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An efficient catalytic detoxification method for polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in fly ash produced by municipal waste incinerator has been studied using palladium on carbon (Pd/C) catalyst. As one of the trace components in fly ash, the detoxification of PCDD/Fs is very difficult because of the interferences of other persistent components with higher concentrations. However, the detoxification reaction of PCDD/Fs shows higher activity in water/isopropanol solution using commercial Pd/C catalyst at 40°C under normal pressure. The results indicated that the catalytic degradation of PCDFs has been found to be easier than that of PCDDs. Moreover, the dechlorination ratios were higher for octa- and hepta-chlorinated congeners than those for tetra- and penta-chlorinated ones. The detoxification process worked well in water. The dechlorination efficiencies of almost all of the PCDD/Fs congeners can reach over 99% within a shorter reaction time. [Copyright &y& Elsevier]

SUWIC’s unique mobile metals emissions monitoring laboratory has been used to measure metal pollutant spikes in the flue gas from a municipal solid waste incinerator, prior to gas clean-up. The laboratory has a heated sampling probe that extends into the plant, allowing the simultaneous on-line measurement of the concentrations of more than 30 metals by Inductively Coupled Plasma–Optical Emission Spectrometry (ICP–OES). As little is known about temporal variation in metal concentrations, this capability is seen as a major advance. The graphs of continuous measurements show that the elemental loading is far from uniform, and that concentrations fluctuate far more than may have been conventionally expected. There are occasional significant spikes in the emission profiles for cadmium and mercury, which are believed to be due to specific items in the waste feed material. Continuous monitoring measurements are of significant value for those seeking to model metal behaviour in combustion and in pollution control devices. [Copyright &y& Elsevier]

Studies the effect of metal nitrates on the formation of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F) during newspaper combustion. Advantages of the use of incineration in the treatment of municipal solid waste; Major disadvantage of incineration process; Explanation on the formation of PCDD/D during incineration; Chloride emission due to dioxin formation in furnaces.

In this conceptual study a feasibility analysis was carried out in order to define the viability of an incineration plant with a capacity of 100 t/d, with energy recovery and environmental safety, in Greece. Using realistic estimates of waste composition and heat content, an appropriate incineration method was selected, as well as near optimum operating conditions of process equipment. The European and Greek legislation related to environmental protection was reviewed. The application of stricter requirements for the incineration of domestic wastes has resulted in increased investment and operational costs. Six emission abatement options were studied and the increase of the total investment and operational cost of their use was estimated. What resulted is that a capacity of 100 t/d incineration with energy recovery and environmental safety is an expensive method, and the increase on cost due to the best available emission control system was calculated as 26% for the investment cost and 6.5% for the operational cost. However, high costs might be compensated from the increased fuel and energy prices, the increased landfill taxes, and increased land values. [ABSTRACT FROM AUTHOR]

Examines the benefits of the use of fluidized bed combustion (FBC) boilers for solid waste incineration and applications for dioxin and furan formations. Function of FBC; Emissions produced by FBC; Applications of FBC.

Reports on a study on the emissions of several pollutants, including polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF), from the open burning of household waste in barrels. Finding that backyard burning emits more PCDD and PCDF on a mass of refuse burned basis than various types of municipal waste combustors.

Provides information on a study which evaluated and compared hydrochloric acid leaching, chloride evaporation, acetic acid leaching and biological leaching as processes of heavy metal removal for municipal solid waste incineration fly ash. Details on the proposed heavy metal removal processes in literature; Discussion on the process evaluation; Results and discussion.

Examines emission of products of incomplete combustion (PICs) resulting from incineration of carbon tetrachloride and dichloromethane. Higher levels of PICs from dichloromethane; Benzene emissions as the major component of the PICs; Indication that benzene emissions are affected by the afterburner air/fuel ratio. INSET: Implications..

Presents a study in which Cr concentrations and speciation were determined in leachate from a municipal solid waste incinerator (MSWI) bottom ash landfill. Reference to debate surrounding the environmental impact of MSWI; Objectives of incineration; What is responsible for the increasing role of MSWI in integrated waste management systems.

Studies the effect of combustion- and sorbent-injection-related parameters on the mechanism of polychlorinated dibenzo-p-dioxin (PCDD) and polychlorinated dibenzofuran (PCDF) formation in waste combustors. Simulation of fly ash loading of a waste combustor; Use of upstream sorbent injection to prevent PCDD and PCDF formation.

