Heavy Metals in Urban Soils of East St. Louis,IL Part II: Leaching Characteristics and Modeling

ABSTRACT

The city of East St. Louis, IL, has a history of abundant industrial activities including smelters of ferrous and non-ferrous metals, a coal-fired power plant, companies that produced organic and inorganic chemicals, and petroleum refineries. Following a gross assessment of heavy metals in the community soils (see Part I of this two-part series), leaching tests were performed on specific soils to elucidate heavy metal-associated mineral fractions and general leachability. Leaching experiments, including the Toxicity Characteristic Leaching Procedure (TLCP) and column tests, and sequential extractions, illustrated the low leachability of metals in East St. Louis soils. The column leachate results were modeled using a formulation developed for fly ash leaching. The importance of instantaneous dissolution was evident from the model. By incorporating desorption/adsorption terms into the source term, the model was adapted very well to the time-dependent heavy metal leachate concentrations. The results demonstrate the utility of a simple model to describe heavy metal leaching from contaminated soils.     

Heavy metals in urban soils of East St. Louis, IL, Part I: Total concentration of heavy metals in soils

The city of East St. Louis, IL, has a history of abundant industrial activities including smelters of ferrous and non-ferrous metals, a coal-fired power plant, companies that produce organic and inorganic chemicals, and petroleum refineries. A protocol for soil analysis was developed to produce sufficient information on the extent of heavy metal contamination in East St. Louis soils. Soil cores representing every borough of East St. Louis were analyzed for heavy metals--As, Cd, Cu, Cr, Hg, Ni, Pb, Sb, Sn, and Zn. The topsoil contained heavy metal concentrations as high as 12.5 ppm Cd, 14,400 ppm Cu, ppm quantities of Hg, 1860 ppm Pb, 40 ppm Sb, 1130 ppm Sn, and 10,360 ppm Zn. Concentrations of Sb, Cu, and Cd were well correlated with Zn concentrations, suggesting a similar primary industrial source. In a sandy loam soil from a vacated rail depot near the bank of the Mississippi River, the metals were evenly distributed down to a 38-cm depth. The clay soils within a half-mile downwind of the Zn smelter and Cu products company contained elevated Cd (81 ppm), Cu (340 ppm), Pb (700 ppm), and Zn (6000 ppm) and displayed a systematic drop in concentration of these metals with depth. This study demonstrates the often high concentration of heavy metals heterogeneously distributed in the soil and provides baseline data for continuing studies of heavy metal soil leachability.     

Heavy metals in urban soils of East St. Louis, IL. Part II: Leaching characteristics and modeling

The city of East St. Louis, IL, has a history of abundant industrial activities including smelters of ferrous and non-ferrous metals, a coal-fired power plant, companies that produced organic and inorganic chemicals, and petroleum refineries. Following a gross assessment of heavy metals in the community soils (see Part I of this two-part series), leaching tests were performed on specific soils to elucidate heavy metal-associated mineral fractions and general leachability. Leaching experiments, including the Toxicity Characteristic Leaching Procedure (TLCP) and column tests, and sequential extractions, illustrated the low leachability of metals in East St. Louis soils. The column leachate results were modeled using a formulation developed for fly ash leaching. The importance of instantaneous dissolution was evident from the model. By incorporating desorption/adsorption terms into the source term, the model was adapted very well to the time-dependent heavy metal leachate concentrations. The results demonstrate the utility of a simple model to describe heavy metal leaching from contaminated soils.     

Characteristics of regional nucleation events in urban East St. Louis

Continuous measurements of aerosol size distributions (3 nm–2 μm) were carried out over a 26 month period (1 April 2001–31 May 2003; 650 days with valid data) in urban East St. Louis, IL, as a part of the US Environmental Protection Agency's Supersite program. This paper analyzes data for the 155 days on which “regional nucleation events” were observed during this study. Such events were observed during every month of the study except January 2003. We observed some differences, however, between events in the summer (defined here as April–September) and winter (December–February). Regional nucleation events were observed more frequently in summer months (36±13% of days) than in winter (8±7%), and nucleated particles grew faster in the summer (6.7±4.8 nm h⁻¹) than in winter (1.8±1.9 nm h⁻¹). The daily maximum in the number concentration of nanoparticles formed by nucleation (4.8±3.5×10⁴ cm⁻³) was highly variable and showed no clear seasonal dependence. Particle formation increased particle concentrations by an average factor of 3.1±2.8. Maximum daily rates of 3 nm particle production (17±20 cm⁻³ s⁻¹) were also highly variable and without a clear seasonal dependence. During these events, particle formation rates were typically near their maxima at 08:00–09:00 a.m., but particle production sometimes persisted at diminishing rates until late in the afternoon (15:00–16:00 p.m.).     

