Co-incineration Of Waste Research Articles

High-temperature corrosion mechanisms of a Ni-based alloy in simulated multi-source organic waste co-incineration environments

Due to the new trend of co-incinerating municipal solid waste (MSW) with sewage sludge, medical waste, or industrial organic waste to attain a “waste-free” status, mixing of multi-source organic wastes (MSOW) increases the complexity of solid waste, which fluctuates the composition of corrosive species in the boiler. The fluctuation of corrosive species alters the alkali metals/S/Cl ratios and increases the uncertainties of high-temperature corrosion of boiler key components. The corrosion behaviors and mechanisms in varying compositions of corrosive species are complex and remain elusive. To investigate the corrosion characteristics during the co-incineration of MSOW, this study examined the corrosion mechanisms of a nickel-based Ni59.08Cr24.31Al10.74W5.3B0.57 alloy in simulated co-incineration environments of MSOW. The environment contained either HCl, NaCl, or SO2 in wet oxygen at 600 °C. For each case experiment, the maximum possible value of each corrosive species expected in the actual incinerator and/or its absence was considered. HCl of either 0 or 1500 ppm, SO2 of 0 or 300 ppm, and NaCl of 0 or 50 mg/cm2 were systematically used in each experiment. The influence of each corrosive condition on the corrosion of the alloy was evaluated by mass gain measurements, and the corrosion mechanisms were elucidated through SEM, EDS mapping, XRD, XPS analyses, and thermodynamic equilibrium calculations. The results revealed that NaCl salt and HCl gas in wet oxygen have complementary effects, which accelerated the corrosion of alloy, reaching ∼ 65.6 mg/cm2 over one week. HCl enhanced the corrosion by affecting the chemical reactions that regenerated NaCl, which participated in prolonged corrosion processes. SO2 reduced the mass gain of the alloy to 38.4 mg/cm2. SO2 participated in the sulfation of NaCl, forming a mixed layer of Na2SO4 and (Al/Cr)2O3, reducing the mass gain by 1.71 times. In the environment without NaCl, SO2 helped in the formation of a protective oxide layer, which prevented HCl from reaching the alloy, reducing the corrosion impact by 23.5 times.

Co-incineration of medical waste in municipal solid waste incineration increased emission of chlorine/brominated organic pollutants

Co-incineration of medical waste (MW) in municipal solid waste incinerators (MSWIs) is a crucial disposal method for emergency disposal of MW and the management of MW in small and medium-sized towns. This study aims to analyze and compare the levels and distribution patterns of chlorine/brominated dioxins and their precursors in fly ash from MSWIs and medical waste incinerators (MWIs) while also focusing on identifying the new pollution concerns that may arise from the co-incineration of municipal solid waste (MSW) mixed with MW (MSW/MW). The concentration of chlorobenzene (CBzs), polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) in fly ash from co-incineration of MSW/MW are 887.4, 134.4 and 27.6 μg/kg, respectively, which are 5.1, 2.0 and 2.9 times higher than that from MSWIs. The levels of polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs) are about three orders of magnitude lower than that of PCDD/Fs. For the fly ash from MSWIs, the predominant PCDD/Fs congener is OCDD, which prefers synthesis and adsorption on fine-grained fly ash. For fly ash from MWIs, the major PCDD/Fs congeners are 1, 2, 3, 4, 6,7, 8-HpCDF, and OCDF, which prefer synthesis and adsorption on coarse-grained fly ash. Correlation analysis exhibited that both 1,2,3-TriCBz and 1,2,4-TriCBz in fly ash have a markedly linear correlation with PCDD/Fs and PCBs, but PBDD/Fs shows a poor negative correlation with PCDD/Fs.

