Municipal Waste Treatment Research Articles

Innovative system of organization, accounting treatment of solid municipal and bulky waste, economic incentives for their separate collection and processing

Introduction. The approach to the creation and development of the system of separate collection and pre-treatment of municipal solid waste (MSW) and bulky waste. At present, Russia is lagging behind in the level of waste disposal, the expedient use of secondary resources. One of the main reasons is the lack of a cost-effective system for managing waste and secondary resources. Despite the deteriorating environmental situation, the closure of landfills for municipal solid waste, the growth of unauthorized landfills, there has been a trend of growth in tariffs for removal and disposal of municipal solid waste (MSW) and bulky waste affecting the entire population of Russia. This problem determines the need to find new scientific and methodological approaches and practical solutions for planning not only the placement of industrial waste disposal infrastructure, but also creating a system for separate collection and pretreatment of MSW and bulky waste in the sources of their formation, justification and optimization of the standards for the accumulation of this waste for citizens. Materials and methods. Materials for conducting a scientific research are: legal acts, standards, guidelines and recommendations, regulatory and technical documentation in the field of waste management, published materials of domestic and foreign scientific research. The methods of scientific research are based on the use of factor, comparative, expert types of analysis. Results. Optimization of the system for calculating the standard of accumulation of MSW and bulky waste is proposed; reducing the financial burden on citizens in terms of tariffs for garbage collection; economic incentives for the population to separate the collection of MSW with the pretreatment of the components of this waste to the level of demanded secondary resources. Conclusions. The introduction of the proposed system will allow achieving socio-economic, environmental, natural resource, political effect, consolidating the society to solve the problem of resource conservation, the use of secondary resources.

Proposed design of a composting facility for the treatment of municipal waste with built-in deodorization system (in Western Macedonia, Greece)

Proposed design of a composting facility for the treatment of municipal waste with built-in deodorization system (in Western Macedonia, Greece)

Model za evaluaciju sistema upravljanja komunalnim otpadom, primena LCA - deo II: Verifikacija modela

The aim of this study was to use the life cycle assessment (LCA) instrument to assess the different municipal solid waste (MSW) management scenarios for the South Bačka region. LCA has proven to be a very effective instrument for identifying strategies that minimize negative environmental impacts. A comparative analysis is very important for decision makers and planners in the waste sector. This paper presents the application of the LCA model described in the Part I of this study. This model combined life cycle inventory model (IWM2) and life cycle impact assessment method (Impact2002+) to compare and evaluate the municipal solid waste system with the purpose of identifying environmental benefits and disadvantages, as well as the economic cost of defined scenarios of waste management systems that could be implemented. The model was applied to a regional municipal waste management system in South Bačka (The Republic of Serbia). Four scenarios of waste management are defined. The scenarios include the combination of different treatments of waste (biological and thermal), and a sanitary landfill. The results show clear differences between the scenarios in the selected indicators and quantify the relative advantages and disadvantages of different waste management scenarios. The model is a useful tool to support decision-makers to choose the technology of solid municipal waste treatment. Also, the participants in the planning of solid waste management will enable a better understanding of the importance of LCA method. Finally, it will help the improvement of the strategic planning process in the field of environmental protection, without which it is impossible to achieve the concept of sustainable development in the AP Vojvodina.

Greenhouse gas emissions from thermal treatment of non-recyclable municipal waste

This paper analyses factors affecting the production of greenhouse gases from the treatment of residual municipal waste. The analysis is conducted so that the environmentally-friendly decision-making criteria may be later implemented into an optimisation task, which allocates waste treatment capacities. A simplified method of life cycle assessment is applied to describe environmental impact of the allocation. Global warming potential (GWP) is employed as a unit to quantify greenhouse gases (GHG) emissions. The objective is to identify the environmental burdens and credits measured by GWP for the three fundamental methods for treatment of residual waste unsuitable for material recovery. The three methods are waste-to-energy (WTE), landfilling and mechanicalbiological treatment (MBT) with subsequent utilization of refuse-derived fuel. The composition of the waste itself and content of fossil-derived carbon and biogenic carbon are important parameters to identify amounts of GHG. In case of WTE, subsequent use of the energy, e.g., in district heating systems in case of heat, is another important parameter to be considered. GWP function dependant on WTE capacity is introduced. The conclusion of this paper provides an assessment of the potential benefits of the results in optimisation tasks for the planning of overall strategy in waste management.

