Mixed Municipal Solid Waste Research Articles

Insight into high-temperature fast pyrolysis characterization, product distribution and interaction effect of municipal solid waste and its components under steam-containing hydrogen-rich syngas atmosphere

This research delves into the field of fast hydropyrolysis of mixed municipal solid waste (MSW), with the goal of understanding product distribution and interactions in a hydrogen-rich condition. Through experimental investigations on MSW and its components, this study thoroughly examines the impact of pyrolysis temperature and gasification atmosphere (30 % H2+30 % CO+20 % CO2+20 % H2O) on the yields and distribution of the three-phase products. As the temperature increases, the gas yield gradually increases, while the yields of tar and char gradually decrease. The introduction of a hydrogen source increases the methane content in the combustible gas, which generally reaches its maximum at 850 °C, and promotes aromatic formation in tar, making aromatics the main component of pyrolysis oil. Notably, aromatics have the highest-octane number in gasoline. This study highlights gasification as a promising technology for converting organic waste into valuable fuel, advancing waste management and energy recovery.

Unveiling the abundance and potential impacts of microplastic contamination in commercial organic fertilizers/compost produced from different solid waste.

This study comprehensively investigated the abundance, morphologies, and polymer types of plastics, larger (1-5mm) and smaller (< 1mm) microplastics (MPs), in organic fertilizers using spectroscopic and microscopic methods. MPs abundance varied depending on the type of waste employed. MPs were detected in 80% of the investigated compost samples, while macro/meso plastics were found in only four samples. Compost from mixed municipal solid waste exhibited the highest MPs contamination (23100 ± 3615 items/kg dry weight), whereas compost produced from canteen waste had the lowest contamination (100 ± 65 items/kg dry weight). Smaller MPs were dominant in all samples. The estimated loads of MPs introduced into agricultural soil exceeded the previous studies. Common morphologies observed were sheet, film, fragment, and fiber, while dominant polymer types were polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), and polystyrene (PS). Heavy metals, including Cr, Cu, Ni, and Pb, were identified in association with MPs. Results indicate that the utilization of appropriate waste for composting and upgrading fertilizer regulations is crucial to protect the environment and human health from smaller MPs.

Forecasting the waste production hierarchical time series with correlation structure

AbstractContinuous increase in society’s prosperity causes overwhelming growth of the produced municipal solid waste. Circular economy initiatives help to solve this problem by creating closed production cycles, where the produced waste is recycled, or its energy is recovered. An embedment of such principles requires implementation of new waste management strategies. However, these novel strategies must be based on the accurate forecasts of future waste flows. Municipal solid waste production data demonstrate behavior of hierarchical time series. Among all possible approaches to hierarchical times series forecasting, this article is focused on the reconciliation of the base waste generation forecasts. The novel method, that is based on the game-theoretically optimal reconciliation of hierarchical time series, is presented. The modified approach enables to incorporate interdependencies between time series using correlation matrix and to obtain the forecasts corresponding to the unique solution of the optimization problem. The potential of the proposed abstract approach is demonstrated on the waste production data of paper, plastics (both primarily sorted by households), and mixed municipal solid waste from the Czech Republic.

Characterization, recyclability, and significance of plastic packaging in mixed municipal solid waste for achieving recycling targets in a Swedish city

About 60% of plastic packaging in Sweden ends up in mixed municipal solid waste (MSW), which is incinerated with energy recovery. This status quo presents a missed opportunity to meet ambitious recycling targets. This study aims to provide a detailed characterization of plastic packaging in mixed MSW to assess its potential for recycling and its significance in improving the overall recycling rate. A case study involving a Swedish city was conducted wherein a sample of 5500 kg of mixed MSW from 920 households was characterized. From the 31% recycling rate, improvement of up to 59% can be achieved by diverting this misplaced plastic packaging into the existing recycling system. An additional 9% increase remains challenging to achieve due to the occurrence of non-recyclable attributes like black and multilayer packaging. The highlighted key enabler is the combination of correct household waste separation behavior and the establishment of mechanical sorting facilities to recover plastic waste from mixed MSW. These recycling potentials and associated challenges are discussed in the context of Sweden's ongoing efforts across the plastic packaging value chain. Furthermore, the importance of extended waste characterization is emphasized as a tool for identifying recycling potentials and monitoring the effectiveness of measures in enhancing circularity and resource-efficiency.

