Environmental Engineering Reference
In-Depth Information
presents various scenarios for its future demand and supply. New sources of phos-
phorus may well be required, including from existing waste sources such as steel-
making slag.
In Chap. 10, the challenge of finding constructive uses for many waste materials
is illustrated when Professor Takahashi looks at a new approach to finding pro-
ductive uses for sludge from the construction and sewage treatment industries. A
method has been developed to produce a fibre-cement stabilized spoil to allow such
materials to be recycled and used either in agriculture soils or landfills. Processing
methods and experimental results from using the resulting sludge are presented in
this chapter.
In Chap. 11, the focus shifts to another important area in recycling -waste plas-
tics, where Professor Yoshioka considers the challenge of obtaining high-value
products through recycling the many different varieties of plastics in the waste
stream. PET can be recycled as raw material for reprocessing PET, but other types
of plastics pose major challenges and are often recycled for only low value uses
such as a source of heat. This chapter looks at current approaches to recycling plas-
tics and how it may be possible to convert them into higher-value raw materials.
The theme of efficient use of resources is developed further in Chap. 12 by Pro-
fessor Kasai who looks at resource and environmental issues raised by the extrac-
tion and refining of iron. Recent resource and environmental trends in the steel
industry are reviewed from the perspective of the mineral sources available, future
population and economic trends, and the potential for meeting demands for steel in
an environmentally-friendly way. Approaches such as using waste plastics as a raw
material instead of coke to improve energy efficiency in steelworks are described,
and a vision of sustainable iron and steel making developed.
The broader issue of resources and recycling of base metals is addressed by Pro-
fessor Nakamura in Chap. 13. Mining of these metals (iron, copper, zinc etc.) causes
major environmental damage through open mining techniques, and thus improv-
ing recycling rates has major environmental benefits as well as potential economic
ones. This chapter looks at recycling technology for these metals and ways in which
they can be recycled from sources such as shredder dusts and fly ash. Recovery of
metal resources from waste electric and electronic equipment is also considered and
a potential systems approach developed to the recycling of Japan's valuable metals.
Associate Professor Managi in Chap. 14 raises a number of questions designed
to encourage students to apply system-wide and lateral thinking. This is already
one of the objectives in the ELTP, but is also expected to gain importance as the
new approach to international global environmental change under the Future Earth
international research initiative gains momentum. Future Earth is explained in this
chapter and how it will require researchers to improve communications with society,
requiring researchers to hone their communication skills and ability to envisage the
interests and viewpoints of different stakeholders. Using the experiences following
the 2011 Great Eastern Japan Earthquake and Tsunami, a number of issues and ques-
tions are raised to stimulate students' thinking, analytical and communication skills.
In the final chapter, the editors offer a synthesis of the range of issues covered in
this topic and consider how our environmental leader students may have benefitted