New multi-source waste co-incineration and clustering park operating model for small- and medium-sized city: A case study in China

With improvements in urban waste management to promote sustainable development, an increasing number of waste types need to be sorted and treated separately. Due to the relatively low amount of waste generated in small- and medium-sized cities, separate treatment facilities for each waste type lack scale, waste is treated at a high cost and low efficiency. Therefore, industrial symbiosis principles are suggested to be used to guide collaborative waste treatment system of multi-source solid wastes, and co-incineration is the most commonly used technology. Most existing studies have focused on co-incineration of one certain waste type (such as sludge or medical waste) with municipal solid waste (MSW), but the systematic design and the comprehensive benefits on a whole city and park level have not been widely studied. Taking the actual operation of a multi-source waste co-incineration park in south-central China as an example, this study conducted a detailed analysis of the waste-energy-water metabolism process of MSW, sludge, food waste, and medical waste co-incineration. The environmental and economic benefits were evaluated and compared with the single decentralized waste treatment mode. The results showed that the multi-source waste co-incineration and clustering park operating model was comprehensively superior to the single treatment mode, greenhouse gases and human toxicity indicators were decreased by 11.87% and 295.74%, respectively, and the internal rate of return of the project was increased by 29.35%. This mainly benefits from the synergy of technical system and the economies of scale. Finally, this research proposed policy suggestions from systematic planning and design, technical route selection, and an innovative management mode in view of the potential challenges.

The impact of pollutant emissions from co-incineration of industrial waste in municipal solid waste incinerators

A large amount of industrial solid waste (including waste plastics, textiles, wood, etc., which are byproducts of industrial production) urgently needs to be treated. Incineration is undoubtedly the most efficient and convenient method. The existing municipal solid waste incineration plants can be transformed to burn such industrial wastes. However, the potential risks associated with high levels of heavy metals in industrial waste and the air pollution caused by co-incineration pose significant challenges to the co-incineration disposal of industrial solid waste. The change of physical and chemical properties of municipal solid waste and the emission characteristics of flue gas pollutants after co-incineration of industrial waste were studied by means of material flow simulation and experiment. In addition, experiments were designed to study the effects of temperature, calcium sulfur ratio and chlorine content on heavy metal emission during the incineration of industrial waste. The results showed that co-incineration of a certain proportion of industrial waste significantly increased the calorific value of municipal solid waste, but excessive mixing of plastic and paper industrial waste would increase the ash content. Co-incineration of plastic industrial waste can significantly increase HCl, and with the increase of temperature, the transformation of Cl to HCl is more thorough. The increase of temperature can promote the migration of Cr, Pb and Se elements to the gas phase. When Cr, Pb, and Se elements are present in the gas phase, they can combine with other gases and aerosols to form particulate matter and toxic substances, causing air pollution. When Ca/S is 1, Ba, Mn, Ni, Zn can effectively reduce the retention rate of elements in the ash. Under certain conditions, chlorine in industrial waste plastics will react with Zn to form tiny particles and low boiling point chlorides, which will increase its volatility. The mineral components in the ash can also be used for making ceramsite and building materials. These results will provide reference for the pollutants controlling during co-incineration of industrial waste and municipal solid waste process.

Inventory of PCDD/Fs and Fly Ash Characteristics during the e-Waste and Municipal Solid Waste Co-Incineration Process

In the face of a challenging situation for yearly e-waste (EW) increment and disposition, EW co-incineration (EWC) with municipal solid waste (MSW) is a promising solution whose emission characteristics remain unclear. This study is conducted in a 400 tons/day MSW incineration (MSWI) plant to characterize polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and fly ash (FA) properties. Analytical methods include high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS) for PCDD/F determination, as well as X-ray diffraction (XRD), X-ray fluorescence (XRF), ion chromatography (IC), and leaching toxicity test for FA. The results indicate that toxic PCDD/F amounts are doubled by EWC in both primary exhaust gas (EG) and FA with international toxic equivalent quantity (I-TEQ) concentrations of 19.00 ± 6.32 ng I-TEQ/Nm3 and 1.33 ± 0.56 ng I-TEQ/g. After the clean-up of the air pollution control system (APCS), emitted PCDD/Fs in solid and gas phases, as well as major air pollutants (CO, NOx, SO2, HCl, and particulate matter), are permissive within the limit values of national standards GB 18485-2014 and GB 16889-2008. Distribution patterns for 136 PCDD/F isomers are analogous in both MSWI and EWC conditions. De novo synthesis is always the major formation route for both EWC and MSWI conditions, while dibenzodioxin/dibenzofuran (DD/DF) chlorination also contributes. The generation of 136 PCDD/Fs is enhanced by EWC, and the correlation coefficients of Cl and Cu in the fuel with the generation of 136 PCDD/F isomers are found to be R = 0.92 and 0.88, respectively. The main components in FA from MSWI and EWC differ less, both containing CaO, SiO2, and Al2O3. However, Cl and Cu contents, as well as leaching toxicity in FA are elevated by EW. Heavy metals, except for Cd, Ni, and Pb, meet the requirement of the standard.

