Analysis And Optimization Of Environmental Performance Of Waste Mobile Phone Recycling System

E-waste(also known as waste electrical and electronic equipment,WEEE)has become one of the fastest growing solid wastes withthe growing market demandand the rapid upgrading of electronic products.As a typical representative of new electronic waste,waste mobile phones are expected to reach 937 million units by 2025.Waste mobile phones are rich in a variety of recycled materials.Adopting appropriate technology can realize efficient recycling of resources,but the environmental impact generated in this process cannot be ignored.At present,China’s waste mobile phone recycling industry is still in a transition stage where both formal and informal sectors coexist.According to the recycling activities of waste mobile phones and the recycling system formed,this paper established applicable environmental performance indicators and method,which are helpful to identify their material metabolism characteristics and environmental benefit level,and then seek improvement opportunities and provide support for promoting the sustainable management of e-waste.Overall,this paper has carried out the following researches:(1)The status of domestic and foreign research in this field and the current status of China’s waste mobile phone recycling industry were analyzed.At present,existing researches mainly focus on the amount of waste mobile phone,recycling mode,the environmental impact of collection and the recycling potential.In China,waste mobile phone collection is still dominated by traditional channels,and Internet collection is on the rise;Most of the discarded mobile phones collected by vendors and stations were transported to Henan,Anhui,and the southeast coast for disassembly;The waste mobile phones from the free collection of manufacturers,sellers and Internet collection are mostly disassembled by formal enterprises;Formal enterprises have deployed large-scale dismantling of waste mobile phones under the background of the new national policy.(2)This paper summarized the concepts and methods of environmental performance.We established the environmental performance evaluation indicators for the e-waste recycling system from the aspects of material metabolism efficiency and eco-environmental benefit based on material flow analysis and life cycle assessment methods,including seven indicators:component reuse rate,recycled material output rate,material metabolism value productivity,human health improvement,ecosystem quality improvement,GHG emission reduction and energy saving.Take the corresponding indicator values under the idealized scenario of the e-waste recycling system as the benchmark to standardize each indicator.(3)Based on the survey data of the waste mobile phone dismantling enterprises and the laboratory disassembly experiments,the material flow analysis method was used to establish the material metabolism model of China’s waste mobile phone recycling system.It was found that 632.30 kg of recycled materials,56.93 kg of reusable PCB components,38.19 kg of reusable LCD screen could be obtained respectively by disassembling 1000 kg of waste mobile phones.And the total resource value was 31,930 yuan,including 27,618 yuan for recycled materials and 4,312 yuan for reused components.Analysis of the contribution of resource value showed that metal cobalt contributes the highest,reaching 33%;copper and gold are the second,accounting for 18% and 16%,respectively.(4)The life cycle impact assessment method IMPACT 2002+ was used to evaluate the eco-environmental benefits of the current recycling system of waste mobile phones.The results showed that the evaluation results of the four damage categories were human health-9.88,ecosystem quality-9.46,climate change-6.53 and resource-5.78.The main influencing factor of human health was the trucking process;The main factors affecting the ecosystem quality are aquatic ecotoxicity and terrestrial ecotoxicity,and the emissions generated during the materials recycling are the main contribution;The main factor affecting climate change is the emission of GHG.The power consumption during the collection process is the largest source of environmental burden contribution;The influencing factors of resource are the non-renewable energy and mineral extraction.Component reuse and material recycling can effectively reduce the consumption of resources and energy,and the contribution of environmental benefits of the two is 99.66% and 2.73%,respectively.(5)Based on the analysis results of material metabolism efficiency and eco-environmental benefits,the standardized values of the environmental performance evaluation indicators of the current Chinese mobile phone recycling system are calculated:component reuse rate 0.809,recycled material output rate 0.871,material metabolism value productivity 0.966,human health improvement 0.478,ecosystem quality improvement 0.820,GHG emission reduction 0.784 and energy saving 0.793.Overall,the material metabolic efficiency indicator shows a good level of performance,and there is still possibility for further optimization in terms of the eco-environmental benefit indicators.Optimization scenarios were proposed from the four aspects of collection,transportation,component reuse and material recycling based on the results of environmental performance assessment,and quantitative analysis of environmental performance was carried out respectively.The results show that the producer-led collection scenario has slightly improved in various environmental performance indicators.The reduction of transport distance under the mature industrial chain scenario only optimizes the human health indicator.Both the encouragement of components reuse scenario and the advanced recycling technology scenario can significantly improve the environmental performance.Further,the former shows its effect mainly in the eco-environmental efficiency indicators,while the latter is more balanced.Overall,this paper based on the life cycle method and tool,proposed a set of evaluation indicator systems suitable for the environmental performance evaluation of e-waste recycling system.Analyzed the environmental performance level of China’s waste mobile phone recycling system and proposed specific environmental performance optimization schemes through the analysis of the evaluation results.This research provided a support for the recycling industry of waste mobile phones in China and have a certain scientific value and practical significance for promoting the sustainable management of waste mobile phones.