Mined areas near the city of Galena, Kansas, provide a source of heavy metal contamination, particularly cadmium (Cd), lead (Pb), and zinc (Zn). The metals move off-site in response to erosion by wind and running water, spreading the contamination beyond its original extent. Phytostabilization of the mine tailings could limit the spread of these heavy metals. The purpose of this study was to attempt field-scale inoculation of tall fescue (Festuca arundinacea Schreb) with mycorrhizal fungi to enhance growth and survival on a metal-contaminated mine spoil, and to study the influence of cattle manure as a soil amendment on basic soil chemical properties and on the chemical fractionation of Cd, Pb, and Zn. No evidence of successful infection by mycorrhizal fungi was found. After the first growing season, vegetative cover reached 71% but then steadily declined to 29% over the next two growing seasons. Extractable soil phosphorus (P) levels remained constant throughout the study and were sufficient for normal plant growth. Extractable potassium (K) levels declined throughout the study and were not sufficient for normal plant growth after the third year. Soil pH decreased from an average of 7.9 early in the study to 6.5 at the end. Plant tissue Zn concentrations suggested Zn phytotoxicity that became worse over the course of the study. Manure increased the amount of organically bound metals and generally decreased exchangeable levels. Between the first and third years of the study, exchangeable forms of metals generally increased while residual forms decreased. These changes are likely the result of the soil acidification that occurred during this same period, and may have contributed to the decline in fescue productivity because of increased problems with Zn phytotoxicity.

Soil-water distribution coefficients $\left(K_d\right)$ were determined for polyaromatic hydrocarbons (PAHs) present in eight separate field samples. The eight samples were from three different sites that contained residues from manufacturing gas plant operations. The experimentally obtained $K_d$ values were determined using batch equilibrium studies conducted over a 7 day period. Aqueous and solid-phase PAH concentrations were measured, a pore-water concentration $\left(C_{\mathrm{pw}}\right)$ was determined, and an experimental sample-water distribution coefficient $\left(K_d\right)$ was calculated for each PAH in each sample. The experimental $K_d$ values were compared to $K_d$ values estimated using literature values of $K_{\mathrm{oc}}$ and the fraction of organic carbon $\left(f_{\mathrm{oc}}\right)$ in the samples $(K_d=K_{\mathrm{oc}}\cdot f_{\mathrm{oc}})\text{.}$ The comparisons indicated that the experimentally obtained $K_d$ values were larger than the estimated $K_d$ values; some experimental $K_d$ values were over 100 times greater than the estimated values. The differences between the experimental sample-specific $K_d$ values and the estimated $K_d$ values were larger for samples containing anthropogenic organic carbon. These comparative results indicate that there can be value in obtaining and using experimentally obtained soil- or sample-specific $K_d$ values for risk-based decisions related to the remediation of contaminated soils.

When a waste generated, treated, or disposed of at a site in the United States is classified as hazardous under the Resource Conservation and Recovery Act and is destined for land disposal, the waste manager responsible for that site must select an approach to comply with land disposal restrictions (LDR) treatment standards. This paper focuses on the approach of obtaining a variance from existing, applicable LDR treatment standards. It describes the types of available variances, which include (1) determination of equivalent treatment (DET); (2) treatability variance; and (3) treatment variance for contaminated soil. The process for obtaining each type of variance is also described. Data are presented showing that historically the U.S. Environmental Protection Agency (EPA) processed DET petitions within one year of their date of submission. However, a 1999 EPA policy change added public participation to the DET petition review, which may lengthen processing time in the future. Regarding site-specific treatability variances, data are presented showing an EPA processing time of between 10 and 16 months. Only one generically applicable treatability variance has been granted, which took 30 months to process. No treatment variances for contaminated soil, which were added to the federal LDR program in 1998, are identified as having been granted.

This paper reports a series of laboratory and field tests that measured the asbestos (chrysotile) fibers released during demolition of gypsum wallboard (GWB) that contained small amounts of chrysotile in the joint mastic. The tests include contractors’ data from two actual demolitions, a controlled demolition of a wall segment, and bench top laboratory tests of gypsum wallboard samples. The results of all these tests indicated that many fibers are released during GWB demolition, but few if any of the fibers were chrysotile. The use of electron microscopy demonstrated that less than 2% of the fibers counted from laboratory and controlled demolitions using light microscopy procedures was asbestos. The actual field demolitions, which included asbestos containing material other than GWB, indicated that less than 4% of the fibers counted using light microscopy procedures was asbestos.