Capitalization of tires waste as derived fuel for sustainable cement production

The co-incineration of tires waste is inexpensive; the questions are referring to the influence over clinker quality and gaseous emissions. The use of tires waste as a waste-derived fuel imposes more researches to establish influence over process parameters, technological availability, costs, kiln design for processing different type of fuels, quality and homogeneity of alternative fuels, the caloric value, quality of clinker, gaseous emission, etc. The data was obtained at an industrial scale, during two periods when 11% tires waste replaces coal, with or without raw mill in function. The results were compared with the period when coal was the only fuel used. The principal objective of this paper is to establish the influence, at the industrial scale, of the use of tires waste on: the technological parameters of the clinker kiln as well as on its energy efficiency and stability; the effects of tires waste incineration on clinker process and properties of clinker, SO2, NOx and heavy metals emission. The experimental results presented in the paper demonstrated that the co-incineration of tires wastes in cement plants have the multiple benefits: save raw materials, reduced CO2 emission, thermo-energy recovery of waste with rich energy content, reduces waste disposal, etc.

Repercussions of clinical waste co-incineration in municipal solid waste incinerator during COVID-19 pandemic

During coronavirus disease 2019 pandemic, the exponential increase in clinical waste (CW) generation has caused immense burden to CW treatment facilities. Co-incineration of CW in municipal solid waste incinerator (MSWI) is an emergency treatment method. A material flow model was developed to estimate the change in feedstock characteristics and resulting acid gas emission under different CW co-incineration ratios. The ash contents and lower heating values of the feedstocks, as well as HCl concentrations in flue gas showed an upward trend. Subsequently, 72 incineration residue samples were collected from a MSWI performing co-incineration (CW ratio <10 wt%) in Wuhan city, China, followed by 20 incineration residues samples from waste that were not co-incineration. The results showed that the contents of major elements and non-volatile heavy metals in the air pollution control residues increased during co-incineration but were within the reported ranges, whereas those in the bottom ashes revealed no significant changes. The impact of CW co-incineration at a ratio <10 wt% on the distribution of elements in the incineration residues was not significant. However, increase in alkali metals and HCl in flue gas may cause potential boiler corrosion. These results provide valuable insights into pollution control in MSWI during pandemic.

ВЕКТОРИ ТРАНСФОРМАЦІЇ ПРАВОВОГО РЕГУЛЮВАННЯ У СФЕРІ ЕНЕРГЕТИЧНОГО ВИКОРИСТАННЯ ВІДХОДІВ

The present article examines the problem of transformation of legal regulation in the field of energy use of waste taking into account both external and internal factors of influence. The main purpose of the article is to specify the vectors of this transformation. One of the vectors is the strengthening of energy specialization of the waste legislation. Within the framework of this issue, the innovations proposed by the draft Law of Ukraine on waste from 04.06.2020 are being considered. Special attention is given to such innovations as waste hierarchy, requirements for incineration and co-incineration of waste, as well as criterion of energy efficiency for incineration facilities. The place of particular energy operation with waste in the waste hierarchy depends on its environmental, resource-saving, energy efficient and other characteristics. The problems of legal regulation in the field of the management of waste from extractive industries with a high energy value are also studied. Another important transformation vector of legal regulation in the field of energy use of waste is a more complete reflection of waste specificity in the energy legislation. The analysis of the laws of Ukraine “On Alternative Energy Sources” and “On Alternative Fuels” shows that the specificity of waste as an energy source is not fully reflected in them. There are new approaches of the Directive (EU) 2018/2001 on the promotion of the use of energy from renewable sources to the regulation of relations in the field of waste as a type of biomass. It is advisable to apply some of these approaches in Ukraine. It is noted that the development of legal regulation along these vectors will contribute to the harmonization of goals of the waste legislation and the energy legislation.