Contribution to Global Warming Potential by waste producers: Identification by reverse logistic modelling

An overview of relevant literature shows how supply chain and network flow models represent useful tools in the area of clean energy generation and processing related waste. This paper deals with a specific network flow problem where the mixed municipal waste as a secondary and partly renewable energy carrier is transported from waste producers (municipalities), through pre-processing facilities, to its final treatment in waste processing units and in which the optimal flow is desired. The results obtained for the minimum total costs, including treatment and transportation, correspond to production and savings of a certain amount of CO2 and other greenhouse gases which is described by Global Warming Potential (GWP). The average cost was 74 EUR/t and average GWP was 37 kg CO2eq/t. The GWP contribution varies among the waste producers as a result of treating waste in different places and various technologies. However, to identify the individual contributions, the detailed waste flow identification is required. The flow distribution is unknown due to the effect of merging and splitting waste streams in the network. For this reason, a consequent network flow problem for exact waste flows identification is proposed. The model follows the principle ideas of multi-commodity network flow modelling and it reveals the variability of cost and GWP contribution for all producers in the investigated area. The proposed method has been tested through a case study considering treatment of mixed municipal waste. The results obtained by the original implementation in GAMS are presented and discussed in detail. The GWP contribution varied between −173 and 880 kg CO2eq/t and significant waste producers were identified in the network regarding GWP. The results are important for setting the target for emission reduction in individual regions and for particular producers. The principle can be applied in general to any commodity and network flow problem.

Rapid conversion from food waste to electricity by combining anaerobic fermentation and liquid catalytic fuel cell

Energy recovery from food waste through anaerobic digestion is an important pathway for municipal waste treatment and renewable energy development. Slow methanogenesis and inhibition risk derived from accumulated volatile fatty acids are two technical challenges in anaerobic digestion of food waste. In this study, a novel system combining anaerobic fermentation and a liquid catalytic fuel cell (denoted AFFC for brevity) is proposed as an efficient alternative in which the fermentation products are used as the cell’s fuel. Results show that the fermentation liquid had an organic content of 15.3 g/L with the majority constituted by volatile fatty acids. The maximum power density of the cell reached 1.2 mW/cm2. After 12 h of continuous operation, the conversion rates of acetic, propionic, butyric, and valeric acids reached 90%, 72%, 71%, and 94%, respectively. Furthermore, total organic carbon content decreased by 93.1% from 6.3 to 0.4 g/L in 60 h, while the removal rate of total nitrogen exceeded 82%. Gas-composition analyses verified that organic carbon and ammonia were converted into CO2 and N2, respectively. Compared with direct treatment of food waste in a cell, the pre-positive anaerobic fermentation degraded macromolecular substances into volatile fatty acids, aided the decomposition of lipids, accelerated the cell reaction, and improved the discharge performance. Compared with conventional anaerobic digestion, AFFC exhibited a higher electrical efficiency of 34% with a shorter treatment time of 6.5 d, implying that AFFC could be a promising method for food waste utilization.

A combination of ammonia stripping and low temperature thermal pre-treatment improves anaerobic post-digestion of the supernatant from organic fraction of municipal solid waste treatment

Municipal Solid Waste is mostly composed of organic material which is often treated in anaerobic reactors in waste treatment plants. In most cases, the obtained digestate undergoes a solid/liquid separation step, producing a liquid fraction (known as anaerobic supernatant) rich in ammonium nitrogen that has to be further treated in order to meet discharge standards. The objective of the present work was to evaluate the feasibility of anaerobic post-digestion (37 °C) of a supernatant rich in carbon and nitrogen from a municipal waste treatment plant. In order to increase the efficiency of the process, a combined pre-treatment consisting of a low-temperature thermal process (75 °C) and ammonia stripping (1.3 Lair Lsupernatant−1 min−1) was applied. The effects of pre-treatment contact time (4 and 8 h) and the hydraulic retention time (HRT) in the anaerobic reactor (20–40 d) were studied. Supernatant pre-treatment with 8-h contact time caused 13% organic matter solubilisation, thus improving methanisation by 18% when the HRT was 40 d. At the same time, ammonia stripping allowed to maintain ammonia concentration in the digester below inhibitory values (less than 100 mg N-NH3 L−1) enabling therefore high methanogenic activity (>0.23 g COD g−1 VS d−1). The final effluent characteristics (low total ammonia nitrogen and aerobically biodegradable organic matter levels) would permit implementing subsequent less energy intensive and more environmental-friendly technologies (such as partial nitritation/anammox) to comply with discharge limits.

