Grantee Research Project Results

Using Plants to Remediate Petroleum-Contaminated Soil

EPA Grant Number: R827015C018
Subproject: this is subproject number 018 , established and managed by the Center Director under grant R827015
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: IPEC University of Tulsa (TU)
Center Director: Sublette, Kerry L.
Title: Using Plants to Remediate Petroleum-Contaminated Soil
Investigators: Thoma, Greg , Beyrouty, Craig , Wolf, Duane
Current Investigators: Thoma, Greg , Wolf, Duane , Ziegler, Susan
Institution: University of Arkansas
EPA Project Officer: Aja, Hayley
Project Period: July 1, 2001 through June 30, 2002 (Extended to May 15, 2003)
RFA: Integrated Petroleum Environmental Consortium (IPEC) (1999) RFA Text |  Recipients Lists
Research Category: Hazardous Waste/Remediation , Targeted Research

Objective:

Introduction

Crude oil-contamination of soil often occurs in areas adjacent to wellheads and storage facilities. Phytoremediation is a promising tool that can be used to remediate such sites and uses plants and agronomic techniques to enhance biodegradation of the hydrocarbon compounds. The research objective of this study was to evaluate fertilizer addition and vegetation establishment on phytoremediation of crude oil-contaminated soil. Our current IPEC phytoremediation studies consist of an on-site field project in southern Arkansas, greenhouse studies, and a mathematical modeling.

Approach:

Field Study

The field site in El Dorado, AR is located in a bermed area that is the site of an intentional spill in 1997 by vandals. The experimental plots consist of four replicates of the following treatments: (1) nonvegetated-nonfertilized control, (2) fescue-ryegrass-alfalfa + fertilizer, and (3) fescue-bermudagrass + fertilizer. Each field plot has 12 microplots ("soil socks") that contain homogenized soil that allow monitoring of the field treatments, on a smaller scale, with less effect of field variability of the contaminant levels.

On 10-12 July 2000, 6 months after establishment of vegetation at the site, soil and plant samples were collected from the plots. Plant shoot biomass and root biomass, length, surface area, and volume for each of the treatments were determined. All plant species appeared to be exhibiting adequate plant growth. The Total Petroleum Hydrocarbon (TPH) and biomarker (hopane) analyses of the soil samples collected 6 months after plot establishment (t=6) are currently being conducted.

A survey was conducted to identify plant species currently growing on petroleum-contaminated sites near the El Dorado, AR field site. Plants that were observed to be growing at the various sites included bermudagrass (Cynodon dactylon L.), yellow nutsedge (Cyperus esculentus L.), fall panicum (Panicum dichotomiflorum Michx.), brome grass (Bromus spp.), and witchgrass (Panicum capillare L.).

Greenhouse Study

Selection of plant species and soil amendments is essential to phytoremediation. The research goal is to identify plants and management techniques to effectively remediate oil-contaminated soil. Germination and survival of 22 plant species in oil-contaminated soil has been determined in a growth chamber study. A greenhouse study evaluated biomass production of 5 plant species in oil-contaminated unamended soil or soil amended with broiler litter, hardwood sawdust, papermill biosolids, or inorganic fertilizer. Oil-contaminated field plots were sampled at 0 to 15-cm and 15 to 45-cm depths and analyzed for TPH and plant nutrients. Treatments were: non-fertilized vegetation-free control; fertilized fescue-ryegrass mixture; or fertilized bermudagrass-fescue mixture. Plant growth, TPH levels, soil nutrients, and oil-degrading microbial levels will be evaluated.

Mathematical Model

We have developed a simple mathematical model of the phytoremediation process that accounts for the "exploration" of contaminated soil by the plant roots. Unlike pesticides, metals, and explosives that are readily transported to the plant via water movement, and thus exposed to the root-zone-enhanced remediation rates, spilled crude oil is not mobile, so root growth through the soil must be accounted for in the model to incorporate the effect of enhanced degradation in the rhizosphere zone. Both the rhizosphere volume and the rate of root turnover are important parameters in this system. However, accurate and precise experimental measurements of the rhizosphere volume are difficult to make, and we are developing tools to estimate these parameters. In addition, we have proposed a simple model for root growth that accounts for annual root turnover, maximum standing biomass, and spatial and temporal distribution.