The article presents a study which explores the relationship between incineration and dioxins and furans in lakedbed sediments in Canada. It states that significant amount of dioxins and furans originate from the air emissions of waste incinerators. It presents a chart which summarizes the findings of the study depicting the toxic equivalencies (TEQs) of the samples collected.

Focuses on the use of catalytic means to destroy dioxins produced in the incineration of wastes. Description of dioxins; Structure of chlorinated dibenzo-p-dioxins and dibenzofurans; Toxic equivalence factors for the most dangerous dioxins; Details of how dioxins are produced from waste incineration; Description of catalytic removal of dioxins.

The article discusses the municipal waste management (MSW) carried out in Thailand through waste incineration by using the byproducts for the construction of roads and emphasizes on the environmental regulations set up by the government to manage waste reduction in Thailand.

In this article the authors discuss the potential for serious environmental threats from the uncontrolled processing of wastes in cement kilns. They note that the use of cement kilns to co-process wastes containing heavy metals is thriving in many developing countries and playing a role in solid waste management, particularly hazardous waste disposal. Topics include the wide and successful use of cement kilns to co-process wastes in the U.S., Europe, and Japan, the fate of hazardous substances during waste co-processing and its associated environmental risks, and the environmental aspects of co-processing wastes containing heavy metals in cement kilns.

The article discusses a research by Christine Wiedinmyer and others at the National Center for Atmospheric Research in Boulder, Colorado, published in the periodical "Environmental Science and Technology" in 2014 related to the environmental aspects of emissions from open burning of rubbish.

Treatment of solid waste continues to be on the political agenda. Waste disposal issues are often viewed from an environmental perspective, but economic and social aspects also need to be considered when deciding on waste strategies and policy instruments. The aim of this paper is to suggest flexible and robust strategies for waste management in Sweden, and to discuss different policy instruments. Emphasis is on environmental aspects, but social and economic aspects are also considered. The results show that most waste treatment methods have a role to play in a robust and flexible integrated waste management system, and that the waste hierarchy is valid as a rule of thumb from an environmental perspective. A review of social aspects shows that there is a general willingness among people to source separate wastes. A package of policy instruments can include landfill tax, an incineration tax which is differentiated with respect to the content of fossil fuels and a weight based incineration tax, as well as support to the use of biogas and recycled materials. [Copyright &y& Elsevier]

Incremental lifetime health risks due to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) emitted from municipal waste incineration (MSWI) facilities were evaluated for resident population in the area of the plant. Risk assessment was performed through a multipathway combined probabilistic/deterministic approach for analyzing the effects of uncertainty and intrinsic variability of the main PCDD/F emission related parameters on final predicted values. Exposure through direct inhalation of contaminated air, soil ingestion, soil dermal contact and diet were considered, with the propagation of the variability of input parameters throughout the evaluation performed with Monte Carlo simulation techniques. The application to a case study representative of two different technological scenarios (modern facilities equipped with BAT – Best Available Technology – and older incinerators) in a location site typical of Northern Italy situation results in median values of the maximum individual excess risk on the order of 10−9 and 10−7 for most recent and older plant configurations, respectively. Corresponding ratios for the 90th and 10th percentile values are around 7 and 9. Individual risk estimates derived for the same scenarios from conventional deterministic approaches, where large conservative assumptions are normally adopted for compensating the lack of knowledge about uncertainty, are essentially comparable with maximum values resulting from the probabilistic approach, thus leading to situations with extreme and very low probabilities of occurrence. PCDD/F health risks from MSWI emissions might thus result largely overestimated if real emission characteristics are not properly considered in the assessment procedure. Sensitivity analysis for identifying the contribution of different input parameters on final predicted risk variance indicates, for the area considered in the simulation, a prevailing influence of PCDD/F stack concentration, with exposures arising from soil deposition phenomena substantially negligible: this latter result further points out the requirements for a very careful identification of base input data values for PCDD/F stack concentrations, at least for those situations where plants are located nearby urban areas. [Copyright &y& Elsevier]

