A coupled source-transport-storage model was developed to determine the origin and path of copper from materials/goods in use in the urban drainage area and the fate of copper in local recipient lakes The model was applied and tested using five small lakes in Stockholm, Sweden. In the case of the polluted lakes Racksta Trask, Trekanten and Langsjon, the source strengths of copper identified by the model were found to be well linked with independently observed copper contents in the lake sediments through the model. The model results also showed that traffic emissions, especially from brake linings, dominated the total load in all five cases Sequential sedimentation and burial proved to be the most important fate processes of copper in all lakes, except Racksta Trask, where outflow dominated The model indicated that the sediment copper content can be used as a tracer of the urban diffuse copper source strength, but that the response to changes in source strength is fairly slow (decades) Major uncertainties in the source model were related to management of stormwater in the urban area, the rate of wear of brake linings and weathering of copper roofs The uncertainty of the coupled model is in addition affected mainly by parameters quantifying the sedimentation and bury processes, such as particulate fraction, settling velocity of particles, and sedimentation rate As a demonstration example, we used the model to predict the response of the sediment copper level to a decrease in the copper load from the urban catchment in one of the case study lakes (C) 2010 Elsevier B.V All rights reserved

Waste electrical and electronic equipment (WEEE), well known as e-waste, is one of the fastest growing waste flows worldwide with increasing complexity in production through distribution to end of life (EoL). In this waste stream, a high number of mobile phones makes e-waste more compelling to examine the whole life of the specific product. In addition, having an interest in e-wastes for informal recycling in developing countries (DC), industrialized countries (IC) export e-wastes to developing countries. The emerging economies of reuse, refurbish and export of used mobile phones not only make the EoL complex, but also make the systems more challenging to sustainability. Since industrial ecology (IE) advocates resource efficiency with closed loop systems, we adapted a system dynamics modeling approach to investigate the dominance paths and driving forces for closing the metal flow loop through the concept of industrial symbiosis and eco-cycle modeling. This study finds higher efficiency for closing the loop in collection systems of used phones, mobile phone use time, and informal recycling in developing countries. By analyzing the dominant parameters, an eco-cycle model is proposed which could enhance a closed loop system by decreasing pressures on non-renewable resources. Improved policy supports accompanying consumer and corporate awareness with responsibility could create a circular consumption in the global mobile phone product system. 

We qualitatively analysed how and why environmental improvement actions often lead to unintended environmental consequences. Different theories are integrated to delineate the underlying system structure causing this system behavior. Causal loop diagram technique is utilized to explore and visualize: how incremental improvements in material and energy efficiency can unintendedly cause consumption to increase; how this consumption rebound effect is linked to generation of waste and pollution; and how this can give rise to social and negative externalities, economic inequalities and other broad unintended consequences in our society. Consumption and incremental innovation are found to be the highest leverage points and reinforcing factors driving unintended environmental consequences in this complex system. The paper in addition explores two potential modes of behaviour dissimilar to those of unintended environmental consequences. These emerging modes of behaviour are product-service systems and environmental policy instruments. Their combination forms a prominent transition pathway from a production-consumption-dispose economy to a so-called circular economy.