An Epidemiological Study of Exposure to Coal Tar Pitch Volatiles Among Coke Oven Workers

Recent studies of mortality among coke plant workers indicate that there is an excess of respiratory cancer among men employed at the coke ovens and that the mortality is related to work areas and length of exposure to coal tar effluents, the body of information presented in this paper is directed to categorization of coke oven jobs into different work areas in terms of exposure to coal tar pitch volatiles developing an index of cumulative exposure to investigate the dose-response relationship between exposure and mortality. The exposure data have been taken from a study conducted by the Pennsylvania Department of Health, State Division of Occupational Health, and mortality data are based on a long-term study of steelworkers, conducted by the Department of Biostatistics, University of Pittsburgh. A summary index calculated for each worker combining the level of exposure and length of time exposed indicates that, as expected, both these factors are related to the development of cancer, particularly cancers of the respiratory system.

Conclusions of note are: Measured levels of coal tar pitch volatiles are 2-3 times higher for men who work at the top of coke ovens as compared to men employed at the side of the ovens. Even though the specific carcinogenic element or elements in the coke oven environment are not known at the present time, in-. creasing levels of exposure to coal tar pitch volatiles are related to art increased risk of dying from malignant neoplasms. Further coal tar pitch volatile measurements need to be made and analyses designed which will specify the dose-response relationship more precisely. This will provide information necessary to evaluate the recommended Threshold Limit Value.     

Economics of Coke Oven Charging Controls

This study was undertaken to determine which of several alternative air pollution abatement systems affords the most economical solution to the control of atmospheric emissions during the charging of coal into by-product coke ovens. The study was limited to the consideration of existing by-product batteries, and the assumption was made that no coking plant has the alternative to do nothing nor will the plant choose to delay abatement through legal procedures. The data indicate that a jumper pipe installation with a new larry car provides the most economical control.     

Aerial Detection of Vegetation Damage Utilizing a Simple 35-mm Camera System

The body of information presented in this paper is directed to environmental scientists interested in the detection of vegetation damage from air pollution. A dual 35-mm camera bank, manually operated from a small aircraft, was tested as a sensor system for detecting vegetation damage caused by air pollution. The cameras were filled with color and color infrared film and attached to a frame so that simultaneous exposure was possible. This gave a matched pair of photographs for each scene.

A test site was selected that contained three very large coal-fired power plants and a complex of beehive coke ovens. The power plants burn medium-sulfur coal (2 to 3%) which, after coal preparation, results in stack emissions of between 1500 and 2000 ppm sulfur dioxide (S0₂). The coke ovens are relatively old and have effectively no pollution controls. The ovens emit hydrogen sulfide, sulfur dioxide, a variety of benzene-based organics, and heavily dust-laden smoke. The areas near the power plants and coke ovens were monitored by photographic overflights on a regular basis. A variety of aerial photographs were made to test for optimum light conditions, exposure times, and altitudes. Field trips were carried out to examine photographed areas at the ground level.

Two areas were found to have vegetation damage on a scale that made aerial photographs useful. One area was damaged from effluent from the coke ovens; another area exhibited symptoms characteristic of oxidant-type damage where low sulfur dioxide concentrations may have been a contributing factor. In each case the 35-mm camera system was a success in terms of detecting and recording the stress. The chief advantages of such a technique are ease of operation, flexibility, and economy. Compared with conventional aerial photography, the savings are considerable. The disadvantages are small area coverage per photograph and difficulty in obtaining vertical photographs that would have a uniform scale. However, for this particular project, these were not serious drawbacks.     

dry coke quenching,air pollution and energy: a status report

Dry quenching of incandescent coke after it has been pushed from the coking ovens is a proved, reliable process that is presently being used in several industrialized countries. Foremost among dry quenching’s advantages are: (1) virtual elimination of air pollutants emitted during quenching; (2) elimination of potential water pollution associated with wet quenching; (3) improvements in the working environment; (4) saving substantial amounts of energy in usable forms; (5) producing more usable coke that is superior to wet-quenched coke. By continuously circulating inert gases through a cooling chamber that contains hot coke, dry quenching recovers waste-heat energy that can be used to produce steam, to produce electricity, to preheat combustion air, to preheat coal, to dry coal, and to preheat feed water supplied to fuel-fired boilers. The pay-out period on the capital investment (approximately $7,100,000) for an installation capable of processing 5500 tons of coke/day is less than four years.     

