My research group is focused on developing solutions to ‘upcycle’ [1] organic-rich waste and to more effectively process wastewater. As individuals and as a society, we generate large quantities of liquid and solid waste every day, and much of this waste contains significant quantities of high-value organic matter and nutrients. Opportunities exist to recover and/or produce high value commodities from these organic-rich waste streams. Unfortunately, our current approach is largely based on ‘managing’ these waste streams....in other words, ‘disposing’ of the waste in a manner that theoretically has minimal impact to human activities (first) and the environment (second). At best we ‘downcycle’ [1] the high value raw material. And these activities are VERY energy intensive....for example, the simple act of reclaiming water from municipal wastewater for a city of 100,000 can consume enough electricity to power approximately 300 homes. While this may not seem all that significant, perhaps most importantly is the fact that an opportunity is lost to maximize recovery of a valuable substrate. If we are going to commit this amount of power to reclaim water, at least we should generate more value in return.

My research group views waste streams and waste management practices through a different lens. We see opportunities….to recover high value compounds....to produce commodities that are of significant value to society – that can replace commodities that are otherwise produced from non-renewable raw materials….and perhaps most importantly, to not simply dispose of the waste for future generations to deal with, but to advance processes that can (optimally) lead to closed loop re-use and/or upcycling [1]. We also see opportunities to apply advanced molecular techniques to learn more about conventional biological WWT processes such that we can design and operate more efficient systems (both in terms of energy demand and nutrient capture). Our focus is to accomplish these objectives using naturally occurring bacteria.

So, what type of research are we currently conducting….

Ø  We are producing biodegradable thermoplastics using naturally occurring bacterial consortia fed wastewater derived from organic-rich waste streams. The plastic exhibits some very exciting material properties. Not only does the process sequester carbon that would otherwise be emitted as CO₂, but the process can generate revenue for waste-producing industries.

Ø  We are investigating, at a macro and molecular level, natural bacterial processes to more efficiently remove soluble orthophosphate from wastewater. Excess phosphorus in natural surface water bodies can lead to advanced eutrophication (water body death), which reduces water quality and adversely affects aquatic organisms, drinking water potential, and recreation, among other beneficial uses.

Ø  We are advancing a new post-anoxic biological nutrient removal process designed to achieve near-complete nitrogen and phosphorus removal using mixed microbial consortia. The process, referred to as the BIOPHO-PX process (trademark in process), also involves nitritation as a means to reduce treatment facility energy demands.

Ø  We are investigating the ability to enhance methane production and reduce pathogens through a novel two-stage anaerobic digestion process that is processing dairy manure. The process readily integrates with other technologies to maximize resource recovery from manure.

Ø  We are investigating biological methods and the ability of existing wastewater processes to remove Cipro, Lipitor, and Carbamazepine from municipal wastewater. Our particular focus in on technologies currently in use at full-scale WWTPs.

Ø  We own and operate three pilot-scale WWTPs. Not only do my students get important hands-on experience at an appropriate scale (which intrinsically makes them better engineers), we are able to conduct our studies at a scale that is relevant to full-scale systems. To learn more go to the Scale Model WWTPs tab.

 1.  McDonough, W. and M. Braungart, Cradle to cradle:  remaking the way we make things. 2002, New York: North Point Press. 193.

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My research activities are currently funded by the National Science Foundation, the United Dairymen of Idaho, the United States Department of Agriculture, the Idaho National Lab, the Idaho Center for Advanced Energy Studies (CAES), and the UI College of Engineering (Faculty Excellence Award).

Broader Research Vision Statement

Future success of advanced engineered biological treatment systems will be predicated on our ability to understand the fundamental interactions of microorganisms with their environment.  Most historical system models were based on the “black box” concept wherein bulk parameters were measured and a model was extrapolated.  While this approach has been successful, yielding in many cases contaminant removal of over 90%, to achieve higher levels of removal while concurrently, and possibly more critically, improving process operational efficiencies we need to understand the intrinsic structure-function link in environmental systems.  Advancements in the field of molecular biology, microbiology, genetics, biotechnology, and proteomics provide environmental engineers additional tools to investigate the fundamental operations occurring in biological systems.  My research activities are focused on integrating these various disciplines and utilizing these tools to (a) develop a fundamental understanding of the structure and function of engineered systems, (b) apply this knowledge in the design of new treatment systems and the optimization of existing technologies, and (c) develop and apply molecular probes that can be applied by field personnel in real-time monitoring and optimization.

