Chemical Waste Incinerator Research Articles

Migration and control of mercury in hazardous chemical waste incineration

This study evaluated the emission and control characteristics of mercury during hazardous chemical waste incineration. Meanwhile, for the complex flue gas conditions generated by hazardous chemical waste incineration, the commercial activated carbon used in the incineration system was modified with CuBr2, and its Hg0 removal performance was tested. The results showed that the major proportion of Hg was in the fly ash, and the content accounted for 74.53 % of the total Hg. The Hg content in the fly ash increased with decreasing fly ash particle size. In the exhaust flue gas, the Hg content was 11.05 % of the total Hg, in which the mass percentages of Hg2+ and Hg0 were 59.08 % and 40.92 %, respectively. The flue gas purification equipment of the incineration system had a removal efficiency of 92.40 % for HgT. The saturated Hg0 removal capacity of the modified activated carbon was improved by 33.51 times. Under simulated incineration flue gas conditions, the modified activated carbon was able to achieve an Hg0 removal efficiency of 92.85 %. The results can contribute to the understanding of Hg emissions from hazardous chemical incineration systems and provide guidance for efficient Hg removal from activated carbon.

Fate and emission behavior of heavy metals during hazardous chemical waste incineration

The fate and emission behavior of heavy metals (As, Cd, Co, Cr, Cu, Ni, Pb, Se, and Zn) from a hazardous chemical waste incinerator were systematically explored. The results show that the main components of incineration fly ashes and slags contain minerals such as salt, plagioclase, pyroxene, gypsum, calcite, and slaked lime. The elements As, Cd, Pb, and Se are enriched in the fly ash particles during flue gas condensation. Co and Ni are more likely to be deposited in the rotary kiln slag and cooling tower slag owing to their lower volatility. Zn, Cr, and Cu are usually volatilized into the flue gas as oxides or chlorides are condensed and enriched in the slag of the cooling tower during the flue gas cooling process. The content of As, Cd, Pb, Ni, Cr, and Se increase with decreasing fly ash particle size. After the flue gas purification equipment was employed, the concentration of particulate metals significantly reduced. In the exhaust flue gas, the concentrations of Cu and Zn are 29.85 and 28.47 μg/m3, those of As, Cr, Ni, Pb, and Se range from 2.54 to 9.25 μg/m3, and those of Co and Cd are 0.42 and 0.13 μg/m3, respectively.

Migration and Control of Mercury in Hazardous Chemical Waste Incineration

Migration and Control of Mercury in Hazardous Chemical Waste Incineration

Polychlorinated Dibenzofurans and Dibenzo-p-Dioxin in Tree Bark from an Industrialized Area: What the 2,3,7,8-Cl Substituted Congeners Tell Us, and What Is Missing

We analyzed polychlorinated dibenzofurans (PCDF) and dibenzo-p-dioxins (PCDD) in 27 tree bark samples from the industrialized area near Sauget, Illinois, USA. The trees were located within 4 km of the W. G. Krummrich (WGK) plant, the oldest and largest chemical plant in Sauget, with 24 of 27 samples collected from residential areas. The percent of total PCDF or PCDD profiles of ten 2,3,7,8- Cl substituted PCDF and seven PCDD congeners is homogeneous: 90% of the variance among the samples is explained by 3 eigenvalues in a principal components analysis. The homogeneity of the data suggests that samples were affected by similar types of sources which may have been influenced by electric power generation, chemical waste incineration, and large-scale thermal production of chlorinated chemicals. Quantitatively, the 2,3,7,8-Cl substituted congener analysis does not account for 90% of the concentration of tetra- and penta-Cl homologues and 80% of hexa-Cl and 50% of hepta-Cl homologues. The World Health Organization stated during establishment of toxic equivalence factors (TEF, 2005 version) that calculation of toxic equivalents (TEQs) is not suitable for abiotic matrices, such as tree bark, which are not involved in human exposures. Our results show that the non-2,3,7,8-Cl substituted congeners have high concentrations and should be included in analysis.