In this paper results of various measurement campaigns at different municipal waste incineration (MWI) plants concerning the change of the PCDD/PCDF isomer distribution in the crude gas during transiently impaired combustion conditions are presented. The focus is on the Cl4DD isomer distributions exemplarily for all other homologue groups to demonstrate the change in PCDD/PCDF formation mechanism at transient combustion conditions. Additionally to crude gas samples, at one plant filter and boiler ash were investigated simultaneously to determine if there is any difference in the isomer distribution between the matrices. For the ash from an electrostatic precipitator (ESP ash), the boiler ash and the corresponding crude gas sample, nearly identical changes in the Cl4DD isomer distribution under transient combustion conditions in relation to the normal operation process could be detected. By comparing the Cl4DD isomer distributions from different incineration plants (two municipal waste incinerators and one little incinerator burning wood chips for heating domestic household) under transient combustion conditions, in all cases the 1,3,6,8- and 1,3,7,9-Cl4DD were dominating the isomer distribution, whereas under normal operation other isomers were predominant. Obviously PCDD/PCDF formation mechanisms under transient combustion conditions are independent from the type of incinerator and of the burned fuel, respectively. Data sets were analyzed with respect to the possible reaction mechanism via chlorophenols and a good correlation of 2,4,6-trichlorophenol during the second phase of a start-up process and during a CO experiment was found. To get more detailed information about possible formation mechanisms, at one plant the dependence of the PCDD/PCDF isomer distribution on the different matrices was studied. Separate analysis of fly ash collected at the boiler exit, subsequent gas phase, ESP ash and boiler ash under normal operation conditions showed that, apart from the fly ash, the Cl4DD isomer distributions are nearly the same in the different matrices. Surprisingly, the Cl4DD isomer distribution of the fly ash was more similar to the distributions found under transient combustion conditions. [Copyright &y& Elsevier]

Biomonitoring of dioxin body burden, as evaluated by PCDD/F levels in blood, has been carried out in a total of 138 adults from general population living in the vicinity of solid waste incinerators in Portugal. Measurements were performed included in cross-sectional surveys within two Environmental Health Surveillance Programs launched in response to ecotoxicological concern in relation to solid waste incinerators near Lisbon and in Madeira Island. Overall conclusion from first published results is indicative that dioxin exposure of global populations cannot be related to the emissions of these facilities, meaning that dioxin sources control seems to be effective in relation to both incinerators. Main objective of present work was to investigate potential determinants of dioxin levels in the studied populations. Findings from this investigation also suggest that incineration does not impact on dioxin blood levels of nearby residents. Follow-up of a small group of individuals (22) from Lisbon gives preliminary indication on temporal control effectiveness of the Lisbon facility. Regarding comparison between PCDD/F levels from Lisbon and Madeira communities, individuals from Lisbon show higher median PCDD/F levels, likely to be better explained by more highly polluted areas in Lisbon than by eventual differences in dietary habits of the studied groups. In fact, analysis performed on the diet of both groups (not detailed in the present study) does not show a statistically significant difference in relation to any of the most relevant foodstuffs in the context of dioxin exposure. Comparison between Lisbon and Madeira in relation to pattern of the single congeners for PCDD/Fs shows a very similar profile. The highest contributions to the PCDD/Fs toxicity came from 12378-PCDD, 23478-PCDF, Hexa-CDD, 2378-TCDD and Hexa-CDF. [Copyright &y& Elsevier]

The PCDD/F concentrations and removal efficiencies achieved with air pollution control devices (APCDs) during different operating periods (start-up, normal operation, and shut-down) at an existing municipal waste incinerator (MWI) in Taiwan are evaluated via stack sampling and analysis. The MWI investigated is equipped with electrostatic precipitators (EP), wet scrubbers (WS), and selective catalytic reduction system (SCR) as APCDs. The sampling results indicate that the PCDD/F concentrations at the EP inlet during start-up period were 15 times higher than that measured during normal operation period. The PCDD/F concentration observed at shut-down period was close to that measured at normal operation period. The CO concentration was between 400 and 1000ppm during start-up period, which was about 50 times higher compared with the normal operation. Hence, combustion condition significantly affected the PCDD/F formation concentration during the waste incineration process. In addition, the distributions of the PCDD/F congeners were similar at different operating periods. During the normal operation and shut-down periods, the EP decreases the PCDD/F concentration (based on TEQ) by 18.4–48.6%, while the removal efficiency of PCDD/Fs achieved with SCR system reaches 99.3–99.6%. Nevertheless, the PCDD/F removal efficiency achieved with SCR was only 42% during the 19-h start-up period due to the low SCR operating temperature (195°C). [Copyright &y& Elsevier]

