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.

Pyrolysis-Based Municipal Solid Waste Management in Poland—SWOT Analysis

Poland’s management of municipal waste, which amounts to over 13 million tons/year, is not efficient—about 60% of the waste is subjected to recovery processes, about 20% of all municipal waste is converted into energy, and almost 40% is landfilled. The authors of this article recognize the potential of pyrolysis as a method of the thermal processing of waste allowing the potential of the energy contained in the waste to be utilized. Pyrolysis is an economically attractive alternative to incineration, with a significantly lower environmental impact, allowing efficient waste management and the use of pyrolysis by-products in the energy sector (pyrolysis gas), or in the building materials sector (biochar). Despite so many advantages, this method is not employed in Poland. The aim of the paper is to indicate a recommended strategy for the application of pyrolysis in Poland as a method of the thermal processing of municipal solid waste. SWOT (strengths, weaknesses, opportunities, threats) analysis was used as a research method. In the first step, on the basis of the literature review, the factors which may affect the use of pyrolysis in Poland were identified. In the second step, five experts evaluated the weights of those factors and the interactions between them. The products of the weights and interactions allowed, in accordance with SWOT analysis methodology, the most desirable strategy of pyrolysis application in Poland to be determined, which turned out to be an aggressive one. This means that pyrolysis as a thermal waste processing method should be implemented on a large scale in Poland to improve the indicators of municipal waste management.

Pengaruh Pupuk Sampah Kota dan dan Pupuk Kandang Sapi terhadapTinggi Tanaman, Panjang Daun, dan Berat Panen Tanaman Pakcoy (Brasica rapa ) pada Andisol di Kabupaten Indramayu

The objective of this research was to find out the effect of municipal solid waste compost and cow manure on plant height, leaf length, and harvest weight of pakcoy (Brasica rapa) in Andisols in Indramayu Regency. This study used a randomized block design factorial with two factors. The first factor is municipal waste compost and the second factor is cow manure. Each of them consisted of 4 levels : 0%, 3.0%, 6.0%, and 9.0% with two replication. The results showed that there was an interaction between municipal solid waste compost and cow manure on the plant heights of pakcoy 14, 21, and 28 HST, but there was no interaction at 7 HST. The statistical results show that the combination of municipal solid waste compost with cow manure has an effect on the height of pakcoy 14, 21, and 28 HST, but the height of pakcoy 7 HST is influenced by the independent influence of cow manure. There was an interaction between municipal solid waste compost and cow manure on the leaf length of pakcoy 7, 14, 21, and 28 HST, and there was an interaction between municipal waste compost and cow manure on the harvest weight of pakcoy. The application of organic matter, both municipal solid waste compost and cow manure to the soil can increase plant height, leaf length, and harvest weight of pakcoy.