The Evolution of Visibility Deterioration and Aerosol Spectra in the St. Louis Urban Plume

Under the auspices of Project METROMEX, studies of visibility de-teoration downwind of St. Louis were conducted during July-August 1974-1975. Estimates of horizontal visual range, standard meteorological data, and aerosol characteristics within the mixing layer were acquired upwind, over, and downwind of the metropolitan area by means of airborne transects. Aerosol number, surface, and volume distributions for particles between 0.025-2.5 µm were generated from the airborne measurement of Aitken nucleus concentrations, cloud condensation nuclei, and aerosols detected in situ with optical probes. Visibility reduction amounting to 50% of prevailing regional upwind visibilities consistently occurs at a distance corresponding to 2-3 hours travel time downwind for an air parcel moving with the mean transport wind. The regions of visibility minimum do not coincide with locations of maximum Aitken nucleus concentrations, but rather correspond in space and time to increased values of cloud condensation nuclei and increased numbers of particles in the 0.1-2.5 µm diameter range. Comparisons of observed aerosol evolution with similar laboratory studies suggest that most of the light scattering aerosols are of secondary origin.     

Day of the week variations of photochemical pollutants in the St. Louis area

As part of the Environmental Protection Agency's Regional Air Pollution Study (RAPS) a network of 25 stations continuously recorded aeromatic data in the Greater St. Louis area. Various photochemical pollutants (O₃, NO, NO₂ and total hydrocarbons) and some selected meteorological variables (wind speed, temperature, and solar radiation) were analyzed with respect to the day of the week using 11 months of data collected during the warm months of the year — periods during which high ozone concentrations were common in St. Louis. The results reveal that the sign (±) of the workday to Sunday differences in the concentration of ozone depends to a large extent on the distance of the measurement from the major emission area of the metropolitan area of St. Louis. The data suggest that this is due to the impact of nitric oxide on the ambient ozone concentrations. This appears to offer at least a partial explanation for some of the contrasting results reported by various investigators regarding the differences in ozone concentrations between weekends and weekdays.     

Sediment processes and mercury transport in a frozen freshwater fluvial lake (Lake St. Louis, QC, Canada)

An open-bottom and a closed-bottom mesocosm were developed to investigate the release of mercury from sediments to the water column in a frozen freshwater lake. The mesoscosms were deployed in a hole in the ice and particulate mercury (Hg_P) and total dissolved mercury (TDHg) were measured in sediments and in water column vertical profiles. In addition, dissolved gaseous mercury (DGM) in water and mercury water/airflux were quantified. Concentrations of TDHg, DGM, and mercury flux were all higher in the open-bottom mesocosm than in the closed-bottom mesocosm. In this paper we focus on the molecular diffusion of mercury from the sediment in comparison with the TDHg accumulation in the water column. We conclude that the molecular diffusion and sediment resuspension play a minor role in mercury release from sediments suggesting that solute release during ebullition is an important transport process for mercury in the lake.     

Radiative heating rates and some optical properties of the St. Louis aerosol,as inferred from Aircraft measurements

Radiative heating rates were determined from measurements made aboard an aircraft flying within and above the St. Louis boundary layer during the Regional Air Pollution Study (RAPS; 1975–1976). In the mean, heating rates tor both solar and infrared radiation were found to diminish steadily from a maximum near the surface to nearly zero above the mixing layer. Similarly, there was a mean decrease in large particle aerosol concentrations and in extinction coefficient with height to insignificant values above the mixing layer. Over the entire mixing depth, there was an average net solar warming and an average net longwave cooling due to the presence of aerosol. When normalized for a 24 h period the solar warming was found to be very slightly less than the magnitude of the long-wave cooling, although the former somewhat exceeded the latter during midday. Derived values of the asymmetry parameter and single scattered albedo were large, the value for each averaging close to 0.9. The ratio of backscatter to absorption for the aerosol was approximately unity.Thus the arosol was not a strongly absorbing material and. consequently, the aerosol healing or cooling rates were not very large within the St. Louis mixing layer and the total (solar + IR) effect of the temperature changes on the atmospheric motions were likely to have been insignificant.     