Conventional and Alternative Sources of Thermal Energy in the Production of Cement—An Impact on CO2 Emission

The article evaluates the reduction of carbon dioxide emission due to the partial substitution of coal with alternative fuels in clinker manufacture. For this purpose, the calculations were performed for seventy waste-derived samples of alternative fuels with variable calorific value and variable share in the fuel mixture. Based on annual clinker production data of the Polish Cement Association and the laboratory analysis of fuels, it was estimated that the direct net CO2 emissions from fossil fuel combustion alone were 543 Mg of CO2 per hour. By contrast with the full substitution of coal with alternative fuels (including 30% of biomass), the emission ranged from 302 up to 438 Mg of CO2 per hour, depending on fuel properties. A reduction of 70% in the share of fossil fuels resulted in about a 23% decrease in net emissions. It was proved that the increased use of alternative fuels as an additive to the fuel mix is also of economic importance. It was determined that thanks to the combustion of 70% of alternative fuels of calorific value from 15 to 26 MJ/kg, the hourly financial profit gain due to avoided CO2 emission and saved 136 megatons of coal totaled an average of 9718 euros. The results confirmed that the co-incineration of waste in cement kilns can be an effective, long-term way to mitigate carbon emissions and to lower clinker production costs. This paper may constitute a starting point for future research activities and specific case studies in terms of reducing CO2 emissions.

Industrial tests of co-combustion of alternative fuel with hard coal in a stoker boiler

ABSTRACT This paper presents the results of industrial research on co-combustion of solid recovered fuel (SRF) with hard coal in a stoker boiler type WR-25. The share of SRF in the fuel mixture was 10%. During the co-combustion of SRF, no technological disturbances of the boiler were noted. The obtained SO2 and NOX emissions were comparable with coal combustion, but dust emissions increased. During the co-combustion of the coal mixture with 10% of alternative fuel, acceptable standards for co-incineration of waste were exceeded for NOx, dust, CO, HCl, HF, heavy metals, dioxins, and furans. The by-products of waste co-combustion with coal were non-hazardous waste. The obtained results constitute a very important contribution to the process of boiler retrofitting toward a waste co-incineration unit, and to meeting the legislative and environmental requirements. Implications: Due to some challenges related to waste storage and transportation, combustion in incineration plants and Waste-to-Energy plants is not possible. The adaptation (formal and technical) of medium scale boilers as co-incineration plants reveals high potential. Nevertheless, the lack of experience and investigations of waste co-combustion in real industrial scale grate boilers is observed. Thus, the implication of this article results consists of the investigations using industrial scale mechanical grate boiler (different from incineration type). Moreover, the investigations were carried out in a low-capacity boiler (~50% of nominal capacity). This novel experience is very important because reduced heat dissipation into the grid caused by high ambient temperatures occurs very frequently. These tests are valuable from the point of view of retrofitting the unit to obtain technological and emission parameters that would allow obtaining the status of a waste co-incinerating unit. The results of these investigations are addressed to power plant management board and engineering staff.

Process of Formaldehyde and Volatile Organic Compounds’ Removal fromWaste Gases

Waste gases that cannot be released into the environment are generated in chemical industrial processes. There are various physico-chemical processes for the treatment of these gases, but in most cases, they present a major cost to the company. There is an EU directive for each industrial area describing the best available techniques (BAT) and the prescribed environmental limits for the maximum discharge of dangerous substances into the environment. The current process for the removal of formaldehyde and volatile organic compounds from waste industrial gases meets EU environmental regulations. However, expected new EU directives will require a significant reduction in formaldehyde and volatile organic compounds’ concentrations in industrial exhaust gases, thus necessitating a new technical solution for the removal of formaldehyde. This paper describes two methods of removing formaldehyde and volatile organic compounds from waste gases, generated by the metal oxide catalyst formaldehyde production processes. The first method involves upgrading existing processes of removing formaldehyde from waste gases with an additional absorption plant, with which emissions can be significantly reduced. The second method describes the co-incineration of waste gases generated by a metal oxide catalyst formaldehyde production process with natural gas in a gas turbine, where formaldehyde and volatile organic compounds are completely removed, while electricity is also produced. The second method is also useful for removing various concentrations of volatile organic compounds from waste gases generated in chemical industrial processes.

