Municipal Solid Waste Samples Research Articles

Study of the physical-chemical characteristics of non-food solid waste combustion

The ignition and combustion processes of six non-food municipal solid waste (MSW) samples of different type were studied. The samples of wood waste, rubber, leather, cardboard, textile and plastic were put into the combustion chamber at a temperature of 600 °C in air medium at atmospheric pressure. The observations were carried out by means of high-frequency video imaging of the combustion process. Based on the obtained results the characteristic times of the ignition delay, combustion of volatiles and carbon residue were defined. The highest values of ignition delay and combustion of the carbon residue times were obtained for rubber sample and were 11.3 and 285 s, respectively. Significant correlation was found between the time of volatiles and carbon residue combustion and the fixed carbon content of the sample: the higher the Cd content, the higher value of respective time. The concentration peaks of the gas-phase products release during combustion of non-food MSW were presented as well.

Characteristics of Heavy Metal Pollutants of PM2.5 from Open Burning of Municipal Solid Waste (MSW) and the Associated Exposure Health Risks

The characteristics and health risk assessment for heavy metal pollutants in PM2.5 discharged from the open burning of municipal solid waste (MSW) in different functional areas were studied using a flue gas diluted sampling system. The two common open burning modes of barrel and natural pile-up burning were considered. The results show that the concentration of zinc (Zn) was the highest among the heavy metals produced by five different components of waste incineration, ranging from 1324.03 to 3703.12 mg·kg-1. The concentration of cadmium (Cd) was the lowest, ranging from 20.25 to 63.68 mg·kg-1. According to the geo-accumulation index, lead (Pb), Zn, arsenic (As), and Cd were highly polluted in the measured MSW samples, and all four of these metals reached moderate or higher levels of pollution under natural pile-up burning methods. The geo-accumulation index of Cd was much higher than 5. The results of the human health risk assessment showed that non-carcinogenic risk values for 8 heavy metals (Pb, Zn, Cu, Mn, As, Cd, Cr, and Ni) by respiratory exposure were less than 1, which is within the safe range. For natural pile-up burning, the total non-carcinogenic risk values for As and Pb for children were higher than 1, indicating a non-carcinogenic risk. The carcinogenic risk values for four carcinogenic elements (As, Cd, Cr, and Ni) were less than 1.0×10-4, but still represented a low potential carcinogenic risk under exposure for long periods of time.

Assessing the ecological impacts of ageing on hazard potential of solid waste landfills: A green approach through vermitechnology

Abstract Information about the layer wise variation in Municipal Solid Waste (MSW) dumps, their environmental consequences, and leaching dynamics are rather scarce. MSW samples were, therefore, collected from three layers of a 30 year old dumping site at Silchar (India). Significant variations in pH, density, and metal toxicity were evidenced in different layers of the MSW pile. Physical characteristics (grain size, porosity etc) noticeably varied along the depth as substantiated by SEM analysis. FTIR analysis further revealed predominance of amines and alkenes in the deeper layers. NPK availability was found to be 1.5–2 folds lower in the deepest layer (L3) than the upper layers (L1 and L2). However, Pb, Cr, and Cd availability was significantly high in the middle layer (L2). Lab scale leaching experiments showed that metals (Fe, Cu, and Pb), phosphates and sulphates can greatly contaminate the soil and aquatic ecosystems in the long run. Visual MINTEQ model predicted possibilities of time dependent long range leaching of Fe, Cu, and Pb. Attributes like pollution index, ecological risk index, and geo-accumulation index also revealed adverse impacts of the deeper landfill layers on the surrounding environment. The potentially toxic MSWs were sanitized via vermitechnology by utilizing the bioaccumulation traits of earthworms (Eisenia fetida). On an average more than 3–5 fold reduction in overall environmental risk could be achieved in the vermicomposted and composted MSW fractions. The N, P, and K levels increased by 85%, 41%, and 68% in the vermicomposted MSW + Cow dung (1:1) feedstock. This also induced greater seed viability than composted mixtures. Finally, the economic evaluation of the treatment technologies was performed to realize their industrial value.