Publications and Presentations:

Publications have been submitted on this subproject: View all 14 publications for this subproject | View all 120 publications for this center

Journal Articles:

Journal Articles have been submitted on this subproject: View all 3 journal articles for this subproject | View all 16 journal articles for this center

Supplemental Keywords:

RFA, Scientific Discipline, Waste, Water, Geographic Area, POLLUTANTS/TOXICS, Contaminated Sediments, Remediation, Chemicals, Chemistry, State, Environmental Microbiology, Hazardous Waste, Bioremediation, Hazardous, Environmental Engineering, degradation, waste treatment, petroleum, contaminated sites, microbial degradation, rhizospheric, petroleum contaminants, biodegradation, decontamination of soil, cleanup, Arkansas, microbes, soils, contaminated soil, bioremediation of soils, contaminants in soil, soil, hydrocarbons, models, phytoremediation, soil microbes

Progress and Final Reports:

2002 Progress Report

Final Report

Main Center Abstract and Reports:

R827015    IPEC University of Tulsa (TU)

Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R827015C001 Evaluation of Road Base Material Derived from Tank Bottom Sludges
R827015C002 Passive Sampling Devices (PSDs) for Bioavailability Screening of Soils Containing Petrochemicals
R827015C003 Demonstration of a Subsurface Drainage System for the Remediation of Brine-Impacted Soil
R827015C004 Anaerobic Intrinsic Bioremediation of Whole Gasoline
R827015C005 Microflora Involved in Phytoremediation of Polyaromatic Hydrocarbons
R827015C006 Microbial Treatment of Naturally Occurring Radioactive Material (NORM)
R827015C007 Using Plants to Remediate Petroleum-Contaminated Soil
R827015C008 The Use of Nitrate for the Control of Sulfide Formation in Oklahoma Oil Fields
R827015C009 Surfactant-Enhanced Treatment of Oil-Contaminated Soils and Oil-Based Drill Cuttings
R827015C010 Novel Materials for Facile Separation of Petroleum Products from Aqueous Mixtures Via Magnetic Filtration
R827015C011 Development of Relevant Ecological Screening Criteria (RESC) for Petroleum Hydrocarbon-Contaminated Exploration and Production Sites
R827015C012 Humate-Induced Remediation of Petroleum Contaminated Surface Soils
R827015C013 New Process for Plugging Abandoned Wells
R827015C014 Enhancement of Microbial Sulfate Reduction for the Remediation of Hydrocarbon Contaminated Aquifers - A Laboratory and Field Scale Demonstration
R827015C015 Locating Oil-Water Interfaces in Process Vessels
R827015C016 Remediation of Brine Spills with Hay
R827015C017 Continuation of an Investigation into the Anaerobic Intrinsic Bioremediation of Whole Gasoline
R827015C018 Using Plants to Remediate Petroleum-Contaminated Soil
R827015C019 Biodegradation of Petroleum Hydrocarbons in Salt-Impacted Soil by Native Halophiles or Halotolerants and Strategies for Enhanced Degradation
R827015C020 Anaerobic Intrinsic Bioremediation of MTBE
R827015C021 Evaluation of Commercial, Microbial-Based Products to Treat Paraffin Deposition in Tank Bottoms and Oil Production Equipment
R827015C022 A Continuation: Humate-Induced Remediation of Petroleum Contaminated Surface Soils
R827015C023 Data for Design of Vapor Recovery Units for Crude Oil Stock Tank Emissions
R827015C024 Development of an Environmentally Friendly and Economical Process for Plugging Abandoned Wells
R827015C025 A Continuation of Remediation of Brine Spills with Hay
R827015C026 Identifying the Signature of the Natural Attenuation of MTBE in Goundwater Using Molecular Methods and "Bug Traps"
R827015C027 Identifying the Signature of Natural Attenuation in the Microbial Ecology of Hydrocarbon Contaminated Groundwater Using Molecular Methods and "Bug Traps"
R827015C028 Using Plants to Remediate Petroleum-Contaminated Soil: Project Continuation
R827015C030 Effective Stormwater and Sediment Control During Pipeline Construction Using a New Filter Fence Concept
R827015C031 Evaluation of Sub-micellar Synthetic Surfactants versus Biosurfactants for Enhanced LNAPL Recovery
R827015C032 Utilization of the Carbon and Hydrogen Isotopic Composition of Individual Compounds in Refined Hydrocarbon Products To Monitor Their Fate in the Environment
R830633 Integrated Petroleum Environmental Consortium (IPEC)
R830633C001 Development of an Environmentally Friendly and Economical Process for Plugging Abandoned Wells (Phase II)
R830633C002 A Continuation of Remediation of Brine Spills with Hay
R830633C003 Effective Stormwater and Sediment Control During Pipeline Construction Using a New Filter Fence Concept
R830633C004 Evaluation of Sub-micellar Synthetic Surfactants versus Biosurfactants for Enhanced LNAPL Recovery
R830633C005 Utilization of the Carbon and Hydrogen Isotopic Composition of Individual Compounds in Refined Hydrocarbon Products To Monitor Their Fate in the Environment
R830633C006 Evaluation of Commercial, Microbial-Based Products to Treat Paraffin Deposition in Tank Bottoms and Oil Production Equipment
R830633C007 Identifying the Signature of the Natural Attenuation in the Microbial Ecology of Hydrocarbon Contaminated Groundwater Using Molecular Methods and “Bug Traps”
R830633C008 Using Plants to Remediate Petroleum-Contaminated Soil: Project Continuation
R830633C009 Use of Earthworms to Accelerate the Restoration of Oil and Brine Impacted Sites