Air quality assessment by tree bark biomonitoring in urban, industrial and rural environments of the Rhine Valley: PCDD/Fs, PCBs and trace metal evidence

Tree barks were used as biomonitors to evaluate past atmospheric pollution within and around the industrial zones of Strasbourg (France) and Kehl (Germany) in the Rhine Valley. The here estimated residence time for trace metals, PCBs and PCDD/Fs in tree bark is >10 years. Thus, all pollution observed by tree bark biomonitoring can be older than 10 years. The PCB baseline concentration (sum of seven PCB indicators (Σ 7PCB ind)) determined on tree barks from a remote area in the Vosges mountains is 4 ng g −1 and corresponds to 0.36 × 10 −3 ng toxic equivalent (TEQ) g −1 for the dioxin-like PCBs (DL-PCBs). The northern Rhine harbor suffered especially from steel plant, waste incinerator and thermal power plant emissions. The polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/Fs) concentrations analyzed in tree barks from this industrial area range between 392 and 1420 ng kg −1 dry-weight (dw) corresponding to 3.9 ng TEQ PCDD/Fs kg −1 to 17.8 ng TEQ PCDD/Fs kg −1, respectively. Highest PCDD/F values of 7.2 ng TEQ kg −1 to 17.8 ng TEQ kg −1 have been observed close to and at a distance of <2 km southwest of the chemical waste incinerator. However, very close to this incinerator lowest TEQ dioxin-like PCB (TEQ DL-PCB) values of 0.006 ng TEQ g −1 have been found. On the other hand close to and southwest and northeast of the steel plant the values are comparatively higher and range between 0.011 ng TEQ g −1 and 0.026 ng TEQ g −1. However, even stronger Σ 7PCB ind enrichments have been observed at a few places in the city center of Kehl, where ΣDL-PCB values of up to 0.11 ng TEQ g −1 have been detected. These enrichments, however, are the result of ancient pollutions since recent long-term measurements at the same sites indicate that the atmospheric PCB concentrations are close to baseline. Emissions from an old landfill of waste and/or great fires might have been the reasons of these PCB enrichments. Other urban environments of the cities of Kehl and Strasbourg show significantly lower Σ 7PCB ind concentrations. They suffer especially from road and river traffic and have typically Σ 7PCB ind concentrations ranging from 11 ng g −1 to 29 ng g −1. The PCB concentration of 29 ng g −1 has been found in tree bark close to the railway station of Strasbourg. Nevertheless, the corresponding TEQ DL-PCB are low and range between 0.2 × 10 −3 ng TEQ g −1 and 7 × 10 −3 ng TEQ g −1. Samples collected near road traffic are enriched in Fe, Sb, Sn and Pb. Cd enrichments were found close to almost all types of industries. Rural environments not far from industrial sites suffered from organic and inorganic pollution. In this case, TEQ DL-PCB values may reach up to 58 × 10 −3 ng TEQ g −1 and the corresponding V, Cr, Co, Ni, and Cd concentrations are comparatively high.

Tracing of Industrial Aerosol Sources in an Urban Environment Using Pb, Sr, and Nd Isotopes

A comprehensive Pb-Sr-Nd isotope tracer study of atmospheric trace metal pollution has been performed in the urban environment of Strasbourg-Kehl. Filter dust of the principal pollutant sources (waste incinerators, thermal power plant and steel plant) and soot of car and ship exhausts have been analyzed. In addition tree barks (as biomonitors) and PM10 have been analyzed to trace and determine the distribution of the pollution in the environment. The industrial sources have highly variable epsilonNd values (-9.7 and -12.5 for incinerators and -17.5 for steel plant). Much higher epsilonNd values have been found for soot of car exhausts (-6 and -6.9). These high values make the Nd isotope system a powerful tool for the discrimination of traffic emissions but especially for the identification of diesel derived particles in the urban environment. The 206Pb/207Pb isotope ratios of gasoline are low (1.089) compared to diesel soot (1.159). The 26Pb/207Pb ratios of 1.151-1.152 for the steel plant and 1.152 for the solid waste incinerator are close to the Pb isotope ratio of diesel. The 87Sr/ 8Sr isotope ratios of the principal industrial sources vary significantly: 0.7095 for the domestic solid waste incinerator, 0.709 for the steel plant, and 0.7087 for car exhaust soot. PM10 aerosols collected in the urban center of Strasbourg show the influence of the pollutant sources at 3-7 km distance from the center. Most of the aerosols Pb isotopic compositions suggest Pb admixtures from at least three sources: a natural background and in function of the wind direction the domestic waste incinerator (S-wind) or the steel plant and the chemical waste incinerator (NE-wind). The traffic contribution can only be estimated with help of Nd isotopes. Therefore the clear identification of different pollutant sources in the urban environment is only possible by combining the three different isotope systems and is based on the fact that significant differences exist between the Pb, Sr, and Nd isotope ratios of the natural atmospheric background and pollutants containing Pb, Sr, and Nd of industrial origin with similar variable 206Pb/207Pb, 87Sr/ 86Sr, and 143Nd/144Nd.

