Showing papers on "Total petroleum hydrocarbon published in 1995"

Predictive model for estimating the extent of petroleum hydrocarbon biodegradation in contaminated soils.

Abstract: A series of solid- and slurry-phase soil bioremediation experiments involving different crude oils and refined petroleum products were performed in order to investigate the factors which affect the maximum extent of total petroleum hydrocarbon (TPH) biodegradation. Utilizing a comprehensive petroleum hydrocarbon characterization procedure involving group type separation analyses, boiling point distributions, and hydrocarbon typing by field desorption mass spectroscopy, initial and final concentrations of specified hydrocarbon classes were determined in each of the seven bioremediation treatments

Bioremediation of petroleum-contaminated soil

Abstract: A pilot-scale study was conducted to evaluate the application of land-farming techniques in bioremediating a soil highly contaminated with petroleum products. A commercial biosupplement, and one prepared with indigenous microorganisms from the contaminated soil, were tested. Application of either of the biosupplements, in addition to the control of pH, moisture, and oxygen levels, resulted in a 94% reduction of the initial total petroleum hydrocarbon concentration (TPHC) (32% mass/mass) over a 70-day period. Implementation of these findings at full scale to bioremediate highly weathered petroleum products showed an average reduction of 89% over 5.5 months. Target levels of 1,400 mg/kg soil were reached from an initial average TPHC concentration of 12,200 mg/kg soil.

TPH and BTEX Quantitation in Gasoline and Diesel Contaminated Soils by Capillary Gas Chromatography-Mass Spectrometry

Abstract: A manual gas chromatographic-mass spectrometric (GC-MS) method for the analysis of total petroleum hydrocarbon (TPH), benzene, toluene, ethyl benzene, o-xylene, m-xylene, and pxylene (BTEX), and naphthalene in gasoline and diesel contaminated soils is described. Multiple groups of ions are monitored to retain the high sensitivity of selected ion monitoring while permitting identification of solutes. Spiked soil samples containing gasoline and diesel with TPH concentrations in the range of 0.5 to 5000 parts per million are used to evaluate the method. The extraction efficiency of different solvents and solvent mixtures is evaluated. Ethyl ether and methylene chloride give quantitative recoveries for both TPH and BTEX from spiked soils. TPH or BTEX analysis by GC-MS provides excellent sensitivity, linearity of quantitation, and peak identification. The method presented here also eliminates time-consuming sample preconcentration steps for diesel-range components

Evaluation of the total petroleum hydrocarbon (TPH) standard for JP‐4 jet fuel

Abstract: The potential for use of alternatives to total petroleum hydrocarbons (TPH) for remediation purposes was examined specifically for JP‐4 fuel. The study objective was to determine the scientific basis for use of fuel constituents other than TPH in establishing soil cleanup standards at JP‐4‐contaminated sites. The general bases for TPH soil cleanup standards or goals were characterized. Problems with the use of TPH for cleanup included its lack of specificity (e.g., method‐, medium‐, and time‐from‐spill‐dependency) as well as the lack of toxicological relevance. JP‐4 fuel constituents (alkanes, BTEX [i.e., benzene, toluene, ethylbenzene, xylenes], polycyclic aromatic hydrocarbons [PAHs, i.e., chrysene], and naphthalenes) were identified as potential TPH alternatives. A series of criteria were applied to assess the viability of the use of specific JP‐4 constituents as TPH alternatives, and to select the most appropriate alternative. Criteria included chemical fate and transport, toxicity, and regul...

