Assessment and Remediation of Contaminated Sediments (ARCS) Program

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Prepared by
Vic Engleman
Science Applications International Corporation
San Diego, CA

for the
Assessment and Remediation of Contaminated Sediments (ARCS) Program
U.S. Environmental Protection Agency
Great Lakes National Program Office
Chicago, Illinois

Bench-Scale Evaluation of Zimpro's Wet Air Oxidation Process on Contaminated Sediments from the Grand Calumet River

U.S. Environmental Protection Agency. May 1994. Abstract, Introduction and Table of Contents for "Bench-Scale Evaluation of Zimpro's Wet Air Oxidation Process on Contaminated Sediments from the Grand Calumet River," EPA 905-R94-007. Chicago, Ill.: Great Lakes National Program Office.

ABSTRACT

The Great Lakes National Program Office (GLNPO) leads efforts to carry out the provisions of Section 118 of the Clean Water Act (CWA) and to fulfill U.S. obligations under the Great Lakes Water Quality Agreement (GLWQA) with Canada. Under Section 118(c)(3) of the CWA, GLNPO was responsible for undertaking a 5-year study and demonstration program for the remediation of contaminated sediments. GLNPO initiated an Assessment and Remediation of Contaminated Sediments (ARCS) Program to carry out this responsibility. In order to develop a knowledge base from which informed decisions may be made, demonstrations of sediment treatment technologies were conducted as part of the ARCS Program. Bench-scale studies of the Zimpro Wet Air Oxidation Process, the subject of this report, took place at Zimpro Passavant Environmental Systems, Inc. (Zimpro) in Rothschild, WI on August 27 to 29, 1991. The primary objective for this effort was to determine the feasibility and cost-effectiveness of the Zimpro wet air oxidation process for treating and removing PAHs. The wet air oxidation process was not expected to treat PCBs, another known primary contaminant group detected in the sediments.

The Zimpro Wet Air Oxidation Process was tested using a sediment obtained from the Grand Calumet River. The concentrations of the contaminants of concern in the sediment were 11.9 mg/kg PCBs and 266 mg/kg PAHs. The PCB and PAH concentrations of 8.5 and <2.84 mg/kg, respectively, were found in the treated solids. This corresponds to PCB and PAH removals of 29 percent and >98.9 percent, respectively. Metals analyses were performed on the treated solids and untreated sediments. The feed sediments and treated solids were analyzed for percent moisture, oil and grease, total organic carbon (TOC), total volatile solids, and pH. Due to the sampling and analytical program for these tests, it was not possible to calculate a mass balance as part of this study.

Table Of Content

Abstract

1. Introduction
1.1 Background
1.2 Objectives and Scope
1.3 Approach

2. Regional Geology and Hydrogeology

3. Site Identification

3.1 Inactive Hazardous Waste Sites in Buffalo River AOC
3.2 Inactive Hazardous Waste Sites With Targeted Contaminants
3.3 Inactive Hazardous Waste Sites Discharging to the Buffalo River
3.4 Inactive Hazardous Waste Sites and Non-Targeted Pollutants

4. Loading Estimate Methodology
4.1 Plane Dispersion Model
4.1.1 Governing Equation and Solution
4.1.2 Parameterization
4.2 Method of Characteristics Model
4.2.1 Governing Equation and Solution
4.2.2 Parameterization

5. Results
5.1 Allied Chemical, Lehigh Valley, MacNaughton-Brooks, Madison Wire, West Seneca
5.2 Buffalo Color

6. Discussion
6.1 Pollutant Loadings via Groundwater
6.2 Uncertainty Associated with Loading Estimates
6.3 Pollutant Loadings via Other Pathways

7. Summary and Recommendations

1.0 EXECUTIVE SUMMARY

The Wet Air Oxidation Process was tested using sediments obtained from the Grand Calumet River. The contaminants of concern in the sediments for these tests were polynuclear aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). Samples of the feed material and the treated solids produced using the Wet Air Oxidation Process were analyzed by Battelle Marine Sciences Laboratory for residual PAH and PCB contamination. The data from these analyses are presented in Tables 1 and 2.

As these data demonstrate, the PAH destruction efficiency for the Grand Calumet River sediment is about 99 percent. The data demonstrate the technical feasibility of the Zimpro Wet Air Oxidation Process for treating and removing PAHs.

Feed material and treated solids were also analyzed for residual PCB concentrations. Table 2 outlines the analytical results obtained by Battelle.