Compressibility and shear strength behaviour of fresh and aged municipal solid wastes

The effects of ageing on the compressibility and shear strength parameters of synthetic representative average municipal solid waste (MSW) compositions of Europe (E), Turkey (T) and the USA (U) were investigated in comparison with those of fresh samples. In addition to the synthetic fresh and aged samples, tests were conducted on natural fresh and aged MSW samples which had been collected from the Manisa landfill. The results have shown that the primary compression index ratio value of the fresh E sample is lower than that of the aged E sample, which has a higher content of paper and cardboard waste. As ageing progresses, the compression index ratio values of T and U samples increased. The results of the large-scale direct shear test present that aged samples have a higher angle of internal friction. In contrast, the cohesion values decrease as ageing progresses. The results have shown that the most important waste constituents affecting the primary compression index ratio of fresh and aged MSW samples are the kitchen and garden waste fraction and the paper and cardboard waste fraction.

Comparison of biogas production obtained from samples of Mitú and Sibundoy municipal solid waste

This study compares the calorific power of biogas obtained from the municipal solid waste (MSW)of two towns in Colombia,whose populations are affected by deficiencies in the supply of electricity. The production of biogas would represent an importantopportunity to meet these needs, taking advantage of the solid waste generated, in whose composition organic material predominates(45 %). For this purpose, MSW samples were taken from the municipalities of Mitú (Vaupés) and Sibundoy (Putumayo), in orderto establish their relevance to produce biogas. For each sample, the organic waste was characterized in terms of its macroscopiccomposition, moisture content, ash, volatile and total solids. Subsequently, the composition of biogas obtained was determinedfrom anaerobic digestion tests with biological sludge as inoculum in different proportions and the calorific value of the gas wascalculated. It was found that organic waste from both municipalities is suitable to produce biogas due to the physicochemicalcharacteristics of the samples, the high methane content generated and, therefore, the satisfactory calorific power for its use in theproduction of electrical energy.

Contribution of Each Combustible Waste to the Element Content of MSW Incineration Residue

To investigate the origin of toxic/beneficial metals in incineration residues, we tried to estimate the contribution of each combustible waste to various elements in incineration residue. Municipal solid waste (MSW) sample to be incinerated was collected from a waste pit of incineration plant A by a crane and compressed according to the quarter method. After excluding metals and incombustibles, the MSW sample was divided along with the material such as kitchen waste, vinyl and plastic, wood, rubber, and so on. Each sample was dried at 105°C for 2 hours to obtain the water content, and cut into small piece. Each sample was placed in a magnetic crucible and closed with a lid, then, heated at 650°C in a muffle furnace to obtain constant weight after ignition loss. After the heat-up and cool down, two-stage extraction consisting of aqua regia decomposition and alkali fusion was carried out on each ash. Each extract was subject to ICP-OES and ICP-MS to determine the element content in each combustible. Element composition of the ash was well correlated with the element composition of actual incineration residues collected at the same incineration plant on the same day of sampling. As a source of toxic metals, 68% of Pb was proved to originate from vinyl and plastic. As for Cd, woods accounted for 38% and rubber and leather accounted for 29%, respectively.

Characterization of Municipal Solid Waste in Malaysia for Energy Recovery

Municipal solid waste (MSW) generation that grows continuously without proper management become worrying phenomenon. Currently, Malaysia is dependent on landfills with almost 85% of waste collected ending up in dumpsites. In order to propose an alternative for solid waste management plan instead of landfill, and to develop a waste-to-energy (WtE) system, the details study of municipal solid waste (MSW) generated is crucial. This paper presents a proposal for energy recovery to produce RDF by studying the characterization of MSW generated in Malaysia; the physical and chemical properties (proximate and ultimate analysis, calorific value or energy content, and thermal analysis) of the waste components to produce a high-quality RDF. The raw MSW sample consisted of 45% organics and food waste, 13% plastics, 9% papers, and 12% diapers. For raw MSW sample, total moisture content, ash content, volatile matter, and fixed carbon were 14.60%, 7.05%, 69.35% and 9% respectively. Gross calorific value is 4538 kcal/kg and carbon content are 45%. The optimum produced RDF sample was found at operating temperature 400°C with total moisture content, ash content, volatile matter, and fixed carbon were 0.75%, 21.65%, 48.35% and 29.22% respectively. Gross calorific value is 6600.15 kcal/kg and carbon content are 64%.