Delayed Healing Effect of Mitomycin-C on Surgical and Laser Wounds

The fate and emission behavior of heavy metals (As, Cd, Co, Cr, Cu, Ni, Pb, Se, and Zn) from a hazardous chemical waste incinerator were systematically explored. The results show that the main components of incineration fly ashes and slags contain minerals such as salt, plagioclase, pyroxene, gypsum, calcite, and slaked lime. The elements As, Cd, Pb, and Se are enriched in the fly ash particles during flue gas condensation. Co and Ni are more likely to be deposited in the rotary kiln slag and cooling tower slag owing to their lower volatility. Zn, Cr, and Cu are usually volatilized into the flue gas as oxides or chlorides are condensed and enriched in the slag of the cooling tower during the flue gas cooling process. The content of As, Cd, Pb, Ni, Cr, and Se increase with decreasing fly ash particle size. After the flue gas purification equipment was employed, the concentration of particulate metals significantly reduced. In the exhaust flue gas, the concentrations of Cu and Zn are 29.85 and 28.47 μg/m3, those of As, Cr, Ni, Pb, and Se range from 2.54 to 9.25 μg/m3, and those of Co and Cd are 0.42 and 0.13 μg/m3, respectively.

Abundance and sources of ambient dioxins in Hong Kong: A review of dioxin measurements from 1997 to 2001

Ambient measurements of seventeen 2,3,7,8-polychlorinated dibenzo- p-dioxin/dibenzofuran congeners (2,3,7,8-PCDD/Fs) have been taken in a number of monitoring programs or ad-hoc studies in Hong Kong. The longest monitoring program started at two locations in the territory in July 1997. The other monitoring efforts are ad-hoc studies, varying from a few coordinated sampling events at multiple sites to a year-long monitoring project that targeted suspected local dioxin sources. In this paper, we examined these measurements to understand the ambient levels, temporal and spatial variation, and possible sources of the 2,3,7,8-PCDD/Fs in Hong Kong. The territory-wide annual average concentration of the dioxins was 0.052 pg I-TEQ/m 3 measured at the regular monitoring stations in the most recent annual cycle of 2000/2001. This level fell at the lower end of the range of dioxin concentrations measured at other urban locations around the world. The dioxin levels showed a clear seasonality in that elevated concentrations were observed in the winter and lower concentrations in the summer at all monitoring sites with one year or more regular measurements. The measurements indicated that the few known local dioxin sources, including a major chemical waste incinerator facility, landfill sites, and vehicular traffic, are not important contributors to ambient dioxins in Hong Kong. On days of high dioxin concentrations, the 2,3,7,8-PCDD/F congeners were observed to have almost identical compositions with a north–northwest to south–southeast spatial gradient in concentrations at different sampling locations in Hong Kong. This observation, along with other collaborative evidence, established a strong link between high dioxin concentration days in Hong Kong and regional transport of the polluted air masses from the north.

CFD Modelling for control of hazardous waste incinerator

The rotary kiln for chemical waste incineration is a poorly defined reactor, and is controlled in a feedback manner. To optimally control such systems, a well-structured database should be built to assist in the control in the feedforward manner. This concept has been explored through computational fluid dynamics (CFD) modelling as an off-line tool. CFD has been widely used in simulation and prediction of fluid flow and the related transport phenomena, but without link to process control. The generation of the CFD database and integration of the CFD predictions to the actual process control situation are discussed in this paper.