Fugitive coke oven gas emission profile by continuous line averaged open-path Fourier transform infrared monitoring

Although most coke oven research is focused on the emission of polycyclic aromatic hydrocarbons, well-known carcinogens, little has been done on the emission of volatile organic compounds, some of which are also thought to be hazardous to workers and the environment. To profile coke oven gas (COG) emissions, we set up an open-path Fourier transform infrared (OP-FTIR) system on top of a battery of coke ovens at a steel mill located in Southern Taiwan and monitored average emissions in a coke processing area for 16.5 hr. Nine COGs were identified, including ammonia, CO, methane, ethane, ethylene, acetylene, propylene, cyclohexane, and O-xylene. Time series plots indicated that the type of pollutants differed over time, suggesting that different emission sources (e.g., coke pushing, quench tower, etc.) were involved at different times over the study period. This observation was confirmed by the low cross-correlation coefficients of the COGs. It was also found that, with the help of meteorological analysis, the data collected by the OP-FTIR system could be analyzed effectively to characterize differences in the location of sources. Although the traditional single-point samplings of emissions involves sampling various sources in a coke processing area at several different times and is a credible profiling of emissions, our findings strongly suggest that they are not nearly as efficient or as cost-effective as the continuous line average method used in this study. This method would make it easier and cheaper for engineers and health risk assessors to identify and to control fugitive volatile organic compound emissions and to improve environmental health.     

Characterisation of volatile organic compounds and polycyclic aromatic hydrocarbons in the ambient air of steelworks

Investigations have been undertaken at two integrated steelworks in the UK to characterise airborne organic micro-pollutants and to assess the contribution of iron ore sintering and coke making operations on the air quality. Concentrations of volatile organic compounds (VOCs), namely benzene, toluene and p-xylene, were measured continuously within the boundary of a coking plant using for the first time differential optical absorption spectrometry (DOAS) between 2004 and 2006. Concentrations were obtained along two monitoring paths surrounding the coke plant and the average benzene concentration measured along both paths over the campaign was 28 μg m^?3. Highest benzene concentrations were associated with winds downwind of the coke oven batteries. Concentrations of polycyclic aromatic hydrocarbons (PAHs) in ambient air were measured during 27 consecutive days in 2005 at three different locations on an integrated steelworks. PAH profiles were determined for each sampling point and compared to coke oven and sinter plant emission profiles showing an impact from the steelworks. The mean benzo [a] pyrene concentration determined in the immediate vicinity of the coke ovens downwind from the battery was 19 ng m^?3, whereas for the two other sites average benzo [a] pyrene concentrations were much lower (around 1 ng m^?3). Data were analysed using principal components analysis (PCA) and results showed that coke making and iron ore sintering were responsible for most of the variation in the PAH concentrations in the vicinity of the investigated plant.     

Control of Coke Oven Emissions by Use of A Closed Pipeline Charging System

The body of information presented in this paper is directed to those individuals concerned with the control of air pollution emissions which occur as a result of the operation of by-product coke plants. It describes a new process which represents a major change in the charging operation wherein preheated coal can be charged to coke ovens via a closed pipeline system thus replacing the conventional larry charging car and thereby eliminating air pollution estimated to be as much as 70% of the total emissions from coke oven operations. Coal is dried and preheated in a continuous fluidized bed process utilizing products of combustion of coke oven gas. The coal is recovered in conventional cyclone collectors and conveyed to the ovens via a new and novel pneumatic conveying system where the gas used is superheated steam. Jet energy repeatedly thrusts the coal upward and forward through the pipe, obtaining a high efficiency of transport of solids ten times that of conventional systems. Major advantages of the process demonstrated to date include (1) elimination of emissions from charging, (2) reduction of emission from pushing, (3) improved battery top working conditions, (4) increased oven productivity as much as 45%.     