PAHs and heavy metals in the surrounding soil of a cement plant Co-Processing hazardous waste

The Chinese government is encouraging domestic cement producers to move from traditional coal power sources to the co-processing of waste as the primary energy source for the industry. In this study, 32 samples collected from the soil surrounding a cement plant in Beijing were analyzed for the presence of 16 U.S. EPA priority polycyclic aromatic hydrocarbons (PAHs) and 12 heavy metals. Ten samples were selected for polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) analysis. The pollution distribution patterns, sources, and potential risks to human health and the environment were investigated and evaluated. The highest concentrations of PCDD/Fs occurred 1200 m downwind from the cement plant. The levels of ∑16 PAHs ranged from 130.6 to 1134.3 μg kg−1 in the sampled soils. Source identification analysis suggested that the cement plant was the most likely source of PAH contamination. The concentrations of most of the heavy metals detected in the sampled soils were close to background levels, except for the levels of cadmium (Cd) and mercury (Hg), which were, on average, two times and six times higher than background values, respectively. The co-incineration of sludge, coal, and hazardous waste in the cement plant is a major contributing cause for the high levels of Hg in the surrounding soil. Risk assessment models, both the incremental lifetime cancer risks (ILCRs) for PAHs and the potential ecological risk index (RI) for heavy metals, indicate potential risks to the population and the environment surrounding the cement plant.

Comparison of dust emissions from an individual wood-fired boiler and dust emissions in the production of the same amount of heat in a combined heat and power plant

Comparison of dust emissions from an individual wood fired boiler (of various types) and of dust emissions during generation of the same amount of heat in a heat and power station were the aim of this work. For the purpose of the calculations the dust emissions from the heat and power station were assumed as the maximum permissible dust emissions, in line with the regulation of the Minister of Environment of 4 November 2014 on emission standards for certain types of installations, fuel combustion sources and waste incineration and co-incineration devices. The emissions of dusts for boilers were assumed based on available publications. For the purposes of the analysis, three boilers of 15 [kW] power were considered. Based on the obtained results it can be stated that the amounts of dust emitted by selected wood-fired boilers are not significantly different from the amount of dust emitted by a heat and power station for the same effect on the recipient’s side. Heating boilers of powers lower than 15 [kW] exist and for some of them the dust emissions are even smaller than for the boilers discussed herewith. The discussed boilers have heating efficiency of 86 %. If their efficiency were to be higher, the concentration of the dust would have been lower. The solid fuel (wood) fired boilers considered in this work are not the best ones on the market with respect the dust emissions. The ongoing development of the fuel combustion technology allows expecting even further reduction of emissions of dusts.

Energy and emission aspects of co-combustion solid recovered fuel with coal in a stoker boiler

The results of industrial research on co-combustion of solid recovered fuel (SRF) with hard coal in a stoker boiler type WR-25 has been presented. The share of SRF in the fuel mixture was 10%. During the co-combustion of SRF, no technological disturbances or significant reduction in energy efficiency of the boiler were noted. Obtained SO2, NOx and CO emissions were comparable with coal combustion but dust emissions increased. During combustion of the coal mixture with a 10% share of SRF in the test boiler WR-25, the emission standards established for the combustion of the dedicated fuel were met. However, comparison of obtained emission results with the emission standards established for co-incineration of waste, revealed the exceedance of permissible levels of HCl, dust, heavy metals, dioxins and furans. Additionally, the residence time of flue gases in over 850°C conditions for the test boiler WR-25 was too short (1.3 seconds) in refer to the legislative requirements (2 seconds) for the thermal conversion of waste.