The effects of anionic and non-ionic surfactant on anaerobic co-digestion of sludge, food wastes and green wastes

Surfactants are widely used and discharged into wastewater treatment plants, which might influence the anaerobic digestion (AD) treatment of municipal waste. In this study, the effects of typical anionic surfactants sodium dodecyl benzene6 sulfonate (SDBS) and non-ionic surfactants APG, on mesophilic anaerobic co-digestion of sludge, food waste, and green waste were investigated. Results indicated that at 5 mg/g, the biogas production was inhibited in SDBS supplemented systems while stimulated in APG-added reactors, with the methane yield of 146.58 L/g VS consumed. At 15 mg/g, the biogas production in both SDBS and APG supplemented reactors was both inhibited. It means the negative or positive effect of APG on AD depends on the dose of APG supplementation. The 16S rRNA gene analysis demonstrated the microbial community structure in the digester was changed due to the addition of surfactant. Bacteroidia significantly increased with the addition of APG and SBDS, while the increase of Clostridia only occurred in APG-added system. The variation of microbial Communities’ structure in APG and SDBS-added digesters might give an explanation for the different efficiencies in these two systems. Thus, the effects of surfactants on the efficiency of AD should be considered during the disposal of municipal organic waste.

Aerosol exposure and risk assessment for green jobs involved in biomethanization

Anaerobic digestion is a consolidated biotechnology able to produce renewable energy from biomasses. In the European countries, quick growth of biogas production from different organic matrices including wastes has been observed. In relation to the characteristics and quantity of the anaerobic digestion of feedstock, there are different technologies, advantages and criticisms. An accurate occupational risk assessment and development of management tools for green jobs involved in the anaerobic digestion plants are due. The aim of this work is to assess the aerosol exposure for such workers, focusing on the bioaerosol risk. Full scale plants for the treatment of organic municipal waste, waste water treatment sludge, agro zootechnical and food producing byproducts were involved for this purpose. The bioaerosol levels were monitored during activities through culturing and biomolecular methods; moreover, the sub-fractionated PM10 and carried endotoxins were measured in different plant areas. Global microbial contamination is higher (>5000 UFC/m3) in the area where organic wastes are handled and pretreated, both for organic municipal waste plants - with a bacterial prevalence - and agro zootechnical plants - with a fungi prevalence. Moreover, the microbial contamination is higher where organic municipal waste is present in respect to other biomasses (ANOVA p < 0.01). Numerous pathogens are carried by the aerosol. HAdV-4 presence is lower than LOQ (50 gene copies/m3) in all the samples. Environmental PM10 reached the 280 μg/m3 level including PM3 for 78%. Endotoxin pollution overtakes the 90 EU/m3 limit sporadically. Personal PM4.5 reached 10 mg/m3 only for maintenance technicians in the pretreatment area for organic municipal waste. The risk can be evaluated under a quantitative and qualitative point of view highlighting risk management improvement for anaerobic digestion plants.

Energy efficiency in municipal waste treatment

The article presents the efficient method of microwave irradiation (SHF) for the municipal liquid waste such as domestic wastewater and sludge. The technical and economic parameters and experimental data, showing the possibilities of microwave electromagnetic radiation using in the sewage and sediment treatment technologies, are given in this article. The traditional electrothermal treatment and SHF processing of the municipal precipitation, taken from the city wastewater treatment plant, have been compared. At the same time, a high rate of heating of the precipitation samples has been noted during the microwave treatment. The technical and economic comparison of three methods (with the usage of the reagents, convection heating and SHF) showed the advantages of using SHF range electromagnetic radiation. The energy efficiency and the cost-effective use of resources during the SHF using for liquid municipal waste treatment have been confirmed.