Impingement Baffles to Reduce Emissions from Coke Quenching

In the production of metallurgical coke, the hot, incandescent coke just removed from the ovens must be cooled rapidly for subsequent handling and to prevent it’s burning. Cooling is usually carried out in quenching stations by spraying with large quantities of water. The violent evaporation of the water results in a carryover of solid particles and liquid mist up the stack of the quench station and into the atmosphere. A research study was conducted to determine means to reduce the emission of particulates from the quench stations. The results of the study showed that louver-type wooden impingement baffles installed in the stack will significantly reduce emissions without interfering with production operations.     

Environmental Progress and Problems: A Chemical Industry Perspective

From 1995 to 2004, in Genoa, Italy, daily concentrations of twelve polycyclic aromatic hydrocarbons (PAHs) were measured in particulate phase (PM10), around a coke oven plant in operation from the 1950s and closed in 2002. The study permitted to identify the coke oven as the main PAH source in Genoa, causing constant exceeding of benzo(a)pyrene (BaP) air quality target (1.0 ng/m3) in the urban area till 1,900 meters distance downwind the plant. For this reason the plant was closed. Distance and daily hours downwind the coke plant were the main sources of variability of toxic BaP equivalent (BaPeq) concentrations and equations that best fitted these variables were experimentally obtained. During full plant activity, annual average BaPeq concentrations, measured in the three sampling sites aligned downwind to the summer prevalent winds, were: 85 ng/m3 at 40 m (site 2, industrial area), 13.2 ng/m3 at 300 m (site 3, residential area) and 5.6 ng/m3 at 575 m (site 4, residential area).

Soon after the coke oven's closure (February 2002) BaPeq concentrations (annual average) measured in residential area, decreased drastically: 0.2 ng/m3 at site 3, 0.4 ng/m3 at site 4. Comparing 1998 and 2003 data, BaPeq concentrations decreased 97.6% in site 3 and 92.8% in site 4.

Samples collected at site 3, during the longest downwind conditions, provided a reliable PAH profile of fugitive coke oven emissions. This profile was significantly different from the PAH profile, contemporary found at site 5, near the traffic flow.

This study demonstrates that risk assessment based only on distance of residences from a coke plant can be heavily inaccurate and confirmed that seasonal variability of BaPeq concentrations and high variability of fugitive emissions of PAHs during coke oven activities require at least one year of frequent and constant monitoring (10-15 samples each month).

Implications: Around a coking plant, polycyclic aromatic hydrocarbons (PAHs), concentrations depend mainly on downwind hours and distance. Equations that best fit these variables were experimentally calculated. Fugitive emissions of an old coke oven did not comply with the threshold BAP air concentration proposed by the World Health Organization (WHO), up to 1,900 m distance. The study identified the PAH profile of fugitive emissions of a coke oven, statistically different from the profile of traffic emissions. During its activity, in the Genoa residential area, 575 m away from the plant, 92.8% of found PAHs was due to coke oven emission only.     

Compounds in Airborne Participates: Salts and Hydrocarbons

Concentrations of 10 polycyclic aromatic hydrocarbons (PAH), the aliphatlcs as a group, sulfate, nitrate, fluoride, acidity, and carbon In the airborne partlculate matter were measured at 16 sites In Cleveland, OH over a 1 year period during 1971 and 1972. Analytical methods used included gas chromatography, colorimetry, and combustion techniques. Uncertainties in the concentrations associated with the sampling procedures, and the analytical methods are evaluated. The data are discussed relative to other studies and source origins. Benzo(a)pyrene and its high concentrations downwind of coke ovens are discussed. Hydrocarbon correlation studies indicated no significant relations among compounds studied.     

Receptor Model Evaluation of the Southeast Michigan Ozone Study Ambient NMOC Measurements