Pharmaceuticals.  Considerable attention has been placed recently on characterizing the occurrence of hormonally-active agents and pharmaceutically-active compounds in general (PhACs) in natural aquatic environments.  PhACs have been detected at the part-per-billion and part-per-trillion range at high frequency in aquatic systems in the U.S. and in Europe, especially in systems where contributions from wastewater treatment plants (WWTPs) are substantial.  Often these synthetic organic compounds pass through the conventional biological treatment systems; recent research suggests that PhACs may be preferentially bound in the biosolids.  These compounds potentially pose a significant risk to the health of humans and wildlife, and hormonally-active agents in particular may bioaccumulate within animals.  The U.S. EPA currently does not have regulatory guidelines for compounds classified as either pharmaceuticals or hormonally-active agents, although a regulatory environment will likely develop in the future, nor do we have a good understanding of appropriate full-scale designs of treatment systems for the removal of these compounds.  Only through integration of microbiology, molecular biology, and engineering will we begin to develop the necessary treatment regimes to remove these contaminants.

Sustainability.  As we attempt to move towards a more sustainable society, one in which human activities are viewed as environmentally benign and processes “green”, we focus not only on the production of chemical commodities from renewable feedstocks, but also on life-cycle analyses of products and associated manufacturing processes.  Within this context, my current research activities have successfully demonstrated the ability to couple wastewater treatment technologies and bacterial thermoplastic synthesis, with further integration into composites production.  However, we are just beginning to penetrate and advance this topic.  Ongoing collaboration with the Idaho National Laboratory will yield a phylogenetic tree for the microorganisms that we have cultured in our thermoplastic producing bioreactors.  With this information we will be able to pursue a number of new research tangents, including process optimization and the development of molecular probes that could be utilized in the operation of a scaled-up process.

Nutrients and Eutrophication.  Anthropogenic activities can result in the release of nutrients into the aquatic environment that create a nutrient imbalance leading to advanced surface water body eutrophication which in turn can incur significant ecological and social damage including adverse impacts associated with water treatment, and reduced recreational value.  Within this context, nitrogen and phosphorus are viewed most critically, as these inorganic compounds are critical nutrients associated with the proliferation of algae, which is a primary indicator of impaired water quality and accelerated eutrophication.  Phosphorus, however, is often the limiting macronutrient, with threshold bulk aqueous concentrations as low as 0.01 to 0.02 mg P L^-1.  Although non-point source discharges arguably contribute the largest load of these critical nutrients, point source discharges such as wastewater treatment facilities nonetheless receive the most attention due to their obtrusiveness and ease with which to regulate.  Moreover, removal of phosphorus from wastewater effluent is often viewed as a panacea in the mitigation of eutrophication.  My current research has identified a potentially critical microbial metabolism associated with biological phosphorus removal.  Additional research is necessary to articulate the complex process mechanistics such that this sustainable engineered process can be utilized more ubiquitously over the current unsustainable practices involving synthetic chemicals.  I am a co-PI on a recently awarded NSF grant to further investigate the subject metabolism and nutrient removal process.

Water Resources.  Water resources are becoming more scarce as our society develops and grows, forcing us to more closely examine opportunities for water reuse.  However, there remain many hurdles before a more comprehensive reuse policy becomes a completely integrated part of communities.  Key questions in this area that must be addressed include: what are the contaminants of concern, how can existing treatment technologies be optimized to remove these contaminants, what types of new treatment systems are necessary, and what are the socioeconomic policies necessary to competitively price structure reclaimed water in a comprehensive water management plan?