An investigation on the effect of elemental sulphur concentration on bioleaching of Cr(III) and other metals from tannery sludge by sludge indigenous sulphur-oxidizing bacteria was performed. Elemental sulphur concentrations ranging from 5 to 40 g/L were tested during this study. The sludge solids concentration was fixed at 40 g/L. The results showed that the sludge pH decrease was faster and sharper with increased sulphur concentration. The time required to achieve the final pH (the lowest pH) was about 15 days irrespective of sulphur concentration. The leaching efficiencies of Cr(III), Al, and Fe, and ${{\mathrm{SO}}_4}^{2-}$ production increased with increasing initial sulphur concentration. However, the leaching efficiencies of Zn, Ca, and Mg were less affected by the initial sulphur concentration. The preferred sulphur concentration for Cr leaching was 20 g/L, from an economic viewpoint. The total and volatile suspended solids decreased during the process. The measurements of sulphur-oxidizing bacteria showed that less-acidophilic thiobacilli as well as acidophilic thiobacilli contributed to the pH reduction in tannery sludge. The sulphur-oxidizing bacteria could survive in tannery sludge at a pH as low as 0.5 at 21°C

In the affluent State of Kuwait, every home contains hazardous substances that have the potential for posing risk to life, health, property, or the environment, if improperly consumed, stored, or disposed. A review of the available literature indicates that no recent information exist on the extent of hazardous substances accidents at homes in Kuwait, or on the level of awareness of households concerning these substances. The objectives of this research study were to determine (1) the type and the quantity of hazardous materials most commonly used at homes in Kuwait; (2) the level of awareness of household heads concerning the disposal of these substances; and (3) the extent of hazardous substance-related accidents and injuries occurring at homes. A simple, yet structured questionnaire was designed, pretested, and employed in a person-survey of a random sample of 1,200 household heads providing the database for the study. A profile of the socioeconomic traits of the sample households, common hazardous substances, and home accidents involving these substances is presented. The interrelationships among these variables are examined and the resulting coefficients of correlations are tested for significance. Findings indicate that toilet cleaners, chlorine bleach, glass/window cleaners, roach killers, oven cleaners, and drain openers, where the top five most commonly consumed hazardous substances at homes in Kuwait. The consumption rates of these substances were also significantly higher for the Kuwaiti sample households when compared to their non-Kuwaiti counterparts. Nearly 15% of the sample households had experienced a hazardous substance use-related accident at home during the last 3 years. Ten percent of the study households were involved in an injurious accident involving the use of these substances during the same time period. The study also found that the level of households’ awareness of hazardous substances is generally low and is in need of continuous improvement.

In the present work, the biosorption potential of a fungal strain isolated from industrial wastewaters contaminated with zinc and other heavy metals has been investigated. Zinc biosorption studies using the fungi were conducted in an optimized media under sterile as well as nonsterile conditions using batch bioreactors. Initial pH of the media was found to be 5.6. The growth of the fungi and specific metal uptake rates were studied in the liquid media with different initial concentrations of zinc ranging from 0 to 10,000 mg/L. The growth of the fungi was not affected at lower concentrations (up to 100 mg/L) of zinc. However, a further increase in the concentration of zinc increased the lag phase duration and decreased the substrate utilization rate. The specific metal uptake by the fungi increased with an increase in initial concentrations of zinc. The effect of a sugar concentration (5–100 g/L) on the growth of the organism and the specific metal uptake by the organism were studied. These studies were carried out using an initial zinc concentration of 100 mg/L. A maximum zinc removal of 18.4 mg/g of dried biomass was observed at 20 g/L sugar concentration. Further increase in sugar concentration did not increase the specific metal uptake by the organism. The effect of pH on the growth of the organism and the specific metal uptake by the organism were also studied in the pH range 2.5–6.5. The optimum pH for the growth and the specific metal uptake was found to be in the pH range 4.5. The effect of inoculum concentration (5–20%v/v) on the growth and the metal uptake capacity of the organism was also studied. A maximum zinc removal of 77 mg/g of dried biomass was observed within 36 h at 500 mg/L of initial zinc concentration and at 20 %(v/v) inoculum concentration. The growth of the organism was also monitored in the presence of other metals such as Pb, Cu, Ni, and Cr, separately. The organism was capable of growing in each case at 100 mg/L initial concentration. Batch studies were also conducted to examine the biosorption potential of the organism adapted to minimal media. The organism was also found to be effective for the removal of zinc from an actual effluent generated by a color picture tube manufacturing industry.