrophobic pollutants in biofilms (Miller and Allen, 2005a,b) and a process to biotreat hydrogen sulphide at temperatures up to 70°C (Datta et al., 2007); the development of low pressure drop biofilters through uniform biomass distribution, utilizing mixed packing and conical biofilters (Yang and Allen, 2005);  coupling of a UV reactor with a biofilter to enhance the treatment of problematic air pollutants (Koh et al., 2004, Mohseni et al., 2005). We have also enhanced biofilter performance on dimethyl sulphide (DMS) 10 fold with methanol addition (Zhang et al., 2006, 2007)  then used  advanced molecular techniques to show how methanol provides a microbial community that is much more robust (less pH sensitive) for DMS removal ( Hayes et al. 2010a,b).

Wastes to Value-Added Products: The overall theme of this aspect of my research is “adding value to wastes via bioprocesses that use mixed microbial communities”. This is especially important as we move towards a more sustainable future based on renewable resources such as biofuels and biorefineries. Taking full advantage of this requires that we develop processes with improved reliability, and predictability, that can treat a wider range of compounds in various wastes and that we expand their ability to produce useful byproducts (e.g.biofuels, biopolymers, biocomposites). The two main research areas are (i) Microalgal biorefinery; and (ii) Optimization of extraction and utilization of bioproducts from waste biosolids.