Recovery of plastic packaging from mixed municipal solid waste. A case study from Austria

Austria must recycle more packaging materials. Especially for plastic packaging waste, significant increases are necessary to reach the EU recycling targets for 2025 and 2030. In addition to improving separate collection and introducing a deposit system for specific fractions, the share of plastic packaging in mixed municipal solid waste (MSW) could be utilized.In Austria, about 1.8milliontonnes of mixed MSW are generated. This includes about 110,000 t/a of plastic packaging waste. Most of the mixed MSW (94 %) is sent directly or via residues from pre-treatment, such as mechanical–biological treatment or waste sorting, to waste incineration. While materials such as glass and metals can also be recovered from the bottom ash, combustible materials such as plastics must be recovered before incineration.This work aims to evaluate the recovery potential of plastic packaging waste in mixed MSW with automated waste sorting. For this purpose, two of the largest Austrian waste sorting plants, with a total annual throughput of about 280,000 t/a, were investigated. The investigation included regular sampling of selected output streams and sorting analysis.The results show that the theoretical recovery potential of plastic packaging from these two plants is 6,500 t/a on average. An extrapolation to Austria results in a potential of about 83,000 t/a. If losses due to further treatment, such as sorting and recycling, are considered, about 30,000 t/a of recyclate could be returned to plastic production. This would correspond to an increase in plastic packaging recycling rate from 25 % to 35 %.

A method for determining the recycling value of unprocessed municipal solid waste in one cubic meter waste composition analysis technique

The transition from conventional landfill-centric waste management to resource-centric methodologies necessitates an enhanced comprehension of municipal solid waste (MSW) composition and its inherent value. Existing methodologies documented in the literature exhibit a lack of standardization, impending the formulation of a systematic engineering approach for MSW characterization and valuation. This study introduces a methodology specifically tailored to discern the composition of waste origination from urban households and evaluate its recyclability within the confines of a circular economy framework, Employing a volume-based measurement approach, aims to estimate the recycling value of waste materials. The study's outcomes contribute significantly to quantifying the potential recycling value that accrues to society. Furthermore, the validation of the proposed protocol elucidates the dynamic nature of recyclable value as it traverses the intricate pathways of the waste supply chain. This insight facilitates the formulation of commercial models grounded in circular economy principles for the effective management of household solid waste. Empirical findings reveal that the total recycling value fluctuates within the range of USD 3.39 and USD 5.76 per cubic meter of waste volume, contingent upon the specific waste composition at the experiment site. Additionally, the proposed methodology uncovers the nuanced variability in MSW composition and recycling value across diverse household collection patterns, identifying mixed plastic, paper, cardboard, mixed MSW, and clothing as primary constituents. The application of this methodology extends beyond mere quantification, providing a foundational framework for simulating the latent recycling value embedded within MSW samples. This, in turn, offers invaluable support to strategy developers, policymakers, and entrepreneurial ventures engaged in the sustainable management of household solid waste. In essence, this study establishes the groundwork for a comprehensive understanding of MSW composition and its recyclability, facilitating informed decision-making in the pursuit of a circular economy.•Novel methodology based on one cubic meter (1m3) composition analysis of Municipal Solid Waste (MSW).•A new method to evaluate the recycling value of Municipal Solid Waste.•A basis for business model development for the waste-to-resource conversion model.

Composition of public waste - a case study from Austria

Waste from public places like parks, pedestrian zones or sidewalks is a visible yet unexploited waste stream. Publications and information on the amounts and makeup of this waste flow are very scarce. To evaluate the resource potential and enable waste management planning, this study aims to assess the quality and quantity of public waste in a detailed waste characterisation campaign. For the first time, an analysis at this level of detail was conducted in a medium-sized town (25,000 inhabitants) in Austria. The sampling campaign included the whole town area. In total, almost 1000 kg of waste was sorted in up to 88 different fractions, which allows the detailed composition of, for example, packaging waste and single-use plastics to be delineated. We found that the amount of waste collected in public street bins is approximately 2.6 % of the total mixed municipal solid waste, resulting in 4.1 kg of public waste per inhabitant annually. The vast majority of this waste is currently collected as mixed waste. The results indicate a high share (52 %) of recyclable materials (glass, metal, paper and lightweight packaging) in mixed public waste, most of which is packaging (44 % of total waste). Other large shares include dog feces (18 % of total waste) and biogenic waste (17 % of total waste). The results lay the foundation for further investigations into, for example, exploiting recycling potential or evaluating possible improvements in separate waste collection in public spaces. Further, the collected data serve as an essential knowledge basis for policymakers and local authorities.

