\u3csup\u3e13\u3c/sup\u3eC NMR Analysis of Biologically Produced Pyrene Residues by \u3cem\u3eMycobacterium\u3c/em\u3e sp. KMS in the Presence of Humic Acid

Cultures of the pyrene degrading Mycobacterium sp. KMS were incubated with [4-13C]pyrene or [4,5,9,10-14C]pyrene with and without a soil humic acid standard to characterize the chemical nature of the produced residues and evaluate the potential for bonding reactions with humic acid. Cultures were subjected to a “humic acid/humin” separation at acidic pH, a duplicate separation followed by solvent extraction of the humic acid/humin fraction, and a high pH separation. 13C NMR analysis was conducted on the resulting solid extracts. Results indicated that the activity associated with solid extracts did not depend on pH and that approximately 10% of the added activity was not removed from the solid humic acid/humin fraction by solvent extraction. 13C NMR analysis supported the conclusion that the majority of pyrene metabolites were incorporated into cellular material. Some evidence was found for metabolite reaction with the added humic material, but this did not appear to be a primary fate mechanism

Mn-Catalyzed Oxidation of Naphthalenediol

This study investigates the effects that manganese(IV) dioxide particles have on 2,3-naphthalenediol at varying pH levels (i.e., initial pH of 4.58, 5.85, and 8.75) and under different organic concentration conditions (4×10−3, 4×10−4, and 4×10−5 M), and assesses the importance of Mn oxides on abiotic catalysis of the multiple-ringed aromatic compound. Proton concentration affected the rates of reductive dissolution; as the pH values increased, the rate of reductive dissolution decreased, as predicted by theory. Also, as the concentration of naphthalenediol increased, the rate of reductive dissolution increased, although not proportionally; thus indicating that a majority of the active sites had been occupied. In addition, the results tend to confirm that electron transfer/organic release from the oxide surface is the rate-limiting step. This study demonstrates that in an oxic environment and in the presence of 2,3-naphthalenediol, MnO2 particles undergo reductive dissolution; in the process, naphthalenediol is oxidized. An oxidation by-product of reductive dissolution is an insoluble polymerized organic. The organic by-product was deep-brown in appearance, very similar to that of humified material. Using infrared spectroscopy, energy-dispersive x-ray analysis, and a microelemental analysis, the humified products appeared to be comprised mainly of constituents originating from naphthalenediol

Human Health Effects Assays

Discussion of the exponential increase in environmental toxicological information and an approach for organizing and using the information was presented by Lu and Wassom.1 A user\u27s guide to the Registry of Toxic Effects of Chemical Substances (RTECS) was published by NIOSH2 that defines the record layouts and describes the types of data contained in the computer tape version of the 1984 Edition of the RTECS.3 A text summarizing information on approximately 800 toxic chemicals was edited by Sittig.4 Milestone publications concerning fundamentals of toxicology with environmental applications included the works of Gentile,5 Ashby,6 Mortel mans,7 Thacker,8 and Ruppert.9 Brusick and Auletta10 discussed the developmental status of bioassays in genetic toxicology reviewed by the U. S. Environmental Protection Agency (EPA) Gene-Tox Work Groups

Approach to Bioremediation of Contaminated Surface Soils

Biological processes, including microbial degradation, have been identified as critical mechanisms for attenuating organic contaminants during transit through the vadose zone to the groundwater. On-site soil remedial measures using biological processes can reduce or eliminate groundwater contamination, thus reducing the need for extensive groundwater monitoring and treatment requirements. On-site remedial systems that utilize the soil as the treatment system accomplish treatment by using naturally occurring microorganisms to treat the contaminants. Treatment often may be enhanced by a variety of physical/chemical methods, such as fertilization, tilling, soil Ph adjustment, moisture control, etc. The development of a bioremediation program for a specific contaminated soil system includes: (1) a thorough site/soil/waste characterization; (2) treatability studies; and (3) design and implementation of the bioremediation plan. Biological remediation of soils contaminated with organic chemicals has been demonstrated to be an alternative treatment technology that can often meet the goal of achieving a permanent clean-up remedy at hazardous waste sites, as encouraged by the U.S. Environmental Protection Agency (U.S. EPA) for implementation of the Superfund Amendments and Reauthorization Act (SARA) of 1986. Bioremediation is especially promising if it is incorporated in a remediation plan that uses an integrated approach to the cleanup of the complete site, i.e., a plan that involves the concept of a treatment train of physical, chemical, and/or biological processes to address remediation of all sources of contaminants at the site

Algae-based biofilm productivity utilizing dairy wastewater: effects of temperature and organic carbon concentration

Photograph Illus. 6.4

Evaluation of Mechanisms of Alteration and Humification of PAHs for Water Quality Management