Effect of the variation of the operating parameters in the production of methane from lignocellulosic waste

Anaerobic digestion has been widely used in recent years for the treatment of agro-industrial or municipal wastes as carbon source to obtain alternative energy sources such as methane (CH4). Great efforts are currently being made to understand this phenomenon, generally as a first approximation in batch experiments, but due to the growing need to produce more environmentally friendly fuels, it is imperative to study the process as a continuous production. Starting from a three-state model and its parametric characterization in batch experiments, this paper analyzes the effect of the variation of two parameters of the mathematical model from continuous balances: the dilution rate (D) and the substrate feeding concentration (Si). The increase in the concentration of substrate in the inflow allows a greater production of methane, while small values allow reaching the trivial solution in the system. The choice of the dilution rate can be solved as an optimization problem since the production reaches a maximum at values close to 4 d_1.

BIOWASTE SEPARATION AT SOURCE AND ITS LIMITATIONS BASED ON SPATIAL CONDITIONS

The European regulation of biodegradable municipal waste (biowaste) treatment places a significant demand on local biowaste separation systems and consequent treatment (composting, anaerobic digestion). When implementing separate collection systems, there is a public demand for systems based on containers and bags. Based on a case study of the city Usti nad Labem in the Czech Republic, the authors illustrate the difficulties encountered in the implementation of this kind of system. A series of factors should be paramount in the organization of biowaste separate collection, including the location of containers, the amount of contaminants, and system parameters (e.g. volume of containers, frequency of collection). The results obtained confirm how a precision-targeted information campaign may contribute towards reducing contamination of biowaste container content. Lower amounts of contaminants imply a simplified biowaste treatment (composting) and increased system efficiency. Furthermore, it was observed that the relocation of biowaste containers, or placing of additional containers in the system, resulted in an increase in public involvement as a result of the added convenience of separate collection proximity of containers. The equipment of the chosen city district by additional 55 containers increases the number of address points covered by the system by approx. 149.20% and the number of inhabitants by about 38.14%. However, this added convenience of separate collection is not cost-neutral, with the increased proximity of containers contributing towards a rise in collection costs including transport, and containers. The increase of collection costs ranges between 105.5 and 156.78% in comparison with the current situation.

The effectiveness of the mechanical treatment of municipal waste using the example of a selected installation

The mechanical treatment of waste using specialized equipment allows the separation of significant amounts of secondary raw materials. To a large extent, the effectiveness of such a process depends on the quality of the input – one efficiency value is achieved during the segregation of mixed municipal waste, and the other one – during preprocessing of waste from separate collection. The work analysed the data on mechanical processing in a mechanical-biological treatment plant for municipal waste. The mechanical part of the installation is equipped with optical-electronic and electromagnetice separators, as well as manual sorting cabins. Results were obtained to compare the efficiency of the separation of secondary raw materials and energy fractions for further use, as well as the amount of undersieve fraction requiring biological stabilization and ballast waste, which are directed to landfilling.

Municipal waste management on the example of the Municipal Waste Management Company in Olsztyn - a case study

This article presents the technological processes associated with waste management on the example of the Municipal Waste Treatment Plant in Olsztyn. Legal acts regulating waste management and the maintenance of cleanliness at the municipal level are discussed. The Municipal Waste Treatment Plant in Olsztyn processes waste from 37 municipalities in the Region of Warmia and Mazury. Waste transported to the plant is separated into sorted waste and mixed waste which undergoes further processing. An innovative solution in the country of drying waste mixed in bioreactors, where aerobic biodegradation occurs, was applied in Olsztyn. As a result of the temperature in this process, the waste is dried without additional energy from the outside. Processed waste is used in the production of alternative fuel. Around 5-15% of the collected waste is not fit for processing, and it is landfilled.

Drying kinetics of RDF: Experimental investigation and modeling

An experimental study was performed to determine the drying characteristics of an oversized fraction of RDF alternative fuel using a laboratory scale hot air dryer at a variety air temperatures and a constant air velocity. For this research the industrial RDF was derived from a Regional Municipal Waste Treatment Facility near the city of Kraków, Poland. The samples of RDF were prepared in two forms: ovesized (unmodified condition) and shreded in a two-drum crusher. In addition, the RDF was sorted into three groups of samples: paper, plastic, textiles. Each form of RDF and each group of samples were dried in hot air dryer at temperatures of 50, 70 i 90 °C and a constant air velocity of 1,5 [m·s-1]. The loss of the the samples mass were measured in a continues manner until the equilibrum moisture content was reached. The effective moisture diffusivity [m2·s-1] and activation energies [kJ·mol-1] was amounted. The analysis of the course of moisture content change concludes that that the drying of the RDF alternative fuel occured mainly in the II period of the process during which the transport of water content was carried out by diffusion. And, to a lesser extent, with the surface heat transfer in II period. Based on the calculated data there was a model determined which presented the best possible matching of the course of moisture content change.