A 35-year monitoring of an Italian landfill: Effect of recirculation of reverse osmosis concentrate on leachate characteristics

“Fossetto” landfill (Monsummano Terme - Tuscany, Italy) started operation in 1988 as a controlled landfill accepting mixed municipal solid waste collected without any attempt of recycling. Then, progressively, following the evolution of the state-of-the-art, it adopted biogas extraction and valorisation systems and mechanical-biological treatment for incoming waste (both since 2003). Finally, since 2006, in the plant is performed on-site reverse osmosis leachate treatment with the concentrated leachate being recirculated back into the landfill body. Recently a new landfill cell, separate from the others, was put in operation adding a capacity of 200,000 m3 to the already available 1,095,000 m3. This plant can provide long term leachate composition data to study the evolution and impact of changing landfill technology and waste composition on various parameters. The rise in leachate production (+84 % in 2018–2022 respect to the period before recirculation) cannot be totally attributable to recirculation but could be also linked to the increase in the amount of landfilled waste. The concentration of certain parameters (NH4+, Cl− and to a less extent of COD) increased (+60 %, +58 %, +17 % respectively in the last five years with respect to the period before recirculation); however, this increase did not influence the performance of the treatment plant. Nevertheless, the overall leachate management would benefit from an optimized reinjection system.

The Treatment of Municipal Solid Waste in Cambodia, Thailand and Vietnam: An Environmental and Technological Analysis of Current and Future Scenarios

The population growth of South-Asian countries is contributing significantly to the escalating volume of municipal solid waste (MSW). Presently, waste management in this region predominantly relies on landfilling, necessitating a shift towards a more sustainable paradigm. To address this imperative, this study explores the feasibility of extending the European-based waste management system for treating MSW in Cambodia, Thailand, and Vietnam. Assuming as current scenario the direct disposal in landfill, the environmental and technical performances of five other proposed scenarios based on the following technologies were assessed: mechanical–biological treatment; incineration; their combination; mechanical recycling; composting and anaerobic digestion. As expected, all alternative technologies showed potential for improving the current scenario. However, from an environmental point of view, incineration of mixed MSW emerged as the sole option that yielded a discernible environmental benefit for all the countries involved in the study (achieving a carbon footprint of about −0.111 t-CO2-Eq./FU). Recycling-based scenarios achieved higher benefits for Thailand and Vietnam (−0.145 and −0.186 t-CO2-Eq./FU, respectively), but not Cambodia (0.072 t-CO2-Eq./FU) due to the lack of valuable materials to recycle. Technical findings showed how separate collection remains the system generating the least amount of waste for disposal (about 0.185 t), having a synergic effect on the combined approach of mechanical–biological treatment and incineration, which boasts the highest specific energy yield (about 0.339 and 1.183 kW/t, for electric and thermal energy, respectively). These results underscore the imperative to extend the analysis to the economic domain, combining diverse criteria to identify the most sustainable solution.

Annual fluctuation of gas concentration within the landfill surface layer in a tropical climate: A case study of a municipal wasteyard

AbstractThis study looks at the annual variations in landfill gas concentrations within the surface layer of the dump as well as the effect of climatic factors on these variations under the tropical climate. The experiment was carried out at part of the Karadiyana landfill, Sri Lanka, containing old mixed municipal solid waste covered by vegetation. The gas concentrations of the landfill surface layer were measured from three gas wells established on the dump surface layer, which contains 2.5 m depth, throughout the year with the measuring of climatic factors. The results show the annual fluctuation of temperature, cumulative rainfall, relative humidity, and atmospheric pressure were 27–42°C, 66.7–357.7 mm, 24.7%–78.2%, and 999.5–1014 mbar around the studied landfill area, and the average concentration value of the CH4, NH3, H2S, and VOCs gases were 18.94 ± 11.49%, 15.48 ± 15.17 mg m−3, 15.06 ± 19.02 mg m−3, and 0.83 ± 0.99 mg m−3, respectively. The rainfall and atmospheric temperature were significant metrological factors influencing the surface layer gas concentrations and showed a significant positive correlation with cumulative rainfall and a negative correlation with atmospheric temperature. The relative humidity shows a moderate positive correlation, and there was no evidence of a considerable impact of atmospheric pressure on the surface layer concentrations. Annual fluctuation is a critical factor for landfill gas emission quantification, and surface layer concentration variation can be used to study the emission fluctuation by considering their relationship.