This paper reports on an intensive study into releases of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans from 19 chemical production facilities in the United States producing, or using, large volumes of chlorine. Releases on-site to air, water and to landfill were assessed as were transfers off-site in materials for disposal or additional treatment. The primary purpose was to develop estimates of releases on a site-specific basis that could be used in the US EPA inventory of dioxin-like compounds, it also serves to increase the database on releases from this industry which are comparatively poorly studied. Releases varied considerably and a prime conclusion of the study is that the presence of multiple processes using different technologies and common wastewater treatment facilities often found on integrated chemical sites means that sector-level approaches in inventory estimates will not give appropriate estimates at the site level. A more detailed study is required using site-specific data where possible. Transfers of data should only be carried out when fully justified on the basis of process characteristics. The largest estimated flows were in residues being transferred off-site for treatment (incineration) or disposal, generally in secure landfills. Releases to water varied widely from essentially non-detectable amounts to more than 5g of PCDD/F (as I-TEQ) annually. Where sites took measures to upgrade processes, air pollution controls and wastewater treatment systems, substantially reductions in releases were observed. [Copyright &y& Elsevier]

The paper reports on global release and mass partitioning in the flux of residues of PCDD/Fs, evaluated with dedicated field campaigns at a municipal solid waste incineration plant during normal and transient operation. Results are compared with those obtained in other installations equipped with furnaces, energy recovery options and flue gas treatment technologies representative of most of the European incineration plants currently in operation. Levels of the pollutants of interest were determined in all the solid, liquid and gaseous residues produced by every single facility, and the results analysed in terms of the effects arising from the fed waste and the configuration of the plant. PCDD/Fs total release between 1.5 and 45μg I-TEQ per ton of burned waste was evaluated, with lower values resulting from the adoption of catalytic conversion process for flue gas treatment. Most of the mass flux emitted is associated with solid residues deriving from activated carbon PCCD/F dry removal options, with significant contributions also from fly ash produced by particulate removal devices located immediately downstream the boiler and from scrubber blowdowns treatment sludge. During transient operating conditions the dioxin total release may increase by 50% with comparison to steady-state functioning. [Copyright &y& Elsevier]

One important criterion for assessment of a POPs destruction technology is the potential formation of new POPs and other toxic by-products, in particular whether the highly toxic PCDDs/PCDFs are formed and under which operation conditions their formation is relevant. For incineration processes the formation mechanisms of PCDDs/PCDFs have been investigated thoroughly and strategies and technologies were developed to minimize their formation and emission. A detailed assessment of non-combustion technologies with respect to PCDD/PCDF formation is, however, lacking to date. A comparison of reaction conditions for PCDD/PCDF formation from precursor formation studies and actual applied conditions of a broad range of POPs destruction technologies in the present paper indicates that the operation conditions for a number of destruction technologies have the potential to generate high concentrations of PCDDs/PCDFs if dioxin precursors are present and that also PCDD/PCDF de novo formation can take place. Therefore a strategy and regulations for a more profound assessment and monitoring of the fate of PCDD/PCDF formation and emission is essential for the evaluation of POP destruction technologies and for a sound risk management of POPs. The present paper aims to provide a critical impulse in this respect, discusses the relevant formation pathways with respect to POPs destruction technologies and proposes a basic framework on how evaluations may be performed. [Copyright &y& Elsevier]

National inventories to estimate releases of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans have been undertaken since the mid 1980s. These inventories were scattered and hard to compare since there was no harmonized method available. With the conclusion of the Stockholm Convention on Persistent Organic Pollutants and its entry into force, Parties to the Convention at the global level, have to establish PCDD/PCDF release inventories and report these results. UNEP Chemicals has developed a methodology that allows developing and developed countries to make estimates of PCDD/PCDF releases into the environment along all vectors. Presently, there are 23 national release inventories available that have been made with this methodology, the Toolkit. Among the most important sources, open fires in agriculture/forests as well as open burning of wastes have been identified as the major sources of PCDD/PCDF. The results from these inventories may serve as the starting point for interventions to reduce or eliminate sources of PCDD/PCDF by application of best available techniques and best environmental practices. The Toolkit will be updated as needs arise. [Copyright &y& Elsevier]