Relationships between direction of wind flow and ozone inflow concentrations at rural locations outside of St. Louis,MO

The relationships between the monthly and seasonal averages of the daily 1200–1500 h O₃ inflow concentrations and wind flow direction have been evaluated. The O₃ measurements used are those during inflow of air parcels from upwind to rural monitoring stations outside of St. Louis, MO. The results obtained are consistent with the O₃ measurements reported from other monitoring studies at rural locations both to the west and east of St. Louis. Although there is a stratospheric component to these ground level rural O₃ concentrations, it is likely that most of the O₃ measured during the warmer months of the year is associated with photochemical O₃ formation in the planetary boundary layer and in the free troposphere. A substantial part of the increments in rural O₃ concentrations which occur from west to east of St. Louis during the warmer months of the year appear best to be accounted for as a result of photochemical formation O₃ precursors from anthropogenic emission sources to the east of St. Louis. Differences in the values of meteorological parameters with wind flow direction account for only a small part of the differences in O₃ concentration observed.     

A chemical model for urban plumes: Test for ozone and particulate sulfur formation in St. Louis urban plume

A chemical model with anthropogenic sources of nitrogen oxides and hydrocarbons is applied to simulate the chemical behaviour of pollutants in the St. Louis urban plume. It is suggested that a substantial increase in peroxy radical concentrations (HO₂,RO₂) in the polluted air mass outside its source region leads to an effective formation of secondary pollutants like ozone and sulfate particles. The model indicates characteristic time for ozone generation in the plume of a few hours. Maximum ozone mixing ratio of 115 ppb is predicted after 4 h transport time outside the source region. Conversion rates of SO₂ to H₂SO₄ through gas phase reactions with hydroxyl and peroxy radicals are estimated to be 1–5%h⁻¹. This leads to an approx 25% conversion of SO₂ to paniculate sulfur in the plume during the day. Agreement with measured ozone concentrations and flow rates of ozone and participate sulfur in the St. Louis plume on 18 July 1975 can be taken as strong indications that ozone and sulfate particle formation in the plume proceeds through the suggested mechanisms.     

Relationships involving fine particle mass,fine particle sulfur and ozone during episodic periods at sites in and around St. Louis,Mo

The measurements during episodic periods in the St. Louis area in 1975 and 1976 of fine particle sulfur, fine particle mass and ozone are related. Such episodes are concentrated into time periods in the late spring and summer months. During such episodes, particle sulfur is the major constituent of the fine particle mass. The sum of the non-sulfur species in the fine particle mass do not show similar episodic patterns as the fine particle sulfur.Elevated concentrations of fine particle sulfur and of ozone usually occur together within the same episodic time periods. However, the day to day variations in fine particle sulfur and of ozone do differ somewhat within these time periods.Both fine particle sulfur and ozone show the influence of regional scale and local scale atmospheric photochemical processes on their formation during episodic time periods. Regional scale boundary layer processes frequently appear to contribute more to fine particle sulfur concentrations than to ozone formation. Local scale primary emissions also contribute to the ambient fine particle sulfur concentrations at core urban locations.     

Comparison of modified montmorillonite adsorbents. Part I: Preparation,characterization and phenol adsorption

This study concerns with the development of modified montmorillonites as adsorbents for water treatment. Polymeric aluminium and iron intercalated forms of montmorillonites have been prepared in the absence and presence of an alkylammonium cationic surfactant (Hexdecyl-trimethyl-ammonium bromide, HDTMA). Montmorillonites intercalated with polymeric Al, Fe, Fe/Al (2:1 Fe to Al ratio in solution), possess large N2 Brunauer-Emmett-Teller (BET) surface areas. XRD data also shows trace amounts of illite and plagioclase within the clay materials. Montmorillonites intercalated with HDTMA, polymeric Fe/HDTMA, polymeric Al/HDTMA and polymeric Fe/Al/HDTMA (1:1 metal to surfactant molar ratio in solution) undergo some losses of N2 BET surface areas. Preliminary adsorption studies on phenol have shown that polymeric Al/HDTMA- and HDTMA-only-modified montmorillonites possess a good affinity for phenol, whereas the polymeric Al/Fe modified- and starting montmorillonites have little affinity for phenol adsorption.     