Assessment of landfill protection systems in Japan– a case study

Landfilling of untreated waste is still seen as an acceptable practice in many developed countries. Sanitary landfills are facilities for the disposal of untreated mixed municipal solid waste as a major waste stream. The Waste Management and Public Cleansing Act of 1970 is the main waste legislation in Japan. Waste management methods differ in Japan from the European Union and other countries. As waste incineration is prevalent in Japan, the final waste disposal rate in landfills is extremely low, occupying less than 5% of the waste generated. In Japan, there are obligatory barrier systems, treatment facilities for leachate and concrete structures for major facilities (waste storage structures, barriers, and leachate treatment facilities), landfill operations (dumping and soil covering) and management facilities (weighing and monitoring equipment) which are identified in the Guideline Manual of Landfill Site. This work examines the landfill protection systems in Japan based on two case studies from selected research facilities.

Life cycle assessment of the hydrothermal carbonization process applied to the wet fraction mechanically separated from municipal mixed waste

The under-sieve fraction (USF), obtained as one of the output streams from the mechanical pretreatment of mixed municipal solid waste, is usually aerobically biologically stabilized before being landfilled. For its characteristics (i.e., moisture and organic content), the USF can be alternatively processed by hydrothermal carbonization (HTC), producing hydrochar to be used for energy production. Based on previous results obtained from laboratory HTC tests of the USF, this work is aimed at evaluating the sustainability of the proposed process from an environmental point of view by applying the Life Cycle Assessment. Various combinations of process parameters (temperature, time, and dry solid-to-water ratios) and two different utilization pathways for hydrochar (the whole amount produced in external lignite power plants or part of it used internally) are compared. The results indicate that environmental performances are mainly connected with process energy consumption: in general, the cases operating at the lowest dilution ratio and the highest temperature provide improved environmental indicators. Co-combusting all the produced hydrochar in external power plants provides better environmental performances than feeding a portion of it to the HTC itself: the avoided effects by displacing lignite are higher than the additional burdens from natural gas use. Then, alternative process water treatments are compared, showing that the burdens added by the process water treatments do not offset the benefits generated by the main HTC process for the major part of the considered environmental indicators.Finally, the proposed process indicates better environmental performances when compared to the conventional method of treating the USF, based on aerobic biostabilization and landfilling.

Sequential Methodology for the Selection of Municipal Waste Treatment Alternatives Applied to a Case Study in Chile

Most municipalities in developing countries lack technical and economic resources to improve their municipal solid waste management (MSWM) system. Therefore, tools are needed that enable the most appropriate solutions to be identified to put waste to better use. This study presents an easy-to-apply sequential methodology for the analysis of MSWM alternatives. The method consists of two stages: (1) screening available technologies based on a small set of key variables; (2) ordering the selected alternatives by a combination of multicriteria methods that integrate local priorities. For this second stage, a basic series of technical, environmental, economic and social indicators is proposed. The methodology is applied to a case study where current management is limited to mixed municipal solid waste (MSW) disposal in a landfill without gas recovery. Seven options for implementing energy recovery in landfill, using mechanical plants to recover part of recyclable material, treating the organic fraction, and employing refuse-derived fuel and/or waste to energy incineration, were evaluated together with the current situation and considering four scenarios. The results identify various alternatives that allow the sustainability of MSWM in the case study to improve. Notwithstanding, today, it is necessary to introduce economic instruments that discourage final disposal to make municipal waste recovery viable.

Heavy metal remediation using chelator-enhanced washing of municipal solid waste compost based on spectroscopic characterization

