Engineers are charged with important technical and business decisions on projects that modify the natural environment by consuming biophysical resources and generating ensuing wastes (Head, 2009; Mitchell, 2000). As economies grow, there is a limit to the availability of raw resources and to the assimilation capacity of Earth to process waste products (Head, 2009; Meadows et al, 1972). Hence, there is a pressing need to exercise resource conservation facilitated through material reuse (Clift, 1998). It is argued that in order to optimise resource use efficiency with concomitant waste minimisation, a systems approach is critical in research and in practice (Baumann et al, 2002). According to the 2nd Law of Thermodynamics, all technology inevitably produces material entropy, which are typically waste by-products. High energy-intensive technologies lead to large amounts of waste that become harder for ecosystems to assimilate, since high entropy wastes are incompatible with the low entropy inherent in nature's biosystems. A logical solution to this incompatibility is to develop engineering solutions based on whole systems integration that capitalise on embodied energy in waste products. These wastes thus become realised as feed streams for other technologies and so serve as a new commodity or reusable resource.
Society has become increasingly concerned about waste generation (eg. Clift, 1998) especially as New Zealand markets its lucrative tourist economy on the "clean-green" image. Recent national policies, including the 2002 Waste Strategy, provided impetus for achieving a vision and target of zero waste initiatives. The New Zealand Ministry for the Environment reported that 93% of raw materials are discarded during processing and do not end up as saleable products (Environment New Zealand, 2007). Consequently, the government is actively promoting a paradigm shift in waste management as a means of disassociating the volume of waste generated with economic growth, as outlined in the 2007 cabinet policy paper "POL (07) 132--Towards a Sustainable New Zealand". This aims to achieve economic wealth without compromising our environmental capital and is a good step towards implementing sustainable development through triple-bottomline (ecologic, economic and social) principles. It is therefore relevant to reassess how we manage our wastes and seek creative and innovative yet cost-effective opportunities to reuse these wastes. This rethinking in the waste management sector has been previously outlined (Clift, 1998) and the paradigm shift is essential so that many wastes can actually be realised as commodities or "misplaced" resources. This provided motivation for prescribing the "wastes to commodities" undergraduate research assignment that presents as a teaching model to foster integrated problem-solving and creativity required for sustainable engineering.
Engineers are responsible for creative and innovative solutions to solve challenging technical problems (Head, 2009). As such, it is important to facilitate creative opportunities in an engineering learning context to enable graduates to practice creative, challenging and sustainable problem-solving facilitating professional intrapreneurialship (Menzel, 2007). In a prerequisite course (Ecological Engineering 1), engineering students learnt the theoretical principles of "Eco-Logical" Engineering, including resource conservation. By cementing these fundamentals in a desktop research assignment presented here, students were empowered to think creatively and in an integrated holistic manner, while seeking practical solutions for reducing our nation's waste footprint. This paper presents a model (with detailed results) of how engineering students were guided in seeking sustainable solutions for real-world and contextual waste engineering challenges through ecological engineering research.
Ecological engineering is a discipline established in Europe and North America about 30 years ago, but with roots in ancient China (Odum & Odum, 2003). …