Waste Composition Evaluation for Solid Waste Management Guideline in Highland Rural Tourist Area in Thailand

This study investigated municipal solid waste generation rate and its compositionincluding the level of knowledge, attitude and practice on municipal solid waste (MSW) management of highland rural tourist area in Chiang Rai Province, Mae Salong Nok Sub-district, Thailand in order to propose the guidelines for effective MSW in rural tourist areas. Samples of MSW were collected during weekdays and several weekends, and separated into 4 categories: general,recyclable, organic and hazardous waste. About 40 % of the MSW consisted of organic waste; plastic bags were widely present, comprising more than 60 % of the mass of the general waste group. Level of knowledge, attitude and practice(KAP) on MSW was evaluated using questionnaires. While respondents scored 80 % and 76 %, respectively, on their level of knowledge of, and attitude to MSW, practice fell far short at only 37 %. The results led to a recommendation to strengthen waste separation at source, implement waste reduction and recycling concepts to reduce the volume of plastic bags, and introduce composting of food waste. The study also highlights economic and financial benefits of waste recycling. Additional value-added could be derived from the organic waste recycling program by promoting production of bioextracts and compost at household level, in order to reduce the amount of organic wastes and carbon emissions. The general and recyclable wastes could also be converted to energy as refuse-derived fuel 2 (RDF-2); the estimated average heating value of this RDF-2 was 23.56 MJ kg-1. To sustain MSW management in tourist areas, environmental education and environmental awareness campaigns are needed, using the appropriate local languages for communication, and introduction of a fairer system based on the polluter-pays principle for the business sector.

Experimental Study on Compression and Intrinsic Permeability Characteristics of Municipal Solid Waste

Compression and gas permeability characteristics of municipal solid waste (MSW) are of great significance to the design, construction, management, and operation of landfill. The objective of this paper was to study the compression and gas permeability characteristics of MSW. A compressing test device and gas permeability test device for MSW were introduced, and laboratory tests were carried out. The test results showed that the final strains at the vertical loads of 100 kPa, 200 kPa, 300 kPa, and 400 kPa were 35.8%, 45.1%, 49.2%, and 55.1%, respectively. The natural logarithm of void ratio and pressure was linearly correlated at different times. Intrinsic permeability measured without considering gas compressibility was smaller than that measured with considering gas compressibility. Intrinsic permeability of MSW decreased with the increase of the inlet pressure. It was suggested that the inlet pressure should be set to 3 kPa for the indoor gas permeability test of MSW. Intrinsic permeability of MSW decreases with the increase of water content and compression displacement. Power function and logarithmic model were suitable for the fitting of permeability and porosity of manually prepared fresh MSW samples, while the K‐C model was not suitable. With the increase of moisture content, the coefficient and power index of the power function model decreased gradually. And the slope and intercept of the double logarithmic model also decreased gradually with the increase of moisture content.

Environmental burden by an open dumpsite in urban India

Open municipal solid waste (MSW) dumpsites are nowadays looming hotspots for water, air, and land pollution. Fresh and old MSW samples collected from a dumpsite in the coastal city of India were analyzed for moisture content, volatile content, energy content, elements, and toxic heavy metals. The compositional analysis results showed that fresh MSW consisted of 36% by weight bio-waste (food waste, yard waste, coconut waste) and around 30% recyclable materials (plastics, paper, cardboard, and metals). Approximately, 62% of the total fresh MSW was found to be combustible materials (plastics, paper, textile, rubber, cardboard, yard waste, and coconut husks). The analysis of old MSW samples collected from different depths (3–4 m and 6–7 m) showed the dominance of plastics (25–33%) and mixed residue (28–55%) having high energy content. Measurements of gaseous emission below 6–7 m from the surface indicated a higher concentration of methane (CH4:5.85 ± 0.12%) and lower concentration of carbon monoxide (CO: 3.82 ± 1.3 ppm), and hydrogen sulfide (H2S:10.15 ± 2.2 ppm). Haphazard dumping, waste characteristics, waste pile compaction processes and heat propagation due to deliberate fire may stimulate spontaneous fires.