Due to high metal toxicity, mixed municipal solid waste (MSW) compost is difficult to use. This study detected the presence of heavy metals (Cd, Cu, Pb, Ni, and Zn) in MSW compost through mineralogical analysis using X-ray diffraction (XRD) and performed topographical imaging and elemental mapping using a scanning electron microscope and energy dispersive X-ray analysis (SEM-EDX). Ethylenediaminetetraacetic acid (EDTA), a typical chelator, is tested to remove heavy metals from Indian MSW compost (New Delhi and Mumbai). It deals with two novel aspects, viz., (i) investigating the influence of EDTA-washing conditions, molarity, dosage, MSW compost-sample size, speed, and contact time, on their metal removal efficiencies, and (ii) maximizing the percentage removal of heavy metals by determining the optimal process control process parameters. These parameters were optimized in a batch reactor utilizing Taguchi orthogonal (L25) array. The optimization showed that the removal efficiencies were 96.71%, 47.37%, and 49.94% for Cd, Pb, and Zn in Delhi samples, whereas 45.55%, 79.52%, 59.63%, 82.31%, and 88.40% for Cd, Cu, Pb, Ni, and Zn in Mumbai samples. Results indicate that the removal efficiency of heavy metals was greatly influenced by EDTA-molarity. Fourier-transform infrared spectroscopy (FTIR) confirmed the presence of hydroxyl group, which aids heavy metal chelation. The results reveal the possibility of EDTA to reduce the hazardous properties of MSW compost.

Development of lower heating value prediction models and estimation of energy recovery potential of municipal solid waste and RDF incineration

Due to heterogeneity in municipal solid waste (MSW) characteristics and composition, the already available heating value estimation methods cannot be accurately applied for the cities of developing countries. In this study, both linear and non-linear approaches have been used for the development of lower heating value (LHV) prediction models. The models have been developed based on the physical composition, proximate analysis, and ultimate analysis of both mixed MSW and combustible components (food waste, yard waste, plastic, paper & cardboard, textile & rubber) separately. In total, six multiple linear regression (MLR) models and six artificial neural network (ANN) models have been developed. All of them can be used for the timely decision making as per the availability of data and requirements with a sufficient level of accuracy. The physical composition based LHV prediction models (both MLR and ANN) showed highest prediction performance. The models developed using combustible components showed slightly better prediction capabilities than mixed MSW based models. Further, in this study, an appropriate refuse-derived fuel (RDF) mix has been determined based on the ease of recovery of the individual waste components from the mixed MSW stream. Finally, the energy recovery potential from mass-burn incineration and RDF incineration has been evaluated. The energy recovery potential of proposed RDF (combination of plastic, paper & cardboard, textile & rubber and yard waste) and mixed MSW was found to be 1310 kWh/tonne and 837 kWh/tonne of dry weight respectively.

Experimental investigation of lab scaled sink & float based segregation process for mixed municipal solid waste

Experimental investigation of lab scaled sink & float based segregation process for mixed municipal solid waste

Evaluating the Environmental and Economic Performance of Municipal Solid Waste Disposal by All-Component Resource Recovery

Disposal of municipal solid waste (MSW) has become increasingly challenging. In this study, we used life cycle assessment (LCA) to evaluate environmental impacts and financial performance of a new approach for MSW disposals, namely All-components Resource Recovery (AcRR), which is based on automatic sorting. We compared AcRR with the standardized Waste-to-Energy incineration (WtE) to provide decision-making support for MSW management. The results show that WtE and AcRR are both good MSW resource treatment methods. Through MSW disposal, WtE generates electricity, while AcRR generates secondary resources such as metals, plastics, pulp and organic fertilizers. WtE releases trace amounts of HCl, PM10, heavy metals, dioxins and dust, while AcRR does not produce such pollutants; AcRR produces more odor gases such as SO2 and H2S. AcRR produces four environmental issues, i.e., Global Warming, Acidification, Photochemical Ozone Synthesis, and Eutrophication, each of which has a smaller impact than WtE; WtE has two more impacts than AcRR: Human Toxicity and Soot and Ashes. The total environmental impact potential of WtE is 3.38 times that of AcRR, and the greenhouse gas emission equivalent is 6.82 times that of AcRR. The cost of construction and operation of AcRR is lower than that of WtE, while the net profit of AcRR is much higher. In conclusion, AcRR is able to screen the mixed MSW into various secondary resources with less environmental emissions and environmental impacts and better financial performance; it may be a promising MSW disposal approach, especially for small cities, but a corresponding supporting industrial system is needed.