PCB and PCDD/DF concentrations in EGG and poultry meat samples from known urban and rural locations in wales and england

A survey was undertaken of PCB and PCDD/DF congeners in eggs and poultry meat from a smallholding close to a chemical waste incinerator, other sites in the surrounding district, and three rural locations. The concentrations from the site close to the incinerator were appreciably greater than those found elsewhere, although the contrast was less marked for poultry meat than eggs. All types of poultry produce displayed noticeable variations in congener composition when the samples were grouped according to geographical origin. These results support the view that the environment in which poultry live does influence the PCB and PCDD/DF characteristics of their products. Exposure calculations indicated that consumption of eggs from the site close to the incinerator would constitute a substantial proportion of recommended daily intakes for such contaminants and at the present time these products are not being eaten.

The Panteg monitoring project: comparing PCB and dioxin concentrations in the vicinity of industrial facilities

This paper describes the design, implementation and outcome of a research project which investigated concentrations of PCBs and PCDD/DFs (more commonly known as dioxins and furans) in the Panteg district of Pontypool, south Wales. The project was initiated in response to public concerns regarding the operations of a chemical waste incinerator located in the area and was undertaken by a multidisciplinary team based at the University of East Anglia. Sampling was carried out around a number of industrial facilities in the Panteg district and involved a variety of environmental compartments (e.g. soil, grass, air, milk, eggs, poultry and vegetables). The results provided evidence of some unusual environmental contamination in a strip of land 200 m wide around the eastern boundary of the incineration plant. Fugitive emissions from the site appeared to be substantially responsible for this situation and exposure calculations indicated that eggs were potentially the major source of higher PCB and PCDD/DF intakes. Since the start of the project substantial alterations have been made to the incinerator and, overall, the research does seem to have resolved a number of uncertainties and helped to reduce local concerns.

PCB and PCDD/DF congeners in locally grown fruit and vegetable samples in Wales and England

A survey was undertaken of PCB and PCDD/DF congeners in fruit and vegetables grown in an urban areas close to a chemical waste incinerator and three rural locations. All of the concentrations detected were low and there was considerable overlap between those found in urban and rural samples. Some similarities with the congeners composition of air samples were identified and concentrations in apple skin were noticeably higher than those in the flesh of the fruit. These results suggest that atmospheric deposition was an important contamination pathway. Assessments using the highest concentrations found indicated that consumption of such fruit and vegetables would represent an additional 3% of the normal dietary intake for PCBs and 8% for PCDD/DFs.

A new generation of Rh�ne-Poulenc DeNOx catalyst: DN115

Anticipating more stringent emission limits, Rhone-Poulenc has developed a new generation of selective catalytic reduction (SCR) catalyst named DN115 improving performances especially at low temperature. Data on the commercially available vanadium oxide-based catalyst DN115 are presented. Effects of operating temperature, pressure, gas composition and space velocity are also investigated. A kinetic model has been established. The DN115 catalyst is also effective for the control of a variety of other NOx emissions, such as industrial boilers like chemical waste incineration or other chemical processes.

Toxicity from ragwort and fat cow syndrome, or from industrial chemicals: the value of epidemiological analysis for interpreting clinico-pathological findings

When livestock in close proximity to industries develop signs of ill-defined disease, toxic effects from industrial pollution should be considered in the differential diagnosis. In establishing the final diagnosis, epidemiological methods should be applied to supplement the clinical and pathological techniques. This viewpoint is illustrated by two case-histories describing episodes of cattle disease in central Scotland. A long-established and successful dairy herd in central Scotland sustained severe morbidity and mortality amongst animals which had grazed on a field beside a recently established dump which contained wastes from a chemical waste incinerator. An official investigation concluded that the episode of disease was the result of ragwort poisoning; this diagnosis was reached on clinical and pathological grounds only. A similarly unexpected and severe epidemic occurred a few years later in another dairy herd, about 1 km further away from that incinerator (which was also within 100m of a municipal incinerator). The official investigation, which again focused on clinical and pathological criteria, led to the diagnosis of fat cow syndrome. In the first episode, contaminated water drained from the chemical waste dump on to the cows' field; in the second episode, the relevant field was affected by airborne pollution from the two waste incinerators mentioned earlier. In both episodes, the epidemiological features, which were not examined systematically by the original investigators, were consistent with the hypothesis that these episodes resulted from exposures to toxic contaminants.

