Sustainable municipal organic waste management in Shiraz, Iran

The purpose of this thesis is to identify possible treatment approaches that could be adopted and implemented in Shiraz (IRAN), for sustainable organic waste management. This work consists of five phases: evaluation of the current situation in the study area, mapping the state-of-the-knowledge in the field of organic waste treatment in Germany, assessment of the compost derived from mixed and source-separated waste streams, adapting sustainable concepts that are applicable to addressing the whole supply chain and examining the approaches to provide the ideal conditions during dry seasons

Promoting source separation of Biowaste for a Sustainable Circular Economy in the Baltic Region

BackgroundThe European Union Waste Framework Directive mandates the separate collection and sustainable utilization of biowaste at the source in member states from January 1, 2024, to achieve the EU's target of recycling 65% of municipal solid waste by 2035. However, less than 50% of municipal biowaste is being collected separately in member states. This presents significant challenges for the Baltic countries, where some need to develop new collection systems and waste treatment facilities, while others must improve their existing systems. Moreover, up to 60% of biowaste still ends up in residual waste bins, which poses a concern for the solid waste management system. Study AreaThe cities examined in this study include Bornholm, Lappeenranta, Rostock, and Gdańsk distributed across different countries. The selected cities are located within the geographical vicinity of the Baltic Sea, a brackish inland sea in Northern Europe  (Figure 1).MethodsThis study was a collaborative effort involving experts from Germany, Finland, Denmark, and Poland The methodology employed in this study involved an extensive review of scientific literature and seven discussion meetings from January to March 2023 between involved experts. The research aimed to identify the challenges, gaps, and potential measures to improve the source separation of biowaste in the Baltic region.ResultsManagement of biowaste varies significantly due to consumption patterns, economic wealth, regional policies, technical infrastructure, and public awareness. The studied areas have national-level regulations on biowaste source separation and landfill bans. Aside from Germany, other countries have recently implemented these regulations, leading to a transitional phase in biowaste management.Local authorities often struggle to adapt solutions to their specific context due to limited flexibility and resources. Sharing experiences and knowledge can mitigate repeating mistakes, foster cross-border collaboration, and enhance local authorities' capacity to improve biowaste source separation.</div

Potential of Producing Compost from Source-Separated Municipal Organic Waste (A Case Study in Shiraz, Iran)

Developing countries face serious environmental, social and economic challenges in managing different types of organic waste. Proper treatment strategies should be adopted by solid waste management systems in order to address these concerns. Among all of the treatment options for organic waste, composting is the most approved method as an effective strategy to divert solid waste from landfills. This experimental research aimed to examine the potential of producing compost from source-separated municipal organic waste in Shiraz, Iran. Market waste (fruits and vegetables) and garden waste (plant residues) were used as the raw input materials. They were subjected to the windrow pile composting method in an open site area. The process was monitored against several physical, chemical and biological parameters. In-situ measurements (temperature and moisture content) were carried out on a daily basis. Sampling and lab analyses were conducted over the period of the biological treatment. The final product was of acceptable moisture and nutrient levels, pH, Electrical Conductivity (EC), and Carbon/Nitrogen ratio. All of the analyzed compost samples had lower concentrations of heavy metals than the Iranian and German standards. Overall, the results obtained revealed that composting is a promising method for municipal organic waste treatment. The findings also imply the effectiveness of the source-separation collection method in the production of high-quality compost

Process Waters from Hydrothermal Carbonization of Waste Biomasses like Sewage Sludge: Challenges, Legal Aspects, and Opportunities in EU and Germany

Hydrothermal carbonization (HTC) has developed considerably over the last 15 years and offers a viable alternative for the utilization of municipal and industrial organic waste such as sewage sludge. However, the technology has yet to establish itself as a valorization process for waste biomasses (2024) and is not yet a recognized state of the art. Nevertheless, the HTC technology could gain greater relevance in the future, especially as an alternative valorization pathway for sewage sludge. During HTC, significant amounts of HTC process water (PW) are produced as a byproduct. The process water is inorganically and organically polluted and has to be treated, as it would be a burden on water bodies and thus on the environment if left untreated. In the EU and specifically Germany, industrial wastewater producers like HTC-plant operators are obliged to treat their industrial wastewater before discharging it into the environment. In addition to a large amount of PW and its treatment to the required limits, the organic load and possible persistent and toxic substances pose major challenges for plant operators. Many proven processes from industrial wastewater treatment were transferred for the treatment of PW. Treatment of the PW in a manner that is industrially viable, economically viable, and efficient is crucial for the effective commercialization of HTC technology. In this, the challenges and opportunities of PW composition, management, and treatment, including legal aspects, are mainly discussed. Therefore, the legal framework in the European Union and specifically for Germany will be elaborated. Furthermore, different treatment pathways are also highlighted

A review of plastic waste circular actions in seven developing countries to achieve sustainable development goals

Plastic waste circularity is a priority at a global level. Sustainable development goals (SDGs) set the ways to go, and the circular economy principles underlined the ‘green’ strategies to be employed. However, in practice, there is still much to do, especially in developing countries, where open burning and open dumping still represent the common way of plastic waste disposal. This review aims to analyse current plastic waste circular approaches in low-middle income settings. Seven countries were selected based on the economic level and data availability from the authors, and analysed to collect and critically discuss the actions implemented at a city level. Examples of waste minimization and recycling strategies, selective collection systems and public campaigns are reported from Africa, Asia and Latin America. First, a background analysis related to physical and governance aspects of municipal solid waste management systems of the chosen settings was conducted. The assessment was focused on the treatment processes or minimization actions. Then, the applicability of the projects to achieve the SDGs was commented on. The outcomes of the research underline the need to: (1) scale up small-scale and pilot projects, (2) disseminate good practices in more low- to middle-income settings, (3) create synergies among international partners for further replications in cities. Urgent solutions to plastic waste pollution are needed. The review presented practical actions to be implemented now to boost plastic waste circularity in developing cities