Sustainability science and engineering: the emergence of a new metadiscipline

A case is made for growth of a new metadiscipline of sustainability science and engineering. This new field integrates industrial, social, and environmental processes in a global context. The skills required for this higher level discipline represent a metadisciplinary endeavor, combining information and insights across multiple disciplines and perspectives with the common goal of achieving a desired balance among economic, environmental, and societal objectives. Skills and capabilities that are required to support the new metadiscipline are summarized. Examples of integrative projects are discussed in the areas of sustainability metrics and integration of industrial, societal, and environmental impacts. It is clear that a focus on green engineering that employs pollution prevention and industrial ecology alone are not sufficient to achieve sustainability, because even systems with efficient material and energy use can overwhelm the carrying capacity of a region or lead to other socially unacceptable outcomes. To meet the educational and human resource needs required for this new discipline, the technological and environmental awareness of society must be elevated and a sufficient and diverse pool of human talent must be attracted to this discipline.     

Enantioselective biotransformation of chiral PCBs in whole poplar plants

Chiral PCBs have been used as molecular probes of biological metabolic processes due to their special physical, chemical, and biological properties. Many animal studies showed the enantioselective biotransformation of chiral PCBs, but it is unclear whether plants can enantioselectively biotransform chiral PCBs. In order to explore the enantioselectivity of chiral PCBs in whole plants, poplars (Populus deltoides × nigra, DN34), a model plant with complete genomic sequence, were hydroponically exposed to 2,2',3,5',6-pentachlorobiphenyl (PCB95) and 2,2',3,3',6,6'-hexachlorobiphenyl (PCB136) for 20 days. PCB95 and PCB136 were shown to be absorbed, taken-up and translocated in whole poplars, and they were detected in various tissues of whole poplars. However, the enantioselectivity of poplar for PCB95 and PCB136 proved to be quite different. The first eluting enantiomer of PCB95 was enantioselectively removed in whole poplar, especially in the middle and bottom xylem. It was likely enantioselectively metabolized inside poplar tissues, in contrast to racemic mixtures of PCB95 remaining in hydroponic solutions in contact with plant roots of whole and dead poplars. Unlike PCB95, PCB136 remained nearly racemic in most parts of whole poplars after 20 days exposure. These results suggest that PCB136 is more difficult to be enantioslectively biotransformed than PCB95 in whole poplars. This is the first evidence of enantioselectivity of chiral PCBs in whole plants, and suggests that poplars can enantioselectively biotransform at least one chiral PCB.     

Phytoremediation of MTBE from a groundwater plume

The feasibility of phytoremediation to both remediate and hydraulically contain a methyl tert-butyl ether (MTBE)-contaminated groundwater plume was investigated in a three-phase study that included the following elements: (i) a laboratory bioreactor study that examined the fate and transport of 14C-radiolabeled MTBE in hybrid poplar trees, (ii) a novel approach for a mathematical modeling study that investigated the influence of deep-rooted trees on unsaturated and saturated groundwater flow, and (iii) a field study at a Houston site with MTBE-contaminated groundwater where hybrid poplar trees were planted. In the laboratory study, the predominant fate pathway was uptake and evapotranspiration of [14C]-MTBE from leaves and stems of poplar cuttings rooted in hydroponic solution. The modeling study demonstrates that phytohydraulic containment of MTBE in groundwater by deep-rooted trees can be achieved. The field study demonstrated significant groundwater uptake of groundwater by deep-rooted trees via direct measurement in the first three seasons. The use of vegetation may provide a cost-effective in-situ alternative for containment and remediation of MTBE-contaminated groundwater plumes.     

Peer reviewed: East central europe: an environment in transition

Major changes in the governments and economies of this highly polluted region are improving air and water quality.     

Peer reviewed: what course for carbon trading?

Although still without a legislative mandate, a marketplace for carbon trading is beginning to develop.