Profiles of polychlorinated biphenyls (PCBs) in cement kilns co-processing solid waste

Co-incineration of sewage sludge in cement kilns can be used for its disposal. In the present study, samples were collected from three cement production runs where sewage sludge and other wastes (e.g. municipal solid waste, waste acid and wet sewage sludge) were co-processed. The samples were analyzed for polychlorinated biphenyls (PCBs). The dioxin-like (dl)-PCB concentrations in the stack gases from run 1, 2, and 3 were 344.6, 548.7, and 104.3 pg m−3, respectively. The toxic equivalency (TEQs) values for runs 1, 2, and 3 were 5.6, 8.9, and 0.7 pg TEQ Nm−3, respectively. Calculation of net emissions for the three runs indicated that the co-incineration of other waste in addition to sewage sludge in cement kilns would not increase emission of the dl-PCBs. PCB concentrations in samples from the suspension boiler and humidifier tower, kiln-end bag filter, and cyclone preheater were much higher than those in samples from the kiln head area, indicating that these stages will be important for controlling PCB formation. Chlorinated biphenyl (CB)-77, CB-105 and CB-118 were the major dl-PCB congeners, CB-52, CB-101 were the major indicator PCB congeners, and tetra-CB to hexa-CB were the major homologues for the total input or output materials.

Dioxin-like pcb emissions from cement kilns during the use of alternative fuels

The substitution of combustion fuels in cement plants is increasing throughout many countries, and its individual performance is constantly assessed against strict regulatory standards. For cement plants within Australia, normal operations remain to use petroleum coal as the dominate energy source at the precalciner, avoiding the opportunity to reduce carbon-based resources and pollutant emissions (such as carbon dioxide, oxides of nitrogen, persistent organic pollutants) whilst providing the necessary energy needs through resource recovery. This paper presents stack emission monitoring of health-critical dl-PCB (dioxin-like polychlorinated biphenyl) congeners during the substitution of alternative fuels at ten Australian cement plants, and to distinguish statistical similarities between other key pollutants (such as polychlorinated dibenzo-p-dioxins and furans (PCDD-F) and hydrogen halogens) and amongst the fuels used. Sampling of plant emissions was performed during normal operations (as baseline trials) and with the varied substitution rates of waste oil, solvents, chipped wood, refuge waste, carbon dust, shredded tyres and black sand (as experimental trials).The extraction of field and analytical data during these trials allowed for determining the total and individual unit mass of dl-PCB and PCDD-F isomers, standardised to 10% O2 and to World Health Organization (2005) toxicity equivalence (TEQ) values. The findings showed waste co-incineration during cement operations does reduce health-critical congeners of dioxins and dl-PCBs whilst providing the necessary energy and calcination needs. Experimental trials showed all dl-PCBs and PCB TEQ are below the internationally regulated Stockholm Convention article of 10pg TEQ/Nm3. In several cases, an increased rate of substituted fuel also identified a consistent reduction to baseline dl-PCBs. The distribution of toxic isomers (TCDD-F and PeCDD-F) were shown to be predominate during waste oil, wood chips, and solvent trials. Whereas the use of TDFs consistently showed a lower toxicity contribution. The distribution of dl-PCBs toxic congeners showed PCB-126 (3,3′,4,4′,5-Pentachlorobiphenyl) to be greatly present during the co-incineration of waste oil, wood chips, solvents and TDF trials. Principle component analysis identified a statistical predominance from the 1,2,3,7,8-PeCDF (Pentachlorodibenzofuran) and 1,2,3,4,7,8-HxCDF (Hexachlorodibenzofuran) congeners, while dl-PCBs TEQs had similar correlation amongst combustion fuels with major contributions being from the PCB-126 and PCB-169 (3,3′,4,4′,5,5′-Hexachlorobiphenyl) congeners.

Inhalation Exposure to Dioxins and dl-PCBs Depending on the Season in Upper Silesia, Poland: A Pilot Study.