The destruction efficiency for PCBs was only 29 percent, but the wet air oxidation process was not expected to treat PCBs.

Metal analyses were performed on the treated solids and untreated sediments (see Section 4.2.1.3). The Battelle analyses demonstrate that the treatment process, as expected, had little effect on metals removal from the sediments.

The feed and treated solids were analyzed for percent moisture, oil and grease, TOC, total volatile solids, and pH (see Table 3). The percent moisture decreased. Ninety percent of the oil and grease was removed. TOC and treated volatile solids were reduced more than 50 percent. The pH dropped to 6.5.

Because of the nature in which the organic material is oxidized, the TOC analysis shown in Table 11 was used to calculate the mass balance of the solids. The summation of the percent recovery results indicates that 90 percent of the material charged to the reactor was recovered after treatment. After correcting for the amount of sample oxidized during treatment and the amount known to be lost in Run Number 4, about 94 percent of the original sample was accounted for. Since all the species containing carbon and hydrogen in the sediment were not known and the organics were being oxidized to carbon dioxide and water, it was not possible to conduct a more detailed mass balance.

Small vials of the residuals from the treatability test were retained and given to the EPA Technical Project Manager for the GLNPO for "show" purposes. All quantities of the test products (solids and filtrate) from the treatability test were sent to the analytical laboratory, Battelle, for analysis. Due to the small quantities generated from the tests, none were retained and shipped to EPA for possible further treatability studies.

Zimpro has estimated the capital costs of units to treat 10,000, 40,000, and 100,000 yd^[3] of sediment at rates of 10 (60 TPD), 20 (120 TPD), and 40 gpm (240 TPD). These estimates are approximately $4,500,000 for the 10 gpm unit; $5,600,000 for the 20 gpm unit; and $7,300,000 for the 40 gpm unit. The sediment would be treated at a rate of 60 to 240 tons per day using 10 to 40 gpm units operated on a 24 hour per day, 5 days per week, 50 weeks per year basis. The cost of treating the sediment is estimated to be $329, $203, and $133/yd^[3] for the 10, 20, and 40 gpm units respectively. This estimate by Zimpro includes capital and operating costs but does not account for the costs associated with site excavation, civil work, applicable taxes, pre-screening needs, and overall site management and disposition of the residuals.

2.0 INTRODUCTION

In order to develop a knowledge base from which informed decisions may be made, bench-and pilot-scale demonstrations of sediment treatment technologies were conducted as part of the ARCS Program. Information from remedial activities supervised by the U.S. Army Corps of Engineers and the Superfund program wre also utilized. The Engineering/Technology (ET) Work Group was charged with overseeing the development and application of the bench- and pilot-scale tests.

Science Applications International Corporation (SAIC) was contracted to provide technical support to the ET Work Group. As part of this effort, SAIC was charged with conducting bench-scale treatability studies on designated sediments to evaluate the removal of specific organic contaminants. The bench-scale studies of the Zimpro Wet Air Oxidation Process, the subject of this report, took place at Zimpro Passavant Environmental Systems, Inc. (Zimpro) in Rothschild, Wisconsin on August 27 to 29, 1991. The primary objective for this effort was to determine the feasibility and cost-effectiveness of the Zimpro wet air oxidation process for treating and removing PAHs. The wet air oxidation process was not expected to treat PCBs, another known primary contaminant group detected in the sediments.

LIST OF FIGURES

ARCS Priority Areas of Concern
Grand Calumet River Sample Location
Wet Oxidation Flow Diagram for the Zimpro Wet Air Oxidation Process
Conditions of Phase I Tests
Percent Destruction of PAH in Solids as a Function of Operating Conditions

LIST OF TABLES

Summary of Total PAHs
Summary of Total PCBs
Characterization of Feed Sediments and Treated Solids
Battelle Analysis - Characterization of Feed Sediments
Wet Oxidation Feed
SAIC's Analysis Schedule for Phase II Wet Air Oxidation of Grand Calumet River Sediments
Zimpro Analyses
Feed and Treated Solids PAH Concentrations
Total PCBs
Metal Concentrations in the Feed and Treated Solids
Reduction Percentages for Other Parameters
PAH Concentrations in the Filtrate
PCB Concentrations in the Filtrate
Wet Oxidation Feed and Output
Time Required to Process Harbor Sediments as a Function of Unit Size
System Design Parameters Selected by Zimpro
Capital Costs and Estimated Utility Requirements
Annual Operating and Maintenance Costs for Treating Dredged Sediments