Low intervention soil remediation approaches

Abstract: Traditional bioremediation approaches have been used to treat petroleum source contamination in readily accessible soils and sludges. Contamination under existing structures is a greater challenge. Options to deal with this problem have usually been in the extreme (i.e., to dismantle the facility and excavate to an acceptable regulated residual, or to pump and treat for an inordinately long period of time). The excavated material must be further remediated and cleanfill must be added to close the excavation. If site assessments were too conservative or incomplete, new contamination adulterating fill soils may result in additional excavation at some later date. Innovative, cost-efficient technologies must be developed to remove preexisting wastes under structures and to reduce future remediation episodes. An innovative soil bioremediation treatment method was developed and evaluated in petroleum hydrocarbon contaminated (PHC) soils at compressor stations of a natural gas pipeline running through Louisiana. The in-situ protocol was developed for remediating significant acreage subjected to contamination by petroleum-based lubricants and other PHC products resulting from a chronic leakage of lubricating oil used to maintain the pipeline itself. Initial total petroleum hydrocarbon (TPH) measurements revealed values of up to 12,000 mg/kg soil dry weight. The aim of the remediation project was to reduce TPH concentration in the contaminated soils to a level of <200 mg/kg soil dry weight, a level negotiated to be acceptable to state and federal regulators. After monitoring the system for 122 days, all sites showed greater than 99-percent reduction in TPH concentration.

Biopile treatability, bioavailability, and toxicity evaluation of a hydrocarbon-impacted soil

Abstract: A parametric study was conducted to evaluate use and enhancement of engineered biopiles to remediate weathered, hydrocarbon-impacted soil. The study used fifteen 1.2-yd{sup 3} biopiles under continuous vacuum aeration for 45 wk. Various amendments, evaluated for their effectiveness to enhance remediation, including bulking materials, inorganic fertilizer, waste activated sludge, and a surfactant. The average total petroleum hydrocarbon (TPH) concentration was reduced approximately 55%, with no significant difference between any of the treatment amendments or controls. Posttreatment soil samples were subjected to 6-wk slurry reactor tests, achieving an additional 15% TPH reduction, for a total of 70%. Because these reductions fell short of treatment goals, toxicity tests were conducted to determine if an acceptable, risk-based, treatment endpoint had been reached. Despite TPH residuals, neither treated nor untreated soils were found to be toxic. The low toxicity of this soil was attributed to sorption mechanisms that left residuals sequestered, but slowly available for biodegradation, greatly reducing or eliminating toxicity and bioavailability.

Overview of Bioventing Technology for the Remediation of Petroleum Hydrocarbon Contamination

Abstract: Bioventing is an innovative technology for the treatment of vadose zone soils contaminated by a wide variety of petroleum distillate fuels. Bioventing stimulates the in situ biodegradation of the hydrocarbon contaminants by providing oxygen to the native soil microorganisms. This technology is a variant of soil venting or soil vapor extraction (SVE) technology. The bioventing process utilizes a much lower air flow rate than typically is used in SVE. These lower air flow rates are designed to provide adequate oxygen to sustain microbial degradation while minimizing hydrocarbon loss through volatilization.

A laboratory assessment of air sparging performance on oil-contaminated soil

Abstract: The efficacy of air sparging to remediate a subsurface plume of transformer oil is evaluated in a comprehensive laboratory study. Shake flask assays containing contaminated soil indicated the oil was highly (>80%) biodegradable by indigenous bacteria when oxygen, nitrogen, and phosphorous were supplied. From 50 to 60% of the oil was removed from the soil in a 169-day biodegradation rate study performed in laboratory soil columns designed to mimic air sparged conditions. Maximal total petroleum hydrocarbon (TPH) biodegradation rates of {approximately}70 mg/kg per day were observed in nutrient (N and P) amended columns at 23 C, based upon O{sub 2} uptake and CO{sub 2} production. The total TPH biodegraded in these columns was 3-fold higher than in an unamended control column.

An unnecessary addition of chlorobenzene as a reference standard in EPA method 418.1 for the determination of total petroleum hydrocarbons

Abstract: Total petroleum hydrocarbons in water samples as well as solid wastes are quantified using U.S. EPA Method 418.1. This method involves the liquid-liquid extraction of the total petroleum hydrocarbon followed by quantitative determination using infrared spectroscopy. A series of standard solutions are prepared by mixing iosoctane, hexadecane and chlorobenzene as the reference standards. The absorption of the standard and sample solutions is measured at 2930 cm -1 . In the present study, it was discovered that chlorobenzene does not have any appreciable absorption at 2930 cm -1 and therefore does not contribute toward the overal absorptions of the standard solutions. We conclude that the addition of carcinogenic chlorobenzene for the preparation of standard solutions as described in Method 418.1 is unnecessary and leads to a value of total petroleum hydrocarbons which is 33% higher than what may actually be present