Analysis of cost–benefit in life-cycle of plastic solid waste: combining waste flow analysis and life cycle cost as a decision support tool to the selection of optimum scenario

Millions of tons of plastic are consumed annually in the world due to its significant characteristics such as durability, flexibility, and low weight. High consumption has made plastic one of the most important municipal solid waste compounds, the quantity of which has increased in recent decades. Plastic solid wastes are known as a threat to the environment, and its efficient management in various aspects such as cost–benefit requires decision-making tools. This study was assessing the cost–benefit of plastic solid waste management by development of an economic model, and definition of different scenarios to change plastic solid waste management status. The results showed that 8971 tons of plastic solid waste were generated annually in the studied city. The plastic solid wastes were finally transferred to either recycling or landfilling site through 5 identified routes. 83 percent of the total recycled plastic solid waste was due to post-separation routes, and only 7.7 percent of the total plastic solid waste was recycled from the source separation route. The economic comparison of scenarios showed that with the aggregation of post-separation routes, the net revenue of plastic solid waste management increases by 334,000 euro per year while increasing the public participation and the ratio of source separation route raises net revenue by 875,000 euro per year, which was the best economic condition among the scenarios. Using life cycle cost method and it’s respected developed economic model truly satisfied the conditions of both, the current plastic solid waste management and the alternative scenarios, and hence can be adopted as a tool for decision-making.

     

A subsystem input–output decomposition analysis of CO<Subscript>2</Subscript> emissions in the service sectors: a case study of Beijing,China

The carbon emissions in service sectors have attracted increasing attention around the world. However, few studies have examined the driving forces for CO₂ emissions from service sectors in developing countries. With the process of accelerating industrialization, China’s service sectors are facing growing pressure to pursue energy savings and emission reductions, especially in several developed regions. In this paper, in order to better understand how CO₂ emissions in Beijing’s service sectors have evolved, we utilized a subsystem input–output decomposition analysis to study the pattern and driving factors of consumption-based emissions in Beijing’s service sectors. The results showed that the transportation sector and the Scientific Studies Technical Services sector caused the most CO₂ emissions in Beijing’s service sectors. The emission intensity effect potentially reduced CO₂ emissions by 10,833 Mt, primarily due to the decreased energy intensity of non-service sectors. Effects of demand and technology were mainly responsible for the increased CO₂ emissions in Beijing’s service sectors. Such influence was mainly related to the external component of service sectors, indicating a strong pull effect exerted by service sectors on non-service sectors. Thus, decarbonizing the supply chain of service sectors and improving the energy intensity are necessary to alleviate CO₂ emissions in Beijing.