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Section Ten PHYSICAL-CHEMICAL: METALS PRESENCE, FATE, AND IMPACT 38 LEACHING PROCESS FOR REMOVAL OF HEAVY METALS IN SOIL Alton Day Stone, Senior Environmental Scientist Pennoni Associates Inc. Hopkinton, Massachusetts 01748 James C. O'Shaughnessy, Professor Department of Civil & Environmental Engineering Worcester Polytechnic Institute Worcester, Massachusetts 01609 ABSTRACT This paper presents the results of bench-scale experiments conducted to evaluate heavy metals sorption and desorption phenomena for soils common to New England, and the suitability of soil leaching (flushing) for in-situ remediation of soils contaminated with heavy metals. The results of the investigations indicated that the soil physical parameters mass fines/unit mass soil, bulk density, coefficient of uniformity, and coefficient of concavity were not good predictors of soil sorptive or desorption capacity. INTRODUCTION Environmental contamination by heavy metals is relatively common. Lead, often in high concentrations is ubiquitous in urban soils due to the past use of leaded gasolines and paints. Formerly, arsenic was widely used as a general pesticide. The majority of sites contaminated with concentrated heavy metals are associated with industrial processes such as mining, smelting, plating, coating, machining and manufacturing, and locations where disposal of associated wastes has occurred. The Environmental Protection Agency (EPA)1 estimates that approximately 10% of the Superfund sites involve heavy metal contamination. Concentration ranges of metals reported in soil at EPA sites are included in Table I. In recognition of the hazard posed by exposures to heavy metals, federal and state agencies have established regulations to limit environmental contamination and reduce human and environmental exposures. The EPA currently lists 13 heavy metals as "priority pollutants" under the Comprehensive Environmental Recovery, Compensation and Liability Act (CERCLA) commonly known as "Superfund": antimony, arsenic, beryllium, cadmium, chromium, copper, lead, mercury, nickel, selenium, silver, thallium, zinc. Each of these metals, except barium and copper, is listed as a "hazardous material" in the Massachusetts Contingency Plan (MCP, 310 CMR 40.0000), promulgated under M.G.L. c. 21e the "Oil and Hazardous Materials Act." Industrial solid wastes which contain sufficient leachable amounts of certain metals (Table I), as determined by the Toxicity Characteristic Leaching Procedure (TCLP) chemical analytical procedure, are listed "hazardous wastes" which are regulated under the Resource Conservation and Recovery Act (RCRA). The TCLP extraction (leaching) analysis is intended to duplicate leaching of the waste by rainwater in the open environment. If the extract contains a metal concentration above an established criteria, the waste exhibits the characteristic of "toxicity," and is classified as hazardous. These wastes are considered to be potential sources of environmental 52nd Purdue Industrial Waste Conference Proceedings. 1997. Ann Arbor Press. Chelsea, Michigan 48118. Printed in U.S.A. 377
Object Description
Purdue Identification Number | ETRIWC199738 |
Title | Leaching process for removal of heavy metals in soil |
Author |
Stone, Alton Day O'Shaughnessy, James C. |
Date of Original | 1997 |
Conference Title | Proceedings of the 52nd Industrial Waste Conference |
Conference Front Matter (copy and paste) | http://earchives.lib.purdue.edu/u?/engext,20307 |
Extent of Original | p. 377-394 |
Collection Title | Engineering Technical Reports Collection, Purdue University |
Repository | Purdue University Libraries |
Rights Statement | Digital object copyright Purdue University. All rights reserved. |
Language | eng |
Type (DCMI) | text |
Format | JP2 |
Date Digitized | 2009-11-03 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Resolution | 300 ppi |
Color Depth | 8 bit |
Description
Title | page 377 |
Collection Title | Engineering Technical Reports Collection, Purdue University |
Repository | Purdue University Libraries |
Rights Statement | Digital object copyright Purdue University. All rights reserved. |
Language | eng |
Type (DCMI) | text |
Format | JP2 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Transcript | Section Ten PHYSICAL-CHEMICAL: METALS PRESENCE, FATE, AND IMPACT 38 LEACHING PROCESS FOR REMOVAL OF HEAVY METALS IN SOIL Alton Day Stone, Senior Environmental Scientist Pennoni Associates Inc. Hopkinton, Massachusetts 01748 James C. O'Shaughnessy, Professor Department of Civil & Environmental Engineering Worcester Polytechnic Institute Worcester, Massachusetts 01609 ABSTRACT This paper presents the results of bench-scale experiments conducted to evaluate heavy metals sorption and desorption phenomena for soils common to New England, and the suitability of soil leaching (flushing) for in-situ remediation of soils contaminated with heavy metals. The results of the investigations indicated that the soil physical parameters mass fines/unit mass soil, bulk density, coefficient of uniformity, and coefficient of concavity were not good predictors of soil sorptive or desorption capacity. INTRODUCTION Environmental contamination by heavy metals is relatively common. Lead, often in high concentrations is ubiquitous in urban soils due to the past use of leaded gasolines and paints. Formerly, arsenic was widely used as a general pesticide. The majority of sites contaminated with concentrated heavy metals are associated with industrial processes such as mining, smelting, plating, coating, machining and manufacturing, and locations where disposal of associated wastes has occurred. The Environmental Protection Agency (EPA)1 estimates that approximately 10% of the Superfund sites involve heavy metal contamination. Concentration ranges of metals reported in soil at EPA sites are included in Table I. In recognition of the hazard posed by exposures to heavy metals, federal and state agencies have established regulations to limit environmental contamination and reduce human and environmental exposures. The EPA currently lists 13 heavy metals as "priority pollutants" under the Comprehensive Environmental Recovery, Compensation and Liability Act (CERCLA) commonly known as "Superfund": antimony, arsenic, beryllium, cadmium, chromium, copper, lead, mercury, nickel, selenium, silver, thallium, zinc. Each of these metals, except barium and copper, is listed as a "hazardous material" in the Massachusetts Contingency Plan (MCP, 310 CMR 40.0000), promulgated under M.G.L. c. 21e the "Oil and Hazardous Materials Act." Industrial solid wastes which contain sufficient leachable amounts of certain metals (Table I), as determined by the Toxicity Characteristic Leaching Procedure (TCLP) chemical analytical procedure, are listed "hazardous wastes" which are regulated under the Resource Conservation and Recovery Act (RCRA). The TCLP extraction (leaching) analysis is intended to duplicate leaching of the waste by rainwater in the open environment. If the extract contains a metal concentration above an established criteria, the waste exhibits the characteristic of "toxicity," and is classified as hazardous. These wastes are considered to be potential sources of environmental 52nd Purdue Industrial Waste Conference Proceedings. 1997. Ann Arbor Press. Chelsea, Michigan 48118. Printed in U.S.A. 377 |
Resolution | 300 ppi |
Color Depth | 8 bit |
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