A comparison of methods for early prediction of anaerobic biogas potential on biologically treated municipal solid waste

Anaerobic gas production tests, generically Biochemical Methane Potential (BMP) or Biogas Potential (BP) tests, are often used to assess biodegradability, though long duration limits their utility. This research investigated whether simple modelling approaches could provide a reliable earlier prediction of total biogas production. Data were assessed from a non-automated biogas test on a large number of both fresh and processed municipal solid waste (MSW) samples, sourced from a mechanical biological treatment (MBT) plant. Non-linear models of biogas production curves were useful in identifying a suitable test endpoint, supporting a test duration of 50 days. Biogas production at 50 days (B50) was predicted using the first 14 days of test data, using (a) linear correlation, (b) a new linearisation process, and (c) non-linear kinetic models. Prediction errors were quantified as relative root mean squared error of prediction (rRMSEP), and bias. Predictions from most models were improved by removing the initial exponential increase phase. Linear correlation gave the most precise and accurate predictions at 14 days (rRMSEP = 2.8%, bias under 0.05%) and allowed acceptable prediction (rRMSEP <10%) both at 8 days, and at 6 days using separate correlations for each sample type. Of the other predictions, the new linearisation process gave the lowest rRMSEP (10.6%) at 14 days. More complex non-linear models conferred no advantage in prediction of B50. These results demonstrate that early prediction of anaerobic gas production is possible for a well-optimised test, using only basic equipment and without recourse to external data sources or complex mathematical modelling.

Physical, chemical and geotechnical characterization of fly ash, bottom ash and municipal solid waste from Telangana State in India

Utilization of fly ash, bottom ash and municipal solid waste in the field of geotechnical engineering necessitates determination of its physical, chemical, morphological and engineering properties. This paper presents detailed physical, chemical and geotechnical characterization of fly ash, bottom ash and municipal solid waste from Telangana State in India. Fly ash and bottom ash samples were collected from Kakatiya thermal power station in India. Municipal solid waste (MSW) sample was collected from Borabanda municipal dump site in the city of Hyderabad, India. From the experimental results, it is noticed that specific gravity of fly ash, bottom ash and municipal solid waste were found to be 1.86, 1.77 and 2.2 respectively. Presence of quartz and mullite; quartz, mullite and calcium carbonate; and quartz and corundum are found to be predominant in fly ash, bottom ash and MSW respectively. The peak friction angle of fly ash, bottom ash and municipal solid waste were found to be 37.02°, 33.77° and 35.23° respectively. Permeability characteristics of fly ash, bottom ash and municipal solid waste were observed to be 1.01E−04 cm/s, 2.01E−04 cm/s and 1.16E−04 cm/s respectively. From the observation of experimental results, it can be concluded that fly ash, bottom ash and municipal solid waste from Telangana state are effective material to be used as backfill material, filter material and embankment construction.

Characterizing preferential flow in landfilled municipal solid waste

Municipal solid waste (MSW) is a porous medium comprising macropores and matrix, such that the flow pattern often takes the form of preferential flow. The objective of this paper was to study the preferential flow in MSW and to quantify the flow character. Dye tracing tests and solute breakthrough tests were carried out using MSW samples taken from different depths of a landfill. Test procedures were proposed to make the sectioning of MSW sample easy. The MSW columns were dyed and then sectioned in the horizontal and vertical direction. Digital image processing technology was used to investigate the preferential flow pattern. In order to quantitatively characterize the preferential flow in MSW, regression analysis was performed on the breakthrough curves using the bimodal probability density model. The dye tracing tests show that more preferential flow happened under a higher application rate, under higher initial water content, and in shallow MSW. The results of vertical sectioning tests are consistent with that of horizontal sectioning tests, showing that the test procedure has no obvious influence on the preferential flow pattern in MSW. The results of the solute breakthrough tests show that between 55 and 70% of the total solute was transported through large pores. The modeled proportion of solute movement through large pores decreases as the depth and age increase, and increases as the application rate increases. The results are beneficial to simulate water and solute migration in MSW using a dual-porosity model.

