The assessment of waste management systems for electrical and electronic equipment (WEEE) from developed economies (Germany, Sweden and Italy) and developing countries (Romania and Bulgaria), is discussed covering the period 2007–2014. The WEEE management systems profiles are depicted by indicators correlated to WEEE life cycle stages: collection, transportation and treatment. The sustainabil ity of national WEEE management systems in terms of greenhouse gas emissions is presented, together with the greenhouse gas efficiency indicator that underlines the efficiency of WEEE treatment options. In the countries comparisons, the key elements are: robust versus fragile economies, the overall waste man agement performance and the existence/development of suitable management practices on WEEE. Over the life cycle perspective, developed economies (Germany, Sweden and Italy) manage one order of magnitude higher quantities of WEEE compared to developing countries (Romania and Bulgaria). Although prevention and reduction measures are encouraged, all WEEE quantities were larger in 2013, than in 2007. In 2007–2014, developed economies exceed the annual European collection target of 4 kg WEEE/capita, while collection is still difficult in developing countries. If collection rates are estimated in relationship with products placed on market, than similar values are registered in Sweden and Bulgaria, followed by Germany and Italy and lastly Romania. WEEE transportation shows different pat terns among countries, with Italy as the greatest exporter (in 2014), while Sweden treats the WEEE nationally. WEEE reuse is a common practice in Germany, Sweden (from 2009) and Bulgaria (from 2011). By 2014, recycling was the most preferred WEEE treatment option, with the same kind of rates performance, over 80%, irrespective of the country, with efforts in each of the countries in developing spe cial collection points, recycling facilities and support instruments. The national total and the recycling carbon footprints of WEEE are lower in 2013 than in 2007 for each country, the order in reducing the environmental impacts being: Germany, Italy, Sweden, Bulgaria and Romania. The negative values indi cate savings in greenhouse gas emissions. In 2013, the GHG efficiency shows no differences of the WEEE management in the developed and developing countries.
Keywords: WEEE ، Waste management profile ، Sustainability ، Carbon footprint ، EU

This paper presents two models (classical and VMI-CS coordination) for a two-level closed-loop supply chain with a manufacturer and a retailer with a facility to remanufacture used items. The paper considers three critical environmental issues, which are the energy used in production (manufacturing and re manufacturing) processes, GHG emissions from production and transportation activities (subject to a penalty tax), and the number of times to remanufacture (recover) a used item. Numerical results show that the traditional optimization approach, which minimises the sum of inventory related costs, sug gested less remanufacturing, fewer recovery times and more GHG emissions and energy usage; a result of operating at high production rates. The VMI-CS model was shown to be more economical than the classical model for a wide range of manufacturing rates, but not necessarily a more environmentally responsible choice. An extensive numerical analysis was conducted to enrich the discussion and to draw some managerial insights on how to make environmentally conscious decisions.
Keywords: Closed-loop supply chains | Green supply chains | Greenhouse gas emissions | Carbon emissions | Remanufacturing | Energy

In response to global warming, it is urgent to control and reduce greenhouse gas (GHG) emissions, especially from the supply chain perspective. The most often discussed topic in this domain indicates that emission trading scheme (ETS) could be employed as one of policy instruments for supply chain emis sions management. Via mathematical models, scholars have shown that the employment of emission trading is affecting supply chain performances (both environmental and economic) in different levels. However, previous literature focus on the cost-effectiveness analysis only from the mathematical aspect. To provide policy-makers and companies with the theoretical bases on this hot topic, it is significant to discuss how ETS, one of market-based instruments, could be imposed in the context of supply chain from the mechanical point of view. By incorporating ideas from relevant literature, this paper generates two concepts/modes in imposing ETS on supply chain: jointly imposed supply chain emission trading (e.g., jointly imposed SC-ETS) and separately imposed supply chain emission trading (e.g., separately imposed SC-ETS). It illustrates the working principles of both concepts/modes and conducts a sandbox example to analyze the cost-effectiveness of them. Furthermore, this paper discusses the challenges and opportu nities of implementing two modes from practical aspects. Results of quantitative analysis and discussion show that for the sake of both policy-makers and supply chain companies, the separately imposed SC ETS allowing selling permits would be so far the better mode to manage supply chain GHG emissions compared to the jointly imposed SC-ETS.
Keywords:Emission trading scheme|Supply chain greenhouse gas emissions|Supply chain emission trading

This study develops a multi-level programming model from a life cycle perspective for performing shale gas supply chain system. A set of leader-follower-interactive objectives with emphases of environmental, economic and energy concerns are incorporated into the synergistic optimization process, named MGU MEM-MWL model. The upper-level model quantitatively investigates the life-cycle greenhouse gas (GHG) emissions as controlled by the environmental sector. The middle-level one focuses exclusively on system benefits as determined by the energy sector. The lower-level one aims to recycle water to min imize the life-cycle water supply as required by the enterprises. The capabilities and effectiveness of the developed model are illustrated through real-world case studies of the Barnett, Marcellus, Fayetteville, and Haynesville Shales in the US. An improved multi-level interactive solution algorithm based on satis factory degree is then presented to improve computational efficiency. Results indicate that: (a) the end use phase (i.e., gas utilization for electricity generation) would not only dominate the life-cycle GHG emissions, but also account for 76.1% of the life-cycle system profits; (b) operations associated with well hydraulic fracturing would be the largest contributor to the life-cycle freshwater consumption when gas use is not considered, and a majority of freshwater withdrawal would be supplied by surface water; (c) nearly 95% of flowback water would be recycled for hydraulic fracturing activities and only about 5% of flowback water would be treated via CWT facilities in the Marcellus, while most of the wastewater gen erated from the drilling, fracturing and production operations would be treated via underground injec tion control wells in the other shale plays. Moreover, the performance of the MGU-MEM-MWL model is enhanced by comparing with the three bi-level programs and the multi-objective approach. Results demonstrate that the MGU-MEM-MWL decisions would provide much comprehensive and systematic policies when considering the hierarchical structure within the shale-gas system.
Keywords: Multi-level programming | Life cycle | Shale gas | Greenhouse gas | Energy | Water supply