Introduction: Creosote-pentachlorophenol (PCP) is a mixture commonly used as a wood preservative in the U.S. (1). A 1988 survey (2) indicated that 1,397 wood preserving waste contaminated sites exist in the United States consisting of 555 active wood treatment plants and 842 inactive plants. Stinson (3) indentifed 58 wood preserving sites on the National Priorities List, of which 51 have PCP and/or creosote or polycyclic aromatic hydrocarbon (PAH) contamination. Principal classes of organic constituents present in creosote waste are PAHs (~85% by weight) and phenolics. PAHs with less than three fused benzene rings comprise 69% (i.e., naphthalene, anthracene and phenanthrene); PAHs with more than three rings, such as pyrne, benzo(a)pyrene, and benz(a)anthracene, dibenz(a,h)anthracene, and indeno(1,2,3-c,d)pyrene comprise 16% by weight of creosote. Phenolics comprise 2% to 17% of creosote. Nitrogen- and sulfur- containing heterocyclic compounds may comprise up to 13% of creosote by weight. Creosote and creosote components including phenol and several PAHs have been reported to be mutagenic, teratogenic, fetotoxic and/or toxic (4,5) and have been designated as hazardous wastes under the Resource Conservation and Recovery Act of 1976 (6) and as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980. PCP is often added to creosote to enhace the wood preservation potential due to its bactericidal and fungicidal properties. PCP is also toxic to lower and higher plants (algicide, herbicide), to invertegrate and vertebrate animals (insecticide, molluscicide), and to man. Toxicity of PCP and potentical for uptake by organisms are pH-dependent, since PCP is a weak acid with a Ka of about 10^-5. Both bioaccumulation and toxicity increase as pH decreases due to the greated penetration of cell membranes by non-ionized PCP molecules than by pentachlorophenate ions (1). Therefore PCP may inhibit microbial degradation of other compounds in creosote-PCP waste, including oil and grease. Contaminated vadose zone soil systems generally consist of four phases: 1)aqueous; 2) gas; 3) oil (commonly referred to as non-aqueous phase liquid, or NAPL); and 4)solid, which has two components, and inorganic mineral compartment and an organic matter compartment (organic carbon-humic substances). Interphase tranfer potential for waste constituents among oil (waste or NAPL), water, air, and solid (organic and inorganic) phase of a soil system is affected by the relative affinity of the waste constituents for each phase. Measurement of waste constitutents in all four phases is generally not done in treatability studies, especially in complex environmental samples (7). High molecular weight (greater than 3 rings) PAHs are hydrophobic and essentially not mobile dur to their low volatilities and water solubilities. Bulman et al. (8) and Keck et al. (9) observed that sorption of B(a)P to soil was the dominant mechanism of loss. Studies have shown that immobilization of some xenobiotics can be accomplished by incorporation into soil humus, or sorption into the clay lattice of soil (10). Humification and sorption have not been extensively evaluated for PAHs in creosote contaminated soil. PCP is, in general, more mobile in high pH soils than in acidic soils. At low pH, PCP exists as a free acid (non-ionized) and readily adsorbs to soil particles. At high pH, PCP exists in the ionized form (pKa = 4.7) as the negatively charged pentachlorophenate anion, and is more mobile. In a study by Choi and Aomine (11), apparent adsorption of PCP was greatest in strongly acid soil and in soils with high organic matter content. Apparent adsoprtion was shown to include both the mechanisms of adsorption on soil colloids and precipitation in the soil micelle and in the external liquid phase, depending on the soil pH. Pionteck (12) also observed that although soil organic matter is important in determining the extent of odsorption of PCP, an even more important soil property is pH. Adsorption of PCP was shown to be reversible. Therefore, PCP may not be permanently immobilized in the soil phase, but may be slowly released into and move through the soil (1). A wide range of soil organisms, including bacteria, fungi, cyanobacteria and eukaryotic algae, have been shown to have the enzymatic capacity to oxidize PAHs. Metabolites from the degradation of large PAHs identified in these studies are responsible for toxic, mutagenic, and/or carcinogenic responses in animal species and many indicate epoxide intermediates (13-20). Presense of PCP may inhibit microbial degradation of other organics, including PAHs, oil and grease, etc. Despite a high degree of chlorination, PCP has been shown to be degraded in soil. Microbial deconposition appears to be the primary detoxification mechanism. Success was the highest in those studies that used acclimated or inoculated (with acclimated species) systems. The ability to degrade PCP may not be uniform among microorganisms, and adaptation of microbial populations to PCP and control of pH may play important roles in its degradation (1). Laboratory studies (7, 12) of the biodegradation potential of creosote wood preservative waste have shown that hazardous parent components were degraded, transformed, or immobilized in certain soil systems. In a study by Aprill et al. (21) on the biodegradation potential of creosote, the apparent degradation of four non-carcinogenic PAHs and four carcinogenic PAHs ranged from 54% to 90% and 24% to 53% of mass added, respectively. Aprill et al. (21) defined apparent degradation as the measurement of changes in concentrations of specific constituents in solvent extracts of soil samples with time of incubation. The reduction in concentration of the higher molecular weight PAHs was correlated with oil and grease content of the waste. Degradation of a chemical in soil may not result in the complete mineralization of a hazardous waste, but may render waste constituents less harzardous or nonhazardous through transformations (1,7,21). However in some cases detoxification does not occur (22). Studies (23-30_ conducted with 14C labeled compounds often report collection of the radiolabelled carbon in carbon dioxide trapping solutions to indicate degradation or mineralization. However, collection of the radiolabelled carbon in a carbon dioxide trapping solution may be misleading in two ways, i.e., 1) liberation of CO2 may not be concurrent with complete degradation of the total mass present because of accumulation of metabolites in the soil (31), or 2) measurement of radiolabelled carbon may not indicate mineralization if colatilized parent compound or labeled metabolites are collected in the trapping solution in addition to 14C2 (32, 33). Torstensson and Stenstrom (31) recommend that the rate of decomposition of a substance should be defined by direct measurement of its disappearance. However, direct measurement of the disappearance of hydrophobic organics from soil systems cannot be defined as degration because of other loss mechanisms including volatilization or soption to soil solids. Sorbed organics that cannot be removed from soil by organic solvents cannot be easily identified or analyzed. There is a current lack of knowledge concering the behavior of PAHs in complex environmental vadose zone soil samples. This study was undertaken, using a chemical mass balance appreaoch, to determine the distribution of radiolabelled carbon, parent compounds, and transformation products of the radiolabelled PAH compounds, benzo(a)pyrene (B(a)P) and pyrene, among aqueous, gas, and solid phases of a non-contaminated and contaminated (creosote-PCP) vadose zone soil over time of incubation. The apparent degradation of unlabeled PAHs and changes in the toxicity of the water-soluble (aqueous) fraction were also measured