Test and validation of a simple dioxin sampling train for high temperature chemical waste incineration

In order to analyze the off gases from high temperature chemical waste incineration for PCDD and PCDF a simple sampling train was constructed. The efficiency was checked in the laboratory by connecting it to an experimental set up for the generation of a dioxin loaden gas stream. The experiments demonstrate that the proposed sampling train is adequate for tetra through octachlorinated dioxins and dibenzofurans.

PCB, PCDD and PCDF concentrations in soils from the Kirk Sandall/ Edenthorpe/ Barnby Dun area

This study presents baseline concentrations of PCBs, PCDDs and PCDFs around the site proposed for a chemical waste incinerator near Doncaster. They add to the sparse urban and rural background data available for concentrations of these compounds in the UK. The results show PCB levels between 2 and 11 ppb and I-TEQ values between 3 and 20 ppt for the dioxins and furans. These values indicate that the area has, at present, a very low contamination of these species and is comparable with a rural environment.

Environmental assessment at and around a chemical waste treatment facility I — Measurements on PCDFs and PCDDs

In view of the concerns that environmentally unacceptable levels of PCDDs and PCDFs may result from the incineration of chemical waste which includes PCBs, measurements have been made at and around a chemical waste incinerator in the UK. Techniques for stack gas sampling are discussed, together with methods for unambiguous measurement of 2,3,7,8-TCDD at levels below 0.01 ppt using high resolution GC-MS. Stack gas samples were collected during the combustion of differing chemical wastes, and soil and dust samples were collected both near the incinerator site, and at remote locations which provided background data.

Cost Estimates for Several Hazardous Waste Disposal Options

Cost information was collected in the New Jersey area and analyzed for selected hazardous waste disposal methods. These methods include fuel blending of chemical wastes, landfill disposal, chemical waste incineration, hazardous waste treatment, acid-base neutralization, oil and solvent recovery, and cyanide detoxification treatment and disposal.

Application of Dry Flue Gas Scrubbing to Hazardous Waste Incineration

Dry scrubbing of the flue gas from chemical waste incineration is becoming an increasingly viable alternative to wet scrubbing. This paper discusses the relative advantages and disadvantages of wet and dry scrubbing systems and compares the relative capital and operating costs. The design parameters of the dry scrubbing process are discussed, including reagent atomization, gas dispersion, gas temperatures, and particulate removal. The history of dry scrubbing process applications is discussed, including the successful European hazardous waste systems. Finally, a comparison is made among three very different hazardous waste incinerators in the U.S. that will utilize dry scrubbing systems.

Observations and assessment relating to incineration of chlorinated chemical wastes

Tests have been carried out on the chemical waste incinerator operated by Re-Chem International at Bonnybridge, Scotland, to determine whether any emissions of polychlorodibenzo-p-dioxins (PCDD) or polychlorodibenzofurans (PODF) occurred during incineration under typical conditions of certain organo-chlorine feedstocks. No detectable emissions of PCDDs or PCDFs were found during the incineration of 2,4,5-I esters, pentachlorophenol residues or PCB in liquid form. A just measurable amount of 2,3,7,8 TCDF was detected during the incineration of large intact capacitors and prior shredding, or puncturing, is preferred. The measured levels of PCDDs and PCDFs in soils collected in the vicinity of the Bonnybridge plant were found to be comparable to or less than those reported in urban or rural environments elsewhere. The reported detection of these compounds in a soil sample collected in 1877 suggests that they may be ubiquitous. It is demonstrated that cows grazing close to the Bonnybridge incinerator are unlikely to have suffered ill-effects from these emissions.