Evaluating the stress–strain behavior of MSW with landfill aging

Mechanical behavior of municipal solid waste (MSW) is of great importance due to many landfill slide failures in recent decades. MSW is the major structural element in landfill which is more complicated than soil owing to nonlinear and time-dependent behavior. In this study to determine the effect of aging on MSW, 60 large-scale direct shear tests with dimensions of 300 × 300 × 150 mm were conducted on samples with three ages of fresh, 3 and 6 months. The tests had four vertical stress increments of 20, 50, 100, and 200 kPa under three different shear displacement rates of 0.8, 8, and 19 mm/min. After the evaluation of shear strength parameters, the hyperbolic model was presented to predict the stress–strain behavior of Kahrizak Landfill MSW as a sample of a disposal site in developing countries. Results indicate that shear strength of MSW samples increases with aging and also curves of hyperbolic function match with the results of direct shear tests. The hyperbolic model was first presented for soil with utilizing results of triaxial tests; however, applying results of direct shear tests for predicting the stress–strain behavior of MSW leads to a more accurate model due to the effect of fiber reinforcement and diversity in MSW composition.

Theory of Sampling (TOS) applied to characterisation of Municipal Solid Waste (MSW)—a case study from France

Author Summary: Knowing the composition of household waste is a prerequisite for effective implementation of municipal solid waste (MSW) management facilities. To meet increasing regulations, facilities in terms of collection, sorting and treatment are becoming more sophisticated and expensive: performance reliability partly depends on a valid, representative knowledge of waste composition. In France, the current method of characterisation of household waste is MODECOMTM, a guide to organise and manage analysis campaigns with the primary objective of evaluating the recyclable or the packaging material content of waste, or to determine the variations and characteristics related to the nature of housing, for example. Implementation of this methodology leads to primary MSW samples, which are successively screened and sorted into a set of standard categories. Although it is possible to determine the composition of household waste in this fashion, at the end of these operations looms the question of its accuracy. Even if the mass of fully sorted MSW samples (usually around 500&nbsp;kg) may seem high, this is actually extremely small compared to the total lot from which it was sampled (several hundreds of tons, sometimes much more). The Theory of Sampling of particulate materials (TOS), as initially developed by Pierre Gy in the context of the mineral industry, is quite applicable also to household waste. In particular, it allows an estimate of the Fundamental Sampling Error (FSE) to be calculated for each of the sorted categories. From real-world examples of French MSW characterisations, this contribution shows which data are needed and how the FSE formulas are implemented, illustrating how it is possible to ascribe individual total error estimates for each category. This general overview will help local implementation efforts.

Evaluation of combustibility and energy potential of municipal solid waste: The case of Esenler Municipality

Waste management legislation has been amended and a policy has been set up to reduce the amount of waste sent to landfills within the framework of the EU regulations adoptions in Turkey. In this respect, the disposal of biodegradable wastes on landfills have been introduced and restricted with The Regulation on Landfilling of Wastes. For this purpose, the use of mechanical, biological and thermal processes to reduce waste amounts is envisaged. In this study, solid wastes produced in Esenler Municipality is characterized. Representative municipal solid waste (MSW) samples were collected and calorific values of MSW obtained from different socio-economic regions within the study area were examined.