High Intensity Land Treatment (HILT) Practices

Land treatment is categorized in the Resource Conservation and Recovery Act of 1976 (RCRA) as one of the land disposal options for managing hazardous waste constituents within the defined treatment zone before such constituents can be transported to surface water, groundwater, or air. Under the authroity of Subtitle C of RCFA, the U.S. Environmental Protection Agency has promulgated regulations governing the treatment and disposal of hazardous wastes in land treatment units (40 CFR, Part 264, Subpart M, July 26, 1982). The objectives of this report were to identify land treatment facilities meeting the defined high intensity land treatment (HILT) criteria, and to describe the operation and management practices used at HILT facilities. A final objective was to compare operation and mangement practices used at HILT facilities with RCRA guidelines. The information needed to accomplish the objectives was obtained with data collection packets. A total of twelve land treatment facilities completed the data collection packets. Six of these land treatment facilities qualified as HILT facilities qualified as HILT facilities under the defined criteria used in this report. This repot was submitted in partial fulfillment of Cooperative Agreement No. CR-810979-02-0 by the Utah Water Research Laboratory at Utah State University, under the sponsorship of the Robert S. Kerr Environmental Research Laboratory, U.S. Environmental Protection Agency

Existing Empirical Kinetic Models in Biochemical Methane Potential (BMP) Testing, Their Selection and Numerical Solution

Biochemical Methane Potential (BMP) tests are a crucial part of feasibility studies to estimate energy recovery opportunities from organic wastes and wastewater. Despite the large number of publications dedicated to BMP testing and numerous attempts to standardize procedures, there is no “one size fits all” mathematical model to describe biomethane formation kinetic precisely. Importantly, the kinetics models are utilized for treatability estimation and modeling processes for the purpose of scale-up. A numerical computation approach is a widely used method to determine model coefficients, as a replacement for the previously used linearization approach. However, it requires more information for each model and some range of coefficients to iterate through. This study considers existing empirical models used to describe biomethane formation process in BMP testing, clarifies model nomenclature, presents equations usable for numerical computation of kinetic parameters as piece-wise defined functions, defines the limits for model coefficients, and collects and analyzes criteria to evaluate and compare model goodness of fit

Review of In-Place Treatment Techniques for Contaminated Surface Soils - Volume 2: Background Information for In Situ Treatment

This second volume of a two volume manual on in-place treatment of hazardous waste contaminated soil supports the treatment methodology described in Volume 1 (EPA- ). The information presented on monitoring to determine treatment effectiveness, characterization and evaluation of the behavior and fate of hazardous constituents in soil/waste systems, and properties (including adsorption, degradation, and volatilization parameters) for various compounds is intended to help the manual user in making more complex decisions and in selecting analyses concerning site, soil, and waste interactions. This report was submitted in partial fulfillment of Contract No. 68-03-3113 by Utah State University under the sponsorship of the U.S. Environmental Protection Agency. The report covers the period December 1982 to December 1984 and work was completed as of January 1984