Remote Sensing Tools Assist in Environmental Forensics. Part I: Traditional Methods

This is part one of a two-part discussion, in which we will provide an overview of the use of aerial photography, topographic mapping and photogrammetry in environmental enforcement actions. The visualization of spatial relationships of natural and man-made features can focus the scope of environmental investigation, and provide a simple, yet quantitative, historical record of changes in conditions on a site. Aerial photography has been used in environmental remote sensing since the early part of the 20th century. Aerial photos are valuable tools for environmental assessment because they provide objective, detailed documentation of surface conditions at a specific time. Furthermore, they can generally be obtained even in cases where access on the ground is denied to investigators. From aerial photos, precise quantitative information can be collected using photogrammetry. Such measurement and positional data can be produced in digital format for input into a Geographic Information System (GIS) for computerized analysis and display. Other information derived from aerial photographs requires specialized photointerpretive skills and experience. These include the recognition of vegetation mortality, oil-spill damage, and the ecological quality of water bodies. The location, extent and historical change of hazardous waste sites can be documented on topographic maps. These maps are often created from aerial photographs, and display the extent and location of real-world features by symbolizing them. The major advantage of maps over aerial photos is that maps can show things that are not visible from the air, while omitting unnecessary and distracting information. Because maps are derived products, they may contain bias in content and presentation, and they must be backed up by careful documentation and quality assurance protocols.     

Remote Sensing Tools Assist in Environmental Forensics. Part I: Traditional Methods

This is part one of a two-part discussion, in which we will provide an overview of the use of aerial photography, topographic mapping and photogrammetry in environmental enforcement actions. The visualization of spatial relationships of natural and man-made features can focus the scope of environmental investigation, and provide a simple, yet quantitative, historical record of changes in conditions on a site. Aerial photography has been used in environmental remote sensing since the early part of the 20th century. Aerial photos are valuable tools for environmental assessment because they provide objective, detailed documentation of surface conditions at a specific time. Furthermore, they can generally be obtained even in cases where access on the ground is denied to investigators. From aerial photos, precise quantitative information can be collected using photogrammetry. Such measurement and positional data can be produced in digital format for input into a Geographic Information System (GIS) for computerized analysis and display. Other information derived from aerial photographs requires specialized photointerpretive skills and experience. These include the recognition of vegetation mortality, oil-spill damage, and the ecological quality of water bodies. The location, extent and historical change of hazardous waste sites can be documented on topographic maps. These maps are often created from aerial photographs, and display the extent and location of real-world features by symbolizing them. The major advantage of maps over aerial photos is that maps can show things that are not visible from the air, while omitting unnecessary and distracting information. Because maps are derived products, they may contain bias in content and presentation, and they must be backed up by careful documentation and quality assurance protocols.     

Concentrations of Heavy Metals in Hair and Nails of Young Pakistanis: Correlation with Dietary Elements

Hair and nail samples from young Pakistani adults were separately analyzed for quantification of Cd, Cr, Cu, Ni, Pb, and Zn concentrations. The concentrations of these metals were also analyzed in commonly consumed local foods to evaluate potential correlation of hair and nail concentrations with diet. Pearson correlation coefficients ranged from 0.349 to 0.999, demonstrating diet to be a significant contributor for accumulation of heavy metals in humans.     

Assessment of aliphatic-aromatic copolyester biodegradable mulch films. Part I: field study

The objective of this work was to study the use of new biodegradable films in agriculture under open field conditions. Three biodegradable mulch films made from modified biodegradable polyester of different thicknesses and colors (black and white) and a conventional low density polyethylene (LDPE) mulch film were used to cover the beds of tomato plants. Changes in physical appearance of the films were recorded as well as changes in their mechanical, optical, and physical properties. Once tomato harvest was completed, the conventional LDPE mulch film was removed and all the tomato plants were cut using a mower. The biodegradable mulch films were plowed into the soil. The change in the appearance of the film was recorded and samples of each film after plowing were characterized according to the properties mentioned above. After the biodegradable films photodegraded, cross-link formation occurred within the films which promoted brittleness. Titanium dioxide, an additive used to produce white color in the films, catalyzed the photodegradation, while carbon black used for black color stabilized the photodegradation. The white films started to degrade after two weeks while it took about eight weeks for the black films to significantly degrade. The black biodegradable film seems to be a more promising alternative as a mulch film because of the comparable yields and weed suppression ability to conventional mulch film.     

Decomposition of organohalogen compounds in municipal solid waste incineration plants. Part I: Chlorofluorocarbons

Disposal of chlorofluorocarbons in a municipal solid waste incinerator has been studied. Destruction of CFC-11 (trichloromonofluoromethane) and CFC-113 (trichlorotrifluoroethane) was found to be better than 99.9%. Neither emission limits for hydrogen chloride or hydrogen fluoride specified in the 17^th BImSchV are exceeded during CFC incineration nor could formation of toxic halogenated organic compounds like dibenzo-p-dioxins or dibenzofurans be observed.