Laboratory studies on effect of fiber content on dynamic characteristics of municipal solid waste

The dynamic characterization of municipal solid waste (MSW), especially in regions with high seismicity, is of considerable importance in the stability assessment of landfills. Additionally, findings indicated that the response of MSW under dynamic loadings is significantly affected by fibrous material. Therefore, a comprehensive strain-controlled cyclic triaxial testing program was performed on MSW samples retrieved from a landfill in the Kahrizak area, Tehran province. The tests were conducted on fresh MSW specimens (with a diameter of 100 mm) with different percentage of fibers in the consolidated undrained condition. The potential reinforcing capability of fibers and their impacts on changes in the MSW composition were investigated under variations of different factors including confining pressure, loading frequency, Poisson’s ratio, and loading cycles. From the results of the study, increasing fiber content in specimens resulted in improved elastic behavior of MSW under dynamic loadings, irrespective of the test conditions, such that the normalized shear modulus reduction curves shifted to the right, while the damping ratio curves exhibited no specific trend. However, it is necessary to simultaneously consider the impact of fiber contents, confining stress and shear strain on the variation rates of normalized shear modulus reduction values. This trend is attributed to the greater values of stiffness from changing the composition when compared with the one generated by obtained reinforcement within the studied strain range. Given the lack of systematic evaluations on the effect of the fibrous waste materials on the dynamic response of MSW, the results of this study provide additional insight into the seismic analysis of landfills.

Service Road Construction Using Cement Stabilized MSW at the Karadiyana Open Dumpsite, Sri Lanka

Dumping of municipal solid waste (MSW) on low-land is a waste disposal method used by most of the municipal councils in Sri Lanka. Rapid economic development, population growth, inadequate infrastructure and land scarcity have made it necessary to introduce improvements to MSW dump sites in the country. Setting up of new dumping sites is now being discouraged due to public pressure and steps are underway to optimize the existing dump yards. In this regard, the heights of the fills will have to be increased after the locations have been completely filled up with MSW although owing to poor style of dumping and very low bearing capacity of the fill, most of these locations will not be able to accommodate any further filling up. The situation at the dump site at Karadiyana is also same. Thus, a decision has been taken to have cement stabilized service roads as access roads to this dump site. Several samples were collected along the proposed service road stretch and basic studies on them were undertaken using Proctor compaction and California bearing ratio (CBR) tests to classify and investigate their present capacities. The values obtained are far below the values stipulated by ICTAD. After the MSW samples were stabilized with different cement proportions, it was observed that compared to the CBR of unimproved MSW, the CBR of cement stabilized MSW is significantly higher and that it exceeds the minimum value specified by ICTAD.

Multi-material classification of dry recyclables from municipal solid waste based on thermal imaging

There has been a significant rise in municipal solid waste (MSW) generation in the last few decades due to rapid urbanization and industrialization. Due to the lack of source segregation practice, a need for automated segregation of recyclables from MSW exists in the developing countries. This paper reports a thermal imaging based system for classifying useful recyclables from simulated MSW sample. Experimental results have demonstrated the possibility to use thermal imaging technique for classification and a robotic system for sorting of recyclables in a single process step. The reported classification system yields an accuracy in the range of 85–96% and is comparable with the existing single-material recyclable classification techniques. We believe that the reported thermal imaging based system can emerge as a viable and inexpensive large-scale classification-cum-sorting technology in recycling plants for processing MSW in developing countries.

Factors affecting the shear strength behavior of municipal solid wastes

In this study, the shear strength behavior of European (E-1), Turkey (T-1), and United States of America (U-1) average synthetic municipal solid waste (MSW) compositions were investigated. The large-scale direct shear tests were conducted using fresh and aged MSW samples collected from the Manisa Landfill. The natural samples’ test results were compared with synthetic samples. The affecting factors such as ageing, waste composition, and waste type (synthetic and natural) on the shear strength of MSWs were investigated. The effect of composition was evaluated using three main and six modified synthetic MSW compositions. In addition to the synthetic fresh MSW samples, synthetic aged samples were also used. Angle of shearing resistance decreased with increasing organic content whereas cohesion intercept increased with increasing organic content. The fresh and aged wastes with higher coarse fraction lead to a higher angle of shearing resistance. The synthetic aged samples had higher internal friction angles but lower cohesion values than the synthetic fresh samples. Waste with average European composition had the highest internal friction angle as it has the highest fibrous content. On the other hand, the highest cohesion belonged to the Turkey composition, which had the highest organic matter ratio. The main differences between E-1, T-1 and U-1 samples in terms of compositions were observed. The results of this study indicated that shear strength of waste significantly depends on composition and hence a site specific evaluation is recommended.