An innovative solution for drying municipal waste in the process of producing alternative fuel on the example of the Municipal Waste Management Company in Olsztyn – a case study

This article presents an innovative solution for drying waste in bioreactors on the example of the Municipal Waste Treatment Plant (ZUOK) in Olsztyn. Shredded mixed waste undergoes fermentation in bioreactors and produces heat for waste drying. Waste transported to the plant is divided into sorted waste which is recycled and mixed waste which is processed into different size fractions. Processed waste is used in the production of alternative fuel which can be burned in dedicated systems in cement plants or incineration plants. Around 5-15% of waste cannot be processed and is landfilled.

Regional use of European Funds in municipal waste management in Poland

The level of management of municipal waste management has a very real impact on life. Consequently, this can be associated with high risks both locally and globally. Thanks to the use of modern solutions for the management of municipal waste, the level of impact of municipal waste on the environment can be significantly reduced. However, modern solutions are associated with the high cost of building the plant and the whole system for managing the management of municipal waste. In addition to costs, the level of awareness of the people, their habits, traditions and education, is vital for improving the situation. Article aims to explore and familiarize use of European funds in the management of municipal waste in Poland. Will examine the distribution channels of these measures. The article will present three projects co-financed from European funds implemented by one of the Regional Installation of Municipal Waste Treatment.

Microbiological and Energetic Assessment of the Effects of the Biodrying of Fuel Produced from Waste

Abstract Biological drying (biodrying) is one of the methods of biological processing of waste, used mainly as part of the mechanical biological treatment of mixed municipal waste. Biological drying uses the heat released during the decomposition of organic matter to reduce the amount of water in dried waste. The aim of the analyses was to provide a microbiological and energetic (fuel) assessment of the process of biodrying of alternative fuel (RDF) obtained by mechanical sorting of mixed municipal waste. The resulting alternative fuel (obtained with just sorting) is characterised by varied moisture content and the presence of diverse groups of microorganisms. The analyses were intended to assess 3 alternative methods of biodrying of alternative fuel in order to produce a stable end product for utility power generation and the cement industry. The analyses were performed using special bioreactors equipped with custom (innovative) fluidised bed, aeration system (air flow rate 500 m3 · h−1), effluents drain systems, post-process air offtake and 4 temperature sensors. The assessment of the impact of the employed bed aeration methods on the quality of the alternative fuel was performed in 3 repetitions with the same external parameters. The obtained results show that after 8 days of biodrying, in the most favourable option, the moisture content in the fuel was reduced to the level of 18.7%, i.e. by 39%, the resulting fuel was microbiologically stable and the calorific value of the fuel was increased on average by 3.2 MJ · kg−1.

Mechanical Heat Treatment (MHT) of Municipal Waste in the Context of Circular Economy

Mechanical Heat Treatment (MHT) of Municipal Waste in the Context of Circular Economy

Life Cycle Assessment of Mechanical–Biological Treatment of Mixed Municipal Waste

Abstract The aim of this study is to quantify the environmental exchanges associated with the mechanical–biological treatment (MBT) of mixed municipal waste, for a specific MBT plant, based on the annual operation data for the year 2015. Modeling of environmental performance of the MBT technology is done on actual, real data of the operating plant, taking into account particular, explicit outputs and efficiencies of the plant. Results contribute to quantitative understanding of MBT technology and its environmental impact, including the impacts from individual unit processes within MBT. The study is based on Life Cycle Assessment methodology, employing the EASETECH model. One megagram of mixed municipal waste entering the MBT plant is adopted as the functional unit. The system boundaries cover the whole value chain from collection and transport of mixed municipal waste through mechanical and biological operations until final treatment of end-waste generated in the MBT plant. Results of modeling show the MB...