Assessment of the Fragility of the Municipal Waste Sector in Serbia Using System Dynamics Modelling

This research develops a novel methodology for municipal waste management in Serbia, based on system dynamics modelling. The methodology shows how a country and relevant institutions should address complexities in the waste management sector. Waste management is a critical issue globally, which heavily impacts the economic development of a country, including the general quality of life within a society. The designed simulation generates different scenarios of the Serbian municipal waste system for reaching the 2035 recycling rate targets. Methodologies such as the theory of constraints, fragility analysis, and systems dynamics were implemented in the model. The scenarios and fragility modelling were conducted with the system dynamics modelling methodology in the Ventity simulation environment. The designed model has elements of discrete event simulations, system dynamics, and agent-based modelling. Importantly, real-world data for the period of five years (from the year 2016 to 2020) was used in the case study. This research undoubtedly reveals that the informal sector is the key source of fragility to the dynamic system considered. During the considered period, the informal sector contributed 62.3% of all separated waste to the system. Consequently, this research concludes that for the waste sector in Serbia to reach the 2035 EU goals, the existing practice in waste management has to be changed significantly and will benefit from the modelling approach used here. The whole system is highly dependent on the informal sector, which, in its current form, is volatile, unregulated, and fragile to aggressive regulative policies.

Greenhouse Gas Emissions Analysis Working toward Zero-Waste and Its Indication to Low Carbon City Development

Low carbon city development and greenhouse gas (GHG) emission mitigation in urban communities are urgent. There is great potential to improve the GHG inventory at the community level. Meanwhile, building zero-waste cities and improving waste treatment efficiency have been significant environmental issues due to the rapid increase of waste generation. This research aims to develop a community-scale GHG emission inventory of the waste sector and improve its accuracy and consistency through applying the bottom-up approach. This study covers both direct and indirect emissions categories of the waste sector with the goal of building a zero-waste community. Honjo Waseda community, located in Japan, was used as a case study community. Energy consumption waste treatment sectors were evaluated and calculated through first-hand field data. GHG emission estimation of the waste sector included waste incineration, residential wastewater, and waste transport. The highest emissions originated from Beisiagate supermarket due to the large waste amount produced, and the CO2-biomass carbon emissions reached approximately 50% of the total emissions. Furthermore, a quantitative analysis of the implementation of new technologies was also conducted. This study created proposals for GHG emission reduction toward a zero-waste community through the comparison of three cases. Case 1 was business as usual; Case 2 proposed a combination of incineration bio-gasification (MBT); Case 3 introduced a combination of solid recovered fuel (SRF) and a bio-gasification system. SRF contributed the most to emission reduction, and Case 3 exhibited the highest energy recovery. Furthermore, comparing the GHG emissions produced by the use of SRF for power generation and heat supply revealed that using SRF as a heat supply reduced more GHG emissions than using SRF for power generation.

Quantifying economic activity in the informal recycling sector in South Africa

Informal waste reclaimers are a key part of South Africa’s recycling economy, being responsible for around 51% of all paper and packaging waste collected in South Africa in 2017. Active in the waste and recycling landscape for more than three decades, their activity predates the earliest voluntary paper and packaging Extended Producer Responsibility schemes. However, these voluntary schemes have been instrumental in scaling South Africa’s recycling economy. Investment by brand owners, retailers, converters and recyclers has helped develop local end-use markets, creating a demand for paper and packaging recyclables and a resultant increase in their collection. An analysis of tonnage and price data shows that the mean estimate of money paid by the private sector to the informal waste sector through the purchase of recyclables at intermediaries such as buy-back centres, was ZAR625 million in 2012, increasing to ZAR872 million in 2017. This private sector ‘investment’ in the local recycling economy has led to direct and indirect job creation and improved livelihoods, particularly for a large, well-established and effective informal waste sector, and has indirectly funded municipal waste diversion strategies, saving municipalities in both the collection and disposal of waste.

The Cost of Reducing Municipal Unsorted Solid Waste: Evidence from Municipalities in Chile

The management of municipal solid waste sector is crucial for a sustainable circular economy. Waste utilities are expected to provide high quality solid waste services at an affordable price. The efficient management of solid waste requires its assessment from an economic and environmental perspective, i.e., eco-efficiency assessment. Although the reduction of unsorted waste incurs an economic cost, its positive externalities are huge for the well-being of society, the environment, and people. Our study quantifies the marginal cost of reducing any unsorted waste using stochastic frontier analysis techniques which allow us to estimate the eco-efficiency of the waste sector. Our empirical approach focuses on the municipal solid waste collection and recycling services provided by several waste utilities in Chile. The results indicate that substantial eco-inefficiency in the sector exists, since the average eco-efficiency score is roughly 0.5 which means that the municipalities could approximately halve their operational costs and unsorted waste to produce the same level of output. The average marginal cost of reducing unsorted waste is 32.28 Chilean pesos per ton, although notable differences are revealed among the waste utilities evaluated. The results provided by this study are of great interest to stakeholders to promote sustainable management solutions and resource efficient solid waste services.