Abstract

Large-scale studies like the Southeast Michigan Ozone Study (SEMOS) have focused attention on quantifying and spedating inventories for volatile organic compounds (VOCs). One approach for evaluating the accuracy of a VOC emission inventory is the development of a chemical mass balance (CMB) receptor model for ambient non-methane organic compound (NMOC) measurements. CMB evaluations of ambient hydrocarbon data provide a sample-specific allocation of emissions to individual source categories. This study summarizes the results of an application of the CMB model to the NMOC data from the SEMOS study. Comparison of CMB results with emission inventory values for the Detroit area show that vehicle emissions are well represented by the inventory, as are architectural coatings and coke ovens. Estimated emissions from petroleum refineries and graphic arts industries are much lower in the inventory than determined from the receptor allocation. Under-reporting of fugitive VOC emissions from petroleum refineries is an ongoing problem. Emissions from graphic arts industries are underestimated in the inventory partly because of the broad characterization of the emission factor (i.e., mass emitted/capita), which may be less useful when specific locations and days are under consideration. This study also demonstrates the effectiveness of the CMB approach when used prospectively to track the implementation of emission control strategies. While vehicle emission concentrations were unchanged from 1988 to 1993, measurement-based CMB results suggest a decrease in evaporative emissions during this time period resulting from Reid vapor pressure (RVP) reductions (from 11.0 psi in 1988 to 8.6 psi in 1993) and fleet turnover. Changes in emissions from coke plants and petroleum refineries were also seen in the CMB allocations for these sources.     

Emission Control in Coking Operations By Use of Stage Charging

At the Clairton Coke Works of the United States Steel Corporation (the world’s largest coke plant), with coal charges of about 30,000 net tons per day, a system designated as “stage charging” has been developed for charging coal into the coke oven chamber without emissions to the atmosphere. The principles of the system are based on controlled sequential flow of the coal from the charging hoppers, during which the oven chamber is maintained under a very slight negative pressure condition by use of steam aspiration in the offtakes for on-the-main charging. The techniques are basic but require knowledge of the coal characteristics, adequate and properly maintained aspirating systems, including clean offtake piping, control of coal volume in the individual hoppers, and last, and probably most important, adherence by the operating crew to specific charging and leveling practices.     

AISI-EPA-Battelle Coke Oven Door Sealing Program

The problem of coke oven door leakage is generally recognized as one for which no proven solution exists. In 1974 the United States Environmental Protection Agency and the American Iron and Steel Institute entered into a jointly funded research project with Battelle Columbus Laboratories. The initial project was to define the problem by literature search, operator interviews and profile measurements of jambs and doors.

Numerous concepts of seal designs were developed and then rated by industry and Battelle reviews. It was determined that a metal-to-metal seal offered the greatest probability of success. It was felt that jamb warpage was the most serious problem to be solved.

In the fall of 1976 another contract was signed by EPA and AISI assigning Battelle the task of developing to the point of fabrication a system to eliminate or significantly reduce leakage from coke oven end closures. This program included mathematical modeling, physical modeling, field data collecting, analysis, and full scale unit design.

A retrofittable door seal design has been developed and preparations are underway for operating evaluation at eight steel plants. The design is retrofittable to the two principal coke oven doors in service and should accommodate the worst jamb warpage usually found.     

褐煤活性炭吸附处理焦化废水

研究褐煤活性炭吸附处理焦化废水的性能，为褐煤活性炭用于废水处理提供理论依据和技术指导。以河南某气化厂的焦化废水为吸附原水，进行褐煤活性炭对酚吸附性能的静态和动态实验。静态实验表明，褐煤活性炭对酚的吸附性能符合弗兰德里希（Freundlich）吸附方程式。在室温条件下，对于150 mL焦化废水，当活性炭的用量为10 g，吸附反应时间为1 h，酚的去除率可达92%以上。动态实验研究表明，当进水酚浓度为3 800 mg/L，吸附1.5 h，活性炭的吸附容量可达21.38 mg/g。水处理的实验研究表明，利用褐煤制备的活性炭，对焦化废水具有良好的处理效果。     

Lysimeter Test of Coke Plant Effluent Disposal to Land in India

ABSTRACT

From the Indian national point of view, the importance of coal carbonizing industries is great and growing. These industries produce huge quantities of highly polluted effluents and discharge them into rivers without proper treatment. A large coke plant of Bharat Coking Coal Ltd. has been surveyed, and the impact of its effluent on surface water quality is discussed. Approximately 175-200 m³ of effluents are discharged from the plant every day. Land application has been considered as a low-cost means of disposal of coke oven effluents. Column lysimeters were prepared by collecting soil from a nearby agricultural field, putting it layerwise into a column, and compacting it carefully to simulate the original in situ conditions. Raw effluents, diluted effluent, and water (as a blank) were applied to the three lysimeters twice a week with a 5 cm flooding. Upon application of diluted effluent (1:1) into lysimeter No. 2, the leachate collected at 190 cm depth was within the tolerance limit of drinking water standard (IS 10,500). The impact of raw and diluted effluent on groundwater quality and soil are discussed. The renovation efficiency of living filter (lysimeter No. 2) was 99.37% for oil and grease, 86.92% for COD, and 53.22% for TDS, and it is estimated that 2.73 hectares of land can be irrigated with the effluents of the coke plant without deteriorating groundwater and soil quality.     

