The development of recycling technology and process of waste electrical and electronic equipment (WEEE), also called electronic waste is becoming a growing interest in the world from the perspective of material recovery and resource conservation. In this study we examined the recycling technology levels of WEEE by both group category and recycling process using expert surveys. Based on the results of the expert surveys conducted, the level of large home appliances was found to be approximately 81.1% (± 6.2% std) when compared with that of the advanced countries, while small home appliances and IT equipment and audio/video equipment were 73.5% (± 6.2% std) and 76.2% (± 6.2% std), respectively. In case of recycling pre-treatment process (e.g., disassembly, size reduction, and separation), the technological levels was found to be approximately 82.2%, while the material recovery process followed by the pretreatment process was estimated to be approximately 68.5%. The results of reliability test for the expert survey showed that the values of coefficient of variation (CV) for the pre-treatment process and material recovery process by group category and recycling process are less than 0.5, which is a guidance limit for the coefficient. Based on the statistical tests (ANOVA and t-test), there is no significant difference of the recycling technological levels among the group category (large home appliances, small home appliances, IT equipment, and audio/video equipment. However, the statistical difference between the pre-treatment process and material recovery process within the group category existed (p-value < 0.05) using t-test. In this study, the results imply that there is still a need for developing a variety of more advanced recycling technologies of WEEE to effectively recover valuable metals and materials from it, especially in the fields of metal recovery and extraction processes.

This paper presents the actual recycling rates and recycling processes of waste plastic recycling facilities using material flow analysis. Determination of actual recycling rates through the processes of waste plastics is a very important subject not only from the point of plastic recycling efficiency energy conversion but also from the perspective of the recycling technology level. In this study, the recycling processes and recycling rates of waste plastic recycling facilities were evaluated by the MFA analysis based on 14 site visits and 25 questionnaires. The MFA methodology based on mass balance approach applied to identify the inputs and outputs of recyclable plastic materials in the recycling processes at recycling facilities. It is necessary to determine the composition and flows of the input materials to be recycled in a recycling facility. A complete understanding of the waste flows in the processes along with the site visit and data surveys for the recycling facilities was required to develop a material flow for the processes and determine the actual recycling rate. The results show that the average actual recycling rates for the recycling facilities by the site visit and the questionnaire was found to be approximately 87.5 ± 7.1% and 84.3 ± 14.5%, respectively. The recycling rates depended upon several factors including the quality of incoming waste plastics, the type and operating conditions of recycling processes, and the type of final products. According to the national statistics, the recycling rate of waste plastics was about 53.7%, while the actual recycling rate at national level was estimated to be approximately 45.1% by considering the recycling performance evaluated as well as the type of recycling process applied. The results of MFA for the recycling processes served as a tool to evaluate the performance of recycling efficiency with regard to the composition of the products during recycling. They may also support the development of the strategy of improvement of recycling processes to maximize resource recovery out of the waste plastic materials.

Quantifying greenhouse gas (GHG) emission is important for evaluating various reduction measures for greenhouse gas, which causes significant negative impacts on earth. To estimate GHG emission from waste sector over the period of between 2000 and 2009 in Daejeon Metropolitan City, the 2006 IPCC (Intergovernmental Panel on Climate Change) and Korean GHG Inventory for local government guidelines and methodologies were employed. Four different waste treatment methods (landfill, incineration, biological treatment, and Sewage wastewater treatment) were evaluated to estimate GHG emission by following the guidelines. The trends of GHG emission rate by direct emission increased between 2000 and 2009 as a result of increased incineration rate. The solid waste sector was directly responsible for 307,700 tonCO2eq/yr in 2009. Incineration contributed approximately 57% of the GHG emission, while landfill disposal was responsible for about 30% of the GHG. Approximately 464,400 tonCO2eq/yr in 2009 was emitted by indirect emission from the waste sector. Based on the results, a variety of measures are needed to reduce the GHG emission from waste sector in Daejeon Metropolitan City along with implementing effective waste source reduction and recycling policy. More specifically, this evaluation proposed that among the possible reduction options, further source separation of recyclables as well as improved diversion of recyclable materials at proposed Daejeon resource recycling complex in 2014 would have the greater benefits for reducing GHG emissions in Daejeon Metropolitan City's waste sector.