The aim of this study was to investigate the seasonal fluctuation of PCDD/Fs and dl-PCBs levels in the ambient air of Upper Silesia in the aspect of human inhalation exposure as well as the estimation of health risk attributed to this exposure pathway to dioxins and dl-PCBs. In the study air samples were taken in five urban districts of Upper Silesia, Poland, where the houses are heated with coal. The same sampling points in summer and winter were analyzed for dioxins/furans and dl-PCBs. In addition, information was collected on awareness of the residents about the co-incineration of plastic waste and effects of this activity on human health. The results show that the average daily exposure of residents of Upper Silesia to TCDD and DLCs in the heating season was about 6.5.-fold higher than in summer. The risk assessment showed that expected excess of cancer cases per 1,000,000 people ranged from 4.5 to 13.2 in winter and from 0.9 to 2.1 in summer. The practice of mixing waste with coal for houses heating has been confirmed by investigated families, who do not associate it with the possibility of negative health effects. Air pollution can be a significant source of dioxin and dl-PCB for people during the winter season, as a result of co-burning coal and waste containing plastics. The dose of dioxins inhaled through the respiratory pathway in winter can be associated with the higher cancer risk in the population of Upper Silesia.

Study on Air Pollutants Emission from Food Waste Co-incineration in Industrial Waste Incinerators

Study on Air Pollutants Emission from Food Waste Co-incineration in Industrial Waste Incinerators

Factors governing particle number emissions in a waste-to-energy plant

Particle number concentration and size distribution measurements were performed on the stack gas of a waste-to-energy plant which co-incinerates municipal solid waste, sewage sludge and clinical waste in two lines. Average total number of particles was found to be 4.0·105cm−3 and 1.9·105cm−3 for the line equipped with a wet flue gas cleaning process and a dry cleaning system, respectively. Ultrafine particles (dp<100nm) accounted for about 97% of total number concentration for both lines, whereas the nanoparticle (dp<50nm) contribution differed slightly between the lines (87% and 84%). The experimental data is explored statistically through some multivariate pattern identifying methods such as factor analysis and cluster analysis to help the interpretation of the results regarding the origin of the particles in the flue gas with the objective of determining the factors governing the particle number emissions. The higher moisture of the flue gas in the wet cleaning process was found to increase the particle number emissions on average by a factor of about 2 due to increased secondary formation of nanoparticles through nucleation of gaseous precursors such as sulfuric acid, ammonia and water. The influence of flue gas dilution and cooling monitored through the variation of the sampling conditions also confirms the potential effect of the secondary new particle formation in increasing the particle number emissions. This finding shows the importance of reporting the experimental conditions in detail to enable the comparison and interpretation of particle number emissions. Regarding the fuel characteristics no difference was observed in terms of particle number concentration and size distributions between the clinical waste feed and the municipal solid waste co-incineration with sludge.

Analytical approach and occurrence for the determination of mass concentration of PCDD/PCDF and dl-PCB in flue gas emissions using long-term sampling devices

In this work, a reliable methodology for the simultaneous analysis of PCDD/PCDF and dioxin-like PCB (dl-PCB) in flue gas emissions collected using continuous sampling devices is proposed. The analytical scheme followed the minimum requirements described in the EU standard EN-1948:1,2,3,4 according to samples containing large amounts of dioxins and dl-PCBs or samples collected over a long period of time of about 4weeks. Parameters, such as reproducibility, precision, limits of detection (LOD), limits of quantification (LOQ), extract aliquot size, analytical blanks, extraction efficiency, as well as the amount of internal standards required for an accurate determination, were assessed.The findings demonstrate the suitability of the proposed analytical scheme for the analysis of PCDD/PCDF and PCB in samples collected using long-term sampling devices. The analysis of five different 5% v/v sample aliquots reported %RSD values lower than 10% for all of the 29 congeners at both low and high levels. Similarly, %RSD values were 3.2 and 2.0 for the low level samples and 0.9 and 1.1%RSD for the high level extracts for PCDD/PCDF and dl-PCB, respectively expressed in total TEQ units. Re-extraction provided values less than 3%, expressed in TEQ. Based on blank analyses, LOD values of 100pg I-TEQ for PCDD/PCDF and 10pg WHO-TEQ for dl-PCB were achieved when 5% v/v aliquots were analyzed.Finally, the proposed analytical approach was tested with samples from a wide range of combustion processes such as hazardous and municipal waste incinerators, as well as cement kilns (with and without waste co-incineration).