活性焦吸附对煤化工废水膜处理工艺的影响

煤化工废水经过生化处理后一般难以达到回用标准，须采用有效的深度处理工艺才能实现废水的资源化利用。通过对比研究方式，采用“混凝-超滤-反渗透工艺”及“混凝-活性焦吸附-超滤-反渗透”2种处理工艺，考察了活性焦吸附对后续膜处理工艺的影响。结果表明，活性焦对废水中的芳香族类等主要污染物具有很好的吸附性能，混凝出水经活性焦吸附后进人膜系统可有效减缓膜污染，降低膜通量的衰减程度并提高产水水质，因此，将活性焦吸附用于煤化工废水膜系统的前处理，采用“混凝-活性焦吸附-超滤-反渗透工艺”深度处理煤化工废水是有效可行的。     

复合生物反应器处理焦化废水试验研究

采用在悬浮相污泥中投入纤维球填料形成单一复合生物反应器来处理焦化废水,研究了各个运行参数对复合生物反应器处理效果的影响,确定出最佳的运行参数,并研究了在最佳运行条件下复合生物反应器对焦化废水中的COD和NH3-N的去除情况。试验结果表明,采用单一复合生物反应器是一种很好的焦化废水处理方法,它能有效地降解焦化废水中的COD和NH3-N等难降解物质,当进水COD和NH3-N分别小于670、260mg／L时,COD和NH3-N的去除率分别可高达94．8％和91．4％。     

Identification and removal of polycyclic aromatic hydrocarbons in wastewater treatment processes from coke production plants

Identification and removal of polycyclic aromatic hydrocarbons (PAHs) were investigated at two coke plants located in Shaoguan, Guangdong Province of China. Samples of raw coking wastewaters and wastewaters from subunits of a coke production plant were analyzed using gas chromatography–mass spectrometry (GC/MS) to provide a detailed chemical characterization of PAHs. The identification and characterization of PAH isomers was based on a positive match of mass spectral data of sample peaks with those for PAH isomers in mass spectra databases with electron impact ionization mass spectra and retention times of internal reference compounds. In total, 270 PAH compounds including numerous nitrogen, oxygen, and sulfur heteroatomic derivatives were positively identified for the first time. Quantitative analysis of target PAHs revealed that total PAH concentrations in coking wastewaters were in the range of 98.5?±?8.9 to 216?±?20.2 μg/L, with 3-4-ring PAHs as dominant compounds. Calculation of daily PAH output from four plant subunits indicated that PAHs in the coking wastewater came mainly from ammonia stripping wastewater. Coking wastewater treatment processes played an important role in removing PAHs in coking wastewater, successfully removing 92 % of the target compounds. However, 69 weakly polar compounds, including PAH isomers, were still discharged in the final effluent, producing 8.8?±?2.7 to 31.9?±?6.8 g/day of PAHs with potential toxicity to environmental waters. The study of coking wastewater herein proposed can be used to better predict improvement of coke production facilities and treatment conditions according to the identification and removal of PAHs in the coke plant as well as to assess risks associated with continuous discharge of these contaminants to receiving waters.     

活性焦表面性质对CUO/AC脱硫性能的影响

分别以不同浓度的硝酸处理活性焦载体,采用硝酸铜溶液浸渍法制备CuO/AC催化剂,利用BET、FT-IR和XRD等方法对载体及催化剂进行表征.考察了不同浓度的硝酸处理对活性焦载体性质的影响,并对制得的催化剂的脱硫性能进行了比较.结果表明,活性焦经过硝酸处理后孔结构参数变化很小,而表面含氧酸性官能团的含量有了很大的提高,使...