Two stage co-pyrolysis improvement to produce synthetic oil and gas simultaneously from mixed municipal solid waste using natural dolomite-based catalyst

Among the two pyrolysis methods, the two-stage type gives better results than the single-stage in converting mixed municipal solid waste (MMSW) into synthetic oil (O-Synthec) and gaseous products (G-Synthec). However, the double energy supply for the heating process in the first and second reactors needs to be considered in terms of efficiency. Therefore to complete the research of two-stage pyrolysis, this study improvised a two-stage co-pyrolysis process supported by a Long Fixed-Bed Catalytic Insert (LFCi) attached to the inner wall of the reactor. In the test, 500 g of MMSW with 8 components was fed into a reactor with LFCi containing a dolomite natural catalyst. The co-pyrolysis process was carried out at a temperature variation of 400–550 °C, and the best results obtained were used as a reference for variations in reaction time from 120 to 210 min. Based on the physical and chemical properties, the co-pyrolysis O-synthec and G-synthec products were subjected to Gas Chromatography Mass Spectrometry (GCMS) analysis and American Society for Testing and Material (ASTM) standard to physical properties test. The results were compared with those of one-stage pyrolysis, direct catalytic and without catalyst. Based on the results, the presence of LFCi in the reactor had a significant effect in increasing the mass yield of O-Synthec at 550 °C with a residence time of 150 min. An increase of 20,14% and decrease 16.77% of O-Synthec and G-Synthec respectively were achieved compared to the uncatalyzed, although the presence of 15.5% peak area oxygenated fractions and 3.0% peak area acid needs to be considered as it impacts the calorific value. The dominant aromatic compound indicates that O-Synthec has similarities with conventional gasoline fuel. Meanwhile, the non-condensable gas (G-Synthec) produced contains a concentration of hydrocarbon compounds in the distribution of C1–C12, which is dominant with tripropylaluminum, formic acid and butenes. The high content of formic acid and tripropylaluminum compounds in G-Synthec must be considered because they are very corrosive and hazardous to the environment.

Energy recovery options for the management of cellulose-based bio-plastics and mixed municipal solid waste

The incomplete degradation of bio-plastics waste is undermining the suitability of current anaerobic digestion (AD) and composting, opening up the exploration of new treatment routes, including mixed waste. Bio-plastics are treated with mixed waste in a mechanical-biological treatment (MBT) plant with the production of a dry fraction for incineration and a biologically stable one for landfill. An alternative post-treatment of the bio-stabilised waste based on AD is possible. It follows that the main goal of this study is to verify the feasibility of managing cellulose-based bio-plastics with mixed municipal waste, comparing the AD of the MBT plant outputs with the possible solution of incineration. Experimental lab tests have been carried out to describe the two processes, whose results were the basis for an economic analysis. The values of biochemical methane potential (BMP) and higher heating value (HHV) are used as an index for AD and incineration, respectively. Samples with and without bio-plastics were created; fresh and processed (7 and 14 days of biostabilization) samples were, thus, analysed. For AD, the fresh waste averaged 177 NmL CH4/gVS and a 22% and 33% decrease in BMP value was achieved after 7 and 14 days of biostabilization, respectively. Samples with and without bio-plastics revealed a similar trend. 7 and 14 days of biostabilization increased the HHV of fresh waste (18.01 J/kg) of 16.1% and 19.7%, respectively. Bio-plastics did not significantly change the HHV. The economic analysis revealed the suitability of both AD and incineration, irrespective of the presence of bioplastics.

Autonomous Home Composting Units for Urban Areas in Greece: The Case Study of the Municipality of Rhodes

A significant issue is reducing the amount of biological waste that is disposed of in landfills, particularly in high-density residential areas. The Wastes Framework Directive (98/2008), in particular, sets forward the legal requirements for source separation in the European Union’s (EU) environmental legislation. The directive sets a target for separate collection of 10% of the organic waste produced in each municipality by 2030, especially with regard to organic waste. The pilot experience of an integrated biowaste management system that supports source separation and urban composting in an Autonomous Composting Unit (ACU) was presented in this study. The Municipality of Rhodes installed five ACUs in various locations. Used food and green waste are the two types of waste that are deposited in the ACUs. The development of a system for the collection of produced biowaste and its treatment at the source, without producing a nuisance, within an urban area, is the goal of this innovation. Since landfilling of mixed municipal solid waste has long been a common practice on the island of Rhodes, as well as in many other locations of insular and mainland Greece, this technique was introduced as a novel implementation and innovation for the region. The results showed that biowaste source separation was successfully carried out by citizens, resulting in high-purity feed. All ACUs produce compost that is of a standard quality. In accordance with the principles of the circular economy, this study showed that ACUs are a sustainable solution for taking a closed unit approach to the biowaste management problem in urban areas.